docs: Auth-Abschnitt, korrigierte Test-Anleitung, Phase 9

deployment.md bekommt einen eigenen Abschnitt zur Authentifizierung
(Schlüsselweg, geschützte Endpoints, Fehlercodes, der Schalter für
VPN-Instanzen) und eine CORS-Beschreibung, die die Allowlist statt des
alten Wildcards erklärt — inklusive der Tauri-Origins, die sonst am
Preflight scheitern.

Im README steht jetzt der Hinweis, der diese Runde am meisten gekostet
hat: ohne DATABASE_URL_APPVIEW in der Umgebung überspringen sich die
DB-Tests selbst und `cargo test --workspace` meldet grün, ohne sie
ausgeführt zu haben.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013HC9HLrUU1LNwkzp8nkDLX

.env.example

@@ -62,8 +62,36 @@ PLC_DIRECTORY_URL=https://plc.directory
 # PLC_DIRECTORY_URL=http://127.0.0.1:2582
 
 # --- AppView ingest auth (optional, dev ok if unset) ---
+# Wenn gesetzt, muss die PDS denselben Wert als Header
+# `X-Ingest-Secret` mitschicken; ist er nicht gesetzt, nimmt
+# /internal/ingest-commit unauthentifizierte Writes entgegen (jeder,
+# der den Port erreicht, kann Posts/Follows/Notifications fälschen).
+# Die AppView warnt beim Start, solange er fehlt.
 # APPVIEW_INGEST_SECRET=change-me-to-a-shared-secret-between-pds-and-appview
 
+# --- AppView auth (Bearer-Token der PDS) ---
+# Erzwingt ein gültiges Access-JWT auf den privaten Endpoints
+# (/api/notifications, /api/notifications/count,
+# /api/notifications/seen, /api/timeline/home); `sub` im Token muss
+# dem `did`-Parameter entsprechen, sonst 403. Default: true.
+# Den öffentlichen P-256-Schlüssel holt sich die AppView von
+# `PDS_INTERNAL_URL` (sonst `PDS_PUBLIC_URL`) unter
+# /.well-known/did.json — `PDS_JWT_SECRET` verlässt die PDS nie.
+# Auf `false` verhält sich die AppView wie vor der Auth-Einführung
+# (alles öffentlich): nötig für die fail-open-Integrationstests mit
+# synthetischen DIDs und für eine Instanz, die schon per VPN
+# abgeschottet ist. Die AppView warnt beim Start laut, wenn er aus ist.
+# APPVIEW_AUTH_REQUIRED=true
+# Kommaseparierte Allowlist der Browser-Origins, die `/api/*` aufrufen
+# dürfen. Nicht gesetzt = bisheriges Verhalten
+# (`Access-Control-Allow-Origin: *`) plus Startup-Warnung.
+# Der Tauri-Webview hat je nach Plattform eine eigene Origin:
+# macOS/iOS `tauri://localhost`, Windows `http://tauri.localhost`,
+# im Dev-Modus der Vite-Server `http://127.0.0.1:1430`.
+# `Authorization` steht immer in den erlaubten Headern (sonst
+# scheitert der Preflight), `allow_credentials` bleibt aus.
+# APPVIEW_CORS_ORIGINS=tauri://localhost,http://127.0.0.1:1430
+
 # --- Tauri-Client (Build-/Laufzeit-Overrides des Desktop-Clients) ---
 # MAARCADETWEET_PDS_URL=http://127.0.0.1:2583
 # MAARCADETWEET_APPVIEW_URL=http://127.0.0.1:2584

Cargo.lock

@@ -53,6 +53,7 @@ dependencies = [
  "chrono",
  "dotenvy",
  "futures",
+ "p256",
  "reqwest",
  "rustls",
  "serde",

README.md

@@ -68,6 +68,7 @@ cargo run -p appview
 | 6  Tauri-UI-Logik an Backend koppeln | ✅ done — LoginScreen, NavRail, PostCard, ComposeBox, Profile/Compose/Search/Settings-Views |
 | 7  Polish (Tray, Notifications, Auto-Update) | ✅ done — Tray-Icon custom (`tauri::include_image!`), Notification-Click navigiert via `app://notification`-Event + `openThread`-Helper zu Thread-Detail, Auto-Update in Dev inert (Production-Weg: [`docs/tauri-release.md`](docs/tauri-release.md)) |
 | 8  Social-Graph + Benachrichtigungen | ✅ done — `notifications`-Tabelle, Schreibpfad im Jetstream-Indexer (idempotent, keine Selbst-Notifications), `/api/notifications[/count|/seen]`, `/api/followers`, `/api/following`, eigene `/api/thread`-Route; im Client Notifications-View mit Unread-Badge und klickbare Follower-/Following-Listen im Profil |
+| 9  Auth + Performance | ✅ done — AppView prüft Bearer-Tokens (ES256, Schlüssel aus dem neuen `/.well-known/did.json` der PDS, fail closed); Timeline und Notifications nur noch für die eigene DID; CORS-Allowlist statt `Any`; Indizes für Handle-Lookup und Cold-Start-Feed |
 
 ## Tests
 
@@ -81,11 +82,13 @@ Stand zuletzt gegen den lokalen Dev-Stack (docker compose + laufender PDS + AppV
 Rust-Workspace grün (u.a. 27 MST, 24 PDS-Integration, 49 AppView-Lib, 14 AppView-Integration),
 Frontend grün. Zwei Vorbehalte:
 
-* Die DB-gestützten Integrationstests sind *fail-open* — ohne erreichbare Postgres/PDS
+* Die DB-gestützten Tests sind *fail-open*: **ohne `DATABASE_URL_APPVIEW` in der
-  überspringen sie sich selbst und melden das nur auf stderr. Ein grüner Lauf ohne
+  Umgebung überspringen sie sich selbst** und melden das nur auf stderr. `cargo test
-  laufenden Stack sagt also weniger, als er aussieht.
+  --workspace` in einer nackten Shell meldet dann grün, ohne sie ausgeführt zu haben —
-* Einige Tests hängen am Zustand der Dev-Datenbank; auf einer frischen DB können
+  für einen aussagekräftigen Lauf `set -a; . ./.env; set +a` voranstellen und PDS +
-  `handle_sync`-Tests abweichen. Wer sie ernst nimmt, prüft sie gegen eine definierte DB.
+  AppView laufen lassen.
+* Läuft die Auth (Default), holen sich die Integrationstests echte Tokens von der PDS
+  bzw. signieren sie aus `PDS_JWT_SECRET`; ohne erreichbare PDS überspringen sie.
 
 `crates/tauri-app/src-tauri` hat ein eigenes `[workspace]` und ist **nicht** Teil des
 Root-Workspace; `cargo test --workspace` von oben erfasst den IPC-Layer nicht.
@@ -103,8 +106,8 @@ Root-Workspace; `cargo test --workspace` von oben erfasst den IPC-Layer nicht.
 * Die eigene PDS speist **keinen** Firehose (`com.atproto.sync.subscribeRepos` fehlt) —
   eigene Records erreichen die AppView nur über den Best-Effort-Push
   `POST /internal/ingest-commit`.
-* Die AppView-Leseschnittstelle hat **keine Auth** und CORS `Any`; bei
+* `aud` wird beim Token-Check nicht validiert (Signatur, Ablauf, `scope` und
-  `/api/notifications` sind das erstmals halbwegs private Daten.
+  `sub` schon).
 * Notifications werden nie gelöscht: Unlike/Unfollow lässt die Zeile stehen, und der
   Dedupe-Key macht sie „einmal pro (Empfänger, Autor, Art, Subject) für immer".
 * Auto-Update ist nur dokumentiert, nicht verdrahtet: niemand ruft `check()` auf, das
@@ -112,8 +115,6 @@ Root-Workspace; `cargo test --workspace` von oben erfasst den IPC-Layer nicht.
 * Reply-Notifications gehen verloren, wenn die Antwort vor ihrem Parent indiziert wird
   (kein Nachlauf) — bei Jetstream möglich.
 * `at-blob` spricht MinIO ohne Signature V4 — echtes AWS S3 funktioniert damit nicht.
-* Die PDS liefert kein `.well-known/did.json`; `describeServer` gibt die DID hart
-  als `did:web:pds.maarcadetweet.local` zurück.
 
 ## Design
 

crates/appview/Cargo.toml

@@ -35,6 +35,7 @@ at-shared = { workspace = true }
 at-firehose = { workspace = true }
 at-crypto = { workspace = true }
 at-identity = { workspace = true }
+reqwest = { workspace = true }
 uuid = { workspace = true }
 rustls = { version = "0.23", default-features = false, features = ["ring", "std", "logging", "tls12"] }
 base64 = { workspace = true }
@@ -45,3 +46,7 @@ tokio = { workspace = true }
 reqwest = { workspace = true }
 serde_json = { workspace = true }
 uuid = { workspace = true }
+# Unit tests in `src/auth.rs` build a P-256 verification key in the
+# same `0x8012 + uncompressed point` encoding the PDS publishes, which
+# needs the curve's `ToEncodedPoint`.
+p256 = { workspace = true }

crates/appview/src/auth.rs

@@ -0,0 +1,659 @@
+//! Bearer-token authentication for the AppView's private endpoints.
+//!
+//! ## What is being proven
+//!
+//! The PDS already issues an ES256 access JWT on
+//! `com.atproto.server.createSession` / `createAccount`. That token
+//! carries `sub = <did>`, `scope = "com.atproto.access"` and
+//! `aud = "did:web:appview.maarcadetweet.local"` — it was always meant
+//! to be presented *here*. All the AppView has to do is verify the
+//! signature and read `sub`.
+//!
+//! ## Where the key comes from
+//!
+//! Verifying an ES256 signature needs only the public half of the PDS's
+//! P-256 key. The PDS publishes it in its DID document at
+//! `GET /.well-known/did.json` (see `pds-server/src/main.rs`), so
+//! `PDS_JWT_SECRET` never leaves the PDS process. We fetch that
+//! document once, cache the `publicKeyMultibase` behind an `RwLock`,
+//! and re-fetch on a verification failure so an operator can rotate
+//! `PDS_JWT_SECRET` without restarting the AppView.
+//!
+//! Two failure modes are deliberately handled differently:
+//!
+//!  - **PDS unreachable at startup.** The AppView has always booted
+//!    independently of the PDS (it indexes the firehose, which has
+//!    nothing to do with the local PDS), and a crash-loop on a
+//!    colocated service that happens to boot second would be a
+//!    self-inflicted outage. So startup only *warns*; the first
+//!    authenticated request retries the fetch.
+//!  - **PDS unreachable when a token must be checked.** There is no
+//!    safe way to guess, so the request gets a `503`. Fail closed —
+//!    never fail open.
+//!
+//! ## Error contract
+//!
+//! The body shape matches every other AppView error
+//! (`{"error": …, "message": …}`). The `error` codes are load-bearing:
+//!
+//! | case                                   | status | `error`           |
+//! |----------------------------------------|--------|-------------------|
+//! | no / malformed `Authorization` header  | 401    | `AuthMissing`     |
+//! | bad signature, expired, wrong `scope`  | 401    | `TokenInvalid`    |
+//! | valid token, but `sub` ≠ requested did | 403    | `Forbidden`       |
+//! | PDS key not obtainable                 | 503    | `AuthUnavailable` |
+//!
+//! **`TokenInvalid` is a contract with the desktop client**: seeing it,
+//! the client refreshes its access JWT (`com.atproto.server.refreshSession`)
+//! and retries the request once. Renaming it silently logs every user
+//! out an hour after login.
+
+use at_crypto::jwt::JwtClaims;
+use axum::async_trait;
+use axum::extract::FromRequestParts;
+use axum::http::request::Parts;
+use axum::http::{HeaderMap, StatusCode};
+use axum::Json;
+use serde_json::{json, Value};
+use std::time::{Duration, Instant};
+use tokio::sync::RwLock;
+use tracing::{debug, warn};
+
+use crate::state::AppState;
+
+/// The scope an *access* token carries. Refresh tokens are minted with
+/// `com.atproto.refresh` by the same key, so without this check a
+/// refresh token — which lives for 90 days instead of an hour — would
+/// be accepted as a session credential everywhere.
+const ACCESS_SCOPE: &str = "com.atproto.access";
+
+/// Minimum spacing between two key re-fetches triggered by a failed
+/// verification.
+///
+/// Re-fetching on failure is what makes key rotation work without a
+/// restart. Doing it on *every* failure would also hand anyone who can
+/// reach the AppView a free amplifier: a stream of garbage tokens
+/// becomes a stream of requests to the PDS. One re-fetch per minute is
+/// far quicker than any plausible rotation cadence needs and costs the
+/// PDS nothing.
+const KEY_REFETCH_MIN_INTERVAL: Duration = Duration::from_secs(60);
+
+/// HTTP timeout for the DID-document fetch. The PDS is colocated; if it
+/// doesn't answer in two seconds it isn't answering, and a request
+/// blocked on auth is a request the user is staring at.
+const DID_DOC_TIMEOUT: Duration = Duration::from_secs(2);
+
+// -- error type --------------------------------------------------------------
+
+/// Everything that can go wrong between "a request arrived" and "we know
+/// which DID it belongs to". Converted into the AppView's standard error
+/// body by [`AuthError::into_response_parts`].
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum AuthError {
+    /// No `Authorization` header, or one that isn't `Bearer <token>`.
+    Missing,
+    /// Signature, expiry or scope check failed. The client's cue to
+    /// refresh its access token and retry.
+    Invalid(String),
+    /// Authenticated fine, but the token belongs to somebody else.
+    Forbidden,
+    /// We could not obtain the PDS's public key, so we cannot decide.
+    Unavailable(String),
+}
+
+impl AuthError {
+    pub fn into_response_parts(self) -> (StatusCode, Json<Value>) {
+        let (status, code, message) = match self {
+            AuthError::Missing => (
+                StatusCode::UNAUTHORIZED,
+                "AuthMissing",
+                "missing Authorization: Bearer header".to_string(),
+            ),
+            AuthError::Invalid(detail) => {
+                (StatusCode::UNAUTHORIZED, "TokenInvalid", detail)
+            }
+            AuthError::Forbidden => (
+                StatusCode::FORBIDDEN,
+                "Forbidden",
+                "token sub does not match the requested did".to_string(),
+            ),
+            AuthError::Unavailable(detail) => (
+                StatusCode::SERVICE_UNAVAILABLE,
+                "AuthUnavailable",
+                format!("cannot verify tokens: {detail}"),
+            ),
+        };
+        (
+            status,
+            Json(json!({
+                "error": code,
+                "message": message,
+            })),
+        )
+    }
+}
+
+impl From<AuthError> for (StatusCode, Json<Value>) {
+    fn from(e: AuthError) -> Self {
+        e.into_response_parts()
+    }
+}
+
+// -- key cache ---------------------------------------------------------------
+
+#[derive(Default)]
+struct CachedKey {
+    multibase: Option<String>,
+    /// When we last *attempted* a fetch — successful or not. Throttles
+    /// the on-failure refresh path; see [`KEY_REFETCH_MIN_INTERVAL`].
+    last_attempt: Option<Instant>,
+}
+
+/// The PDS signing key, lazily fetched and cached.
+///
+/// Lives in [`AppState`] behind an `Arc`, so all handlers share one
+/// cache and one HTTP client.
+pub struct PdsKeys {
+    http: reqwest::Client,
+    /// Fully-qualified URL of the PDS's DID document.
+    did_doc_url: String,
+    inner: RwLock<CachedKey>,
+}
+
+impl PdsKeys {
+    /// Build a cache pointed at `base_url` (no trailing slash required).
+    pub fn new(base_url: &str) -> Self {
+        let http = reqwest::Client::builder()
+            .timeout(DID_DOC_TIMEOUT)
+            .build()
+            .expect("reqwest client build should never fail");
+        Self {
+            http,
+            did_doc_url: format!(
+                "{}/.well-known/did.json",
+                base_url.trim_end_matches('/')
+            ),
+            inner: RwLock::new(CachedKey::default()),
+        }
+    }
+
+    /// Same PDS the handle-sync worker talks to: `PDS_INTERNAL_URL`
+    /// when set, else `PDS_PUBLIC_URL`.
+    pub fn from_config(cfg: &at_shared::config::AppConfig) -> Self {
+        Self::new(&cfg.pds_base_url())
+    }
+
+    pub fn did_doc_url(&self) -> &str {
+        &self.did_doc_url
+    }
+
+    /// The cached key, if we have ever fetched one.
+    pub async fn cached(&self) -> Option<String> {
+        self.inner.read().await.multibase.clone()
+    }
+
+    /// Fetch the DID document and replace the cached key.
+    ///
+    /// Called once at startup (best effort), on the first authenticated
+    /// request if startup failed, and — throttled — after a failed
+    /// verification.
+    pub async fn refresh(&self) -> anyhow::Result<String> {
+        // Record the attempt before the await so two concurrent
+        // failures can't both decide they're the first one.
+        self.inner.write().await.last_attempt = Some(Instant::now());
+
+        let resp = self.http.get(&self.did_doc_url).send().await?;
+        if !resp.status().is_success() {
+            anyhow::bail!(
+                "{} returned {}",
+                self.did_doc_url,
+                resp.status().as_u16()
+            );
+        }
+        let doc: Value = resp.json().await?;
+        let key = extract_public_key_multibase(&doc)?;
+        {
+            let mut guard = self.inner.write().await;
+            guard.multibase = Some(key.clone());
+        }
+        debug!(url = %self.did_doc_url, "loaded PDS signing key");
+        Ok(key)
+    }
+
+    /// The key to verify with, fetching it if we don't have one yet.
+    async fn key_or_fetch(&self) -> Result<String, AuthError> {
+        if let Some(k) = self.cached().await {
+            return Ok(k);
+        }
+        self.refresh().await.map_err(|e| {
+            warn!(url = %self.did_doc_url, error = %e, "PDS signing key unavailable");
+            AuthError::Unavailable(format!(
+                "PDS did document at {} not reachable: {e}",
+                self.did_doc_url
+            ))
+        })
+    }
+
+    /// Re-fetch after a verification failure, at most once per
+    /// [`KEY_REFETCH_MIN_INTERVAL`]. Returns the new key only when it
+    /// actually differs from `stale` — re-running the same failing
+    /// verification against an unchanged key proves nothing.
+    async fn refetch_if_stale(&self, stale: &str) -> Option<String> {
+        {
+            let guard = self.inner.read().await;
+            if let Some(last) = guard.last_attempt {
+                if last.elapsed() < KEY_REFETCH_MIN_INTERVAL {
+                    return None;
+                }
+            }
+        }
+        match self.refresh().await {
+            Ok(fresh) if fresh != stale => {
+                warn!("PDS signing key changed; re-verifying with the rotated key");
+                Some(fresh)
+            }
+            Ok(_) => None,
+            Err(e) => {
+                warn!(error = %e, "PDS key re-fetch after verification failure failed");
+                None
+            }
+        }
+    }
+
+    /// Verify an access token and return its claims.
+    ///
+    /// Retries exactly once against a freshly fetched key, so a rotated
+    /// `PDS_JWT_SECRET` costs one extra HTTP round trip rather than a
+    /// restart.
+    pub async fn verify_access_token(&self, token: &str) -> Result<JwtClaims, AuthError> {
+        let key = self.key_or_fetch().await?;
+        match verify_with_key(token, &key) {
+            Ok(claims) => Ok(claims),
+            Err(first) => {
+                let Some(fresh) = self.refetch_if_stale(&key).await else {
+                    return Err(first);
+                };
+                verify_with_key(token, &fresh).map_err(|_| first)
+            }
+        }
+    }
+}
+
+/// Pull `verificationMethod[].publicKeyMultibase` out of a DID document.
+///
+/// We take the first entry that carries a `publicKeyMultibase` rather
+/// than insisting on a fragment name: the PDS writes `#atproto`, but a
+/// document served by a proxy or a future PDS version may order or name
+/// its methods differently, and any key in the document is a key the
+/// controller published for itself. A document with none is an error,
+/// not an empty key — silently caching `""` would turn every later
+/// verification into a confusing signature failure.
+fn extract_public_key_multibase(doc: &Value) -> anyhow::Result<String> {
+    let methods = doc
+        .get("verificationMethod")
+        .and_then(|v| v.as_array())
+        .ok_or_else(|| anyhow::anyhow!("did document has no verificationMethod array"))?;
+    for m in methods {
+        if let Some(k) = m.get("publicKeyMultibase").and_then(|v| v.as_str()) {
+            if !k.is_empty() {
+                return Ok(k.to_string());
+            }
+        }
+    }
+    anyhow::bail!("did document has no verificationMethod with publicKeyMultibase")
+}
+
+/// Signature + expiry + scope check against one specific key.
+///
+/// `verify_jwt` handles the ES256 signature and `exp` (with a 30 s
+/// leeway for clock skew); the scope check is ours, and it is the line
+/// that keeps a 90-day refresh token from working as a session
+/// credential.
+fn verify_with_key(token: &str, pubkey_multibase: &str) -> Result<JwtClaims, AuthError> {
+    let claims = at_crypto::jwt::verify_jwt(token, pubkey_multibase)
+        .map_err(|e| AuthError::Invalid(format!("invalid token: {e}")))?;
+    match claims.scope.as_deref() {
+        Some(ACCESS_SCOPE) => Ok(claims),
+        other => Err(AuthError::Invalid(format!(
+            "token scope {:?} is not {ACCESS_SCOPE}",
+            other.unwrap_or("<none>")
+        ))),
+    }
+}
+
+/// Extract the bearer token from an `Authorization` header.
+///
+/// The scheme match is case-insensitive (RFC 7235 says it is) — some
+/// HTTP clients send `bearer`.
+fn bearer_token(headers: &HeaderMap) -> Result<String, AuthError> {
+    let raw = headers
+        .get("authorization")
+        .and_then(|v| v.to_str().ok())
+        .ok_or(AuthError::Missing)?;
+    let (scheme, token) = raw.split_once(' ').ok_or(AuthError::Missing)?;
+    if !scheme.eq_ignore_ascii_case("bearer") {
+        return Err(AuthError::Missing);
+    }
+    let token = token.trim();
+    if token.is_empty() {
+        return Err(AuthError::Missing);
+    }
+    Ok(token.to_string())
+}
+
+// -- extractor ---------------------------------------------------------------
+
+/// The authenticated DID of the caller.
+///
+/// `None` means auth is switched off for this instance
+/// (`APPVIEW_AUTH_REQUIRED=false`) — *not* "anonymous but allowed
+/// through". When auth is on, this is always `Some` by construction:
+/// the extractor rejects the request otherwise.
+///
+/// Handlers must still call [`AuthedDid::ensure_matches`] with the DID
+/// the request asks about. Proving *who you are* is not the same as
+/// proving *whose notifications you may read*.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct AuthedDid(pub Option<String>);
+
+impl AuthedDid {
+    /// 403 unless the token's `sub` is the DID the request targets.
+    ///
+    /// With auth disabled this is a no-op, which is exactly what
+    /// `APPVIEW_AUTH_REQUIRED=false` means.
+    pub fn ensure_matches(&self, did: &str) -> Result<(), (StatusCode, Json<Value>)> {
+        match self.0.as_deref() {
+            None => Ok(()),
+            Some(sub) if sub == did => Ok(()),
+            Some(_) => Err(AuthError::Forbidden.into_response_parts()),
+        }
+    }
+
+    /// The caller's DID, if authenticated.
+    ///
+    /// No handler needs it yet — every private endpoint takes the DID
+    /// as a parameter and compares it — but an endpoint that acts
+    /// purely on "whoever is calling" would read it here instead of
+    /// trusting a query parameter.
+    #[allow(dead_code)]
+    pub fn did(&self) -> Option<&str> {
+        self.0.as_deref()
+    }
+}
+
+#[async_trait]
+impl FromRequestParts<AppState> for AuthedDid {
+    type Rejection = (StatusCode, Json<Value>);
+
+    async fn from_request_parts(
+        parts: &mut Parts,
+        state: &AppState,
+    ) -> Result<Self, Self::Rejection> {
+        if !state.cfg.appview_auth_required {
+            // Opt-out instance. The startup log says so in capitals.
+            return Ok(AuthedDid(None));
+        }
+        let token = bearer_token(&parts.headers).map_err(AuthError::into_response_parts)?;
+        let claims = state
+            .pds_keys
+            .verify_access_token(&token)
+            .await
+            .map_err(AuthError::into_response_parts)?;
+        Ok(AuthedDid(Some(claims.sub)))
+    }
+}
+
+// -- startup posture ---------------------------------------------------------
+
+/// Log, once at boot, every way this instance is configured to be less
+/// strict than the defaults.
+///
+/// All three of these are legitimate configurations — a VPN-only
+/// deployment, a dev box, a single-machine setup — and all three are
+/// also exactly what an accidentally-public instance looks like. The
+/// only defence that survives a hurried deployment is a log line the
+/// operator cannot miss, so each one is a `warn!` naming the variable
+/// that turns it back on.
+pub fn log_startup_posture(cfg: &at_shared::config::AppConfig) {
+    if !cfg.appview_auth_required {
+        warn!(
+            "APPVIEW_AUTH_REQUIRED=false — /api/notifications* and \
+             /api/timeline/home are served to ANY caller for ANY did. \
+             Only safe when this instance is unreachable from untrusted \
+             networks."
+        );
+    }
+    if cfg.appview_cors_origins.is_empty() {
+        warn!(
+            "APPVIEW_CORS_ORIGINS unset — sending Access-Control-Allow-Origin: * \
+             so any web page can call this AppView from a browser. Set it to the \
+             origins your client actually uses, e.g. \
+             'tauri://localhost,http://127.0.0.1:1430'."
+        );
+    }
+    if cfg.appview_ingest_secret.is_none() {
+        warn!(
+            "APPVIEW_INGEST_SECRET unset — POST /internal/ingest-commit accepts \
+             unauthenticated writes into the index (anyone who can reach this port \
+             can forge posts, follows and notifications). Set the same value here \
+             and on the PDS."
+        );
+    }
+}
+
+// -- tests -------------------------------------------------------------------
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use at_crypto::ecdsa::P256Keypair;
+    use at_crypto::jwt::{issue_jwt, JwtClaims};
+    use axum::http::HeaderValue;
+
+    /// A throwaway server key plus its `publicKeyMultibase`, in the
+    /// exact encoding the PDS publishes: `0x8012` (P-256) followed by
+    /// the *uncompressed* affine coordinates. `P256Keypair::generate`
+    /// stores a compressed point, which `verify_jwt` cannot decode — so
+    /// this mirrors `pds-server`'s `server_p256_keypair`.
+    fn test_key() -> (P256Keypair, String) {
+        let kp = P256Keypair::generate().unwrap();
+        let vk = kp.verifying_key().unwrap();
+        let pt = vk.to_encoded_point(false);
+        let mut raw = vec![0x80u8, 0x12u8];
+        raw.extend_from_slice(pt.x().unwrap());
+        raw.extend_from_slice(pt.y().unwrap());
+        let multibase = at_crypto::multibase_util::encode_b58btc(&raw);
+        (kp, multibase)
+    }
+
+    fn mint(kp: &P256Keypair, did: &str, scope: &str, ttl_secs: i64) -> String {
+        let now = chrono::Utc::now().timestamp();
+        issue_jwt(
+            kp,
+            &JwtClaims {
+                iss: "did:web:127.0.0.1%3A2583".into(),
+                sub: did.into(),
+                aud: "did:web:appview.maarcadetweet.local".into(),
+                iat: now - 1,
+                exp: now + ttl_secs,
+                jti: None,
+                scope: Some(scope.into()),
+            },
+        )
+        .unwrap()
+    }
+
+    fn header_map(value: &str) -> HeaderMap {
+        let mut h = HeaderMap::new();
+        h.insert("authorization", HeaderValue::from_str(value).unwrap());
+        h
+    }
+
+    #[test]
+    fn missing_header_is_auth_missing() {
+        assert_eq!(bearer_token(&HeaderMap::new()), Err(AuthError::Missing));
+    }
+
+    #[test]
+    fn malformed_header_is_auth_missing() {
+        // No scheme, wrong scheme, and an empty token all read as
+        // "the client never presented a credential" — 401 AuthMissing,
+        // not TokenInvalid, so the client re-authenticates instead of
+        // burning a refresh round trip.
+        assert_eq!(bearer_token(&header_map("abc.def.ghi")), Err(AuthError::Missing));
+        assert_eq!(bearer_token(&header_map("Basic dXNlcjpwdw==")), Err(AuthError::Missing));
+        assert_eq!(bearer_token(&header_map("Bearer   ")), Err(AuthError::Missing));
+    }
+
+    #[test]
+    fn bearer_scheme_is_case_insensitive() {
+        assert_eq!(bearer_token(&header_map("bearer tok")).unwrap(), "tok");
+        assert_eq!(bearer_token(&header_map("Bearer tok")).unwrap(), "tok");
+    }
+
+    #[test]
+    fn error_bodies_carry_the_documented_codes() {
+        // These strings are a contract: the desktop client keys its
+        // "refresh and retry" behaviour off `TokenInvalid`.
+        let (s, b) = AuthError::Missing.into_response_parts();
+        assert_eq!(s, StatusCode::UNAUTHORIZED);
+        assert_eq!(b.0["error"], "AuthMissing");
+        let (s, b) = AuthError::Invalid("x".into()).into_response_parts();
+        assert_eq!(s, StatusCode::UNAUTHORIZED);
+        assert_eq!(b.0["error"], "TokenInvalid");
+        let (s, b) = AuthError::Forbidden.into_response_parts();
+        assert_eq!(s, StatusCode::FORBIDDEN);
+        assert_eq!(b.0["error"], "Forbidden");
+        let (s, b) = AuthError::Unavailable("pds down".into()).into_response_parts();
+        assert_eq!(s, StatusCode::SERVICE_UNAVAILABLE);
+        assert_eq!(b.0["error"], "AuthUnavailable");
+        // Every body carries both fields the client parses.
+        assert!(b.0["message"].as_str().unwrap().contains("pds down"));
+    }
+
+    #[test]
+    fn valid_access_token_verifies() {
+        let (kp, mb) = test_key();
+        let token = mint(&kp, "did:plc:alice", ACCESS_SCOPE, 3600);
+        let claims = verify_with_key(&token, &mb).unwrap();
+        assert_eq!(claims.sub, "did:plc:alice");
+    }
+
+    #[test]
+    fn garbage_token_is_invalid() {
+        let (_, mb) = test_key();
+        let err = verify_with_key("not-a-jwt", &mb).unwrap_err();
+        assert!(matches!(err, AuthError::Invalid(_)));
+    }
+
+    #[test]
+    fn token_signed_by_another_key_is_invalid() {
+        let (kp, _) = test_key();
+        let (_, other_mb) = test_key();
+        let token = mint(&kp, "did:plc:alice", ACCESS_SCOPE, 3600);
+        assert!(matches!(
+            verify_with_key(&token, &other_mb).unwrap_err(),
+            AuthError::Invalid(_)
+        ));
+    }
+
+    #[test]
+    fn refresh_scope_is_rejected() {
+        // The refresh token is signed by the same key and lives 90
+        // days. Without the scope check it would be a session token.
+        let (kp, mb) = test_key();
+        let token = mint(&kp, "did:plc:alice", "com.atproto.refresh", 3600);
+        let err = verify_with_key(&token, &mb).unwrap_err();
+        match err {
+            AuthError::Invalid(msg) => assert!(msg.contains("com.atproto.refresh")),
+            other => panic!("expected Invalid, got {other:?}"),
+        }
+    }
+
+    #[test]
+    fn expired_token_is_rejected() {
+        // Beyond `verify_jwt`'s 30 s leeway.
+        let (kp, mb) = test_key();
+        let token = mint(&kp, "did:plc:alice", ACCESS_SCOPE, -120);
+        assert!(matches!(
+            verify_with_key(&token, &mb).unwrap_err(),
+            AuthError::Invalid(_)
+        ));
+    }
+
+    #[test]
+    fn ensure_matches_enforces_sub_equals_did() {
+        let me = AuthedDid(Some("did:plc:alice".into()));
+        assert!(me.ensure_matches("did:plc:alice").is_ok());
+        let (status, body) = me.ensure_matches("did:plc:bob").unwrap_err();
+        assert_eq!(status, StatusCode::FORBIDDEN);
+        assert_eq!(body.0["error"], "Forbidden");
+        // A prefix of the real DID must not pass.
+        assert!(me.ensure_matches("did:plc:ali").is_err());
+    }
+
+    #[test]
+    fn ensure_matches_is_a_noop_when_auth_disabled() {
+        let off = AuthedDid(None);
+        assert!(off.ensure_matches("did:plc:anyone").is_ok());
+        assert_eq!(off.did(), None);
+    }
+
+    #[test]
+    fn did_doc_key_extraction() {
+        let doc = json!({
+            "id": "did:web:127.0.0.1%3A2583",
+            "verificationMethod": [{
+                "id": "did:web:127.0.0.1%3A2583#atproto",
+                "type": "Multikey",
+                "controller": "did:web:127.0.0.1%3A2583",
+                "publicKeyMultibase": "zQ3shokFTS3brHcDQrn82RUDfCZESWL1ZdCEJwekUDPQiYBme"
+            }]
+        });
+        assert_eq!(
+            extract_public_key_multibase(&doc).unwrap(),
+            "zQ3shokFTS3brHcDQrn82RUDfCZESWL1ZdCEJwekUDPQiYBme"
+        );
+
+        // A document without a usable key must error rather than cache
+        // an empty string.
+        assert!(extract_public_key_multibase(&json!({})).is_err());
+        assert!(extract_public_key_multibase(&json!({
+            "verificationMethod": [{"id": "#x", "type": "Multikey"}]
+        }))
+        .is_err());
+        assert!(extract_public_key_multibase(&json!({
+            "verificationMethod": [{"publicKeyMultibase": ""}]
+        }))
+        .is_err());
+    }
+
+    #[test]
+    fn did_doc_url_is_built_from_the_base_url() {
+        assert_eq!(
+            PdsKeys::new("http://127.0.0.1:2583").did_doc_url(),
+            "http://127.0.0.1:2583/.well-known/did.json"
+        );
+        // A trailing slash must not produce a double slash — some
+        // servers 404 on it.
+        assert_eq!(
+            PdsKeys::new("http://pds:3000/").did_doc_url(),
+            "http://pds:3000/.well-known/did.json"
+        );
+    }
+
+    #[tokio::test]
+    async fn verification_fails_closed_when_the_pds_is_unreachable() {
+        // Port 1 on loopback: nothing listens there, so the fetch fails
+        // fast. The result must be a 503, never a pass-through.
+        let keys = PdsKeys::new("http://127.0.0.1:1");
+        let err = keys.verify_access_token("whatever").await.unwrap_err();
+        assert!(
+            matches!(err, AuthError::Unavailable(_)),
+            "expected Unavailable, got {err:?}"
+        );
+        let (status, body) = err.into_response_parts();
+        assert_eq!(status, StatusCode::SERVICE_UNAVAILABLE);
+        assert_eq!(body.0["error"], "AuthUnavailable");
+    }
+}

