fix(node): bound GraphQL query cost (#552)

* fix(node): bound GraphQL query cost

* fix(node)!: bound repo names so emitted cursors always parse

The reposPage cursor embeds base64(JSON(owner_did, name)) while
parse_repo_cursor rejects cursors over 4096 bytes, but repo names were
unbounded on every write path. A single long-named visible repo made the
server emit an endCursor it then rejected as "invalid repository cursor",
dead-ending pagination for every caller past that row.

Bound names to MAX_REPO_NAME_LEN (100 bytes) at the create_repo and
fork_repo handlers via a shared validate_repo_name helper (bad charset is
still a 400), and reject overlong peer-supplied names in
Db::upsert_mirror_repo (the sync caller already drops the error and skips
the mirror).

Also in this round:
- docs/graphql-pagination.md states the 200 page-size maximum and corrects
  the over-budget remedy: a smaller limit does not reduce the reposPage or
  repos price, which is charged at the full MAX_VISIBLE_REPO_PAGE_SIZE
  scan regardless of limit.
- Tests pin refUpdates(limit: -1) clamping to zero rows, the
  parse_repo_cursor wrong-shape-JSON arm with its exact "invalid
  repository cursor" message, the longest-admissible-name cursor
  round-trip, and the mirror write-path rejection.

BREAKING CHANGE: the GraphQL `repos` field now returns an error instead of
the full list when more than MAX_VISIBLE_REPO_PAGE_SIZE (200) repositories
are visible; larger lists must use `reposPage` with `limit`/`after`.
Repository names are additionally limited to 100 bytes at creation, fork,
and mirror-registration time.

* fix(node): address beardthelion P3 findings on name bound and input messages

- Assert each rejection's own message in the reposPage invalid-inputs
  loop: the loop no longer accepts either message for every query, so a
  misattributed message (limit arm returning the cursor message) goes red.
- Pin the create/fork name-bound wiring through the handler: new test
  drives create_repo with an overlong name via test_state_lazy and asserts
  the 400; deleting the validate_repo_name call site would proceed to the
  lazy DB pool and fail with a connection error instead.
- Document the API-side vs disk-side validate_repo_name divergence on the
  new function, and tie the store's literal 100 to MAX_REPO_NAME_LEN so
  the two validators cannot drift apart on length.

---------

Co-authored-by: Marlowe <[email protected]>
Co-authored-by: cairn-intern <[email protected]>

CONTRIBUTING.md

@@ -81,7 +81,7 @@ time once updated.
 
 **Requirements:**
 - Rust stable (≥ 1.91) — install via [rustup](https://rustup.rs)
-- PostgreSQL — required for the node. Use the bundled `docker-compose.yml` for local dev.
+- PostgreSQL 16+ — required for the node (it uses `pg_input_is_valid`, which exists only on PostgreSQL 16 and later). Use the bundled `docker-compose.yml` for local dev.
 - Docker (optional, for full-stack local testing)
 
 **Environment variables:**

README.md

@@ -53,6 +53,7 @@ Good today:
 
 - Local or Docker node startup.
 - Postgres-backed repo metadata.
+- Bounded GraphQL queries with [repository pagination](docs/graphql-pagination.md).
 - Bare git repository storage.
 - Git smart-HTTP clone/fetch/push.
 - RFC 9421-signed writes.

crates/gitlawb-node/src/api/events.rs

@@ -11,7 +11,8 @@ use crate::state::AppState;
 
 /// Hard ceiling on rows any ref-update feed returns in one request. Shared by the
 /// shared collector's clamp and the per-handler request caps so they can't drift.
-const MAX_VISIBLE_REF_UPDATES: i64 = 200;
+/// `pub(crate)` so the GraphQL complexity meter can price against the same bound.
+pub(crate) const MAX_VISIBLE_REF_UPDATES: i64 = 200;
 
 /// Collect up to `limit` ref-update rows visible to `caller`, newest first,
 /// paging past rows the feed gate drops. Filtering after a plain SQL `LIMIT`

crates/gitlawb-node/src/api/ipfs.rs

@@ -8367,6 +8367,7 @@ mod tests {
     #[tokio::test]
     async fn get_by_cid_per_source_cap_sheds_same_source_admits_other() {
         let mut state = crate::test_support::test_state_lazy();
+        state.db.pool().close().await;
         // Global pool has room; the per-source cap is 1.
         state.git_ipfs_walk_semaphore = Arc::new(Semaphore::new(8));
         state.git_ipfs_walk_per_caller = crate::rate_limit::PerCallerConcurrency::new(1, 100);
@@ -8393,16 +8394,23 @@ mod tests {
             "a source at its per-source /ipfs walk cap must shed 503 with global capacity free"
         );
 
+        let bytes = axum::body::to_bytes(resp.into_body(), 1024).await.unwrap();
+        let body: serde_json::Value = serde_json::from_slice(&bytes).unwrap();
+        assert_eq!(body["error"], "overloaded");
+
         // A DIFFERENT source is NOT shed by the per-source cap: it clears admission and
-        // proceeds (then errors on the lazy DB, which is not a 503).
+        // proceeds to the closed DB, which has a distinct db_unavailable error code.
         let resp = ipfs_router(state)
             .oneshot(get_cid(&cid, Some(other)))
             .await
             .unwrap();
-        assert_ne!(
-            resp.status(),
-            StatusCode::SERVICE_UNAVAILABLE,
-            "a different source must not be shed by the per-source cap"
+        assert_eq!(resp.status(), StatusCode::SERVICE_UNAVAILABLE);
+        let bytes = axum::body::to_bytes(resp.into_body(), 1024).await.unwrap();
+        let body: serde_json::Value = serde_json::from_slice(&bytes).unwrap();
+        assert_eq!(
+            body["error"],
+            crate::error::DB_UNAVAILABLE_CODE,
+            "a different source must clear admission and reach the closed database"
         );
     }
 