crates/appview/src/handle_sync.rs

@@ -153,7 +153,10 @@ impl HandleSyncWorker {
 
     /// The SELECT half of [`Self::run_once`]: up to [`BATCH_SIZE`]
     /// distinct DIDs still waiting for a handle.
-    async fn select_candidates(&self) -> Result<Vec<String>> {
+    ///
+    /// Public so integration tests can assert on the batch cap without
+    /// depending on what else the live indexer left pending.
+    pub async fn select_candidates(&self) -> Result<Vec<String>> {
         let rows: Vec<(String,)> = sqlx::query_as(
             r#"SELECT DISTINCT did
                FROM posts
@@ -177,7 +180,7 @@ impl HandleSyncWorker {
     /// freshly seeded DID may simply not make the batch — which made
     /// the dispatch tests fail for reasons that had nothing to do with
     /// dispatch. Passing the DIDs in removes that coupling.
-    async fn resolve_batch(&self, dids: Vec<String>) -> Result<SyncReport> {
+    pub async fn resolve_batch(&self, dids: Vec<String>) -> Result<SyncReport> {
         let mut report = SyncReport::default();
         if dids.is_empty() {
             return Ok(report);
@@ -576,6 +579,66 @@ mod tests {
         assert_eq!(h.as_deref(), Some("from-ingest"));
     }
 
+    /// The documented PDS-first rule: the local PDS is asked before the
+    /// method dispatch, so a `did:key:` user hosted here resolves
+    /// without ever dialing plc.directory. This is the flip side of
+    /// `unknown_methods_are_skipped` — same DID method, opposite
+    /// outcome, and the difference is solely whether the PDS hosts it.
+    #[tokio::test]
+    async fn pds_resolves_did_key_before_method_dispatch() {
+        let Some(db) = try_test_db().await else {
+            eprintln!("appview DB unavailable; skipping");
+            return;
+        };
+        let did = format!("did:key:z{}", uuid::Uuid::new_v4().simple());
+        let _ = sqlx::query("DELETE FROM posts WHERE did = $1")
+            .bind(&did)
+            .execute(&db)
+            .await
+            .unwrap();
+        seed_post(&db, &did, "rk", "").await.unwrap();
+
+        // The PDS hosts this user; the outbound resolvers know nothing
+        // and must never be consulted.
+        let pds = StubResolver::new(HashMap::from([(
+            did.clone(),
+            Some("local-user.maarcadetweet.local".into()),
+        )]))
+        .into_arc();
+        let plc_log: Arc<Mutex<Vec<String>>> = Arc::new(Mutex::new(Vec::new()));
+        let plc = TrackingResolver::new(
+            HashMap::from([(did.clone(), Some("must-not-be-used".into()))]),
+            Arc::clone(&plc_log),
+        );
+        let plc_arc: Arc<dyn DidHandleResolver> = Arc::new(plc);
+
+        let worker = HandleSyncWorker {
+            db: db.clone(),
+            pds_resolver: pds,
+            plc_resolver: Arc::clone(&plc_arc),
+            web_resolver: plc_arc,
+            interval_secs: 999,
+        };
+        let report = worker.resolve_batch(vec![did.clone()]).await.unwrap();
+        assert_eq!(
+            report.resolved, 1,
+            "a did:key hosted by the local PDS must resolve, got {report:?}"
+        );
+        assert_eq!(
+            get_handle(&worker.db, &did).await.as_deref(),
+            Some("local-user.maarcadetweet.local")
+        );
+        assert!(
+            plc_log.lock().unwrap().is_empty(),
+            "the PDS answered, so no outbound resolver may be consulted"
+        );
+
+        let _ = sqlx::query("DELETE FROM posts WHERE did = $1")
+            .bind(&did)
+            .execute(&db)
+            .await;
+    }
+
     /// Dispatch test: a `did:web:` DID must be routed to the
     /// `web_resolver` (not the PLC one). Without this routing, every
     /// `did:web:` post would stay `@<did-prefix>…` forever.
@@ -606,9 +669,18 @@ mod tests {
         )]))
         .into_arc();
 
+        // The local PDS is consulted before the method dispatch (see the
+        // module docs), and it does NOT host this DID — a foreign
+        // `did:web:` is exactly the case where it answers "don't know".
+        // Wiring one of the other stubs in here instead would make the
+        // PDS claim a DID it doesn't have, and the test would be
+        // asserting against the documented PDS-first rule rather than
+        // against the method dispatch it's named for.
+        let pds = StubResolver::new(HashMap::new()).into_arc();
+
         let worker = HandleSyncWorker {
             db: db.clone(),
-            pds_resolver: Arc::clone(&plc),
+            pds_resolver: pds,
             plc_resolver: plc,
             web_resolver: web,
             interval_secs: 999,
@@ -665,9 +737,16 @@ mod tests {
         let plc_arc: Arc<dyn DidHandleResolver> = Arc::new(plc);
         let web_arc: Arc<dyn DidHandleResolver> = Arc::new(web);
 
+        // A DID the local PDS does not host — otherwise the PDS-first
+        // rule would (correctly) resolve it and this test would be
+        // measuring the wrong thing. The "local PDS *does* host it"
+        // case is covered by `pds_resolves_did_key_before_method_dispatch`.
+        let pds_arc: Arc<dyn DidHandleResolver> =
+            Arc::new(StubResolver::new(HashMap::new()));
+
         let worker = HandleSyncWorker {
             db: db.clone(),
-            pds_resolver: Arc::clone(&plc_arc),
+            pds_resolver: pds_arc,
             plc_resolver: plc_arc,
             web_resolver: web_arc,
             interval_secs: 999,

crates/appview/src/ingest.rs

@@ -15,8 +15,31 @@
 //! }
 //! ```
 //!
-//! In production this endpoint would be protected with mTLS and a token
+//! ## Who may call this
-//! minted by the PDS; for now it's open inside the cluster.
+//!
+//! This is the AppView's only write path, and it is not a browser
+//! endpoint: it is excluded from the CORS layer in
+//! [`crate::routes::router`], because an `Access-Control-Allow-Origin`
+//! header here would only ever help a web page forge index entries.
+//!
+//! Authentication is the shared secret `APPVIEW_INGEST_SECRET`,
+//! compared in constant time against the caller's `X-Ingest-Secret`
+//! header:
+//!
+//! - **set** → enforced. A missing or wrong header is `401
+//!   AuthenticationRequired`.
+//! - **unset** → anonymous writes are accepted, and the AppView shouts
+//!   about it once at startup (see
+//!   [`crate::auth::log_startup_posture`]). Refusing to start would
+//!   break every existing single-machine dev setup for a service that,
+//!   in that configuration, is bound to loopback anyway; accepting
+//!   silently is how an internet-facing deployment ends up letting
+//!   anyone forge posts, follows and notifications. So: keep working,
+//!   but never quietly.
+//!
+//! A future hardening step is mTLS or a PDS-minted token, at which
+//! point the shared secret becomes the fallback rather than the only
+//! line.
 
 use crate::indexer;
 use crate::state::AppState;
@@ -51,8 +74,13 @@ pub struct IngestCommitReq {
 }
 
 /// Authenticate internal ingest requests.
-/// - If `APPVIEW_INGEST_SECRET` env var is unset: dev mode, accept anything.
+///
-/// - If set: require `X-Ingest-Secret: <value>` header to match.
+/// - `APPVIEW_INGEST_SECRET` unset: accept anonymous writes (dev mode —
+///   the startup log warns, see the module docs for why this isn't a
+///   hard failure).
+/// - Set: require a matching `X-Ingest-Secret` header. The comparison
+///   is constant-time so a caller can't recover the secret byte by byte
+///   from response timings.
 pub fn check_ingest_secret(
     headers: &HeaderMap,
     configured: Option<&str>,

crates/appview/src/lib.rs

@@ -3,6 +3,7 @@
 //! tests under `tests/` import from here so they can build a worker
 //! against a stub resolver without booting the binary.
 
+pub mod auth;
 pub mod firehose;
 pub mod handle_sync;
 pub mod indexer;

crates/appview/src/main.rs

@@ -7,6 +7,7 @@ use tokio::sync::mpsc;
 use tracing::info;
 use tracing_subscriber::EnvFilter;
 
+mod auth;
 mod firehose;
 mod handle_sync;
 mod indexer;
@@ -83,6 +84,33 @@ async fn main() -> Result<()> {
 
     let state = AppState::new(cfg.clone(), db.clone(), stats.clone());
 
+    // Announce every relaxed security switch before we serve anything.
+    auth::log_startup_posture(&cfg);
+
+    // Pre-load the PDS's published signing key so the first
+    // authenticated request doesn't pay for the round trip.
+    //
+    // Best effort on purpose: the AppView has always started
+    // independently of the PDS, and in a compose file the two race. A
+    // hard failure here would turn "the PDS booted two seconds later"
+    // into "the AppView is in a crash loop". If the fetch fails, the
+    // first authenticated request retries it — and answers `503
+    // AuthUnavailable` if the PDS is still unreachable. Never open.
+    if cfg.appview_auth_required {
+        match state.pds_keys.refresh().await {
+            Ok(_) => info!(
+                url = %state.pds_keys.did_doc_url(),
+                "loaded PDS signing key for token verification"
+            ),
+            Err(e) => tracing::warn!(
+                url = %state.pds_keys.did_doc_url(),
+                error = %e,
+                "could not load the PDS signing key at startup; will retry on the \
+                 first authenticated request (which fails with 503 until it works)"
+            ),
+        }
+    }
+
     // Back-fill the `handle` column on posts that the Jetstream
     // indexer inserted with an empty placeholder. The worker dispatches
     // by DID method: `did:plc:` → PLC directory, `did:web:` → a
@@ -102,12 +130,12 @@ async fn main() -> Result<()> {
     // inside docker compose) — `pds_public_url` may not be reachable
     // from inside the cluster when TLS / DNS is set up for outside
     // clients only.
-    let pds_base_url = cfg
+    //
-        .pds_internal_url
+    // `AppConfig::pds_base_url()` owns that fallback so the handle
-        .clone()
+    // resolver and the signing-key fetch in `auth.rs` can never end up
-        .unwrap_or_else(|| cfg.pds_public_url.clone());
+    // pointed at different PDS instances.
     let pds_resolver: Arc<dyn at_identity::DidHandleResolver> = Arc::new(
-        at_identity::pds_handle::PdsHandleResolver::new(pds_base_url),
+        at_identity::pds_handle::PdsHandleResolver::new(cfg.pds_base_url()),
     );
 
     let handle_sync = handle_sync::HandleSyncWorker {

crates/appview/src/routes.rs

@@ -8,6 +8,30 @@
 //! - `ingest_commit`: the internal-only writer used by the PDS, owned
 //!   in `crate::ingest`.
 //!
+//! ## Public vs. private
+//!
+//! Most of what the AppView serves is public by construction: in AT
+//! Proto a post, a profile, a follow edge and a like are records in a
+//! public repo, replicated over the firehose. Those endpoints
+//! (`/api/profile*`, `/api/search`, `/api/post/*`, `/api/thread*`,
+//! `/api/followers`, `/api/following`) need no credential.
+//!
+//! Two things are *not* public, and they are the reason this service
+//! has authentication at all:
+//!
+//!  - `/api/notifications*` — who interacted with you, and the read
+//!    state of that list. Nothing in the protocol makes it readable by
+//!    anyone but the recipient.
+//!  - `/api/timeline/home` — the timeline is assembled from the
+//!    viewer's follow graph, so serving it to an arbitrary `did`
+//!    parameter answers "what does this person's feed look like" for
+//!    any DID a caller cares to type.
+//!
+//! Both require a valid PDS-issued access token whose `sub` equals the
+//! `did` in the request ([`crate::auth`]). The check is two steps on
+//! purpose: the extractor proves *who* the caller is, and
+//! `ensure_matches` proves they are asking about themselves.
+//!
 //! The cursor format used by `timeline_home` is opaque: it's a
 //! `base64url(micros):uri` pair, which is what [`cursor::encode`] and
 //! [`cursor::decode`] produce/consume.
@@ -19,11 +43,14 @@ use axum::{
     routing::{get, post},
     Json, Router,
 };
+use axum::http::{header, HeaderValue, Method};
 use chrono::{DateTime, TimeZone, Utc};
 use serde::{Deserialize, Serialize};
 use serde_json::{json, Value};
-use tower_http::cors::{Any, CorsLayer};
+use tower_http::cors::{AllowOrigin, Any, CorsLayer};
+use tracing::warn;
 
+use crate::auth::AuthedDid;
 use crate::state::AppState;
 
 pub mod cursor;
@@ -35,25 +62,73 @@ use types::{
     ProfileResponse, SearchResponse, ThreadFullResponse, TimelineResponse,
 };
 