crates/gitlawb-node/src/api/repos.rs

@@ -247,6 +247,40 @@ pub struct InfoRefsQuery {
 
 // ── Handlers ──────────────────────────────────────────────────────────────
 
+/// Validate a repository name at the create/fork write paths. The charset is
+/// restricted, and the length is bounded so every cursor the server emits
+/// parses back: `repo_cursor` embeds the name in a base64(JSON) cursor that
+/// `parse_repo_cursor` rejects over 4096 bytes (#465 4th round).
+///
+/// This is the API-side validator, and it deliberately differs from the
+/// stricter disk-side `validate_repo_name` in `git/repo_store.rs`: this one
+/// admits names the store rejects (empty, leading `-`, non-ASCII
+/// alphanumeric) and rejects `.`, which the store allows. The divergence
+/// predates this bound (#412 owns the fork half), so a store-rejected name
+/// still fails later at `repo_store.init` after the proof is spent. Do not
+/// "fix" the divergence here; the length bound below is the one that keeps
+/// emitted cursors parseable, and it is shared via `MAX_REPO_NAME_LEN` so the
+/// two validators cannot drift apart on length.
+fn validate_repo_name(name: &str) -> Result<()> {
+    // Sanitize name: alphanumeric, hyphens, underscores only
+    if !name
+        .chars()
+        .all(|c| c.is_alphanumeric() || c == '-' || c == '_')
+    {
+        return Err(AppError::BadRequest(
+            "repo name must contain only alphanumeric characters, hyphens, and underscores".into(),
+        ));
+    }
+    // Byte length, not char count: the cursor budget is measured in bytes.
+    if name.len() > crate::db::MAX_REPO_NAME_LEN {
+        return Err(AppError::BadRequest(format!(
+            "repo name must be at most {} bytes",
+            crate::db::MAX_REPO_NAME_LEN
+        )));
+    }
+    Ok(())
+}
+
 /// POST /api/v1/repos
 /// Create a new repository. Requires HTTP Signature auth.
 pub async fn create_repo(
@@ -261,16 +295,7 @@ pub async fn create_repo(
     // rejected request (bad name, already exists) never burns a valid proof.
     let proof = crate::icaptcha::verify_request(&headers, &auth.0)?;
 
-    // Sanitize name: alphanumeric, hyphens, underscores only
-    if !req
-        .name
-        .chars()
-        .all(|c| c.is_alphanumeric() || c == '-' || c == '_')
-    {
-        return Err(AppError::BadRequest(
-            "repo name must contain only alphanumeric characters, hyphens, and underscores".into(),
-        ));
-    }
+    validate_repo_name(&req.name)?;
 
     // default_branch is caller-supplied and becomes a PR's target_branch when the
     // PR omits one, which is interpolated into a git revision argument. Validate
@@ -3774,15 +3799,7 @@ pub async fn fork_repo(
     let fork_name = req.name.unwrap_or_else(|| source.name.clone());
     let forker_did = auth.0;
 
-    // Validate fork name
-    if !fork_name
-        .chars()
-        .all(|c| c.is_alphanumeric() || c == '-' || c == '_')
-    {
-        return Err(AppError::BadRequest(
-            "repo name must contain only alphanumeric characters, hyphens, and underscores".into(),
-        ));
-    }
+    validate_repo_name(&fork_name)?;
 
     // Same barrier every other repo-creation route goes through. The character
     // allowlist above is vacuously true on an empty name, and `repo_disk_path`
@@ -5049,6 +5066,50 @@ mod tests {
         peer_mock.assert_async().await;
     }
 
+    #[test]
+    fn repo_name_validation_rejects_bad_charset_and_overlong_names() {
+        assert!(validate_repo_name("ok-name_123").is_ok());
+        assert!(validate_repo_name(&"a".repeat(crate::db::MAX_REPO_NAME_LEN)).is_ok());
+        // The bound is in bytes: the cursor budget is measured in bytes.
+        let overlong = "a".repeat(crate::db::MAX_REPO_NAME_LEN + 1);
+        let err = validate_repo_name(&overlong).unwrap_err();
+        assert!(
+            matches!(err, AppError::BadRequest(_)),
+            "overlong name must be a 400, got: {err:?}"
+        );
+        assert!(validate_repo_name("bad name!").is_err());
+        // Empty names were already admissible before the length bound; the
+        // bound does not change that.
+        assert!(validate_repo_name("").is_ok());
+    }
+
+    #[tokio::test]
+    async fn create_repo_rejects_overlong_name_through_handler() {
+        // Pins the wiring: `create_repo` must call `validate_repo_name`
+        // before any database access. The lazy state never connects, so
+        // deleting the call site would let the handler proceed to `get_repo`
+        // and fail with a connection error instead of BadRequest.
+        let state = crate::test_support::test_state_lazy();
+        let overlong = "a".repeat(crate::db::MAX_REPO_NAME_LEN + 1);
+        let err = create_repo(
+            State(state),
+            Extension(AuthenticatedDid(OWNER_DID.to_owned())),
+            axum::http::HeaderMap::new(),
+            Json(CreateRepoRequest {
+                name: overlong,
+                description: None,
+                is_public: true,
+                default_branch: "main".into(),
+            }),
+        )
+        .await
+        .unwrap_err();
+        assert!(
+            matches!(err, AppError::BadRequest(ref msg) if msg.contains("at most")),
+            "overlong name through create_repo must be a 400, got: {err:?}"
+        );
+    }
+
     #[test]
     fn upload_pack_request_finalizes_only_with_done_pktline() {
         let want = "0032want 1111111111111111111111111111111111111111\n";
@@ -9179,6 +9240,7 @@ mod tests {
     /// A pkt-line receive-pack body carrying one branch-create ref update, so the
     /// handler's post-receive tail resolves a non-empty new-tip set (the delta
     /// scan's git stages run).
+    #[cfg(unix)]
     fn ref_update_body(new_sha: &str) -> axum::body::Bytes {
         let line = format!("{ZERO_SHA} {new_sha} refs/heads/main");
         axum::body::Bytes::from(format!("{:04x}{}0000", line.len() + 4, line))
@@ -11636,6 +11698,7 @@ mod tests {
         )
     }
 