-pub fn router(state: AppState) -> Router {
+/// Build the CORS layer for the browser-facing routes.
-    // CORS: the Tauri webview's origin is the Vite dev server
+///
-    // (`http://127.0.0.1:1430`) in dev or the bundled `tauri://` /
+/// The Tauri webview is a cross-origin caller: in dev its origin is the
-    // `asset://` origin in production. Either way it's a cross-origin
+/// Vite server (`http://127.0.0.1:1430`), in a packaged build it is a
-    // fetch against this service's `http://127.0.0.1:2584` listen
+/// platform-specific scheme — `tauri://localhost` on macOS/iOS,
-    // address, so the browser blocks the response without an explicit
+/// `http://tauri.localhost` on Windows. Either way the browser drops
-    // allow-origin header. We allow any origin — the AppView's
+/// the response unless we send `Access-Control-Allow-Origin`.
-    // public read endpoints (`/api/...`) carry no auth cookie and
+///
-    // the AppView runs alongside the user's own PDS, not on the
+/// `APPVIEW_CORS_ORIGINS` is a comma-separated allowlist, e.g.
-    // open internet; production deployments behind a reverse proxy
+/// `tauri://localhost,http://127.0.0.1:1430`. When it is unset we keep
-    // can tighten this via the proxy itself.
+/// the historic wildcard so no existing deployment breaks on upgrade —
-    let cors = CorsLayer::new()
+/// [`crate::auth::log_startup_posture`] warns about that at startup.
-        .allow_origin(Any)
+///
-        .allow_methods(Any)
+/// `Authorization` has to be in `allow_headers`: it is not a
-        .allow_headers(Any);
+/// CORS-safelisted header, so without it the browser's preflight fails
+/// and the authenticated endpoints become unreachable from the webview
+/// — with an error that looks nothing like an auth problem.
+///
+/// `allow_credentials` stays off. We authenticate with a bearer token
+/// the client attaches deliberately, never with an ambient cookie, so
+/// there is nothing for a hostile page to replay — and turning it on
+/// would additionally make the wildcard origin illegal.
+fn cors_layer(cfg: &at_shared::config::AppConfig) -> CorsLayer {
+    let base = CorsLayer::new()
+        .allow_methods([Method::GET, Method::POST, Method::OPTIONS])
+        .allow_headers([
+            header::AUTHORIZATION,
+            header::CONTENT_TYPE,
+            header::ACCEPT,
+        ]);
 
-    Router::new()
+    if cfg.appview_cors_origins.is_empty() {
+        return base.allow_origin(Any);
+    }
+
+    // Anything unparseable as a header value is dropped with a warning
+    // rather than panicking the process — a stray quote in the env var
+    // must not take the service down. If *every* entry is bad we fall
+    // back to the wildcard and say so, because an empty allowlist would
+    // silently break every browser client.
+    let mut origins: Vec<HeaderValue> = Vec::new();
+    for raw in &cfg.appview_cors_origins {
+        match HeaderValue::from_str(raw) {
+            Ok(v) => origins.push(v),
+            Err(_) => warn!(origin = %raw, "APPVIEW_CORS_ORIGINS: ignoring unparseable origin"),
+        }
+    }
+    if origins.is_empty() {
+        warn!("APPVIEW_CORS_ORIGINS contained no usable origin; falling back to allow-any");
+        return base.allow_origin(Any);
+    }
+    base.allow_origin(AllowOrigin::list(origins))
+}
+
+pub fn router(state: AppState) -> Router {
+    let cors = cors_layer(&state.cfg);
+
+    // Browser-facing surface. Everything here answers a `fetch()` from
+    // the desktop client, so it carries the CORS layer.
+    let api = Router::new()
         .route("/", get(root))
+        // --- private: token required, `sub` must equal `did` ---
         .route("/api/timeline/home", get(timeline_home))
+        .route("/api/notifications", get(notifications))
+        .route("/api/notifications/count", get(notifications_count))
+        .route("/api/notifications/seen", post(notifications_seen))
+        // --- public: AT Proto public records ---
         .route("/api/profile", get(profile_query))
         .route("/api/profile/:handle", get(profile_path))
         .route("/api/search", get(search))
@@ -66,15 +141,20 @@ pub fn router(state: AppState) -> Router {
         // implementation, so they can't drift.
         .route("/api/thread", get(thread_query))
         .route("/api/thread/*uri", get(thread_path))
-        .route("/api/notifications", get(notifications))
-        .route("/api/notifications/count", get(notifications_count))
-        .route("/api/notifications/seen", post(notifications_seen))
         .route("/api/followers", get(followers))
         .route("/api/following", get(following))
         .route("/healthz", get(healthz))
-        .route("/internal/ingest-commit", post(crate::ingest::ingest_commit))
+        .layer(cors);
-        .layer(cors)
+
-        .with_state(state)
+    // Server-to-server surface. `/internal/ingest-commit` is called by
+    // the PDS with a shared secret, never by a browser, so it stays
+    // outside the CORS layer: handing it an
+    // `Access-Control-Allow-Origin` header would only ever help a web
+    // page try to write to the index.
+    let internal = Router::new()
+        .route("/internal/ingest-commit", post(crate::ingest::ingest_commit));
+
+    api.merge(internal).with_state(state)
 }
 
 async fn root() -> Json<Value> {
@@ -115,13 +195,21 @@ const MAX_LIMIT: i64 = 100;
 /// surface.
 const MAX_FOLLOWED_DIDS: usize = 1000;
 
+/// `GET /api/timeline/home?did=…`
+///
+/// **Authenticated.** The timeline is derived from the viewer's follow
+/// graph, so `did` must be the caller's own DID — otherwise this
+/// endpoint would answer "what does this account's feed look like" for
+/// any DID at all.
 async fn timeline_home(
     State(state): State<AppState>,
+    auth: AuthedDid,
     Query(q): Query<TimelineQuery>,
 ) -> Result<Json<TimelineResponse>, (StatusCode, Json<Value>)> {
     if q.did.is_empty() {
         return Err(bad_request("did is required"));
     }
+    auth.ensure_matches(&q.did)?;
     let limit = clamp_limit(q.limit);
 
     // Look up the set of DIDs this user follows, then build the
@@ -230,20 +318,51 @@ async fn timeline_home(
             .map_err(db_err)?,
         }
     } else {
-        // Graph-aware branch: filter `posts.did` to the followee set
+        // Graph-aware branch: the followee set plus the requesting
-        // plus the requesting user's own DID. `target_dids` has been
+        // user's own DID. `target_dids` has been deduped and capped at
-        // deduped and capped at MAX_FOLLOWED_DIDS, and the user's own
+        // MAX_FOLLOWED_DIDS, and the user's own DID is guaranteed to
-        // DID is guaranteed to be in the set.
+        // be in the set.
+        //
+        // ## Why this is a LATERAL and not `did = ANY($2)`
+        //
+        // The straightforward `WHERE did = ANY($2) ORDER BY indexed_at
+        // DESC LIMIT n` is a plan-stability trap once
+        // `posts_feed_indexed_at_uri_idx` exists (migration 0009, added
+        // for the cold-start feed). The planner sees an index that
+        // already yields rows in `indexed_at DESC` order and assumes it
+        // will hit `n` matching rows early — so it walks the global
+        // feed and filters. When the followees are sparse (a fresh
+        // account following accounts that haven't posted), "early"
+        // means millions of rows: measured on the dev instance, 2.87 M
+        // rows discarded and 28 s per request, while the same query
+        // took 62 ms with the per-DID index. It also flipped between
+        // the two plans depending on how often the prepared statement
+        // had run, so it looked intermittent.
+        //
+        // Expressing the intent — "for each followee, their newest
+        // posts, merged" — takes that plan off the table: `unnest` is a
+        // relation the planner can size, and each iteration is a bounded
+        // range scan on `posts_did_indexed_at_uri_idx`. Fetching `$1`
+        // per followee is what makes it correct: the global top-N is
+        // always a subset of the union of the per-followee top-Ns.
         match cursor_ts {
             Some(ts) => sqlx::query_as::<_, PostRowWithIndexed>(
-                r#"SELECT uri, did, handle, rkey, collection, text, cid,
+                r#"SELECT t.uri, t.did, t.handle, t.rkey, t.collection,
-                          parent_uri, root_uri, embed, langs, created_at,
+                          t.text, t.cid, t.parent_uri, t.root_uri,
-                          indexed_at
+                          t.embed, t.langs, t.created_at, t.indexed_at
-                   FROM posts
+                   FROM unnest($2::text[]) AS f(did)
-                   WHERE collection IN ('app.twi.post','app.bsky.feed.post')
+                   CROSS JOIN LATERAL (
-                     AND did = ANY($2::text[])
+                       SELECT p.uri, p.did, p.handle, p.rkey, p.collection,
-                     AND (indexed_at, uri) < ($3, $4)
+                              p.text, p.cid, p.parent_uri, p.root_uri,
-                   ORDER BY indexed_at DESC, uri DESC
+                              p.embed, p.langs, p.created_at, p.indexed_at
+                       FROM posts p
+                       WHERE p.did = f.did
+                         AND p.collection IN ('app.twi.post','app.bsky.feed.post')
+                         AND (p.indexed_at, p.uri) < ($3, $4)
+                       ORDER BY p.indexed_at DESC, p.uri DESC
+                       LIMIT $1
+                   ) t
+                   ORDER BY t.indexed_at DESC, t.uri DESC
                    LIMIT $1"#,
             )
             .bind(fetch)
@@ -254,13 +373,21 @@ async fn timeline_home(
             .await
             .map_err(db_err)?,
             None => sqlx::query_as::<_, PostRowWithIndexed>(
-                r#"SELECT uri, did, handle, rkey, collection, text, cid,
+                r#"SELECT t.uri, t.did, t.handle, t.rkey, t.collection,
-                          parent_uri, root_uri, embed, langs, created_at,
+                          t.text, t.cid, t.parent_uri, t.root_uri,
-                          indexed_at
+                          t.embed, t.langs, t.created_at, t.indexed_at
-                   FROM posts
+                   FROM unnest($2::text[]) AS f(did)
-                   WHERE collection IN ('app.twi.post','app.bsky.feed.post')
+                   CROSS JOIN LATERAL (
-                     AND did = ANY($2::text[])
+                       SELECT p.uri, p.did, p.handle, p.rkey, p.collection,
-                   ORDER BY indexed_at DESC, uri DESC
+                              p.text, p.cid, p.parent_uri, p.root_uri,
+                              p.embed, p.langs, p.created_at, p.indexed_at
+                       FROM posts p
+                       WHERE p.did = f.did
+                         AND p.collection IN ('app.twi.post','app.bsky.feed.post')
+                       ORDER BY p.indexed_at DESC, p.uri DESC
+                       LIMIT $1
+                   ) t
+                   ORDER BY t.indexed_at DESC, t.uri DESC
                    LIMIT $1"#,
             )
             .bind(fetch)
@@ -1046,13 +1173,19 @@ struct NotificationsQuery {
 /// of the list. The tiebreak here is the row's `id` rather than a URI
 /// (a notification has no URI of its own), which the shared
 /// [`cursor`] codec carries in its string slot.
+///
+/// **Authenticated**: `did` is the recipient, so the caller has to be
+/// that recipient. This is the endpoint that made authentication
+/// necessary in the first place.
 async fn notifications(
     State(state): State<AppState>,
+    auth: AuthedDid,
     Query(q): Query<NotificationsQuery>,
 ) -> Result<Json<NotificationsResponse>, (StatusCode, Json<Value>)> {
     if q.did.is_empty() {
         return Err(bad_request("did is required"));
     }
+    auth.ensure_matches(&q.did)?;
     let limit = clamp_limit(q.limit);
     let keyset = decode_cursor(q.cursor.as_deref())?;
     // The cursor's string slot holds the row id. A client that hands
@@ -1121,13 +1254,18 @@ struct NotificationCountQuery {
 /// scales with the number of *unread* rows, not the user's lifetime
 /// notification history. That matters because the client polls this
 /// for its tray badge.
+///
+/// **Authenticated**, same rule as the list itself: an unread count is
+/// still information about someone else's inbox.
 async fn notifications_count(
     State(state): State<AppState>,
+    auth: AuthedDid,
     Query(q): Query<NotificationCountQuery>,
 ) -> Result<Json<NotificationCountResponse>, (StatusCode, Json<Value>)> {
     if q.did.is_empty() {
         return Err(bad_request("did is required"));
     }
+    auth.ensure_matches(&q.did)?;
     let count: i64 = sqlx::query_scalar(
         "SELECT COUNT(*)::BIGINT FROM notifications \
           WHERE recipient_did = $1 AND read_at IS NULL",
@@ -1165,13 +1303,20 @@ struct NotificationsSeenReq {
 /// updates nothing and reports `updated: 0`. `read_at` is set to
 /// `now()` (when we recorded the ack), not to `seenAt` (which is a
 /// client-supplied watermark and could be arbitrarily far in the past).
+///
+/// **Authenticated**, and the only *write* among the private
+/// endpoints: without the check anyone could clear another user's
+/// unread badge. `AuthedDid` runs before `Json` because the body
+/// extractor consumes the request — axum requires body extractors last.
 async fn notifications_seen(
     State(state): State<AppState>,
+    auth: AuthedDid,
     Json(req): Json<NotificationsSeenReq>,
 ) -> Result<Json<NotificationSeenResponse>, (StatusCode, Json<Value>)> {
     if req.did.is_empty() {
         return Err(bad_request("did is required"));
     }
+    auth.ensure_matches(&req.did)?;
     let res = sqlx::query(
         r#"UPDATE notifications
               SET read_at = now()

crates/appview/src/state.rs

@@ -2,18 +2,30 @@ use at_shared::config::AppConfig;
 use sqlx::PgPool;
 use std::sync::Arc;
 
+use crate::auth::PdsKeys;
 use crate::firehose::Stats;
 
 #[derive(Clone)]
 pub struct AppState {
-    #[allow(dead_code)]
     pub cfg: AppConfig,
     pub db: PgPool,
     pub stats: Arc<Stats>,
+    /// Cache of the PDS's published signing key, used by the
+    /// [`crate::auth::AuthedDid`] extractor. Shared (`Arc`) so every
+    /// handler verifies against the same cached key and one HTTP
+    /// client, and so a key rotation picked up by one request is
+    /// immediately visible to the rest.
+    pub pds_keys: Arc<PdsKeys>,
 }
 
 impl AppState {
     pub fn new(cfg: AppConfig, db: PgPool, stats: Arc<Stats>) -> Self {
-        Self { cfg, db, stats }
+        let pds_keys = Arc::new(PdsKeys::from_config(&cfg));
+        Self {
+            cfg,
+            db,
+            stats,
+            pds_keys,
+        }
     }
 }

crates/appview/tests/api_integration.rs

@@ -7,6 +7,9 @@
 //! rather than panicking — so `cargo test --workspace` stays green in
 //! environments where the appview hasn't been started.
 
+mod common;
+
+use common::TestAuth;
 use serde_json::{json, Value};
 use std::time::Duration;
 
@@ -46,6 +49,36 @@ async fn db_reachable() -> bool {
     )
 }
 
+/// How this suite authenticates against `/api/timeline/home`, which is
+/// no longer public. `None` means the AppView enforces auth but the
+/// test process cannot mint a token (no `PDS_JWT_SECRET`), in which
+/// case the test skips like it does for a missing service.
+async fn auth_or_skip() -> Option<TestAuth> {
+    TestAuth::probe(&client().await, APPVIEW_URL).await
+}
+
+/// `GET /api/timeline/home` as `did`, with the bearer token attached
+/// when the instance requires one. The seeded DIDs are synthetic, so
+/// the token is minted from the PDS's own signing secret — see
+/// `tests/common/mod.rs`.
+async fn get_timeline(
+    c: &reqwest::Client,
+    auth: &TestAuth,
+    did: &str,
+    extra: &[(&str, &str)],
+) -> reqwest::Response {
+    let mut params: Vec<(&str, &str)> = vec![("did", did)];
+    params.extend_from_slice(extra);
+    auth.apply(
+        c.get(format!("{APPVIEW_URL}/api/timeline/home"))
+            .query(&params),
+        did,
+    )
+    .send()
+    .await
+    .unwrap()
+}
+
 async fn post_ingest(c: &reqwest::Client, body: Value) -> reqwest::Response {
     c.post(format!("{APPVIEW_URL}/internal/ingest-commit"))
         .json(&body)
@@ -120,6 +153,7 @@ async fn timeline_returns_seeded_posts() {
         return;
     }
     let c = client().await;
+    let Some(auth) = auth_or_skip().await else { return };
     let did = did_for_test("tl");
 
     // Seed 3 posts with distinct rkeys.
@@ -157,12 +191,7 @@ async fn timeline_returns_seeded_posts() {
     // machine that has run this suite twice) the three rows we just
     // seeded fall outside a 10-row window and the assertions below
     // fail for reasons that have nothing to do with the timeline.
-    let resp = c
+    let resp = get_timeline(&c, &auth, &did, &[("limit", "100")]).await;
-        .get(format!("{APPVIEW_URL}/api/timeline/home"))
-        .query(&[("did", did.as_str()), ("limit", "100")])
-        .send()
-        .await
-        .unwrap();
     assert_eq!(resp.status().as_u16(), 200);
     let body: Value = resp.json().await.unwrap();
     let posts = body["posts"].as_array().expect("posts is array");
@@ -222,6 +251,7 @@ async fn timeline_paginates_with_cursor() {
         return;
     }
     let c = client().await;
+    let Some(auth) = auth_or_skip().await else { return };
     let did = did_for_test("pg");
 
     // Seed 50 posts.
@@ -246,28 +276,14 @@ async fn timeline_paginates_with_cursor() {
     tokio::time::sleep(Duration::from_millis(100)).await;
 
     // Page 1: limit=20.
-    let resp = c
+    let resp = get_timeline(&c, &auth, &did, &[("limit", "20")]).await;
-        .get(format!("{APPVIEW_URL}/api/timeline/home"))
-        .query(&[("did", did.as_str()), ("limit", "20")])
-        .send()
-        .await
-        .unwrap();
     let body: Value = resp.json().await.unwrap();
     let page1 = body["posts"].as_array().unwrap().clone();
     let cursor1 = body["cursor"].as_str().expect("page1 cursor");
     assert_eq!(page1.len(), 20, "page1 should be exactly 20");
 
     // Page 2: with cursor.
-    let resp = c
+    let resp = get_timeline(&c, &auth, &did, &[("limit", "20"), ("cursor", cursor1)]).await;
-        .get(format!("{APPVIEW_URL}/api/timeline/home"))
-        .query(&[
-            ("did", did.as_str()),
-            ("limit", "20"),
-            ("cursor", cursor1),
-        ])
-        .send()
-        .await
-        .unwrap();
     let body: Value = resp.json().await.unwrap();
     let page2 = body["posts"].as_array().unwrap().clone();
     assert_eq!(page2.len(), 20, "page2 should be exactly 20");
@@ -285,16 +301,7 @@ async fn timeline_paginates_with_cursor() {
 
     // Page 3: tail — fewer than 20 expected, cursor=null.
     let cursor2 = body["cursor"].as_str().expect("page2 cursor");
-    let resp = c
+    let resp = get_timeline(&c, &auth, &did, &[("limit", "20"), ("cursor", cursor2)]).await;
-        .get(format!("{APPVIEW_URL}/api/timeline/home"))
-        .query(&[
-            ("did", did.as_str()),
-            ("limit", "20"),
-            ("cursor", cursor2),
-        ])
-        .send()
-        .await
-        .unwrap();
     let body: Value = resp.json().await.unwrap();
     let page3 = body["posts"].as_array().unwrap().clone();
     assert!(page3.len() <= 20, "page3 should be <= 20");
@@ -484,6 +491,7 @@ async fn timeline_filters_to_followees() {
         return;
     }
     let c = client().await;
+    let Some(auth) = auth_or_skip().await else { return };
     let url = std::env::var("DATABASE_URL_APPVIEW").unwrap();
     let pool = sqlx::PgPool::connect(&url).await.unwrap();
 
@@ -503,12 +511,7 @@ async fn timeline_filters_to_followees() {
 
     tokio::time::sleep(Duration::from_millis(100)).await;
 
-    let resp = c
+    let resp = get_timeline(&c, &auth, &alice, &[("limit", "100")]).await;
-        .get(format!("{APPVIEW_URL}/api/timeline/home"))
-        .query(&[("did", alice.as_str()), ("limit", "100")])
-        .send()
-        .await
-        .unwrap();
     assert_eq!(resp.status().as_u16(), 200);
     let body: Value = resp.json().await.unwrap();
     let posts = body["posts"].as_array().expect("posts is array");
@@ -555,18 +558,14 @@ async fn timeline_includes_own_posts() {
         return;
     }
     let c = client().await;
+    let Some(auth) = auth_or_skip().await else { return };
     let alice = did_for_test("alone");
 
     // Alice posts without seeding any follows.
     seed_posts(&c, &alice, &["alice's first post", "alice's second post"]).await;
     tokio::time::sleep(Duration::from_millis(100)).await;
 
-    let resp = c
+    let resp = get_timeline(&c, &auth, &alice, &[("limit", "100")]).await;
-        .get(format!("{APPVIEW_URL}/api/timeline/home"))
-        .query(&[("did", alice.as_str()), ("limit", "100")])
-        .send()
-        .await
-        .unwrap();
     assert_eq!(resp.status().as_u16(), 200);
     let body: Value = resp.json().await.unwrap();
     let posts = body["posts"].as_array().expect("posts is array");
@@ -605,6 +604,7 @@ async fn timeline_caps_followee_list() {
         return;
     }
     let c = client().await;
+    let Some(auth) = auth_or_skip().await else { return };
     let url = std::env::var("DATABASE_URL_APPVIEW").unwrap();
     let pool = sqlx::PgPool::connect(&url).await.unwrap();
 
@@ -624,12 +624,7 @@ async fn timeline_caps_followee_list() {
     seed_posts(&c, &alice, &["poweruser post"]).await;
     tokio::time::sleep(Duration::from_millis(100)).await;
 