+    #[cfg(unix)]
     fn f2a_log(log: &std::path::Path) -> String {
         std::fs::read_to_string(log).unwrap_or_default()
     }
@@ -11643,6 +11706,7 @@ mod tests {
     /// Withheld-walk children run so far. `ls-tree` is the walk's signature child
     /// (`blob_paths` lists every reachable commit's tree); the delta scan and the
     /// full-scan fallback use `rev-list` / `cat-file` instead.
+    #[cfg(unix)]
     fn f2a_walks(log: &std::path::Path) -> usize {
         f2a_log(log)
             .lines()
@@ -11654,6 +11718,7 @@ mod tests {
     /// the withheld walk actually runs rather than taking the no-rule shortcut).
     /// The repo's on-disk path is passed to the tail directly, so no repo_store or
     /// receive-pack plumbing is involved.
+    #[cfg(unix)]
     async fn f2a_state(
         pool: sqlx::PgPool,
         git_bin: &str,
@@ -11685,6 +11750,7 @@ mod tests {
         (state, rec)
     }
 
+    #[cfg(unix)]
     fn f2a_update(ref_name: &str, new_sha: &str) -> Vec<RefUpdate> {
         vec![RefUpdate {
             old_sha: ZERO_SHA.to_string(),
@@ -11693,6 +11759,7 @@ mod tests {
         }]
     }
 
+    #[cfg(unix)]
     const F2A_PUSHER: &str = "did:key:z6MkF2aPusherAAAAAAAAAAAAAAAAAAAAAAAAAA";
 
     /// When publish durability is fenced, the tail must not run walks or take
@@ -11805,6 +11872,7 @@ mod tests {
     }
     /// Poll `cond` until it holds, with a bound so a regression fails the test
     /// rather than hanging the suite.
+    #[cfg(unix)]
     async fn f2a_wait_for(mut cond: impl FnMut() -> bool, what: &str) {
         let deadline = std::time::Instant::now() + std::time::Duration::from_secs(20);
         while !cond() {
@@ -11819,6 +11887,7 @@ mod tests {
     /// A `rev-list --objects` line names the tips a DELTA scan was asked to resolve,
     /// so it attributes that scan to one push's tips. The withheld walk's own
     /// `rev-list --all` / `ls-tree` lines never carry a tip as an argument this way.
+    #[cfg(unix)]
     fn f2a_delta_scanned(log: &std::path::Path, tip: &str) -> bool {
         f2a_log(log)
             .lines()
@@ -11967,6 +12036,7 @@ mod tests {
 
     /// Mount a Pinata upload endpoint that assigns every object the same CID, and
     /// point the state at it. Returns the server (kept alive by the caller) and CID.
+    #[cfg(unix)]
     async fn f2a_pinata(state: &mut AppState) -> (mockito::ServerGuard, String) {
         let cid = "bafyf2acoalescedmapping".to_string();
         let mut server = mockito::Server::new_async().await;
@@ -11986,6 +12056,7 @@ mod tests {
 
     /// Poll the branch to CID table until the push's mapping lands (the Pinata
     /// worker is detached), bounded so a regression fails rather than hangs.
+    #[cfg(unix)]
     async fn f2a_wait_for_branch_cid(
         db: &crate::db::Db,
         slug: &str,
@@ -12005,6 +12076,7 @@ mod tests {
         }
     }
 
+    #[cfg(unix)]
     fn f2a_slug(rec: &crate::db::RepoRecord) -> String {
         format!(
             "{}/{}",
@@ -12139,6 +12211,7 @@ mod tests {
     // and `z6p2fail`), and owner-only push is on by default, so the identity has to
     // follow the repo each push targets rather than being fixed for both.
 
+    #[cfg(unix)]
     fn p2_push(
         state: &AppState,
         owner: &str,
@@ -12157,6 +12230,7 @@ mod tests {
         )
     }
 
+    #[cfg(unix)]
     fn p2_logged(log: &std::path::Path, prefix: &str) -> bool {
         f2a_log(log).lines().any(|l| l.starts_with(prefix))
     }
@@ -13152,6 +13226,7 @@ exit 0
     /// runs exactly one `rev-list --all`, so this counts the walks that were attempted
     /// (the `ls-tree` counter above cannot: a walk whose enumeration fails never gets
     /// to `ls-tree`).
+    #[cfg(unix)]
     fn f2b_walk_attempts(log: &std::path::Path) -> usize {
         f2a_log(log)
             .lines()

crates/gitlawb-node/src/db/mod.rs

@@ -6,6 +6,20 @@ use std::time::Duration;
 use tracing::info;
 use uuid::Uuid;
 