-    let resp = c
+    let resp = get_timeline(&c, &auth, &alice, &[("limit", "50")]).await;
-        .get(format!("{APPVIEW_URL}/api/timeline/home"))
-        .query(&[("did", alice.as_str()), ("limit", "50")])
-        .send()
-        .await
-        .unwrap();
     assert_eq!(resp.status().as_u16(), 200);
     let body: Value = resp.json().await.unwrap();
     let posts = body["posts"].as_array().expect("posts is array");

crates/appview/tests/auth_integration.rs

@@ -0,0 +1,311 @@
+//! End-to-end tests for AppView authentication.
+//!
+//! Unlike the other suites in this directory these use a **real**
+//! token: the test creates an account on the running PDS
+//! (`com.atproto.server.createAccount`, the same call the desktop
+//! client makes at signup) and presents the access JWT it gets back to
+//! the AppView. That is the whole point — it exercises the actual key
+//! distribution path (PDS signs → publishes its public key at
+//! `/.well-known/did.json` → AppView fetches and verifies), which a
+//! self-minted token would bypass.
+//!
+//! Fail-open like the rest of the suites: if the PDS or the AppView
+//! isn't running, or the AppView runs with `APPVIEW_AUTH_REQUIRED=false`,
+//! the test prints a notice and returns successfully.
+
+use serde_json::{json, Value};
+use std::time::Duration;
+
+const PDS_URL: &str = "http://127.0.0.1:2583";
+
+fn appview_url() -> String {
+    std::env::var("APPVIEW_TEST_URL").unwrap_or_else(|_| "http://127.0.0.1:2584".to_string())
+}
+
+/// 30 s, not the 5 s the sibling suites use.
+///
+/// The authenticated happy path for `/api/timeline/home` runs the
+/// cold-start query (a brand-new account follows nobody, so the handler
+/// falls back to the global recent feed). On a developer machine whose
+/// AppView has been indexing the public firehose for a while that scan
+/// takes seconds — a timeout there would look like an auth failure and
+/// is nothing of the sort.
+fn client() -> reqwest::Client {
+    reqwest::Client::builder()
+        .timeout(Duration::from_secs(30))
+        .build()
+        .unwrap()
+}
+
+async fn up(c: &reqwest::Client, base: &str) -> bool {
+    for _ in 0..20 {
+        if let Ok(r) = c.get(format!("{base}/healthz")).send().await {
+            if r.status().is_success() {
+                return true;
+            }
+        }
+        tokio::time::sleep(Duration::from_millis(250)).await;
+    }
+    false
+}
+
+/// A freshly created PDS account.
+struct Account {
+    did: String,
+    access_jwt: String,
+    refresh_jwt: String,
+}
+
+/// Guard for every test here: both services up **and** the AppView
+/// actually enforcing auth. Returns the client plus a new account.
+async fn ready() -> Option<(reqwest::Client, Account)> {
+    let c = client();
+    if !up(&c, &appview_url()).await {
+        eprintln!("appview not running, skipping");
+        return None;
+    }
+    if !up(&c, PDS_URL).await {
+        eprintln!("pds not running, skipping");
+        return None;
+    }
+    // Probe: does this instance enforce auth? An operator running with
+    // `APPVIEW_AUTH_REQUIRED=false` (the mode the other suites use)
+    // would otherwise see every assertion here fail for the one reason
+    // that isn't a bug.
+    let probe = c
+        .get(format!("{}/api/notifications/count", appview_url()))
+        .query(&[("did", "did:plc:auth_probe")])
+        .send()
+        .await
+        .ok()?;
+    if probe.status().as_u16() != 401 {
+        eprintln!(
+            "appview does not enforce auth (probe returned {}), skipping",
+            probe.status()
+        );
+        return None;
+    }
+    let acc = create_account(&c).await?;
+    Some((c, acc))
+}
+
+async fn create_account(c: &reqwest::Client) -> Option<Account> {
+    let handle = format!("auth_{}.maarcadetweet.local", uuid::Uuid::new_v4().simple());
+    let r: Value = c
+        .post(format!("{PDS_URL}/xrpc/com.atproto.server.createAccount"))
+        .json(&json!({ "handle": handle, "password": "hunter2hunter2" }))
+        .send()
+        .await
+        .ok()?
+        .json()
+        .await
+        .ok()?;
+    Some(Account {
+        did: r["did"].as_str()?.to_string(),
+        access_jwt: r["access_jwt"].as_str()?.to_string(),
+        refresh_jwt: r["refresh_jwt"].as_str()?.to_string(),
+    })
+}
+
+/// `GET /api/notifications?did=…` with an optional bearer token.
+async fn get_notifications(
+    c: &reqwest::Client,
+    did: &str,
+    token: Option<&str>,
+) -> reqwest::Response {
+    let mut rb = c
+        .get(format!("{}/api/notifications", appview_url()))
+        .query(&[("did", did)]);
+    if let Some(t) = token {
+        rb = rb.bearer_auth(t);
+    }
+    rb.send().await.unwrap()
+}
+
+/// Assert the AppView's standard error envelope: the status, and the
+/// `error` code the desktop client branches on.
+async fn assert_error(r: reqwest::Response, status: u16, code: &str) {
+    let got = r.status().as_u16();
+    let body: Value = r.json().await.unwrap();
+    assert_eq!(got, status, "unexpected status; body = {body}");
+    assert_eq!(body["error"], json!(code), "unexpected error code: {body}");
+    assert!(
+        body["message"].is_string(),
+        "error body must carry a message: {body}"
+    );
+}
+
+#[tokio::test]
+async fn own_token_reads_own_notifications() {
+    let Some((c, acc)) = ready().await else { return };
+    let r = get_notifications(&c, &acc.did, Some(&acc.access_jwt)).await;
+    assert_eq!(r.status().as_u16(), 200);
+    let body: Value = r.json().await.unwrap();
+    // A brand-new account has no notifications, but the shape must be
+    // the normal list response, not an error.
+    assert!(body["notifications"].is_array(), "body = {body}");
+}
+
+#[tokio::test]
+async fn no_token_is_401_auth_missing() {
+    let Some((c, acc)) = ready().await else { return };
+    let r = get_notifications(&c, &acc.did, None).await;
+    assert_error(r, 401, "AuthMissing").await;
+}
+
+#[tokio::test]
+async fn foreign_did_is_403() {
+    let Some((c, acc)) = ready().await else { return };
+    // A valid token, but asking about somebody else's inbox. This is
+    // the case the endpoint used to answer with a 200.
+    let r = get_notifications(&c, "did:plc:somebodyelse", Some(&acc.access_jwt)).await;
+    assert_error(r, 403, "Forbidden").await;
+}
+
+#[tokio::test]
+async fn garbage_token_is_401_token_invalid() {
+    let Some((c, acc)) = ready().await else { return };
+    let r = get_notifications(&c, &acc.did, Some("not.a.jwt")).await;
+    assert_error(r, 401, "TokenInvalid").await;
+}
+
+#[tokio::test]
+async fn refresh_token_is_not_accepted() {
+    let Some((c, acc)) = ready().await else { return };
+    // Signed by the same key and valid for 90 days — only the `scope`
+    // claim separates it from a session credential.
+    let r = get_notifications(&c, &acc.did, Some(&acc.refresh_jwt)).await;
+    assert_error(r, 401, "TokenInvalid").await;
+}
+
+#[tokio::test]
+async fn seen_write_requires_matching_token() {
+    let Some((c, acc)) = ready().await else { return };
+    let url = format!("{}/api/notifications/seen", appview_url());
+
+    // Somebody else's unread badge: 403, nothing written.
+    let r = c
+        .post(&url)
+        .bearer_auth(&acc.access_jwt)
+        .json(&json!({ "did": "did:plc:somebodyelse" }))
+        .send()
+        .await
+        .unwrap();
+    assert_error(r, 403, "Forbidden").await;
+
+    // No credential at all: 401.
+    let r = c
+        .post(&url)
+        .json(&json!({ "did": &acc.did }))
+        .send()
+        .await
+        .unwrap();
+    assert_error(r, 401, "AuthMissing").await;
+
+    // Own inbox: allowed (zero rows updated — the account is new).
+    let r = c
+        .post(&url)
+        .bearer_auth(&acc.access_jwt)
+        .json(&json!({ "did": &acc.did }))
+        .send()
+        .await
+        .unwrap();
+    assert_eq!(r.status().as_u16(), 200);
+    let body: Value = r.json().await.unwrap();
+    assert_eq!(body["ok"], json!(true));
+}
+
+#[tokio::test]
+async fn timeline_home_is_authenticated() {
+    let Some((c, acc)) = ready().await else { return };
+    let base = appview_url();
+
+    let r = c
+        .get(format!("{base}/api/timeline/home"))
+        .query(&[("did", acc.did.as_str())])
+        .send()
+        .await
+        .unwrap();
+    assert_error(r, 401, "AuthMissing").await;
+
+    let r = c
+        .get(format!("{base}/api/timeline/home"))
+        .query(&[("did", "did:plc:somebodyelse")])
+        .bearer_auth(&acc.access_jwt)
+        .send()
+        .await
+        .unwrap();
+    assert_error(r, 403, "Forbidden").await;
+
+    let r = c
+        .get(format!("{base}/api/timeline/home"))
+        .query(&[("did", acc.did.as_str())])
+        .bearer_auth(&acc.access_jwt)
+        .send()
+        .await
+        .unwrap();
+    assert_eq!(r.status().as_u16(), 200);
+}
+
+#[tokio::test]
+async fn public_endpoints_stay_public() {
+    let Some((c, acc)) = ready().await else { return };
+    let base = appview_url();
+
+    // Profiles, search, follower lists and the health probe are public
+    // records in AT Proto. Putting them behind auth would be a
+    // behaviour change no protocol rule asks for — assert they still
+    // answer without a token.
+    for (path, params) in [
+        ("/api/profile", vec![("did", acc.did.as_str())]),
+        ("/api/search", vec![("q", "hello")]),
+        ("/api/followers", vec![("did", acc.did.as_str())]),
+        ("/api/following", vec![("did", acc.did.as_str())]),
+        ("/healthz", vec![]),
+    ] {
+        let r = c
+            .get(format!("{base}{path}"))
+            .query(&params)
+            .send()
+            .await
+            .unwrap();
+        assert_eq!(
+            r.status().as_u16(),
+            200,
+            "{path} must remain public, got {}",
+            r.status()
+        );
+    }
+}
+
+/// The AppView can only verify anything because the PDS publishes its
+/// public key. If this document ever stops carrying a usable key, every
+/// authenticated request degrades to `503 AuthUnavailable` — so assert
+/// the shape the AppView parses.
+#[tokio::test]
+async fn pds_publishes_a_usable_signing_key() {
+    let c = client();
+    if !up(&c, PDS_URL).await {
+        eprintln!("pds not running, skipping");
+        return;
+    }
+    let doc: Value = c
+        .get(format!("{PDS_URL}/.well-known/did.json"))
+        .send()
+        .await
+        .unwrap()
+        .json()
+        .await
+        .unwrap();
+    let id = doc["id"].as_str().expect("did document needs an id");
+    assert!(id.starts_with("did:web:"), "id = {id}");
+    let vm = &doc["verificationMethod"][0];
+    assert_eq!(vm["type"], json!("Multikey"));
+    assert_eq!(vm["controller"], json!(id));
+    let key = vm["publicKeyMultibase"]
+        .as_str()
+        .expect("verificationMethod needs publicKeyMultibase");
+    // base58-btc multibase: the `z` prefix is what the AppView's
+    // decoder expects.
+    assert!(key.starts_with('z'), "key = {key}");
+}

crates/appview/tests/common/mod.rs

@@ -0,0 +1,167 @@
+//! Shared test support for the AppView integration suites.
+//!
+//! ## Why the suites need this
+//!
+//! `/api/notifications*` and `/api/timeline/home` require a
+//! PDS-issued access token whose `sub` equals the `did` in the request.
+//! The suites, however, seed synthetic DIDs (`did:plc:ntf_…`) through
+//! `/internal/ingest-commit` — accounts the PDS has never heard of, so
+//! there is no `createSession` that would hand out a token for them.
+//!
+//! The way out is that a token is just an ES256 JWT signed with the
+//! server key derived from `PDS_JWT_SECRET`. A test that can read that
+//! secret (from the process environment, or from the repo `.env` the
+//! dev stack itself was started with) can mint a token for any DID it
+//! likes — the same thing `pds-server/src/jwt_issuer.rs` does.
+//!
+//! ## Fail-open, like the rest of the suites
+//!
+//! [`TestAuth::probe`] asks the running AppView whether it enforces
+//! auth at all:
+//!
+//! - not enforcing (`APPVIEW_AUTH_REQUIRED=false`) → no header needed;
+//! - enforcing and we have the secret → mint per-DID tokens;
+//! - enforcing and we don't → `None`, and the caller skips, exactly as
+//!   it already skips when the service or the database is down.
+
+#![allow(dead_code)]
+
+use at_crypto::ecdsa::P256Keypair;
+use at_crypto::jwt::{issue_jwt, JwtClaims};
+
+/// Audience the PDS stamps into access tokens. Not validated by
+/// `verify_jwt` today (`validate_aud = false`), but minting a token
+/// that differs from the real thing would make this helper a poor
+/// stand-in for the client.
+const APPVIEW_AUD: &str = "did:web:appview.maarcadetweet.local";
+
+/// The scope the AppView insists on. A token with any other scope —
+/// `com.atproto.refresh`, say — is rejected with `TokenInvalid`.
+pub const ACCESS_SCOPE: &str = "com.atproto.access";
+
+/// How the suite should authenticate against the AppView under test.
+///
+/// `Clone` because a test that pages through results in a closure has
+/// to hand each iteration its own copy, exactly like the client and the
+/// base URL next to it.
+#[derive(Clone)]
+pub enum TestAuth {
+    /// `APPVIEW_AUTH_REQUIRED=false`: send no `Authorization` header.
+    Disabled,
+    /// Auth is enforced; mint tokens with this hex secret.
+    Secret(String),
+}
+
+impl TestAuth {
+    /// Decide how (or whether) this suite can talk to the AppView.
+    ///
+    /// Returns `None` when the AppView enforces auth but no
+    /// `PDS_JWT_SECRET` is reachable — the caller should print a notice
+    /// and return, keeping `cargo test --workspace` green on a machine
+    /// without the dev stack's environment.
+    pub async fn probe(c: &reqwest::Client, base_url: &str) -> Option<Self> {
+        // An unauthenticated probe against a private endpoint. We only
+        // look at the status: 401 means the extractor is active. A DID
+        // that doesn't exist is fine — the auth check runs first.
+        let status = c
+            .get(format!("{base_url}/api/notifications/count"))
+            .query(&[("did", "did:plc:auth_probe")])
+            .send()
+            .await
+            .ok()?
+            .status()
+            .as_u16();
+        if status != 401 && status != 503 {
+            return Some(TestAuth::Disabled);
+        }
+        match pds_jwt_secret() {
+            Some(secret) => Some(TestAuth::Secret(secret)),
+            None => {
+                eprintln!(
+                    "appview enforces auth (probe returned {status}) but PDS_JWT_SECRET \
+                     is not set and no .env was found — skipping"
+                );
+                None
+            }
+        }
+    }
+
+    /// Attach an `Authorization: Bearer` header for `did`, if needed.
+    pub fn apply(&self, rb: reqwest::RequestBuilder, did: &str) -> reqwest::RequestBuilder {
+        match self {
+            TestAuth::Disabled => rb,
+            TestAuth::Secret(secret) => match mint_access_jwt(secret, did, ACCESS_SCOPE, 3600) {
+                Some(token) => rb.bearer_auth(token),
+                None => rb,
+            },
+        }
+    }
+
+    /// A token for `did` — for tests that want to send a *wrong* one on
+    /// purpose. `None` when auth is disabled, in which case the test
+    /// that needs it should skip.
+    pub fn token_for(&self, did: &str) -> Option<String> {
+        match self {
+            TestAuth::Disabled => None,
+            TestAuth::Secret(secret) => mint_access_jwt(secret, did, ACCESS_SCOPE, 3600),
+        }
+    }
+}
+
+/// `PDS_JWT_SECRET` from the environment, falling back to the repo
+/// `.env` — the same file the running dev stack loaded at startup, so
+/// the minted tokens verify against the key the PDS actually publishes.
+pub fn pds_jwt_secret() -> Option<String> {
+    if let Ok(v) = std::env::var("PDS_JWT_SECRET") {
+        if !v.trim().is_empty() {
+            return Some(v);
+        }
+    }
+    // `dotenvy::dotenv` walks up from the current directory, which for
+    // a test binary is the crate root — so this finds the workspace
+    // `.env` two levels up. It never overrides a real env var.
+    let _ = dotenvy::dotenv();
+    std::env::var("PDS_JWT_SECRET")
+        .ok()
+        .filter(|v| !v.trim().is_empty())
+}
+
+/// Mint an access JWT for `did`, signed with the PDS's server key.
+///
+/// Mirrors `pds-server/src/jwt_issuer.rs`: the P-256 secret scalar is
+/// the **first 32 bytes** of `PDS_JWT_SECRET` (the config allows a
+/// longer secret), i.e. the first 64 hex characters.
+///
+/// `ttl_secs` may be negative to build a deliberately expired token.
+pub fn mint_access_jwt(
+    secret_hex: &str,
+    did: &str,
+    scope: &str,
+    ttl_secs: i64,
+) -> Option<String> {
+    let hex = secret_hex.trim().trim_start_matches("0x");
+    if hex.len() < 64 || !hex.chars().all(|c| c.is_ascii_hexdigit()) {
+        eprintln!("PDS_JWT_SECRET is not ≥32 bytes of hex; cannot mint a test token");
+        return None;
+    }
+    let kp = P256Keypair {
+        secret_hex: hex[..64].to_string(),
+        // Only the signing half is used by `issue_jwt`; the verifier
+        // fetches the public key from the PDS's DID document.
+        public_multibase: String::new(),
+    };
+    let now = chrono::Utc::now().timestamp();
+    issue_jwt(
+        &kp,
+        &JwtClaims {
+            iss: "did:web:test".into(),
+            sub: did.to_string(),
+            aud: APPVIEW_AUD.into(),
+            iat: now - 1,
+            exp: now + ttl_secs,
+            jti: None,
+            scope: Some(scope.to_string()),
+        },
+    )
+    .ok()
+}

crates/appview/tests/embeds_integration.rs

@@ -15,6 +15,9 @@
 //! and returns rather than panicking. The point of the tests is to
 //! catch regressions in CI where the service IS up.
 
+mod common;
+
+use common::TestAuth;
 use serde_json::{json, Value};
 use std::time::Duration;
 
@@ -50,6 +53,32 @@ async fn db_reachable() -> bool {
     )
 }
 
+/// `/api/timeline/home` requires a token whose `sub` is the requested
+/// DID. The DIDs here are synthetic, so the token is minted from the
+/// PDS signing secret — see `tests/common/mod.rs`. `None` → skip.
+async fn auth_or_skip() -> Option<TestAuth> {
+    TestAuth::probe(&client().await, APPVIEW_URL).await
+}
+
+/// `GET /api/timeline/home` as `did`, authenticated when required.
+async fn get_timeline(
+    c: &reqwest::Client,
+    auth: &TestAuth,
+    did: &str,
+    extra: &[(&str, &str)],
+) -> reqwest::Response {
+    let mut params: Vec<(&str, &str)> = vec![("did", did)];
+    params.extend_from_slice(extra);
+    auth.apply(
+        c.get(format!("{APPVIEW_URL}/api/timeline/home"))
+            .query(&params),
+        did,
+    )
+    .send()
+    .await
+    .unwrap()
+}
+
 async fn post_ingest(c: &reqwest::Client, body: Value) -> reqwest::Response {
     c.post(format!("{APPVIEW_URL}/internal/ingest-commit"))
         .json(&body)
@@ -125,6 +154,7 @@ async fn timeline_includes_embed() {
         return;
     }
     let c = client().await;
+    let Some(auth) = auth_or_skip().await else { return };
     let did = did_for_test("img");
     let uri = seed_post(
         &c,
@@ -160,12 +190,7 @@ async fn timeline_includes_embed() {
     )
     .await;
 
-    let resp = c
+    let resp = get_timeline(&c, &auth, &did, &[("limit", "10")]).await;
-        .get(format!("{APPVIEW_URL}/api/timeline/home"))
-        .query(&[("did", did.as_str()), ("limit", "10")])
-        .send()
-        .await
-        .unwrap();
     assert_eq!(resp.status().as_u16(), 200);
     let body: Value = resp.json().await.unwrap();
     let posts = body["posts"].as_array().unwrap();
@@ -199,6 +224,7 @@ async fn timeline_includes_external_embed() {
         return;
     }
     let c = client().await;
+    let Some(auth) = auth_or_skip().await else { return };
     let did = did_for_test("ext");
     let uri = seed_post(
         &c,
@@ -222,12 +248,7 @@ async fn timeline_includes_external_embed() {
     )
     .await;
 
-    let resp = c
+    let resp = get_timeline(&c, &auth, &did, &[("limit", "10")]).await;
-        .get(format!("{APPVIEW_URL}/api/timeline/home"))
-        .query(&[("did", did.as_str()), ("limit", "10")])
-        .send()
-        .await
-        .unwrap();
     assert_eq!(resp.status().as_u16(), 200);
     let body: Value = resp.json().await.unwrap();
     let posts = body["posts"].as_array().unwrap();
@@ -241,12 +262,7 @@ async fn timeline_includes_external_embed() {
             break;
         }
         tokio::time::sleep(Duration::from_millis(50)).await;
-        let resp = c
+        let resp = get_timeline(&c, &auth, &did, &[("limit", "10")]).await;
-            .get(format!("{APPVIEW_URL}/api/timeline/home"))
-            .query(&[("did", did.as_str()), ("limit", "10")])
-            .send()
-            .await
-            .unwrap();
         let body: Value = resp.json().await.unwrap();
         our = body["posts"]
             .as_array()
@@ -410,6 +426,7 @@ async fn timeline_post_without_embed_has_null_embed() {
         return;
     }
     let c = client().await;
+    let Some(auth) = auth_or_skip().await else { return };
     let did = did_for_test("plain");
     let uri = seed_post(
         &c,
@@ -421,12 +438,7 @@ async fn timeline_post_without_embed_has_null_embed() {
     )
     .await;
 
-    let resp = c
+    let resp = get_timeline(&c, &auth, &did, &[("limit", "10")]).await;
-        .get(format!("{APPVIEW_URL}/api/timeline/home"))
-        .query(&[("did", did.as_str()), ("limit", "10")])
-        .send()
-        .await
-        .unwrap();
     assert_eq!(resp.status().as_u16(), 200);
     let body: Value = resp.json().await.unwrap();
     let our = body["posts"]

crates/appview/tests/handle_sync_integration.rs

@@ -175,8 +175,13 @@ async fn sync_resolves_known_did() {
     seed_post(&db, &did, "rkb", "", "second").await.unwrap();
     assert_eq!(count_empty_handle_for(&db, &did).await.unwrap(), 2);
 
+    // Drive the resolve half with our own DID. `run_once()` scans
+    // globally, ordered by DID and capped at BATCH_SIZE, so on a
+    // database that a live indexer keeps topping up, a freshly seeded
+    // DID isn't guaranteed to make the batch — the assertions below
+    // would then be measuring someone else's rows.
     let worker = worker_with(db.clone(), stub.clone());
-    let report: SyncReport = worker.run_once().await.unwrap();
+    let report: SyncReport = worker.resolve_batch(vec![did.clone()]).await.unwrap();
     assert_eq!(report.resolved, 2, "{report:?}");
     assert_eq!(report.failed, 0);
     assert_eq!(report.skipped, 0);
@@ -224,9 +229,16 @@ async fn sync_skips_already_resolved() {
     .into_arc();
 
     let worker = worker_with(db.clone(), stub.clone());
-    let report = worker.run_once().await.unwrap();
+    // This test is about the SELECT: a DID whose rows already carry a
-    assert_eq!(report.resolved, 0, "{report:?}");
+    // handle must never reach a resolver in the first place. So assert
-    assert_eq!(report.failed, 0);
+    // on `select_candidates()` rather than forcing the DID through
+    // `resolve_batch` — that would consult the resolver by definition
+    // and defeat the `query_count == 0` check below.
+    let candidates = worker.select_candidates().await.unwrap();
+    assert!(
+        !candidates.contains(&did),
+        "a DID that already has a handle must not be selected"
+    );
 
     // Both rows must still carry the pre-existing handle.
     let (cnt,): (i64,) = sqlx::query_as(
@@ -279,7 +291,16 @@ async fn sync_respects_limit() {
     let stub = StubResolver::new(mapping).into_arc();
 
     let worker = worker_with(db.clone(), stub.clone());
-    let report = worker.run_once().await.unwrap();
+    // The cap lives in the SELECT, so assert it there; the report of a
+    // full `run_once()` depends on what else is pending database-wide.
+    let candidates = worker.select_candidates().await.unwrap();
+    assert!(
+        candidates.len() as i64 <= BATCH_SIZE,
+        "select must never exceed BATCH_SIZE, got {}",
+        candidates.len()
+    );
+    let batch: Vec<String> = all_dids.iter().take(BATCH_SIZE as usize).cloned().collect();
+    let report = worker.resolve_batch(batch).await.unwrap();
     assert_eq!(
         report.resolved as i64,
         BATCH_SIZE,
@@ -339,7 +360,7 @@ async fn sync_skips_unresolvable_dids() {
     let stub = StubResolver::new(HashMap::new()).into_arc();
 
     let worker = worker_with(db.clone(), stub.clone());
-    let report = worker.run_once().await.unwrap();
+    let report = worker.resolve_batch(vec![did.clone()]).await.unwrap();
     assert_eq!(report.resolved, 0);
     assert_eq!(report.failed, 0);
     assert_eq!(report.skipped, 1, "{report:?}");
@@ -388,14 +409,21 @@ async fn sync_resolves_did_web_via_web_resolver() {
     let plc_arc: Arc<dyn DidHandleResolver> = plc.into_arc();
     let web_arc: Arc<dyn DidHandleResolver> = web.into_arc();
 
+    // The local PDS is consulted before the method dispatch and does
+    // not host a foreign `did:web:` — wiring one of the other stubs in
+    // here would make it claim a DID it doesn't have, and the test
+    // would assert against the PDS-first rule instead of the dispatch.
+    let pds_arc: Arc<dyn DidHandleResolver> =
+        StubResolver::new(HashMap::new()).into_arc();
+
     let worker = HandleSyncWorker {
         db: db.clone(),
-        pds_resolver: Arc::clone(&plc_arc),
+        pds_resolver: pds_arc,
         plc_resolver: plc_arc,
         web_resolver: web_arc,
         interval_secs: 999,
     };
-    let report = worker.run_once().await.unwrap();
+    let report = worker.resolve_batch(vec![did.clone()]).await.unwrap();
     assert_eq!(
         report.resolved, 1,
         "did:web must resolve through the web resolver, got {report:?}"
@@ -442,14 +470,19 @@ async fn sync_resolves_did_plc_via_plc_resolver() {
     let plc_arc: Arc<dyn DidHandleResolver> = plc.into_arc();
     let web_arc: Arc<dyn DidHandleResolver> = web.into_arc();
 
+    // Same reasoning as the did:web test: the PDS doesn't host this
+    // DID, so the method dispatch is what's under test.
+    let pds_arc: Arc<dyn DidHandleResolver> =
+        StubResolver::new(HashMap::new()).into_arc();
+
     let worker = HandleSyncWorker {
         db: db.clone(),
-        pds_resolver: Arc::clone(&plc_arc),
+        pds_resolver: pds_arc,
         plc_resolver: plc_arc,
         web_resolver: web_arc,
         interval_secs: 999,
     };
-    let report = worker.run_once().await.unwrap();
+    let report = worker.resolve_batch(vec![did.clone()]).await.unwrap();
     assert_eq!(
         report.resolved, 1,
         "did:plc must resolve through the PLC resolver, got {report:?}"

crates/appview/tests/notifications_integration.rs

@@ -14,6 +14,9 @@
 //! API. That's deliberate: it's the only way to catch a mismatch
 //! between what the write path stores and what the read path joins.
 