+/// Maximum visible repositories per page, plus one internal look-ahead row.
+pub(crate) const MAX_VISIBLE_REPO_PAGE_SIZE: usize = 200;
+
+/// Maximum repository name length in bytes. `repo_cursor` embeds the name in
+/// a base64(JSON) cursor that `parse_repo_cursor` rejects over 4096 bytes, so
+/// every write path must bound the name: a cursor the server emits must
+/// always parse back (#465 4th round). 100 bytes keeps the longest possible
+/// cursor an order of magnitude under the parse limit.
+pub(crate) const MAX_REPO_NAME_LEN: usize = 100;
+
+/// Maximum agent tasks returned per query. Shared by the GraphQL `tasks`
+/// complexity meter and the resolver clamp so they can't drift.
+pub(crate) const MAX_VISIBLE_TASK_PAGE_SIZE: i64 = 200;
+
 // ── Public data types ─────────────────────────────────────────────────────────
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
@@ -405,6 +419,17 @@ impl Db {
         Self { pool }
     }
 
+    /// Test-only: access the underlying Postgres connection pool.
+    ///
+    /// The production accessor was removed on main (ed76adf) once every
+    /// production caller had migrated to typed `Db` methods; this restores
+    /// it for tests only, for the raw-SQL fixtures and closed-pool cases in
+    /// this change that have no typed equivalent.
+    #[cfg(test)]
+    pub fn pool(&self) -> &PgPool {
+        &self.pool
+    }
+
     /// Test-only: apply the full schema to a fresh pool. `#[sqlx::test]`
     /// provisions an empty per-test database, so DB-backed tests must run this
     /// before seeding. Reuses the production `migrate()` path (the advisory lock
@@ -1594,6 +1619,16 @@ impl Db {
         machine_id: Option<&str>,
         quarantined: bool,
     ) -> Result<()> {
+        // Peer-supplied names are bound like the local write paths: an
+        // unbounded name would make reposPage emit a cursor longer than the
+        // 4096-byte parse limit, dead-ending pagination for every caller past
+        // that row (#465 4th round). The sync caller drops the error and skips
+        // the mirror.
+        if name.len() > MAX_REPO_NAME_LEN {
+            anyhow::bail!(
+                "mirror repo name exceeds {MAX_REPO_NAME_LEN} bytes: refusing to register"
+            );
+        }
         let now = Utc::now().to_rfc3339();
         let id = format!("{owner_short}/{name}");
         // `quarantined` is set only on first insert (the admission decision).
@@ -1885,6 +1920,73 @@ impl Db {
         Ok(rows.into_iter().map(row_to_repo).collect())
     }
 
+    /// A bounded, mirror-deduplicated page ordered by owner key and repository
+    /// name. Apply root visibility before LIMIT: private rows must not consume
+    /// page slots or influence continuation metadata. The root-rule predicate
+    /// mirrors `visibility::listable_at_root`; a differential test pins it.
+    /// Malformed reader JSON denies that repo to non-owners without failing the page.
+    /// Cursors only select a position and never confer read authority.
+    ///
+    /// Performance note: the page orders and keyset-filters on
+    /// `(owner_key, name)` under `COLLATE "C"`, but the existing
+    /// `idx_repos_owner_key_name` index is built on the database default
+    /// collation and cannot serve that ordering, so each page sorts the full
+    /// deduped repo set before the keyset filter applies: O(total repos) work
+    /// per page. This is accepted (pages are capped at
+    /// `MAX_VISIBLE_REPO_PAGE_SIZE` rows over a narrow projection). A
+    /// C-collation expression index was deliberately not added in a migration:
+    /// versions 27-35 are claimed by other in-flight branches (Gitlawb/node#384
+    /// claims 27-35, #464 claims 27-28) and the runner keys applied migrations
+    /// on the version integer alone, so a colliding entry would be silently
+    /// skipped on whichever side merges second. Revisit once that range lands
+    /// or clears.
+    pub async fn list_visible_repos_page(
+        &self,
+        caller: Option<&str>,
+        after: Option<(&str, &str)>,
+        limit: usize,
+    ) -> Result<Vec<RepoRecord>> {
+        let sql = format!(
+            "{}
+             SELECT d.id, d.name, d.owner_did, d.description, d.is_public,
+                 d.default_branch, d.created_at, d.updated_at, d.disk_path,
+                 d.forked_from, d.machine_id
+             FROM deduped d
+             LEFT JOIN LATERAL (
+                 SELECT reader_dids FROM visibility_rules v
+                 WHERE v.repo_id = d.id AND v.path_glob ~ '^/*([*][*])*$'
+                 ORDER BY v.path_glob DESC LIMIT 1
+             ) root_rule ON TRUE
+             WHERE (
+                 ($2::text IS NOT NULL AND ({key}) = $2)
+                 OR CASE WHEN root_rule.reader_dids IS NULL THEN d.is_public
+                    WHEN NOT pg_input_is_valid(root_rule.reader_dids, 'jsonb') THEN FALSE
+                    WHEN jsonb_typeof(root_rule.reader_dids::jsonb) = 'array' THEN
+                        COALESCE(root_rule.reader_dids::jsonb ? $3::text, FALSE)
+                        AND NOT EXISTS (
+                            SELECT 1 FROM jsonb_array_elements(root_rule.reader_dids::jsonb) reader
+                            WHERE jsonb_typeof(reader) <> 'string'
+                        )
+                    ELSE FALSE END
+             )
+             AND ($4::text IS NULL OR (({key}) COLLATE \"C\", d.name COLLATE \"C\") > ($4, $5::text))
+             ORDER BY ({key}) COLLATE \"C\", d.name COLLATE \"C\"
+             LIMIT $6",
+            Self::dedup_cte(),
+            key = OWNER_KEY_CASE_SQL,
+        );
+        let rows = sqlx::query(&sql)
+            .bind(None::<&str>)
+            .bind(caller.map(normalize_owner_key))
+            .bind(caller)
+            .bind(after.map(|(owner, _)| normalize_owner_key(owner)))
+            .bind(after.map(|(_, name)| name))
+            .bind(limit.min(MAX_VISIBLE_REPO_PAGE_SIZE + 1) as i64)
+            .fetch_all(&self.pool)
+            .await?;
+        Ok(rows.into_iter().map(row_to_repo).collect())
+    }
+
     /// Repos currently quarantined (admitted as mirrors but withheld from every
     /// listing surface). `list_all_repos_deduped` excludes these (its `DEDUP_CTE`
     /// filters `quarantined = FALSE`), so a gate that resolves a slug against the

crates/gitlawb-node/src/git/repo_store.rs

@@ -118,7 +118,7 @@ impl RepoStore {
     /// Test-only: every guard from this store parks in `release` right before the
     /// `pg_advisory_unlock` await, until `gate` is notified. Dropping the future
     /// while it is parked reproduces a client disconnect inside `release`.
-    #[cfg(test)]
+    #[cfg(all(test, unix))]
     pub fn with_pre_unlock_gate(mut self, gate: Arc<tokio::sync::Notify>) -> Self {
         self.pre_unlock_gate = Some(gate);
         self
@@ -126,7 +126,7 @@ impl RepoStore {
 
     /// Test-only: how many write guards from this store have reached the Tigris upload
     /// site. See [`RepoWriteGuard::release`].
-    #[cfg(test)]
+    #[cfg(all(test, unix))]
     pub fn tigris_upload_site_reached(&self) -> usize {
         self.upload_site_reached
             .load(std::sync::atomic::Ordering::SeqCst)
@@ -1717,8 +1717,11 @@ fn validate_repo_name(repo_name: &str) -> Result<()> {
     if repo_name.is_empty() {
         anyhow::bail!("repo_name is empty");
     }
-    if repo_name.len() > 100 {
-        anyhow::bail!("repo_name exceeds 100 chars");
+    // Byte bound shared with the API-side validator via `MAX_REPO_NAME_LEN`:
+    // the two validators differ on charset by design, but must not drift on
+    // length, or an API-admitted name fails here after the proof is spent.
+    if repo_name.len() > crate::db::MAX_REPO_NAME_LEN {
+        anyhow::bail!("repo_name exceeds {} chars", crate::db::MAX_REPO_NAME_LEN);
     }
     // Repo names are `[A-Za-z0-9._-]+` minus path-traversal traps.
     if repo_name.contains("..") {

crates/gitlawb-node/src/graphql/mod.rs

@@ -3,7 +3,7 @@ pub mod query;
 pub mod subscription;
 pub mod types;
 
-use async_graphql::Schema;
+use async_graphql::{Schema, SchemaBuilder};
 use std::sync::Arc;
 
 use crate::db::Db;
@@ -14,6 +14,22 @@ use subscription::SubscriptionRoot;
 
 pub type GitlawbSchema = Schema<QueryRoot, MutationRoot, SubscriptionRoot>;
 
+// Keep ordinary schema discovery and application queries usable while
+// bounding validation work and the number of resolver selections per request.
+const GRAPHQL_MAX_COMPLEXITY: usize = 400;
+// The current public schema is shallow; this leaves headroom for composed
+// clients and the canonical getIntrospectionQuery without allowing
+// recursively nested documents to grow unchecked.
+const GRAPHQL_MAX_DEPTH: usize = 14;
+
+fn apply_query_limits<Query, Mutation, Subscription>(
+    builder: SchemaBuilder<Query, Mutation, Subscription>,
+) -> SchemaBuilder<Query, Mutation, Subscription> {
+    builder
+        .limit_complexity(GRAPHQL_MAX_COMPLEXITY)
+        .limit_depth(GRAPHQL_MAX_DEPTH)
+}
+
 /// Client-facing message for GraphQL resolver failures that wrap a real
 /// `sqlx::Error`. The real error is logged server-side; never put sqlx/Postgres
 /// detail in the GraphQL `errors` array (#250).
@@ -81,7 +97,7 @@ pub fn build_schema(
     ref_update_tx: tokio::sync::broadcast::Sender<RefUpdateBroadcast>,
     task_event_tx: tokio::sync::broadcast::Sender<TaskEventBroadcast>,
 ) -> GitlawbSchema {
-    Schema::build(QueryRoot, MutationRoot, SubscriptionRoot)
+    apply_query_limits(Schema::build(QueryRoot, MutationRoot, SubscriptionRoot))
         .data(db)
         .data(ref_update_tx)
         .data(task_event_tx)
@@ -91,6 +107,10 @@ pub fn build_schema(
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::api::events::MAX_VISIBLE_REF_UPDATES;
+    use crate::db::{MAX_VISIBLE_REPO_PAGE_SIZE, MAX_VISIBLE_TASK_PAGE_SIZE};
+    use async_graphql::{EmptyMutation, EmptySubscription, Object, Value};
+    use std::sync::atomic::{AtomicUsize, Ordering};
 
     #[test]
     fn graphql_db_err_opaques_sqlx_chain() {
@@ -160,6 +180,668 @@ mod tests {
         assert!(!err.message.contains("failed to open"));
     }
 