+mod common;
+
+use common::TestAuth;
 use serde_json::{json, Value};
 use std::time::Duration;
 
@@ -55,8 +58,12 @@ async fn db_pool() -> Option<sqlx::PgPool> {
 }
 
 /// Guard used at the top of every test. Returns `None` (→ skip) unless
-/// both the HTTP service and the database are up.
+/// the HTTP service is up, the database is reachable, **and** we know
-async fn ready() -> Option<(reqwest::Client, sqlx::PgPool)> {
+/// how to authenticate: `/api/notifications*` now requires a token
+/// whose `sub` is the requested DID, and the DIDs seeded here are
+/// synthetic, so the token has to be minted from the PDS's signing
+/// secret. See `tests/common/mod.rs`.
+async fn ready() -> Option<(reqwest::Client, sqlx::PgPool, TestAuth)> {
     if !wait_for_appview_db().await {
         eprintln!("appview not running, skipping");
         return None;
@@ -65,7 +72,32 @@ async fn ready() -> Option<(reqwest::Client, sqlx::PgPool)> {
         eprintln!("appview DB unreachable, skipping");
         return None;
     };
-    Some((client().await, pool))
+    let c = client().await;
+    let auth = TestAuth::probe(&c, &appview_url()).await?;
+    Some((c, pool, auth))
+}
+
+/// `GET <url>` against a private endpoint, carrying the token for
+/// `did` when the instance enforces auth.
+fn authed_get(
+    c: &reqwest::Client,
+    auth: &TestAuth,
+    url: String,
+    did: &str,
+) -> reqwest::RequestBuilder {
+    auth.apply(c.get(url), did)
+}
+
+/// `POST <url>` against a private endpoint. Same rule as
+/// [`authed_get`] — `/api/notifications/seen` is a write into one
+/// user's read state.
+fn authed_post(
+    c: &reqwest::Client,
+    auth: &TestAuth,
+    url: String,
+    did: &str,
+) -> reqwest::RequestBuilder {
+    auth.apply(c.post(url), did)
 }
 
 async fn post_ingest(c: &reqwest::Client, body: Value) -> reqwest::Response {
@@ -181,7 +213,7 @@ async fn seed_follow(c: &reqwest::Client, follower: &str, subject: &str) {
 #[tokio::test]
 async fn notifications_list_count_and_seen() {
     let base = appview_url();
-    let Some((c, _pool)) = ready().await else {
+    let Some((c, _pool, auth)) = ready().await else {
         return;
     };
     let alice = did_for_test("alice");
@@ -196,8 +228,7 @@ async fn notifications_list_count_and_seen() {
     let reply_uri = seed_reply(&c, &carol, &post_uri, &post_uri, "carol's reply").await;
     seed_follow(&c, &bob, &alice).await;
 
-    let resp = c
+    let resp = authed_get(&c, &auth, format!("{base}/api/notifications"), &alice)
-        .get(format!("{base}/api/notifications"))
         .query(&[("did", alice.as_str()), ("limit", "50")])
         .send()
         .await
@@ -253,8 +284,7 @@ async fn notifications_list_count_and_seen() {
     }
 
     // The unread count agrees with the list.
-    let resp = c
+    let resp = authed_get(&c, &auth, format!("{base}/api/notifications/count"), &alice)
-        .get(format!("{base}/api/notifications/count"))
         .query(&[("did", alice.as_str())])
         .send()
         .await
@@ -264,8 +294,7 @@ async fn notifications_list_count_and_seen() {
     assert_eq!(body["count"], json!(3));
 
     // Mark everything seen.
-    let resp = c
+    let resp = authed_post(&c, &auth, format!("{base}/api/notifications/seen"), &alice)
-        .post(format!("{base}/api/notifications/seen"))
         .json(&json!({ "did": alice }))
         .send()
         .await
@@ -276,8 +305,7 @@ async fn notifications_list_count_and_seen() {
     assert_eq!(body["updated"], json!(3));
 
     // Idempotent: a second call updates nothing and still succeeds.
-    let resp = c
+    let resp = authed_post(&c, &auth, format!("{base}/api/notifications/seen"), &alice)
-        .post(format!("{base}/api/notifications/seen"))
         .json(&json!({ "did": alice }))
         .send()
         .await
@@ -286,8 +314,7 @@ async fn notifications_list_count_and_seen() {
     assert_eq!(body["updated"], json!(0));
 
     // Count is now zero and the rows carry a read_at.
-    let resp = c
+    let resp = authed_get(&c, &auth, format!("{base}/api/notifications/count"), &alice)
-        .get(format!("{base}/api/notifications/count"))
         .query(&[("did", alice.as_str())])
         .send()
         .await
@@ -295,8 +322,7 @@ async fn notifications_list_count_and_seen() {
     let body: Value = resp.json().await.unwrap();
     assert_eq!(body["count"], json!(0));
 
-    let resp = c
+    let resp = authed_get(&c, &auth, format!("{base}/api/notifications"), &alice)
-        .get(format!("{base}/api/notifications"))
         .query(&[("did", alice.as_str())])
         .send()
         .await
@@ -311,8 +337,7 @@ async fn notifications_list_count_and_seen() {
         "/api/notifications",
         "/api/notifications/count",
     ] {
-        let resp = c
+        let resp = authed_get(&c, &auth, format!("{base}{path}"), &alice)
-            .get(format!("{base}{path}"))
             .query(&[("did", "")])
             .send()
             .await
@@ -326,7 +351,7 @@ async fn notifications_list_count_and_seen() {
 #[tokio::test]
 async fn notifications_skip_self_interactions() {
     let base = appview_url();
-    let Some((c, _pool)) = ready().await else {
+    let Some((c, _pool, auth)) = ready().await else {
         return;
     };
     let alice = did_for_test("solo");
@@ -335,8 +360,7 @@ async fn notifications_skip_self_interactions() {
     seed_reply(&c, &alice, &post_uri, &post_uri, "and replying too").await;
     seed_follow(&c, &alice, &alice).await;
 
-    let resp = c
+    let resp = authed_get(&c, &auth, format!("{base}/api/notifications"), &alice)
-        .get(format!("{base}/api/notifications"))
         .query(&[("did", alice.as_str())])
         .send()
         .await
@@ -355,7 +379,7 @@ async fn notifications_skip_self_interactions() {
 #[tokio::test]
 async fn notifications_paginate_with_cursor() {
     let base = appview_url();
-    let Some((c, _pool)) = ready().await else {
+    let Some((c, _pool, auth)) = ready().await else {
         return;
     };
     let alice = did_for_test("popular");
@@ -372,9 +396,9 @@ async fn notifications_paginate_with_cursor() {
         let c = c.clone();
         let alice = alice.clone();
         let base = base.clone();
+        let auth = auth.clone();
         async move {
-            let mut req = c
+            let mut req = authed_get(&c, &auth, format!("{base}/api/notifications"), &alice)
-                .get(format!("{base}/api/notifications"))
                 .query(&[("did", alice.as_str()), ("limit", "5")]);
             if let Some(cur) = cursor {
                 req = req.query(&[("cursor", cur.as_str())]);
@@ -417,8 +441,7 @@ async fn notifications_paginate_with_cursor() {
     assert_eq!(all.len(), 12);
 
     // A mangled cursor is a 400, not a silent restart at page 1.
-    let resp = c
+    let resp = authed_get(&c, &auth, format!("{base}/api/notifications"), &alice)
-        .get(format!("{base}/api/notifications"))
         .query(&[("did", alice.as_str()), ("cursor", "!!!garbage!!!")])
         .send()
         .await
@@ -431,7 +454,7 @@ async fn notifications_paginate_with_cursor() {
 #[tokio::test]
 async fn notifications_seen_respects_watermark() {
     let base = appview_url();
-    let Some((c, _pool)) = ready().await else {
+    let Some((c, _pool, auth)) = ready().await else {
         return;
     };
     let alice = did_for_test("watermark");
@@ -442,8 +465,7 @@ async fn notifications_seen_respects_watermark() {
 
     // Read back the first notification's indexed_at — that's the
     // watermark a client would echo after rendering page 1.
-    let body: Value = c
+    let body: Value = authed_get(&c, &auth, format!("{base}/api/notifications"), &alice)
-        .get(format!("{base}/api/notifications"))
         .query(&[("did", alice.as_str())])
         .send()
         .await
@@ -461,8 +483,7 @@ async fn notifications_seen_respects_watermark() {
     let second = did_for_test("late");
     seed_like(&c, &second, &post_uri).await;
 
-    let resp = c
+    let resp = authed_post(&c, &auth, format!("{base}/api/notifications/seen"), &alice)
-        .post(format!("{base}/api/notifications/seen"))
         .json(&json!({ "did": alice, "seenAt": watermark }))
         .send()
         .await
@@ -475,8 +496,7 @@ async fn notifications_seen_respects_watermark() {
     );
 
     // The later one is still unread.
-    let body: Value = c
+    let body: Value = authed_get(&c, &auth, format!("{base}/api/notifications/count"), &alice)
-        .get(format!("{base}/api/notifications/count"))
         .query(&[("did", alice.as_str())])
         .send()
         .await
@@ -487,8 +507,7 @@ async fn notifications_seen_respects_watermark() {
     assert_eq!(body["count"], json!(1));
 
     // snake_case spelling must work identically.
-    let resp = c
+    let resp = authed_post(&c, &auth, format!("{base}/api/notifications/seen"), &alice)
-        .post(format!("{base}/api/notifications/seen"))
         .json(&json!({ "did": alice, "seen_at": null }))
         .send()
         .await
@@ -502,7 +521,7 @@ async fn notifications_seen_respects_watermark() {
 #[tokio::test]
 async fn followers_and_following_lists() {
     let base = appview_url();
-    let Some((c, _pool)) = ready().await else {
+    let Some((c, _pool, _auth)) = ready().await else {
         return;
     };
     let hub = did_for_test("hub");
@@ -591,7 +610,8 @@ async fn followers_and_following_lists() {
     assert_eq!(unique.len(), seen.len(), "paged followers repeat: {seen:?}");
     assert_eq!(seen.len(), 3, "paging lost a follower: {seen:?}");
 
-    // `did` is mandatory.
+    // `did` is mandatory. These two stay public — a follow edge is a
+    // public record — so no token is involved.
     for path in ["/api/followers", "/api/following"] {
         let resp = c
             .get(format!("{base}{path}"))
@@ -610,7 +630,7 @@ async fn followers_and_following_lists() {
 #[tokio::test]
 async fn thread_returns_parents_and_replies() {
     let base = appview_url();
-    let Some((c, _pool)) = ready().await else {
+    let Some((c, _pool, _auth)) = ready().await else {
         return;
     };
     let a = did_for_test("root");
@@ -689,7 +709,7 @@ async fn thread_returns_parents_and_replies() {
 #[tokio::test]
 async fn post_by_uri_stays_backwards_compatible() {
     let base = appview_url();
-    let Some((c, _pool)) = ready().await else {
+    let Some((c, _pool, _auth)) = ready().await else {
         return;
     };
     let a = did_for_test("compat_a");

crates/at-shared/src/config.rs

@@ -7,6 +7,17 @@ fn default_handle_sync_interval() -> u64 {
     300
 }
 
+/// Default for `APPVIEW_AUTH_REQUIRED`.
+///
+/// `true` — the AppView's private endpoints (notifications, home
+/// timeline) reject unauthenticated requests. Fail closed: an operator
+/// who forgets the variable gets the safe behaviour, and the only way
+/// to serve another user's notifications to an anonymous caller is to
+/// opt out explicitly.
+fn default_auth_required() -> bool {
+    true
+}
+
 #[derive(Debug, Clone, Deserialize)]
 pub struct AppConfig {
     pub pds_host: String,
@@ -46,6 +57,27 @@ pub struct AppConfig {
     /// directory. Default: 300s (5 minutes).
     #[serde(default = "default_handle_sync_interval")]
     pub appview_handle_sync_interval_secs: u64,
+    /// Whether the AppView enforces bearer-token auth on the endpoints
+    /// that serve a single user's private data (`/api/notifications*`,
+    /// `/api/timeline/home`). Default `true`.
+    ///
+    /// Set `APPVIEW_AUTH_REQUIRED=false` to get the pre-auth behaviour
+    /// (every endpoint public). That mode exists for two callers:
+    /// the fail-open integration suites, which seed synthetic DIDs the
+    /// PDS has never issued a token for, and an instance that is
+    /// already isolated at the network layer (VPN / private subnet).
+    /// The AppView warns loudly at startup when it is off.
+    #[serde(default = "default_auth_required")]
+    pub appview_auth_required: bool,
+    /// Browser origins allowed to call the AppView's `/api/*` routes,
+    /// from the comma-separated `APPVIEW_CORS_ORIGINS`. Empty means
+    /// "no allowlist configured" — the AppView then keeps the historic
+    /// `Access-Control-Allow-Origin: *` behaviour and warns at startup.
+    ///
+    /// Example (Tauri webview origins differ per platform):
+    /// `APPVIEW_CORS_ORIGINS=tauri://localhost,http://127.0.0.1:1430`
+    #[serde(default)]
+    pub appview_cors_origins: Vec<String>,
 }
 
 impl AppConfig {
@@ -82,6 +114,183 @@ impl AppConfig {
                 .ok()
                 .and_then(|s| s.parse().ok())
                 .unwrap_or_else(default_handle_sync_interval),
+            appview_auth_required: std::env::var("APPVIEW_AUTH_REQUIRED")
+                .ok()
+                .map(|s| parse_bool_env(&s))
+                .unwrap_or_else(default_auth_required),
+            appview_cors_origins: std::env::var("APPVIEW_CORS_ORIGINS")
+                .ok()
+                .map(|s| parse_csv_env(&s))
+                .unwrap_or_default(),
         })
     }
+
+    /// The `did:web:` DID of *this* PDS, derived from `PDS_PUBLIC_URL`.
+    ///
+    /// One derivation, two consumers: `com.atproto.server.describeServer`
+    /// (which used to return a hardcoded `did:web:pds.maarcadetweet.local`
+    /// no matter what the operator configured) and
+    /// `GET /.well-known/did.json`, which publishes the server's signing
+    /// key under exactly this id. If those two ever disagreed, a client
+    /// that trusts `describeServer` would fetch the key document of a
+    /// different identity.
+    pub fn pds_did(&self) -> String {
+        did_web_from_url(&self.pds_public_url)
+    }
+
+    /// Base URL the AppView uses to reach the PDS.
+    ///
+    /// `PDS_INTERNAL_URL` when set (the cluster-internal hostname),
+    /// otherwise `PDS_PUBLIC_URL`. Both the handle-sync resolver and the
+    /// signing-key fetch go through here, so the two can't end up
+    /// talking to different PDS instances.
+    pub fn pds_base_url(&self) -> String {
+        self.pds_internal_url
+            .clone()
+            .unwrap_or_else(|| self.pds_public_url.clone())
+    }
+}
+
+/// Interpret an environment variable as a boolean.
+///
+/// Accepts the spellings people actually type in a `.env` file. Anything
+/// unrecognised counts as `false` for an explicitly-set variable — the
+/// caller decides what an *absent* variable means (see
+/// [`default_auth_required`]), and a typo like `APPVIEW_AUTH_REQUIRED=ture`
+/// must never silently read as "on" when the operator's intent was to
+/// switch something off... nor as "off" for a security switch. Since
+/// this is only reached when the variable *is* set, and the only
+/// security-relevant user of it defaults to `true` when unset, we treat
+/// unknown values as `false` and rely on the startup warning to make a
+/// disabled auth switch impossible to miss in the logs.
+fn parse_bool_env(raw: &str) -> bool {
+    matches!(
+        raw.trim().to_ascii_lowercase().as_str(),
+        "1" | "true" | "yes" | "on"
+    )
+}
+
+/// Split a comma-separated environment variable into trimmed,
+/// non-empty entries. `"a, b,,c "` → `["a", "b", "c"]`.
+fn parse_csv_env(raw: &str) -> Vec<String> {
+    raw.split(',')
+        .map(|s| s.trim().to_string())
+        .filter(|s| !s.is_empty())
+        .collect()
+}
+
+/// Turn an `http(s)://host[:port][/path]` URL into a `did:web:` DID.
+///
+/// The did:web method spec maps the authority to the method-specific
+/// id, with two wrinkles that matter here:
+///
+///  - a port is **percent-encoded** (`:` → `%3A`), because a bare colon
+///    already separates the DID's own segments. `http://127.0.0.1:2583`
+///    is therefore `did:web:127.0.0.1%3A2583`, *not*
+///    `did:web:127.0.0.1:2583` (which would parse as host `127.0.0.1`
+///    plus a path segment `2583`).
+///  - path segments, if any, are appended separated by `:`.
+///
+/// The default ports (80/443) are kept rather than stripped: the
+/// resolution rule is a textual one, and a client that reverses this
+/// mapping has to end up at the same URL we serve the document from.
+pub fn did_web_from_url(url: &str) -> String {
+    // Strip the scheme. We accept a bare `host:port` too, which is what
+    // a misconfigured `PDS_PUBLIC_URL` often contains.
+    let rest = url
+        .trim()
+        .trim_start_matches("https://")
+        .trim_start_matches("http://")
+        .trim_end_matches('/');
+    // Drop any userinfo (`user@host`) and query/fragment — neither has
+    // a place in a did:web identifier.
+    let rest = rest.split(['?', '#']).next().unwrap_or(rest);
+    let rest = rest.rsplit('@').next().unwrap_or(rest);
+
+    let mut parts = rest.split('/');
+    let authority = parts.next().unwrap_or("");
+    let host = authority.replacen(':', "%3A", 1);
+    let mut did = format!("did:web:{host}");
+    for segment in parts.filter(|s| !s.is_empty()) {
+        did.push(':');
+        did.push_str(segment);
+    }
+    did
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn did_web_encodes_port_as_percent_3a() {
+        // The dev default. A literal colon here would be read as a
+        // did:web path segment, so it has to be percent-encoded.
+        assert_eq!(
+            did_web_from_url("http://127.0.0.1:2583"),
+            "did:web:127.0.0.1%3A2583"
+        );
+        assert_eq!(
+            did_web_from_url("https://pds.example.com:8443"),
+            "did:web:pds.example.com%3A8443"
+        );
+    }
+
+    #[test]
+    fn did_web_without_port_is_plain_host() {
+        assert_eq!(
+            did_web_from_url("https://pds.maarcadetweet.local"),
+            "did:web:pds.maarcadetweet.local"
+        );
+        // Trailing slash must not produce an empty path segment.
+        assert_eq!(
+            did_web_from_url("https://pds.example.com/"),
+            "did:web:pds.example.com"
+        );
+        // Scheme-less input is tolerated.
+        assert_eq!(did_web_from_url("pds.example.com"), "did:web:pds.example.com");
+    }
+
+    #[test]
+    fn did_web_appends_path_segments_with_colons() {
+        assert_eq!(
+            did_web_from_url("https://example.com/user/alice"),
+            "did:web:example.com:user:alice"
+        );
+        // Port + path together: only the port gets percent-encoded.
+        assert_eq!(
+            did_web_from_url("http://example.com:2583/pds"),
+            "did:web:example.com%3A2583:pds"
+        );
+    }
+
+    #[test]
+    fn did_web_ignores_userinfo_query_and_fragment() {
+        assert_eq!(
+            did_web_from_url("https://user@example.com?x=1#frag"),
+            "did:web:example.com"
+        );
+    }
+
+    #[test]
+    fn bool_env_accepts_common_spellings() {
+        for on in ["1", "true", "TRUE", "  yes ", "on"] {
+            assert!(parse_bool_env(on), "{on} should parse as true");
+        }
+        for off in ["0", "false", "no", "off", "", "nonsense"] {
+            assert!(!parse_bool_env(off), "{off} should parse as false");
+        }
+    }
+
+    #[test]
+    fn csv_env_trims_and_drops_empties() {
+        assert_eq!(
+            parse_csv_env("tauri://localhost, http://127.0.0.1:1430 ,,"),
+            vec![
+                "tauri://localhost".to_string(),
+                "http://127.0.0.1:1430".to_string()
+            ]
+        );
+        assert!(parse_csv_env("   ").is_empty());
+    }
 }

crates/pds-server/src/jwt_issuer.rs

@@ -39,7 +39,13 @@ pub fn issue_access_jwt(
     let now = chrono::Utc::now().timestamp();
     let exp = now + 3600;
     let claims = JwtClaims {
-        iss: format!("did:web:{}", cfg.pds_public_url.trim_start_matches("http://").trim_start_matches("https://")),
+        // Same derivation as `describeServer` and `/.well-known/did.json`
+        // (`AppConfig::pds_did`), so a verifier can take `iss`, resolve
+        // the did:web document and arrive at the key this token is
+        // signed with. The previous inline version dropped the
+        // percent-encoding of the port, producing an `iss` that no
+        // did:web resolver could follow.
+        iss: cfg.pds_did(),
         sub: did.to_string(),
         aud: "did:web:appview.maarcadetweet.local".into(),
         iat: now,

crates/pds-server/src/main.rs

@@ -73,6 +73,7 @@ pub fn router(state: AppState) -> Router {
     Router::new()
         .route("/", get(root))
         .route("/healthz", get(healthz))
+        .route("/.well-known/did.json", get(did_document))
         .route(
             "/xrpc/com.atproto.server.describeServer",
             get(describe_server),
@@ -163,9 +164,69 @@ async fn healthz() -> Json<serde_json::Value> {
     Json(json!({ "ok": true }))
 }
 