+    fn production_test_schema() -> GitlawbSchema {
+        let pool = sqlx::postgres::PgPoolOptions::new()
+            .connect_lazy("postgres://localhost/unused")
+            .unwrap();
+        production_test_schema_with_db(Arc::new(Db::for_testing(pool)))
+    }
+
+    fn production_test_schema_with_db(db: Arc<Db>) -> GitlawbSchema {
+        build_schema(
+            db,
+            tokio::sync::broadcast::channel(1).0,
+            tokio::sync::broadcast::channel(1).0,
+        )
+    }
+
+    #[tokio::test]
+    async fn ref_update_subscription_alias_budget() {
+        assert_subscription_alias_budget("refUpdates { repo }").await;
+    }
+
+    #[tokio::test]
+    async fn task_event_subscription_alias_budget() {
+        assert_subscription_alias_budget("taskEvents { taskId }").await;
+    }
+
+    async fn assert_subscription_alias_budget(field: &str) {
+        use futures::StreamExt;
+        use std::time::Duration;
+        let pool = sqlx::postgres::PgPoolOptions::new()
+            .connect_lazy("postgres://localhost/unused")
+            .unwrap();
+        let (ref_tx, _) = tokio::sync::broadcast::channel(16);
+        let (task_tx, _) = tokio::sync::broadcast::channel(16);
+        let schema = build_schema(
+            Arc::new(Db::for_testing(pool)),
+            ref_tx.clone(),
+            task_tx.clone(),
+        );
+        for count in [7, 8] {
+            let fields = (0..count)
+                .map(|n| format!("r{n}: {field}"))
+                .collect::<Vec<_>>()
+                .join(" ");
+            let query = format!("subscription {{ {fields} }}");
+            let mut responses = Box::pin(schema.execute_stream(query));
+            if count == 8 {
+                let response = tokio::time::timeout(Duration::from_secs(1), responses.next())
+                    .await
+                    .expect("over-budget subscriptions must reject before waiting for events")
+                    .expect("the validation error must be returned");
+                assert_eq!(response.errors.len(), 1);
+                assert_eq!(response.errors[0].message, "Query is too complex.");
+                assert_eq!(ref_tx.receiver_count() + task_tx.receiver_count(), 0);
+                continue;
+            }
+            // Poll the accepted operation far enough to register its receivers.
+            assert!(
+                tokio::time::timeout(Duration::from_millis(30), responses.next())
+                    .await
+                    .is_err()
+            );
+            assert_eq!(ref_tx.receiver_count() + task_tx.receiver_count(), 7);
+            let _ = ref_tx.send(RefUpdateBroadcast {
+                repo: "owner/repo".into(),
+                ref_name: "refs/heads/main".into(),
+                old_sha: "0".repeat(40),
+                new_sha: "1".repeat(40),
+                pusher_did: "did:key:test".into(),
+                node_did: "did:key:node".into(),
+                timestamp: "2026-01-01T00:00:00Z".into(),
+                owner_did: "did:key:test".into(),
+            });
+            let _ = task_tx.send(TaskEventBroadcast {
+                task_id: "task".into(),
+                old_status: "pending".into(),
+                new_status: "claimed".into(),
+                by_did: "did:key:test".into(),
+                at: "2026-01-01T00:00:00Z".into(),
+            });
+            let response = tokio::time::timeout(Duration::from_secs(1), responses.next())
+                .await
+                .unwrap()
+                .unwrap();
+            assert!(response.errors.is_empty(), "{:?}", response.errors);
+            assert_ne!(response.data, Value::Null);
+            drop(responses);
+            assert_eq!(ref_tx.receiver_count() + task_tx.receiver_count(), 0);
+        }
+    }
+
+    #[sqlx::test]
+    async fn production_mutation_budget_accepts_seven_and_rejects_eight(pool: sqlx::PgPool) {
+        let db = Arc::new(Db::for_testing(pool));
+        db.run_migrations().await.unwrap();
+        let caller = "did:key:reviewer";
+        let now = chrono::Utc::now().to_rfc3339();
+        for index in 0..8 {
+            db.create_task(&crate::db::AgentTask {
+                id: format!("task-{index}"),
+                repo_id: None,
+                kind: "test".into(),
+                status: "pending".into(),
+                delegator_did: caller.into(),
+                assignee_did: None,
+                capability: "test".into(),
+                ucan_token: None,
+                payload: None,
+                result: None,
+                created_at: now.clone(),
+                updated_at: now.clone(),
+                deadline: None,
+            })
+            .await
+            .unwrap();
+        }
+        let schema = production_test_schema_with_db(db.clone());
+        for count in [8, 7] {
+            let fields = (0..count)
+                .map(|n| {
+                    format!("r{n}: claimTask(id: \"task-{n}\", assigneeDid: \"{caller}\") {{ id }}")
+                })
+                .collect::<Vec<_>>()
+                .join(" ");
+            let response = schema
+                .execute(
+                    async_graphql::Request::new(format!("mutation {{ {fields} }}"))
+                        .data(crate::auth::AuthenticatedDid(caller.into())),
+                )
+                .await;
+            if count == 8 {
+                assert_eq!(response.errors.len(), 1);
+                assert_eq!(response.errors[0].message, "Query is too complex.");
+                assert_eq!(
+                    db.list_tasks(Some("pending"), None, 8).await.unwrap().len(),
+                    8
+                );
+                continue;
+            }
+            assert!(response.errors.is_empty(), "{:?}", response.errors);
+            assert_eq!(
+                response
+                    .data
+                    .into_json()
+                    .unwrap()
+                    .as_object()
+                    .unwrap()
+                    .len(),
+                7
+            );
+            assert_eq!(