+/// `GET /.well-known/did.json` — the PDS's own DID document.
+///
+/// This is how the AppView (and any other relying party) learns the
+/// P-256 public key that the access JWTs in
+/// `Authorization: Bearer …` are signed with. Without it the AppView
+/// could not verify a token at all, and the only alternative would be
+/// shipping `PDS_JWT_SECRET` to a second service — a private signing
+/// key crossing a service boundary, for a check that needs nothing but
+/// the public half.
+///
+/// Nothing in this response is secret. `publicKeyMultibase` is the
+/// uncompressed P-256 point derived from `PDS_JWT_SECRET` by
+/// [`jwt_issuer::server_p256_public_multibase`]; the secret itself
+/// never leaves this process.
+///
+/// The document id is [`AppConfig::pds_did`], i.e. it follows
+/// `PDS_PUBLIC_URL` — so a `did:web:` resolver that starts from the DID,
+/// rebuilds the URL and fetches this path lands back here rather than at
+/// some other host's document.
+async fn did_document(State(state): State<AppState>) -> Result<Json<serde_json::Value>, (axum::http::StatusCode, Json<serde_json::Value>)> {
+    let did = state.cfg.pds_did();
+    let public_multibase = jwt_issuer::server_p256_public_multibase(&state.cfg).map_err(|e| {
+        // A malformed `PDS_JWT_SECRET` is the one way this fails, and
+        // it is exactly the failure that also breaks every token this
+        // server issues — surface it instead of publishing a document
+        // with a missing key.
+        (
+            axum::http::StatusCode::INTERNAL_SERVER_ERROR,
+            Json(json!({
+                "error": "InternalServerError",
+                "message": format!("server key unavailable: {e}"),
+            })),
+        )
+    })?;
+    Ok(Json(json!({
+        "@context": [
+            "https://www.w3.org/ns/did/v1",
+            "https://w3id.org/security/multikey/v1",
+        ],
+        "id": did,
+        "verificationMethod": [{
+            // `#atproto` is the fragment AT Proto uses for a repo's
+            // signing key; we reuse it for the server key so a generic
+            // did:web consumer finds it in the usual place.
+            "id": format!("{did}#atproto"),
+            "type": "Multikey",
+            "controller": did,
+            "publicKeyMultibase": public_multibase,
+        }],
+        "service": [{
+            "id": "#atproto_pds",
+            "type": "AtprotoPersonalDataServer",
+            "serviceEndpoint": state.cfg.pds_public_url,
+        }],
+    })))
+}
+
 async fn describe_server(State(state): State<AppState>) -> Json<DescribeServerResp> {
     Json(DescribeServerResp {
-        did: "did:web:pds.maarcadetweet.local".into(),
+        // Derived from `PDS_PUBLIC_URL`, never hardcoded — see
+        // `AppConfig::pds_did`. The same value ids the document at
+        // `/.well-known/did.json`.
+        did: state.cfg.pds_did(),
         available_user_domains: vec![state
             .cfg
             .pds_handle_dns_zone

crates/pds-server/tests/pds_integration.rs

@@ -38,11 +38,86 @@ async fn describe_server() {
         .json()
         .await
         .unwrap();
-    assert!(r["did"].is_string());
+    // The DID is derived from `PDS_PUBLIC_URL`, not hardcoded — so we
+    // assert the *shape* (any deployment must produce a did:web) and
+    // leave the exact value to `at_shared::config`'s unit tests.
+    let did = r["did"].as_str().expect("describeServer must return a did");
+    assert!(did.starts_with("did:web:"), "did = {did}");
     assert!(r["available_user_domains"].is_array());
     assert_eq!(r["invite_code_required"], json!(false));
 }
 
+/// `GET /.well-known/did.json` — the document the AppView fetches to
+/// learn the key our access tokens are signed with.
+///
+/// Two properties matter beyond "it returns JSON": the document's `id`
+/// must be the same DID `describeServer` advertises (otherwise a client
+/// that trusts one and resolves the other ends up at a different
+/// identity), and it must carry a usable `publicKeyMultibase`.
+#[tokio::test]
+async fn did_document_publishes_the_server_key() {
+    if !wait_for_pds().await {
+        eprintln!("pds not running, skipping");
+        return;
+    }
+    let c = client().await;
+    let doc: Value = c
+        .get(format!("{}/.well-known/did.json", PDS_URL))
+        .send()
+        .await
+        .unwrap()
+        .json()
+        .await
+        .unwrap();
+
+    let id = doc["id"].as_str().expect("did document needs an id");
+    assert!(id.starts_with("did:web:"), "id = {id}");
+
+    let described: Value = c
+        .get(format!("{}/xrpc/com.atproto.server.describeServer", PDS_URL))
+        .send()
+        .await
+        .unwrap()
+        .json()
+        .await
+        .unwrap();
+    assert_eq!(
+        described["did"].as_str().unwrap(),
+        id,
+        "describeServer and the did document must name the same identity"
+    );
+
+    let vm = &doc["verificationMethod"][0];
+    assert_eq!(vm["type"], json!("Multikey"));
+    assert_eq!(vm["controller"], json!(id));
+    assert_eq!(vm["id"], json!(format!("{id}#atproto")));
+    let key = vm["publicKeyMultibase"]
+        .as_str()
+        .expect("verificationMethod needs publicKeyMultibase");
+    // base58-btc multibase — the `z` prefix the AppView's decoder wants.
+    assert!(key.starts_with('z'), "key = {key}");
+
+    // And it really is the key our tokens verify against: mint a
+    // session and check the access JWT against the published key.
+    let handle = format!("didjson_{}.maarcadetweet.local", uuid::Uuid::new_v4().simple());
+    let acc: Value = c
+        .post(format!("{}/xrpc/com.atproto.server.createAccount", PDS_URL))
+        .json(&json!({"handle": handle, "password": "hunter2hunter2"}))
+        .send()
+        .await
+        .unwrap()
+        .json()
+        .await
+        .unwrap();
+    let jwt = acc["access_jwt"].as_str().expect("access_jwt");
+    let claims = at_crypto::jwt::verify_jwt(jwt, key)
+        .expect("access token must verify against the published key");
+    assert_eq!(claims.sub, acc["did"].as_str().unwrap());
+    assert_eq!(claims.scope.as_deref(), Some("com.atproto.access"));
+    // `iss` is the same did:web the document identifies.
+    assert_eq!(claims.iss, id);
+}
+
 #[tokio::test]
 async fn create_account_session_refresh_resolve() {
     if !wait_for_pds().await {

crates/tauri-app/src-tauri/src/appview_client.rs

@@ -1,8 +1,30 @@
 //! Thin HTTP client the Tauri commands use to talk to the AppView.
 //!
-//! All four methods return parsed JSON or a stringified error that the
+//! Every method returns parsed JSON or a stringified error that the
 //! Tauri command layer surfaces to the Svelte frontend as the
 //! `Result::Err` payload.
+//!
+//! # Authentication
+//!
+//! The AppView's *viewer-scoped* endpoints require the account's access
+//! JWT in an `Authorization: Bearer` header, and additionally check that
+//! the token's `sub` equals the `did` query parameter:
+//!
+//!   * `GET  /api/timeline/home`
+//!   * `GET  /api/notifications`
+//!   * `GET  /api/notifications/count`
+//!   * `POST /api/notifications/seen`
+//!
+//! Those four methods therefore take an `access_jwt` argument (last, the
+//! same position `pds_client.rs` uses). Everything else —
+//! `/api/profile*`, `/api/search`, `/api/post/{uri}`, `/api/thread`,
+//! `/api/followers`, `/api/following` — stays public and deliberately
+//! sends no token, so the read-only views keep working while logged out.
+//!
+//! On an auth failure the AppView answers `401` with
+//! `{"error":"AuthMissing"|"TokenInvalid","message":…}` or `403` with
+//! `{"error":"Forbidden",…}`. See [`status_error`] for why the response
+//! body must survive into the error message.
 
 use anyhow::{anyhow, Context, Result};
 use reqwest::Client;
@@ -58,9 +80,10 @@ pub struct SearchResponse {
 ///
 /// `like_count` and `repost_count` are included when the server
 /// resolves a real post; they're `None` for the "not in index"
-/// sentinel response (where `post` is null). The AppView has no
+/// sentinel response (where `post` is null). `/api/post/{uri}` is a
-/// auth yet, so we don't get `viewer_liked` / `viewer_reposted`
+/// public endpoint that takes no token, so there is no viewer to
-/// from the server.
+/// resolve against and we don't get `viewer_liked` /
+/// `viewer_reposted`; [`Self::fetch_thread`] with a `viewer_did` does.
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct ThreadResponse {
     pub post: Option<PostDto>,
@@ -192,16 +215,22 @@ impl AppViewClient {
         }
     }
 
-    /// `GET /api/timeline/home?did=&limit=&cursor=`
+    /// `GET /api/timeline/home?did=&limit=&cursor=` — **authenticated**.
+    ///
+    /// `access_jwt` goes out as `Authorization: Bearer`; the AppView
+    /// rejects the call with 401 without it and with 403 when the
+    /// token's `sub` doesn't match `did`.
     pub async fn fetch_timeline(
         &self,
         did: &str,
         cursor: Option<&str>,
         limit: u32,
+        access_jwt: &str,
     ) -> Result<TimelineResponse> {
         let mut req = self
             .client
             .get(format!("{}/api/timeline/home", self.base_url))
+            .bearer_auth(access_jwt)
             .query(&[("did", did), ("limit", &limit.to_string())]);
         if let Some(c) = cursor {
             req = req.query(&[("cursor", c)]);
@@ -211,13 +240,7 @@ impl AppViewClient {
             .await
             .context("appview: failed to send timeline request")?;
         if !resp.status().is_success() {
-            let status = resp.status();
+            return Err(status_error("timeline home", resp).await);
-            let body = resp.text().await.unwrap_or_default();
-            return Err(anyhow!(
-                "appview: timeline home returned {}: {}",
-                status,
-                body
-            ));
         }
         resp
             .json::<TimelineResponse>()
@@ -244,13 +267,7 @@ impl AppViewClient {
             .await
             .context("appview: failed to send profile request")?;
         if !resp.status().is_success() {
-            let status = resp.status();
+            return Err(status_error("profile", resp).await);
-            let body = resp.text().await.unwrap_or_default();
-            return Err(anyhow!(
-                "appview: profile returned {}: {}",
-                status,
-                body
-            ));
         }
         resp
             .json::<ProfileResponse>()
@@ -268,13 +285,7 @@ impl AppViewClient {
             .await
             .context("appview: failed to send profile-by-did request")?;
         if !resp.status().is_success() {
-            let status = resp.status();
+            return Err(status_error("profile-by-did", resp).await);
-            let body = resp.text().await.unwrap_or_default();
-            return Err(anyhow!(
-                "appview: profile-by-did returned {}: {}",
-                status,
-                body
-            ));
         }
         resp
             .json::<ProfileResponse>()
@@ -292,13 +303,7 @@ impl AppViewClient {
             .await
             .context("appview: failed to send search request")?;
         if !resp.status().is_success() {
-            let status = resp.status();
+            return Err(status_error("search", resp).await);
-            let body = resp.text().await.unwrap_or_default();
-            return Err(anyhow!(
-                "appview: search returned {}: {}",
-                status,
-                body
-            ));
         }
         resp
             .json::<SearchResponse>()
@@ -323,13 +328,7 @@ impl AppViewClient {
             .await
             .context("appview: failed to send post request")?;
         if !resp.status().is_success() {
-            let status = resp.status();
+            return Err(status_error("post", resp).await);
-            let body = resp.text().await.unwrap_or_default();
-            return Err(anyhow!(
-                "appview: post returned {}: {}",
-                status,
-                body
-            ));
         }
         resp
             .json::<ThreadResponse>()
@@ -363,13 +362,7 @@ impl AppViewClient {
             .await
             .context("appview: failed to send thread request")?;
         if !resp.status().is_success() {
-            let status = resp.status();
+            return Err(status_error("thread", resp).await);
-            let body = resp.text().await.unwrap_or_default();
-            return Err(anyhow!(
-                "appview: thread returned {}: {}",
-                status,
-                body
-            ));
         }
         resp
             .json::<ThreadFullResponse>()
@@ -377,17 +370,20 @@ impl AppViewClient {
             .context("appview: thread JSON parse")
     }
 
-    /// `GET /api/notifications?did=&limit=&cursor=` — newest first,
+    /// `GET /api/notifications?did=&limit=&cursor=` — **authenticated**;
-    /// same opaque-cursor pagination contract as the timeline.
+    /// newest first, same opaque-cursor pagination contract as the
+    /// timeline.
     pub async fn fetch_notifications(
         &self,
         did: &str,
         cursor: Option<&str>,
         limit: u32,
+        access_jwt: &str,
     ) -> Result<NotificationsResponse> {
         let mut req = self
             .client
             .get(format!("{}/api/notifications", self.base_url))
+            .bearer_auth(access_jwt)
             .query(&[("did", did), ("limit", &limit.to_string())]);
         if let Some(c) = cursor {
             req = req.query(&[("cursor", c)]);
@@ -397,13 +393,7 @@ impl AppViewClient {
             .await
             .context("appview: failed to send notifications request")?;
         if !resp.status().is_success() {
-            let status = resp.status();
+            return Err(status_error("notifications", resp).await);
-            let body = resp.text().await.unwrap_or_default();
-            return Err(anyhow!(
-                "appview: notifications returned {}: {}",
-                status,
-                body
-            ));
         }
         resp
             .json::<NotificationsResponse>()
@@ -411,25 +401,24 @@ impl AppViewClient {
             .context("appview: notifications JSON parse")
     }
 
-    /// `GET /api/notifications/count?did=` — unread count for the
+    /// `GET /api/notifications/count?did=` — **authenticated**; unread
-    /// NavRail badge. Cheap enough to poll (partial index on the
+    /// count for the NavRail badge. Cheap enough to poll (partial index
-    /// server side).
+    /// on the server side).
-    pub async fn notification_count(&self, did: &str) -> Result<NotificationCountResponse> {
+    pub async fn notification_count(
+        &self,
+        did: &str,
+        access_jwt: &str,
+    ) -> Result<NotificationCountResponse> {
         let resp = self
             .client
             .get(format!("{}/api/notifications/count", self.base_url))
+            .bearer_auth(access_jwt)
             .query(&[("did", did)])
             .send()
             .await
             .context("appview: failed to send notification-count request")?;
         if !resp.status().is_success() {
-            let status = resp.status();
+            return Err(status_error("notification count", resp).await);
-            let body = resp.text().await.unwrap_or_default();
-            return Err(anyhow!(
-                "appview: notification count returned {}: {}",
-                status,
-                body
-            ));
         }
         resp
             .json::<NotificationCountResponse>()
@@ -437,9 +426,10 @@ impl AppViewClient {
             .context("appview: notification count JSON parse")
     }
 
-    /// `POST /api/notifications/seen` — mark everything indexed at or
+    /// `POST /api/notifications/seen` — **authenticated**; mark
-    /// before `seen_at` as read. Passing `None` marks *all* currently
+    /// everything indexed at or before `seen_at` as read. Passing `None`
-    /// unread rows. Idempotent; a second call reports `updated: 0`.
+    /// marks *all* currently unread rows. Idempotent; a second call
+    /// reports `updated: 0`.
     ///
     /// The server accepts both `seenAt` and `seen_at`; we send the
     /// camelCase spelling because that's what the wire contract
@@ -448,6 +438,7 @@ impl AppViewClient {
         &self,
         did: &str,
         seen_at: Option<&str>,
+        access_jwt: &str,
     ) -> Result<NotificationSeenResponse> {
         let mut body = serde_json::json!({ "did": did });
         if let Some(ts) = seen_at {
@@ -456,18 +447,13 @@ impl AppViewClient {
         let resp = self
             .client
             .post(format!("{}/api/notifications/seen", self.base_url))
+            .bearer_auth(access_jwt)
             .json(&body)
             .send()
             .await
             .context("appview: failed to send notifications-seen request")?;
         if !resp.status().is_success() {
-            let status = resp.status();
+            return Err(status_error("notifications seen", resp).await);
-            let body = resp.text().await.unwrap_or_default();
-            return Err(anyhow!(
-                "appview: notifications seen returned {}: {}",
-                status,
-                body
-            ));
         }
         resp
             .json::<NotificationSeenResponse>()
@@ -517,9 +503,7 @@ impl AppViewClient {
             .await
             .with_context(|| format!("appview: failed to send {path} request"))?;
         if !resp.status().is_success() {
-            let status = resp.status();
+            return Err(status_error(path, resp).await);
-            let body = resp.text().await.unwrap_or_default();
-            return Err(anyhow!("appview: {} returned {}: {}", path, status, body));
         }
         resp
             .json::<ActorListResponse>()
@@ -528,6 +512,33 @@ impl AppViewClient {
     }
 }
 
+/// Turn a non-2xx AppView response into an `anyhow::Error` whose
+/// message carries the server's response body **verbatim**.
+///
+/// Keeping the body is load-bearing, not cosmetic. The AppView answers
+/// an expired or malformed access token with
+/// `401 {"error":"TokenInvalid","message":…}`, and the frontend's
+/// `safeInvoke` (`src/lib/api/client.ts`) decides whether to refresh the
+/// session and retry by sniffing the *stringified* Rust error for the
+/// literal substring `"TokenInvalid"` (or `"ExpiredSignature"`). The
+/// chain is therefore:
+///
+/// ```text
+/// AppView 401 body ──► status_error() ──► anyhow msg
+///   ──► lib.rs `.map_err(|e| e.to_string())` ──► Tauri IPC reject
+///   ──► safeInvoke's isTokenInvalid() ──► auth_refresh + retry once
+/// ```
+///
+/// Every link is a plain string, so swallowing the body here (e.g.
+/// formatting only the status code) silently breaks token renewal —
+/// the user's timeline just stops updating an hour after login. The
+/// unit tests below pin the substring so that can't regress.
+async fn status_error(label: &str, resp: reqwest::Response) -> anyhow::Error {
+    let status = resp.status();
+    let body = resp.text().await.unwrap_or_default();
+    anyhow!("appview: {} returned {}: {}", label, status, body)
+}
+
 /// Percent-encode every byte of `s` for use as a URL path segment.
 /// `axum`'s path extractor will decode it back. We use this rather
 /// than `url::Url::parse(...).path_segments()` because AT-Protocol
@@ -553,6 +564,9 @@ fn percent_encode_path(s: &str) -> String {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use std::sync::{Arc, Mutex};
+    use tokio::io::{AsyncReadExt, AsyncWriteExt};
+    use tokio::net::TcpListener;
 
     #[test]
     fn percent_encode_path_at_uri() {
@@ -563,4 +577,241 @@ mod tests {
             "at%3A%2F%2Fdid%3Aplc%3Aabc%2Fapp.twi.post%2F3k2"
         );
     }
+
+    // -- mock AppView -------------------------------------------------
+    //
+    // A ~40-line HTTP/1.1 server on an ephemeral port, rather than a
+    // mocking crate, so the test adds no dependency to a workspace that
+    // currently has none for this. It answers every request with a
+    // canned status + body and records each request head so the tests
+    // can assert on the `Authorization` header we did (or deliberately
+    // did not) send.
+
+    /// The raw request heads (request line + header block) the mock saw,
+    /// in arrival order.
+    type Recorded = Arc<Mutex<Vec<String>>>;
+
+    /// Byte offset of the `\r\n\r\n` that ends the header block.
+    fn headers_end(buf: &[u8]) -> Option<usize> {
+        buf.windows(4).position(|w| w == b"\r\n\r\n")
+    }
+
+    /// Announced body length from a request head, if any. Needed so the
+    /// POST test drains the JSON body before the mock closes the socket
+    /// — closing mid-write would surface to `reqwest` as a connection
+    /// error instead of the 401 we're trying to assert on.
+    fn content_length(head: &str) -> usize {
+        head.lines()
+            .find_map(|l| {
+                let (k, v) = l.split_once(':')?;
+                k.trim()
+                    .eq_ignore_ascii_case("content-length")
+                    .then(|| v.trim().parse::<usize>().ok())?
+            })
+            .unwrap_or(0)
+    }
+
+    /// Serve `n` connections, answering each with `status`/`reason` and
+    /// `body`. Returns the base URL to point an [`AppViewClient`] at,
+    /// plus the recording handle.
+    async fn spawn_mock(
+        status: u16,
+        reason: &'static str,
+        body: &'static str,
+        n: usize,
+    ) -> (String, Recorded) {
+        let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
+        let addr = listener.local_addr().unwrap();
+        let recorded: Recorded = Arc::new(Mutex::new(Vec::new()));
+        let rec = recorded.clone();
+        tokio::spawn(async move {
+            for _ in 0..n {
+                let Ok((mut sock, _)) = listener.accept().await else {
+                    return;
+                };
+                let mut buf: Vec<u8> = Vec::new();
+                let mut chunk = [0u8; 2048];
+                loop {
+                    let read = match sock.read(&mut chunk).await {
+                        Ok(0) | Err(_) => break,
+                        Ok(k) => k,
+                    };
+                    buf.extend_from_slice(&chunk[..read]);
+                    if let Some(p) = headers_end(&buf) {
+                        let head = String::from_utf8_lossy(&buf[..p]).into_owned();
+                        if buf.len() - (p + 4) >= content_length(&head) {
+                            rec.lock().unwrap().push(head);
+                            break;
+                        }
+                    }
+                }
+                // `connection: close` keeps every request on a fresh
+                // socket, so the recorded order matches the call order.
+                let resp = format!(
+                    "HTTP/1.1 {status} {reason}\r\n\
+                     content-type: application/json\r\n\
+                     content-length: {}\r\n\
+                     connection: close\r\n\r\n{body}",
+                    body.len()
+                );
+                let _ = sock.write_all(resp.as_bytes()).await;
+                let _ = sock.shutdown().await;
+            }
+        });
+        (format!("http://{addr}"), recorded)
+    }
+
+    /// Value of the `Authorization` header in a recorded request head,
+    /// or `None` when the request carried none.
+    fn auth_header(head: &str) -> Option<String> {
+        head.lines().find_map(|l| {
+            let (k, v) = l.split_once(':')?;
+            k.trim()
+                .eq_ignore_ascii_case("authorization")
+                .then(|| v.trim().to_string())
+        })
+    }
+
+    // -- the contract the TS retry chain depends on -------------------
+
+    /// The AppView's 401 body for an expired access token.
+    const TOKEN_INVALID_BODY: &str =
+        r#"{"error":"TokenInvalid","message":"ExpiredSignature"}"#;
+
+    /// **This is the test the token-renewal path hangs off.**
+    ///
+    /// `src/lib/api/client.ts`'s `safeInvoke` refreshes the session and
+    /// retries exactly once when `isTokenInvalid(e)` matches — and that
+    /// predicate is a substring search for `"TokenInvalid"` /
+    /// `"ExpiredSignature"` over the *stringified* error that came up
+    /// from Rust. The AppView only ever states the code in its JSON
+    /// body, so if [`status_error`] were to drop the body (or truncate
+    /// it to the status code) the retry would never fire and the desktop
+    /// client would sit on a dead timeline until the user restarts it.
+    ///
+    /// So: for each of the four authenticated endpoints, assert the code
+    /// survives verbatim all the way into `Error::to_string()` — which
+    /// is exactly what `lib.rs` hands the Tauri IPC layer via
+    /// `.map_err(|e| e.to_string())`.
+    #[tokio::test]
+    async fn token_invalid_code_survives_into_the_error_string() {
+        let (base, _rec) = spawn_mock(401, "Unauthorized", TOKEN_INVALID_BODY, 4).await;
+        let c = AppViewClient::new(base);
+
+        let errs = vec![
+            c.fetch_timeline("did:plc:me", None, 30, "stale")
+                .await
+                .unwrap_err()
+                .to_string(),
+            c.fetch_notifications("did:plc:me", None, 30, "stale")
+                .await
+                .unwrap_err()
+                .to_string(),
+            c.notification_count("did:plc:me", "stale")
+                .await
+                .unwrap_err()
+                .to_string(),
+            c.mark_notifications_seen("did:plc:me", None, "stale")
+                .await
+                .unwrap_err()
+                .to_string(),
+        ];
+
+        for e in &errs {
+            // The literal the TS `isTokenInvalid()` greps for. Both
+            // spellings it accepts are in this body.
+            assert!(
+                e.contains("TokenInvalid"),
+                "error must carry the AppView's code verbatim, got: {e}"
+            );
+            assert!(
+                e.contains("ExpiredSignature"),
+                "error must carry the AppView's message verbatim, got: {e}"
+            );
+            // The status is useful context, but it is NOT what the retry
+            // keys off — asserting it here documents that both travel.
+            assert!(e.contains("401"), "status should travel too, got: {e}");
+        }
+
+        // Each endpoint still labels itself, so a log line says which
+        // call failed.
+        assert!(errs[0].contains("timeline home"));
+        assert!(errs[1].contains("notifications"));
+        assert!(errs[2].contains("notification count"));
+        assert!(errs[3].contains("notifications seen"));
+    }
+
+    /// The 403 the AppView returns when the token is valid but its
+    /// `sub` doesn't match the `did` query parameter. Deliberately
+    /// *not* something `isTokenInvalid` matches: refreshing wouldn't
+    /// help, so the retry must not fire — but the code still has to
+    /// reach the UI so the message is actionable.
+    #[tokio::test]
+    async fn forbidden_body_survives_and_does_not_look_refreshable() {
+        let (base, _rec) = spawn_mock(
+            403,
+            "Forbidden",
+            r#"{"error":"Forbidden","message":"did does not match token subject"}"#,
+            1,
+        )
+        .await;
+        let c = AppViewClient::new(base);
+
+        let e = c
+            .fetch_timeline("did:plc:someone-else", None, 30, "good-jwt")
+            .await
+            .unwrap_err()
+            .to_string();
+
+        assert!(e.contains("Forbidden"), "got: {e}");
+        assert!(e.contains("403"), "got: {e}");
+        assert!(!e.contains("TokenInvalid"));
+        assert!(!e.contains("ExpiredSignature"));
+    }
+
+    /// The four viewer-scoped endpoints must actually put the JWT on
+    /// the wire — an empty or missing header is a 401 from the server.
+    #[tokio::test]
+    async fn authenticated_endpoints_send_the_bearer_header() {
+        let (base, rec) = spawn_mock(500, "Internal Server Error", "{}", 4).await;
+        let c = AppViewClient::new(base);
+
+        let _ = c.fetch_timeline("did:plc:me", None, 30, "jwt-abc").await;
+        let _ = c.fetch_notifications("did:plc:me", None, 30, "jwt-abc").await;
+        let _ = c.notification_count("did:plc:me", "jwt-abc").await;
+        let _ = c
+            .mark_notifications_seen("did:plc:me", Some("2026-09-09T10:00:00Z"), "jwt-abc")
+            .await;
+
+        let heads = rec.lock().unwrap().clone();
+        assert_eq!(heads.len(), 4, "every call should have reached the server");
+        for h in &heads {
+            assert_eq!(
+                auth_header(h).as_deref(),
+                Some("Bearer jwt-abc"),
+                "missing/!= bearer token in:\n{h}"
+            );
+        }
+        // The POST still carries its JSON body alongside the header.
+        assert!(heads[3].starts_with("POST /api/notifications/seen"));
+    }
+
+    /// The public half of the API must keep working while logged out,
+    /// so it must not grow an `Authorization` header by accident.
+    #[tokio::test]
+    async fn public_endpoints_send_no_authorization_header() {
+        let (base, rec) = spawn_mock(200, "OK", r#"{"posts":[],"q":"hi"}"#, 1).await;
+        let c = AppViewClient::new(base);
+        let r = c.fetch_search("hi", 30).await.unwrap();
+        assert_eq!(r.q, "hi");
+        assert!(auth_header(&rec.lock().unwrap()[0]).is_none());
+
+        let (base2, rec2) = spawn_mock(200, "OK", r#"{"profiles":[],"cursor":null}"#, 2).await;
+        let c2 = AppViewClient::new(base2);
+        c2.fetch_followers("did:plc:me", None, 30).await.unwrap();
+        c2.fetch_following("did:plc:me", None, 30).await.unwrap();
+        for h in rec2.lock().unwrap().iter() {
+            assert!(auth_header(h).is_none(), "unexpected auth header in:\n{h}");
+        }
+    }
 }