+                db.list_tasks(Some("claimed"), Some(caller), 8)
+                    .await
+                    .unwrap()
+                    .len(),
+                7
+            );
+            assert_eq!(
+                db.get_task("task-7").await.unwrap().unwrap().status,
+                "pending"
+            );
+        }
+    }
+
+    #[sqlx::test]
+    async fn production_list_cost_scales_with_the_same_alias_count(pool: sqlx::PgPool) {
+        let db = Arc::new(Db::for_testing(pool));
+        db.run_migrations().await.unwrap();
+        let schema = production_test_schema_with_db(db);
+        // Bounds are per-root named constants so the cases move with the
+        // documented maximums instead of going stale as literals.
+        for (field, selection, max) in [
+            ("refUpdates", "repo", MAX_VISIBLE_REF_UPDATES),
+            ("tasks", "id", MAX_VISIBLE_TASK_PAGE_SIZE),
+            (
+                "reposPage",
+                "nodes { name }",
+                MAX_VISIBLE_REPO_PAGE_SIZE as i64,
+            ),
+        ] {
+            // Two aliases at the maximum always exceed the budget.
+            let fields = (0..2)
+                .map(|n| format!("r{n}: {field}(limit: {max}) {{ {selection} }}"))
+                .collect::<Vec<_>>()
+                .join(" ");
+            let response = schema.execute(format!("{{ {fields} }}")).await;
+            assert_eq!(response.errors.len(), 1);
+            assert_eq!(response.errors[0].message, "Query is too complex.");
+
+            // At limit 1 two aliases fit for the row-priced roots; reposPage
+            // prices the full corpus scan, so a single alias is the most that
+            // fits under the budget.
+            let aliases = if field == "reposPage" { 1 } else { 2 };
+            let fields = (0..aliases)
+                .map(|n| format!("r{n}: {field}(limit: 1) {{ {selection} }}"))
+                .collect::<Vec<_>>()
+                .join(" ");
+            let response = schema.execute(format!("{{ {fields} }}")).await;
+            assert!(response.errors.is_empty(), "{field}: {:?}", response.errors);
+            assert_eq!(
+                response
+                    .data
+                    .into_json()
+                    .unwrap()
+                    .as_object()
+                    .unwrap()
+                    .len(),
+                aliases
+            );
+        }
+    }
+
+    #[tokio::test]
+    async fn production_limits_reject_mutation_aliases_and_large_lists() {
+        let schema = production_test_schema();
+        // Limits are derived from the MAX_* constants so the boundaries move
+        // with the documented maximums instead of going stale as literals.
+        for (prefix, count, field) in [
+            ("mutation", 8, "claimTask(id: \"missing\", assigneeDid: \"did:key:test\") { id }".to_owned()),
+            ("mutation", 8, "createTask(delegatorDid: \"did:key:test\", input: { kind: \"test\", capability: \"test\" }) { id }".to_owned()),
+            ("mutation", 8, "completeTask(id: \"missing\", byDid: \"did:key:test\", input: {}) { id }".to_owned()),
+            ("mutation", 8, "failTask(id: \"missing\", byDid: \"did:key:test\", input: {}) { id }".to_owned()),
+            ("query", 8, "task(id: \"missing\") { id }".to_owned()),
+            ("query", 2, format!("refUpdates(limit: {MAX_VISIBLE_REF_UPDATES}) {{ repo }}")),
+            ("query", 2, format!("tasks(limit: {MAX_VISIBLE_TASK_PAGE_SIZE}) {{ id }}")),
+            ("query", 2, format!("reposPage(limit: {MAX_VISIBLE_REPO_PAGE_SIZE}) {{ nodes {{ name }} }}")),
+            ("query", 8, "reposPage(limit: 1) { nodes { name } }".to_owned()),
+        ] {
+            let fields = (0..count)
+                .map(|n| format!("r{n}: {field}"))
+                .collect::<Vec<_>>()
+                .join(" ");
+            let response = schema.execute(format!("{prefix} {{ {fields} }}")).await;
+            assert_eq!(response.errors.len(), 1, "{:?}", response.errors);
+            assert_eq!(response.errors[0].message, "Query is too complex.");
+        }
+    }
+
+    #[sqlx::test]
+    async fn production_repos_page_serves_the_documented_maximum(pool: sqlx::PgPool) {
+        let db = Arc::new(Db::for_testing(pool));
+        db.run_migrations().await.unwrap();
+        let schema = production_test_schema_with_db(db);
+        for selection in [
+            "nodes { name }",
+            "nodes { name ownerDid } hasNextPage endCursor",
+        ] {
+            let response = schema
+                .execute(format!(
+                    "{{ reposPage(limit: {MAX_VISIBLE_REPO_PAGE_SIZE}) {{ {selection} }} }}"
+                ))
+                .await;
+            assert!(response.errors.is_empty(), "{:?}", response.errors);
+            assert_eq!(
+                response.data.into_json().unwrap()["reposPage"]["nodes"],
+                serde_json::json!([])
+            );
+        }
+    }
+
+    #[tokio::test]
+    async fn seven_root_aliases_are_accepted() {
+        struct Root(Arc<AtomicUsize>);
+        #[Object]
+        impl Root {
+            #[graphql(complexity = "50 + child_complexity")]
+            async fn repos(&self) -> Vec<Nested> {
+                self.0.fetch_add(1, Ordering::Relaxed);
+                vec![Nested]
+            }
+        }
+        let calls = Arc::new(AtomicUsize::new(0));
+        let schema = apply_query_limits(Schema::build(
+            Root(calls.clone()),
+            EmptyMutation,
+            EmptySubscription,
+        ))
+        .finish();
+        let fields = (0..7)
+            .map(|n| format!("r{n}: repos {{ value }}"))
+            .collect::<Vec<_>>()
+            .join(" ");
+        let response = schema.execute(format!("{{ {fields} }}")).await;
+        assert!(response.errors.is_empty(), "{:?}", response.errors);
+        assert_eq!(calls.load(Ordering::Relaxed), 7);
+    }
+
+    #[tokio::test]
+    async fn expensive_root_aliases_are_rejected_before_database_access() {
+        // Use the production builder with a lazy pool: rejection must precede DB access.