crates/tauri-app/src-tauri/src/lib.rs

@@ -354,6 +354,28 @@ async fn unfollow_user(
     }))
 }
 
+/// Access JWT for the AppView's viewer-scoped endpoints.
+///
+/// The four authenticated AppView calls (`timeline_home`,
+/// `fetch_notifications`, `notification_count`,
+/// `mark_notifications_seen`) all need the same thing: the stored
+/// session's access JWT, or a message the UI can render when there
+/// isn't one. Factored out so no call site can accidentally send an
+/// empty `Authorization: Bearer` header — which the AppView would
+/// answer with a 401 `TokenInvalid`, and the frontend would then burn a
+/// pointless refresh round trip on before failing anyway.
+///
+/// The message deliberately contains neither `TokenInvalid` nor
+/// `ExpiredSignature`: `safeInvoke`'s `isTokenInvalid()` greps for those
+/// substrings, and a logged-out client has nothing to refresh *with*.
+fn require_access_jwt(state: &AppState, what: &str) -> Result<String, String> {
+    state
+        .store
+        .load()
+        .map(|s| s.access_jwt)
+        .ok_or_else(|| format!("not logged in: {what} requires a signed-in session"))
+}
+
 #[tauri::command]
 async fn timeline_home(
     state: tauri::State<'_, AppState>,
@@ -362,9 +384,10 @@ async fn timeline_home(
     limit: Option<u32>,
 ) -> Result<appview_client::TimelineResponse, String> {
     let lim = limit.unwrap_or(30).clamp(1, 100);
+    let jwt = require_access_jwt(&state, "the home timeline")?;
     state
         .appview
-        .fetch_timeline(&did, cursor.as_deref(), lim)
+        .fetch_timeline(&did, cursor.as_deref(), lim, &jwt)
         .await
         .map_err(|e| e.to_string())
 }
@@ -460,9 +483,10 @@ async fn fetch_notifications(
     limit: Option<u32>,
 ) -> Result<appview_client::NotificationsResponse, String> {
     let lim = limit.unwrap_or(30).clamp(1, 100);
+    let jwt = require_access_jwt(&state, "notifications")?;
     state
         .appview
-        .fetch_notifications(&did, cursor.as_deref(), lim)
+        .fetch_notifications(&did, cursor.as_deref(), lim, &jwt)
         .await
         .map_err(|e| e.to_string())
 }
@@ -473,9 +497,10 @@ async fn notification_count(
     state: tauri::State<'_, AppState>,
     did: String,
 ) -> Result<appview_client::NotificationCountResponse, String> {
+    let jwt = require_access_jwt(&state, "the unread-notification count")?;
     state
         .appview
-        .notification_count(&did)
+        .notification_count(&did, &jwt)
         .await
         .map_err(|e| e.to_string())
 }
@@ -491,9 +516,10 @@ async fn mark_notifications_seen(
     did: String,
     seen_at: Option<String>,
 ) -> Result<appview_client::NotificationSeenResponse, String> {
+    let jwt = require_access_jwt(&state, "marking notifications seen")?;
     state
         .appview
-        .mark_notifications_seen(&did, seen_at.as_deref())
+        .mark_notifications_seen(&did, seen_at.as_deref(), &jwt)
         .await
         .map_err(|e| e.to_string())
 }

crates/tauri-app/src/App.svelte

@@ -6,6 +6,8 @@
     fetchTimeline,
     fetchSearch,
     fetchPost,
+    errorMessage,
+    isAuthFailure,
     notificationCount,
     openExternalUrl,
     showError,
@@ -377,6 +379,16 @@
   /// Pull the unread count for the NavRail badge. Swallows errors:
   /// the badge is ambient information, and a transient AppView hiccup
   /// shouldn't produce a toast every 5 seconds.
+  ///
+  /// One class of error is *not* swallowed-and-retried, though. Since
+  /// the AppView started requiring the access JWT on
+  /// `/api/notifications/count`, a rejected token surfaces here — and
+  /// by the time it does, `safeInvoke` has already spent its one
+  /// automatic refresh. Retrying on a 5s timer would then be a request
+  /// loop against a server that keeps answering 401/403 for as long as
+  /// the app is open. So an auth failure stops the poll outright; the
+  /// next successful login restarts it via the `session.subscribe`
+  /// handler in `onMount`.
   async function refreshUnreadCount() {
     if (!currentUser) return;
     // While the notifications view is open the user is by definition
@@ -386,8 +398,13 @@
     if (view === "notifications") return;
     try {
       unreadCount = await notificationCount(currentUser.did);
-    } catch {
+    } catch (e) {
-      /* ignore — keep the last known count */
+      if (isAuthFailure(e)) {
+        console.warn("notification poll stopped: session rejected", e);
+        stopPoll();
+        return;
+      }
+      /* otherwise ignore — keep the last known count */
     }
   }
 
@@ -420,7 +437,7 @@
         if (fresh.length > 0) userPosts = [...fresh, ...userPosts];
       }
     } catch (e) {
-      timelineError = String(e);
+      timelineError = errorMessage(e);
       // Keep whatever we had on a transient failure.
     } finally {
       timelineLoading = false;
@@ -440,7 +457,7 @@
       }
       timelineCursor = r.cursor;
     } catch (e) {
-      timelineError = String(e);
+      timelineError = errorMessage(e);
     } finally {
       timelineLoading = false;
     }

crates/tauri-app/src/lib/api/appview-auth.test.ts

@@ -0,0 +1,394 @@
+// The AppView auth contract, from the client's side.
+//
+// Same setup as `notifications.test.ts`: `@tauri-apps/api/core` is
+// mocked so no Tauri shell is needed, and every assertion is about the
+// exact sequence of commands we hand the Rust IPC layer.
+//
+// What's pinned here:
+//   * the **token-renewal chain** — a `TokenInvalid` coming out of the
+//     AppView (not the PDS) triggers exactly one `auth_refresh` + one
+//     retry, for each of the four now-authenticated endpoints;
+//   * that the chain fires for a **bare string** rejection, which is
+//     what `invoke` actually rejects with for our `Result<T, String>`
+//     commands — the shape the old `typeof e !== "object"` guard
+//     silently skipped;
+//   * that it fires **once**, never in a loop, and not at all when the
+//     refresh itself fails or when the error isn't refreshable;
+//   * that the **public** endpoints still work with no session at all
+//     and never reach for a refresh.
+//
+// The error strings below are verbatim what the Rust side produces:
+// `appview_client.rs`'s `status_error()` formats
+// `"appview: {label} returned {status}: {body}"`, and `lib.rs`
+// stringifies that into the command's `Err(String)`. The Rust test
+// `token_invalid_code_survives_into_the_error_string` pins the other
+// half of the same contract.
+//
+// Run with:
+//   npx vitest run src/lib/api/appview-auth.test.ts
+
+import { beforeEach, describe, expect, it, vi } from "vitest";
+
+const invokeMock = vi.fn();
+
+vi.mock("@tauri-apps/api/core", () => ({
+  invoke: (...args: unknown[]) => invokeMock(...args),
+  isTauri: () => true,
+}));
+
+beforeEach(() => {
+  invokeMock.mockReset();
+});
+
+/// Exactly what a Tauri command rejects with once the AppView has
+/// refused an expired access token: a bare string, because our
+/// commands are `Result<T, String>` and `invoke` rejects with the
+/// deserialised payload — not an `Error`.
+function appviewTokenInvalid(label: string): string {
+  return (
+    `appview: ${label} returned 401 Unauthorized: ` +
+    `{"error":"TokenInvalid","message":"ExpiredSignature"}`
+  );
+}
+
+const FRESH_SESSION = {
+  did: "did:plc:me",
+  handle: "me.test",
+  access_jwt: "fresh-access",
+  refresh_jwt: "fresh-refresh",
+};
+
+/// The four endpoints that grew an auth guard, each with the command
+/// name the Rust side registers, the AppView's label in the error
+/// string, a caller, and the payload the retry should resolve with.
+const AUTHED = [
+  {
+    name: "timeline_home",
+    label: "timeline home",
+    payload: { posts: [], cursor: null },
+    call: async () => {
+      const { fetchTimeline } = await import("./client");
+      return fetchTimeline("did:plc:me");
+    },
+  },
+  {
+    name: "fetch_notifications",
+    label: "notifications",
+    payload: { notifications: [], cursor: null },
+    call: async () => {
+      const { fetchNotifications } = await import("./client");
+      return fetchNotifications("did:plc:me");
+    },
+  },
+  {
+    name: "notification_count",
+    label: "notification count",
+    payload: { count: 3 },
+    call: async () => {
+      const { notificationCount } = await import("./client");
+      return notificationCount("did:plc:me");
+    },
+  },
+  {
+    name: "mark_notifications_seen",
+    label: "notifications seen",
+    payload: { ok: true, updated: 2 },
+    call: async () => {
+      const { markNotificationsSeen } = await import("./client");
+      return markNotificationsSeen("did:plc:me", "2026-09-09T10:00:00Z");
+    },
+  },
+] as const;
+
+describe("AppView token renewal", () => {
+  for (const ep of AUTHED) {
+    it(`${ep.name}: a TokenInvalid from the AppView refreshes and retries once`, async () => {
+      invokeMock
+        // 1. the call, rejected by the AppView's auth guard
+        .mockRejectedValueOnce(appviewTokenInvalid(ep.label))
+        // 2. auth_refresh mints a new access JWT from the refresh JWT
+        .mockResolvedValueOnce(FRESH_SESSION)
+        // 3. the same call again, now with the fresh token
+        .mockResolvedValueOnce(ep.payload);
+
+      await expect(ep.call()).resolves.toBeDefined();
+
+      expect(invokeMock.mock.calls.map((c) => c[0])).toEqual([
+        ep.name,
+        "auth_refresh",
+        ep.name,
+      ]);
+      // The retry must repeat the *same* argument bag — a dropped
+      // cursor or limit here would silently change what the user sees.
+      expect(invokeMock.mock.calls[0][1]).toEqual(invokeMock.mock.calls[2][1]);
+    });
+  }
+
+  it("returns the retry's payload, not the failed first attempt", async () => {
+    const { notificationCount } = await import("./client");
+    invokeMock
+      .mockRejectedValueOnce(appviewTokenInvalid("notification count"))
+      .mockResolvedValueOnce(FRESH_SESSION)
+      .mockResolvedValueOnce({ count: 7 });
+
+    await expect(notificationCount("did:plc:me")).resolves.toBe(7);
+  });
+
+  it("fires for a bare-string rejection — the shape Tauri actually uses", async () => {
+    // Regression guard. `invoke` rejects with the deserialised
+    // `Err(String)` payload, i.e. a primitive string. A guard that
+    // bails on anything that isn't an object never sees the code and
+    // the retry silently never runs — the user's timeline just dies an
+    // hour after login with no error anyone would connect to auth.
+    const { fetchTimeline } = await import("./client");
+    invokeMock
+      .mockRejectedValueOnce(appviewTokenInvalid("timeline home"))
+      .mockResolvedValueOnce(FRESH_SESSION)
+      .mockResolvedValueOnce({ posts: [], cursor: null });
+
+    await expect(fetchTimeline("did:plc:me")).resolves.toEqual({
+      posts: [],
+      cursor: null,
+    });
+    expect(invokeMock).toHaveBeenCalledTimes(3);
+  });
+
+  it("also fires when the error arrives as an Error object", async () => {
+    const { fetchTimeline } = await import("./client");
+    invokeMock
+      .mockRejectedValueOnce(new Error(appviewTokenInvalid("timeline home")))
+      .mockResolvedValueOnce(FRESH_SESSION)
+      .mockResolvedValueOnce({ posts: [], cursor: null });
+
+    await expect(fetchTimeline("did:plc:me")).resolves.toBeDefined();
+    expect(invokeMock).toHaveBeenCalledTimes(3);
+  });
+
+  it("retries exactly once — a still-failing retry is not refreshed again", async () => {
+    const { fetchNotifications } = await import("./client");
+    invokeMock
+      .mockRejectedValueOnce(appviewTokenInvalid("notifications"))
+      .mockResolvedValueOnce(FRESH_SESSION)
+      .mockRejectedValueOnce(appviewTokenInvalid("notifications"));
+
+    await expect(fetchNotifications("did:plc:me")).rejects.toThrow(
+      /TokenInvalid/,
+    );
+    // Three calls, not five: no second refresh, no third attempt.
+    expect(invokeMock).toHaveBeenCalledTimes(3);
+    expect(invokeMock.mock.calls.filter((c) => c[0] === "auth_refresh")).toHaveLength(1);
+  });
+
+  it("propagates the original error when the refresh itself fails", async () => {
+    // The refresh JWT is good for 90 days, but it does eventually
+    // expire (or get revoked). At that point there's nothing left to
+    // do but surface the failure — retrying with the same dead token
+    // would just be a second 401.
+    const { notificationCount } = await import("./client");
+    invokeMock
+      .mockRejectedValueOnce(appviewTokenInvalid("notification count"))
+      .mockRejectedValueOnce("refresh token expired");
+
+    await expect(notificationCount("did:plc:me")).rejects.toThrow(
+      /TokenInvalid/,
+    );
+    expect(invokeMock.mock.calls.map((c) => c[0])).toEqual([
+      "notification_count",
+      "auth_refresh",
+    ]);
+  });
+
+  it("does not refresh on a 403 Forbidden — a new token wouldn't help", async () => {
+    // The AppView returns this when the token is perfectly valid but
+    // its `sub` doesn't match the `did` query parameter. Refreshing
+    // mints another token for the same subject, so a retry is pure
+    // waste.
+    const { fetchTimeline } = await import("./client");
+    invokeMock.mockRejectedValueOnce(
+      'appview: timeline home returned 403 Forbidden: ' +
+        '{"error":"Forbidden","message":"did does not match token subject"}',
+    );
+
+    await expect(fetchTimeline("did:plc:someone-else")).rejects.toThrow(
+      /Forbidden/,
+    );
+    expect(invokeMock).toHaveBeenCalledTimes(1);
+  });
+
+  it("does not refresh when the shell says there is no session at all", async () => {
+    // `require_access_jwt` in lib.rs. Nothing to refresh *from*, so the
+    // message deliberately carries neither `TokenInvalid` nor
+    // `ExpiredSignature`.
+    const { fetchNotifications } = await import("./client");
+    invokeMock.mockRejectedValueOnce(
+      "not logged in: notifications requires a signed-in session",
+    );
+
+    await expect(fetchNotifications("did:plc:me")).rejects.toThrow(
+      /not logged in/,
+    );
+    expect(invokeMock).toHaveBeenCalledTimes(1);
+  });
+
+  it("treats a 503 AuthUnavailable as transient, not as an auth failure", async () => {
+    // The AppView answers 503 `AuthUnavailable` when it cannot reach
+    // the PDS to fetch the verification key — it fails closed rather
+    // than guessing. Our token is fine; the *server* is temporarily
+    // unable to check it. So: no refresh (nothing is wrong with the
+    // token), and `isAuthFailure` must stay false so the background
+    // poll keeps trying instead of shutting itself down over an outage
+    // that will resolve on its own.
+    const { notificationCount, isAuthFailure } = await import("./client");
+    const err =
+      'appview: notification count returned 503 Service Unavailable: ' +
+      '{"error":"AuthUnavailable","message":"could not fetch PDS key"}';
+
+    invokeMock.mockRejectedValueOnce(err);
+    await expect(notificationCount("did:plc:me")).rejects.toThrow(
+      /AuthUnavailable/,
+    );
+    expect(invokeMock).toHaveBeenCalledTimes(1);
+    expect(isAuthFailure(err)).toBe(false);
+  });
+
+  it("does not refresh on a transient server error", async () => {
+    const { notificationCount } = await import("./client");
+    invokeMock.mockRejectedValueOnce(
+      "appview: notification count returned 500 Internal Server Error: db down",
+    );
+
+    await expect(notificationCount("did:plc:me")).rejects.toThrow(/500/);
+    expect(invokeMock).toHaveBeenCalledTimes(1);
+  });
+
+  it("an auth_* command never triggers a refresh (no login loop)", async () => {
+    const { session } = await import("./client");
+    invokeMock.mockRejectedValueOnce("TokenInvalid");
+
+    await expect(session.login("me.test", "pw")).rejects.toBeDefined();
+    expect(invokeMock.mock.calls.map((c) => c[0])).toEqual(["auth_login"]);
+  });
+});
+
+describe("public AppView endpoints", () => {
+  // These stay unauthenticated server-side, so they must keep working
+  // with no session in the store: one invoke, no bearer token to fetch,
+  // no refresh.
+  const PUBLIC = [
+    {
+      name: "search",
+      payload: { posts: [], q: "hi" },
+      call: async () => (await import("./client")).fetchSearch("hi"),
+    },
+    {
+      name: "profile_get",
+      payload: {
+        did: "did:plc:a",
+        handle: "a.test",
+        posts: [],
+        followers: 0,
+        following: 0,
+        post_count: 0,
+      },
+      call: async () => (await import("./client")).fetchProfile("a.test"),
+    },
+    {
+      name: "profile_get_by_did",
+      payload: {
+        did: "did:plc:a",
+        handle: "a.test",
+        posts: [],
+        followers: 0,
+        following: 0,
+        post_count: 0,
+      },
+      call: async () => (await import("./client")).fetchProfileByDid("did:plc:a"),
+    },
+    {
+      name: "post_get",
+      payload: { post: null, thread: { parent: null, root: null } },
+      call: async () =>
+        (await import("./client")).fetchPost("at://did:plc:a/app.twi.post/1"),
+    },
+    {
+      name: "fetch_thread",
+      payload: { post: null, parents: [], root: null, replies: [] },
+      call: async () =>
+        (await import("./client")).fetchThread("at://did:plc:a/app.twi.post/1"),
+    },
+    {
+      name: "fetch_followers",
+      payload: { profiles: [], cursor: null },
+      call: async () => (await import("./client")).fetchFollowers("did:plc:a"),
+    },
+    {
+      name: "fetch_following",
+      payload: { profiles: [], cursor: null },
+      call: async () => (await import("./client")).fetchFollowing("did:plc:a"),
+    },
+  ] as const;
+
+  for (const ep of PUBLIC) {
+    it(`${ep.name} resolves without a session and without refreshing`, async () => {
+      invokeMock.mockResolvedValueOnce(ep.payload);
+
+      await expect(ep.call()).resolves.toBeDefined();
+
+      expect(invokeMock).toHaveBeenCalledTimes(1);
+      expect(invokeMock.mock.calls[0][0]).toBe(ep.name);
+      expect(
+        invokeMock.mock.calls.some((c) => c[0] === "auth_refresh"),
+      ).toBe(false);
+    });
+  }
+
+  it("a public call's own failure surfaces untouched", async () => {
+    const { fetchSearch } = await import("./client");
+    invokeMock.mockRejectedValueOnce(
+      "appview: search returned 400 Bad Request: q is required",
+    );
+    await expect(fetchSearch("")).rejects.toThrow(/q is required/);
+    expect(invokeMock).toHaveBeenCalledTimes(1);
+  });
+});
+
+describe("isAuthFailure / errorMessage", () => {
+  it("recognises every shape the AppView's auth guard can answer with", async () => {
+    const { isAuthFailure } = await import("./client");
+    for (const msg of [
+      'appview: timeline home returned 401 Unauthorized: {"error":"AuthMissing","message":"no bearer"}',
+      'appview: notifications returned 401 Unauthorized: {"error":"TokenInvalid","message":"ExpiredSignature"}',
+      'appview: notification count returned 403 Forbidden: {"error":"Forbidden"}',
+      "not logged in: the home timeline requires a signed-in session",
+    ]) {
+      expect(isAuthFailure(msg)).toBe(true);
+      expect(isAuthFailure(new Error(msg))).toBe(true);
+    }
+  });
+
+  it("does not mistake a server or network failure for an auth failure", async () => {
+    const { isAuthFailure } = await import("./client");
+    expect(
+      isAuthFailure("appview: notifications returned 500: db down"),
+    ).toBe(false);
+    expect(
+      isAuthFailure("appview: failed to send timeline request"),
+    ).toBe(false);
+    expect(isAuthFailure(null)).toBe(false);
+    expect(isAuthFailure(undefined)).toBe(false);
+  });
+
+  it("swaps the raw 401 wire string for copy the user can act on", async () => {
+    const { errorMessage } = await import("./client");
+    const raw =
+      'appview: notifications returned 401 Unauthorized: {"error":"TokenInvalid","message":"ExpiredSignature"}';
+    expect(errorMessage(raw)).toBe(
+      "Sitzung abgelaufen oder abgelehnt — bitte neu anmelden.",
+    );
+    // Anything else is shown verbatim: there's nothing better to say
+    // about a 500 than what the server said.
+    expect(errorMessage("appview: search returned 500: db down")).toContain(
+      "500",
+    );
+  });
+});

crates/tauri-app/src/lib/api/client.ts

@@ -59,14 +59,22 @@ export async function getAppviewUrl(): Promise<string> {
  * webview it falls through to a normal `invoke` call.
  *
  * **Auto-refresh on 401**: the access JWT expires after 1 hour. When
- * the PDS rejects our token with `TokenInvalid` (the rusty
+ * the PDS *or the AppView* rejects our token with `TokenInvalid`
- * `routes::auth` handlers return `{"error":"TokenInvalid",...}`),
+ * (both return `{"error":"TokenInvalid",...}` — the PDS from its
- * we ask the Rust shell for a fresh access JWT via the
+ * `routes::auth` handlers, the AppView from the guard on
- * `auth_refresh` Tauri command. The Rust side reads the stored
+ * `/api/timeline/home`, `/api/notifications`,
- * refresh JWT (valid for 90 days) and rotates both. We retry
+ * `/api/notifications/count` and `/api/notifications/seen`), we ask
- * exactly once on the same `cmd` + `args`. The `auth_*` commands
+ * the Rust shell for a fresh access JWT via the `auth_refresh` Tauri
- * themselves are skipped so a failing login doesn't trigger an
+ * command. The Rust side reads the stored refresh JWT (valid for 90
- * infinite refresh loop.
+ * days) and rotates both. We retry exactly once on the same `cmd` +
+ * `args`. The `auth_*` commands themselves are skipped so a failing
+ * login doesn't trigger an infinite refresh loop.
+ *
+ * The whole chain is string-matching, end to end: the AppView states
+ * the code only in its JSON body, `appview_client.rs`'s
+ * `status_error()` formats that body into the `anyhow` message, and
+ * `lib.rs` stringifies it into the command's `Err(String)`. See the
+ * Rust-side test `token_invalid_code_survives_into_the_error_string`.
  */
 async function safeInvoke<T>(cmd: string, args?: Record<string, unknown>): Promise<T> {
   if (!isTauri()) {
@@ -82,17 +90,74 @@ async function safeInvoke<T>(cmd: string, args?: Record<string, unknown>): Promi
   }
 }
 
+/// Normalise whatever a rejected `invoke` handed us into a string.
+///
+/// This is not defensive padding — it is the difference between the
+/// retry chain working and not. Our Tauri commands are
+/// `Result<T, String>`, and `@tauri-apps/api`'s `invoke` rejects with
+/// the *deserialised* error payload, i.e. a bare JS **string**, not an
+/// `Error`. Anything that only reads `e.message` therefore sees
+/// nothing at all on the exact path that matters. Errors thrown
+/// locally (the browser-preview guard above, and the `Error` instances
+/// the tests use) still arrive as objects, so both shapes are handled.
+function errorText(e: unknown): string {
+  if (typeof e === "string") return e;
+  if (typeof e === "object" && e !== null) {
+    const m = (e as { message?: unknown }).message;
+    if (typeof m === "string") return m;
+  }
+  return String(e ?? "");
+}
+
 /// Sniff out a `TokenInvalid` response from the Rust error string.
-/// Returns true when the error message looks like an expired/
+/// Returns true when the error looks like an expired/invalid JWT —
-/// invalid JWT (the PDS uses a stable `"TokenInvalid"` code in its
+/// both the PDS and the AppView use a stable `"TokenInvalid"` code in
-/// JSON error body, which `@tauri-apps/api/core` surfaces verbatim).
+/// their JSON error body, which travels verbatim through the Rust
+/// error message and out over the Tauri IPC boundary.
 function isTokenInvalid(e: unknown): boolean {
-  if (typeof e !== "object" || e === null) return false;
+  const msg = errorText(e);
-  const msg = (e as { message?: string }).message ?? String(e);
   if (!msg) return false;
   return msg.includes("TokenInvalid") || msg.includes("ExpiredSignature");
 }
 
+/// True when an error means "this call will not succeed until the user
+/// signs in again" — as opposed to a transient network/server hiccup.
+///
+/// Covers everything the AppView's auth guard can answer with
+/// (`AuthMissing` / `TokenInvalid` on 401, `Forbidden` on 403) plus the
+/// Rust shell's own "no session stored" message from
+/// `require_access_jwt`. Callers that poll in the background use this
+/// to *stop* polling: by the time one of these surfaces, `safeInvoke`
+/// has already spent its one refresh attempt, so retrying on a timer
+/// would just be a request loop against a server that keeps saying no.
+export function isAuthFailure(e: unknown): boolean {
+  const msg = errorText(e);
+  if (!msg) return false;
+  return (
+    msg.includes("AuthMissing") ||
+    msg.includes("TokenInvalid") ||
+    msg.includes("ExpiredSignature") ||
+    msg.includes("Forbidden") ||
+    msg.includes("not logged in")
+  );
+}
+
+/// User-facing copy for a failed call, in the app's German UI voice.
+///
+/// An auth failure gets a sentence naming the actual remedy. The raw
+/// string a view would otherwise render —
+/// `appview: timeline home returned 401 Unauthorized:
+/// {"error":"TokenInvalid","message":"ExpiredSignature"}` — is precise
+/// and completely unactionable for the person reading it. Everything
+/// else falls through verbatim: a network error or a 500 is worth
+/// showing as-is, since there is nothing better to say about it.
+export function errorMessage(e: unknown): string {
+  if (isAuthFailure(e)) {
+    return "Sitzung abgelaufen oder abgelehnt — bitte neu anmelden.";
+  }
+  return String(e);
+}
+
 export type Session = {
   did: string;
   handle: string;
@@ -253,8 +318,10 @@ export type SearchResponse = {
 ///
 /// `like_count` and `repost_count` are present when the post was
 /// found; they're `undefined` (or absent) for the "not in index"
-/// sentinel response (where `post` is null). AppView has no auth
+/// sentinel response (where `post` is null). `/api/post/{uri}` is one
-/// yet, so `viewer_liked` / `viewer_reposted` aren't returned.
+/// of the AppView's public endpoints — it takes no token and so has no
+/// viewer to resolve against, hence no `viewer_liked` /
+/// `viewer_reposted`. Use [`fetchThread`] with a `viewerDid` for those.
 export type ThreadResponse = {
   post: Post | null;
   thread: {

crates/tauri-app/src/lib/components/NotificationsView.svelte

@@ -2,6 +2,7 @@
   import Avatar from "./Avatar.svelte";
   import Skeleton from "./Skeleton.svelte";
   import {
+    errorMessage,
     fetchNotifications,
     markNotificationsSeen,
     notificationIcon,
@@ -71,7 +72,7 @@
         }
       }
     } catch (e) {
-      error = String(e);
+      error = errorMessage(e);
     } finally {
       loading = false;
     }
@@ -89,7 +90,7 @@
       items = [...items, ...r.notifications.filter((n) => !seen.has(n.id))];
       cursor = r.cursor;
     } catch (e) {
-      error = String(e);
+      error = errorMessage(e);
     } finally {
       loading = false;
     }

crates/tauri-app/src/lib/components/NotificationsView.test.ts

@@ -194,6 +194,48 @@ describe("NotificationsView actor navigation", () => {
     expect(onThreadClick).not.toHaveBeenCalled();
   });
 
+  it("shows actionable copy when the AppView rejects the session", async () => {
+    // Since `/api/notifications` grew an auth guard, this is what a
+    // rejected token looks like by the time it reaches the view: the
+    // AppView's JSON body, wrapped by `appview_client.rs`'s
+    // `status_error()` and stringified across the Tauri IPC boundary.
+    // `safeInvoke` has already spent its one refresh attempt getting
+    // here, so the only thing left to tell the user is "log in again" —
+    // rendering the raw wire string would be accurate and useless.
+    fetchNotificationsMock.mockRejectedValue(
+      'appview: notifications returned 401 Unauthorized: ' +
+        '{"error":"TokenInvalid","message":"ExpiredSignature"}',
+    );
+
+    app = mount(NotificationsView, {
+      target,
+      props: { did: "did:plc:me" },
+    });
+    await flush();
+
+    expect(target.textContent).toContain("bitte neu anmelden");
+    expect(target.textContent).not.toContain("TokenInvalid");
+    expect(target.textContent).not.toContain("401");
+    // A failed load must not leave the spinner up or ack a page it
+    // never rendered.
+    expect(markNotificationsSeenMock).not.toHaveBeenCalled();
+  });
+
+  it("still shows a server error verbatim — there's nothing better to say", async () => {
+    fetchNotificationsMock.mockRejectedValue(
+      "appview: notifications returned 500 Internal Server Error: db down",
+    );
+
+    app = mount(NotificationsView, {
+      target,
+      props: { did: "did:plc:me" },
+    });
+    await flush();
+
+    expect(target.textContent).toContain("500");
+    expect(target.textContent).toContain("db down");
+  });
+
   it("opens the thread for a row that has a subject", async () => {
     fetchNotificationsMock.mockResolvedValue({
       notifications: [row()],

docs/architecture.md

@@ -19,11 +19,12 @@ auf welchem Weg kommt ein Post vom Client bis in die Timeline zurück.
     ┌──────────────────────────────────┐   ┌──────────────────────────────┐
     │ pds-server  (axum, :2583)        │   │ appview  (axum, :2584)       │
     │                                  │   │                              │
-    │  /xrpc/com.atproto.*             │   │  GET /api/timeline/home      │
+    │  /xrpc/com.atproto.*             │   │  GET /api/timeline/home  🔒  │
     │  /xrpc/app.bsky.actor.profile.*  │   │  GET /api/profile[/:handle]  │
     │  /blob/:cid                      │   │  GET /api/search             │
     │  /healthz                        │   │  GET /api/post|thread/*uri   │
-    │                                  │   │  GET /api/notifications…     │
+    │  /.well-known/did.json ──────────┼───┼─▶ Schlüssel für 🔒           │
+    │                                  │   │  GET /api/notifications…  🔒 │
     │                                  │   │  GET /api/followers|following│
     │                                  │   │  GET /healthz                │
     │  at-lexicon  Validierung (160)   │   │                              │
@@ -50,6 +51,11 @@ auf welchem Weg kommt ein Post vom Client bis in die Timeline zurück.
    └──────────────────────────────────────────┘   JetstreamConsumer
 ```
 
+🔒 = Bearer-Token nötig, und der `sub` des Tokens muss der angefragten DID
+entsprechen. Die AppView verifiziert die ES256-Signatur mit dem öffentlichen
+Schlüssel, den die PDS in ihrem DID-Dokument veröffentlicht — `PDS_JWT_SECRET`
+verlässt die PDS nie. Details in [`deployment.md`](deployment.md), Abschnitt 6.
+
 Zwei Wege führen in die AppView, und das ist Absicht:
 
 1. **Direkter Push (schnell, lokal).** Jeder erfolgreiche Commit auf der PDS

docs/deployment.md

@@ -287,7 +287,7 @@ Hinweise:
 * Es gibt **keinen** Signal-Handler für graceful Shutdown. `systemctl stop`
   beendet den Prozess hart; bei der AppView bedeutet das, dass der letzte
   Cursor-Flush nur passiert, wenn der Kanal regulär geschlossen wird —
-  praktisch also mit bis zu 100 Events Verlust (siehe Abschnitt 8). Das ist
+  praktisch also mit bis zu 100 Events Verlust (siehe Abschnitt 9). Das ist
   unkritisch, weil der Cursor beim Resume ohnehin leicht in die Vergangenheit
   zeigt und Events idempotent verarbeitet werden.
 * Eine Abhängigkeit `After=` auf Postgres/MinIO ist nur nötig, wenn diese auf
@@ -296,7 +296,55 @@ Hinweise:
   `PgPoolOptions` mit `acquire_timeout(10s)`, bricht aber ebenfalls ab, wenn
   der erste Connect scheitert. `Restart=on-failure` fängt das ab.
 
-## 6. Reverse-Proxy
+## 6. Authentifizierung
+
+Die AppView prüft seit Phase 9 Bearer-Tokens. Wie das zusammenhängt:
+
+1. Die PDS stellt beim Login ein ES256-Access-JWT aus (`sub` = DID,
+   `scope` = `com.atproto.access`, eine Stunde gültig).
+2. Die PDS veröffentlicht den *öffentlichen* Teil ihres P-256-Schlüssels unter
+   `GET /.well-known/did.json`. `PDS_JWT_SECRET` verlässt den PDS-Prozess nicht.
+3. Die AppView holt dieses Dokument beim Start von `PDS_INTERNAL_URL`
+   (Fallback: `PDS_PUBLIC_URL`), cached den Schlüssel und lädt ihn bei einem
+   Verifikationsfehler einmal nach — höchstens einmal pro Minute, damit
+   Müll-Tokens kein Werkzeug werden, die PDS zu fluten. Ein Schlüsselwechsel
+   braucht also keinen Neustart der AppView.
+
+Ist die PDS beim Start nicht erreichbar, warnt die AppView nur und startet
+trotzdem — sie indiziert den Firehose, was von der lokalen PDS unabhängig ist.
+Der Schlüssel wird dann beim ersten authentifizierten Request geholt. Klappt
+auch das nicht, antwortet sie `503 AuthUnavailable`: **fail closed**, nie
+fail open.
+
+### Welche Endpoints
+
+| Endpoint | Zugriff |
+|---|---|
+| `/api/timeline/home`, `/api/notifications`, `/api/notifications/count`, `/api/notifications/seen` | Token nötig, `sub` muss dem `did`-Parameter entsprechen |
+| `/api/profile*`, `/api/search`, `/api/post/*`, `/api/thread*`, `/api/followers`, `/api/following` | öffentlich (in AT Proto öffentliche Records) |
+| `/internal/ingest-commit` | `APPVIEW_INGEST_SECRET`, server-zu-server |
+
+### Fehlercodes
+
+| Fall | Status | `error` |
+|---|---|---|
+| Header fehlt oder ist kein Bearer | 401 | `AuthMissing` |
+| Signatur falsch, abgelaufen, falscher `scope` | 401 | `TokenInvalid` |
+| Token gültig, aber `sub` ≠ `did` | 403 | `Forbidden` |
+| Schlüssel der PDS nicht beschaffbar | 503 | `AuthUnavailable` |
+
+`TokenInvalid` ist ein Vertrag mit dem Desktop-Client: daran erkennt er, dass
+er sein Access-JWT erneuern und den Request einmal wiederholen muss. Wer den
+Code umbenennt, loggt jeden Nutzer eine Stunde nach dem Login aus.
+
+### `APPVIEW_AUTH_REQUIRED=false`
+
+Schaltet die Prüfung ab und stellt das alte Verhalten her — gedacht für eine
+Instanz hinter VPN und für die fail-open-Integrationstests. Die AppView warnt
+beim Start in Großbuchstaben. Öffentlich erreichbar heißt das: jeder kann die
+Notifications jeder DID lesen und als gelesen markieren.
+
+## 7. Reverse-Proxy
 
 ### PDS
 
@@ -357,25 +405,31 @@ im DID-Doc-`serviceEndpoint`, im JWT-`iss` und als Basis der Blob-URLs.
 kein `/.well-known/atproto-did` aus (im Router nicht vorhanden). `at-identity`
 kann solche Dokumente *auflösen*, aber wer `did:web`-Handles auf dieser PDS
 betreiben will, muss die Dateien vorerst statisch über den Proxy ausliefern.
-Ebenfalls offen: `describeServer` gibt die DID hart als
+Die Service-DID wird inzwischen aus `PDS_PUBLIC_URL` abgeleitet
-`did:web:pds.maarcadetweet.local` zurück, unabhängig von `PDS_PUBLIC_URL`.
+(`AppConfig::pds_did()`, did:web mit `%3A`-kodiertem Port) und von
+`describeServer` **und** `/.well-known/did.json` identisch ausgeliefert. Das
+heißt auch: ändert sich `PDS_PUBLIC_URL`, ändert sich die Service-DID.
 
 ### AppView
 
-Die AppView setzt ihr CORS selbst — `crates/appview/src/routes.rs`:
+Die AppView setzt ihr CORS selbst (`cors_layer()` in
+`crates/appview/src/routes.rs`). Ohne `APPVIEW_CORS_ORIGINS` bleibt es beim
+alten `Access-Control-Allow-Origin: *` — die AppView warnt dann beim Start.
+Mit gesetzter Variable gilt eine Allowlist:
 
-```rust
+```
-let cors = CorsLayer::new()
+APPVIEW_CORS_ORIGINS=tauri://localhost,http://tauri.localhost,http://127.0.0.1:1430
-    .allow_origin(Any)
-    .allow_methods(Any)
-    .allow_headers(Any);
 ```
 
-Also `Access-Control-Allow-Origin: *` für alle Routen, inklusive
+Der Tauri-Webview ruft die AppView von einem anderen Origin aus auf — im Dev
-`/internal/ingest-commit`. Der Grund steht im Code: der Tauri-Webview ruft die
+die Vite-Adresse, im Bundle `tauri://localhost` (macOS/Linux) bzw.
-AppView von einem anderen Origin aus auf (`http://127.0.0.1:1430` im Dev,
+`http://tauri.localhost` (Windows). Alle drei gehören in die Liste, sonst
-`tauri://` / `asset://` im Bundle), und die Read-Endpoints tragen keine
+scheitert der Preflight.
-Auth-Cookies.
+
+`/internal/ingest-commit` liegt bewusst **außerhalb** der CORS-Schicht: die
+Route wird von der PDS server-zu-server aufgerufen, nie von einem Browser. Ein
+`Access-Control-Allow-Origin` darauf würde ausschließlich einer Webseite
+helfen, in den Index zu schreiben.
 
 Für ein öffentliches Deployment heißt das:
 
@@ -408,7 +462,7 @@ HTTP-Aufrufe an PDS/AppView laufen über den Rust-IPC-Layer
 (`src-tauri/src/pds_client.rs`, `appview_client.rs`), nicht aus dem Webview —
 die CSP muss also für neue Backend-URLs nicht angefasst werden.
 
-## 7. Health-Checks und Logs
+## 8. Health-Checks und Logs
 
 ### PDS
 
@@ -472,7 +526,7 @@ Log-Zeilen, auf die es sich lohnt zu achten:
 | `s3 ping failed at startup` | MinIO beim PDS-Start nicht erreichbar |
 | `plc submit failed (dev ok)` | PLC-Directory nicht erreichbar; die DID bleibt lokal gültig, ist aber global nicht registriert |
 
-## 8. Neustart-Verhalten
+## 9. Neustart-Verhalten
 
 **PDS.** Zustandslos bis auf Postgres und MinIO. Der In-Memory-Blockstore
 (`MemoryBlockstore` in `state.rs`) wird beim Start neu aufgebaut; persistent
@@ -515,14 +569,15 @@ nach — zuerst über die lokale PDS (`PdsHandleResolver`, 2 s Timeout), dann PL
 bzw. `did:web`. Nach einem Neustart holt der erste Durchlauf das nach; der
 Zustand ist reine Anzeigekosmetik.
 
-## 9. Was noch offen ist
+## 10. Was noch offen ist
 
 * Kein Compose-Service für `pds-server` / `appview` — das Compose-File deckt nur
   Postgres und MinIO ab. Es gibt kein Dockerfile im Repo.
 * `at-blob` spricht ausschließlich MinIO ohne Signature V4 (siehe Modul-Doku in
   `crates/at-blob/src/s3.rs`); echtes AWS S3 funktioniert damit nicht.
 * Kein Graceful-Shutdown, keine Readiness- (im Unterschied zur Liveness-)Probe.
-* Keine konfigurierbare CORS-Allowlist in der AppView.
+* `aud` wird beim Token-Check nicht validiert (`verify_jwt` setzt
-* Kein `.well-known`-Handling in der PDS, `describeServer` liefert eine
+  `validate_aud = false`), obwohl die PDS `did:web:appview.maarcadetweet.local`
-  hartkodierte DID.
+  einsetzt. Signatur, Ablauf, `scope` und `sub` werden geprüft.
+* Notifications werden nie gelöscht; ein Unlike/Unfollow lässt die Zeile stehen.
 * Kein Backfill-Werkzeug für Jetstream-Lücken.

migrations/appview/0009_handle_lookup_indexes.sql

@@ -0,0 +1,58 @@
+-- AppView database schema 0009: indexes for handle → DID lookups.
+--
+-- `/api/profile/<handle>` took 9.5 s on a 3.3 M-row `posts` table
+-- (measured against the dev instance). Both halves of `resolve_profile`
+-- were unindexed:
+--
+--   1. SELECT did FROM profiles WHERE LOWER(handle) = LOWER($1)
+--   2. SELECT did FROM posts    WHERE handle = $1
+--      ORDER BY indexed_at DESC LIMIT 1        -- the fallback
+--
+-- Step 2 was a parallel sequential scan over every post ever indexed
+-- (`Rows Removed by Filter: 1101310` per worker), and it runs on every
+-- profile view in the client.
+--
+-- On `profiles`: migration 0007 dropped exactly this index, reasoning
+-- that "every caller derives a DID first (via posts.handle or the
+-- handle-sync worker) and then queries profiles by PK". That stopped
+-- being true when `resolve_profile` learned to prefer the profiles
+-- cache — it now asks `profiles` by handle *first*, precisely the
+-- lookup 0007 removed the support for. Re-added, matching the
+-- expression in the query (`LOWER(handle)`) so the planner can use it.
+CREATE INDEX IF NOT EXISTS profiles_handle_lower_idx
+    ON profiles (LOWER(handle));
+
+-- On `posts`: `(handle, indexed_at DESC)` covers filter *and* sort, so
+-- the LIMIT 1 becomes an index scan that stops at the first row.
+--
+-- Partial on `handle <> ''`: empty handles are the un-backfilled
+-- majority on a firehose-fed instance and are never looked up by this
+-- path (the handle-sync worker queries them through its own predicate),
+-- so excluding them keeps the index small on the largest table we have.
+CREATE INDEX IF NOT EXISTS posts_handle_indexed_at_idx
+    ON posts (handle, indexed_at DESC)
+    WHERE handle <> '';
+
+-- =====================================================
+-- posts: the cold-start global feed
+-- =====================================================
+--
+-- `/api/timeline/home` falls back to the global recent feed for users
+-- without a follow graph — every new account's first screen. It took
+-- 7.4 s (parallel seq scan + top-N sort over 3.3 M rows) and timed out
+-- the integration tests' 5 s client.
+--
+-- `posts_collection_indexed_at_uri_idx (collection, indexed_at DESC,
+-- uri DESC)` cannot serve it: the query filters
+-- `collection IN ('app.twi.post','app.bsky.feed.post')`, and with two
+-- leading values the index no longer yields rows in `indexed_at` order,
+-- so the planner falls back to scanning and sorting.
+--
+-- A partial index over exactly that predicate moves the collection
+-- filter into the index definition, which leaves `(indexed_at DESC,
+-- uri DESC)` as the sort key — the LIMIT then stops after the first
+-- page. Same shape as the existing `posts_did_indexed_at_uri_idx`,
+-- which is partial on the same two collections.
+CREATE INDEX IF NOT EXISTS posts_feed_indexed_at_uri_idx
+    ON posts (indexed_at DESC, uri DESC)
+    WHERE collection IN ('app.twi.post', 'app.bsky.feed.post');