+        let schema = production_test_schema();
+        let fields = (0..8)
+            .map(|n| format!("r{n}: repos {{ name }}"))
+            .collect::<Vec<_>>()
+            .join(" ");
+
+        let response = schema.execute(format!("{{ {fields} }}")).await;
+
+        assert_eq!(response.data, Value::Null);
+        assert_eq!(response.errors.len(), 1);
+        assert_eq!(response.errors[0].message, "Query is too complex.");
+    }
+
+    #[tokio::test]
+    async fn ordinary_schema_introspection_remains_available() {
+        let schema = production_test_schema();
+        let canonical_introspection = r#"
+            query IntrospectionQuery {
+              __schema {
+                queryType { name }
+                mutationType { name }
+                subscriptionType { name }
+                types {
+                  ...FullType
+                }
+                directives {
+                  name
+                  description
+                  locations
+                  args {
+                    ...InputValue
+                  }
+                }
+              }
+            }
+
+            fragment FullType on __Type {
+              kind
+              name
+              description
+              fields(includeDeprecated: true) {
+                name
+                description
+                args {
+                  ...InputValue
+                }
+                type {
+                  ...TypeRef
+                }
+                isDeprecated
+                deprecationReason
+              }
+              inputFields {
+                ...InputValue
+              }
+              interfaces {
+                ...TypeRef
+              }
+              enumValues(includeDeprecated: true) {
+                name
+                description
+                isDeprecated
+                deprecationReason
+              }
+              possibleTypes {
+                ...TypeRef
+              }
+            }
+
+            fragment InputValue on __InputValue {
+              name
+              description
+              type { ...TypeRef }
+              defaultValue
+            }
+
+            fragment TypeRef on __Type {
+              kind
+              name
+              ofType {
+                kind
+                name
+                ofType {
+                  kind
+                  name
+                  ofType {
+                    kind
+                    name
+                    ofType {
+                      kind
+                      name
+                      ofType {
+                        kind
+                        name
+                        ofType {
+                          kind
+                          name
+                          ofType {
+                            kind
+                            name
+                          }
+                        }
+                      }
+                    }
+                  }
+                }
+              }
+            }
+        "#;
+        let response = schema.execute(canonical_introspection).await;
+        assert!(
+            response.errors.is_empty(),
+            "canonical introspection query failed against production schema: {:?}",
+            response.errors
+        );
+        assert_ne!(response.data, Value::Null);
+    }
+
+    #[tokio::test]
+    async fn ref_updates_and_tasks_single_alias_max_limit_complexity_contract() {
+        let pool = sqlx::postgres::PgPoolOptions::new()
+            .connect_lazy("postgres://localhost/unused")
+            .unwrap();
+        pool.close().await;
+        let (ref_tx, _) = tokio::sync::broadcast::channel(16);
+        let (task_tx, _) = tokio::sync::broadcast::channel(16);
+        let schema = build_schema(Arc::new(Db::for_testing(pool)), ref_tx, task_tx);
+
+        // refUpdates(limit: MAX_VISIBLE_REF_UPDATES):
+        // Single-field selection has child_complexity 1 -> cost 100 + 200 + 1 = 301 <= 400.
+        // It passes validation and reaches the resolver (which yields db error on lazy pool).
+        let single_ref = schema
+            .execute(format!(
+                "{{ refUpdates(limit: {MAX_VISIBLE_REF_UPDATES}) {{ repo }} }}"
+            ))
+            .await;
+        assert!(
+            !single_ref
+                .errors
+                .iter()
+                .any(|e| e.message == "Query is too complex."),
+            "single-field refUpdates at max limit must pass complexity validation: {:?}",
+            single_ref.errors
+        );
+        assert!(
+            single_ref
+                .errors
+                .iter()
+                .any(|e| e.message == GRAPHQL_DB_ERROR_MESSAGE),
+            "single-field refUpdates at max limit must reach the resolver: {:?}",
+            single_ref.errors
+        );
+
+        // Two-field selection has child_complexity 2 -> cost 100 + 200 + 2 = 302 <= 400.
+        // The documented max-200 request stays reachable with multiple fields
+        // (the old multiplicative price rejected it at 450); it passes
+        // validation and reaches the resolver like the single-field case.
+        let multi_ref = schema
+            .execute(format!(
+                "{{ refUpdates(limit: {MAX_VISIBLE_REF_UPDATES}) {{ repo refName }} }}"
+            ))
+            .await;
+        assert!(
+            !multi_ref
+                .errors
+                .iter()
+                .any(|e| e.message == "Query is too complex."),
+            "two-field refUpdates at max limit must pass complexity validation: {:?}",
+            multi_ref.errors
+        );
+        assert!(
+            multi_ref
+                .errors
+                .iter()
+                .any(|e| e.message == GRAPHQL_DB_ERROR_MESSAGE),
+            "two-field refUpdates at max limit must reach the resolver: {:?}",
+            multi_ref.errors
+        );
+
+        // tasks(limit: MAX_VISIBLE_TASK_PAGE_SIZE):
+        // Single-field selection has child_complexity 1, so the cost is
+        // 50 + MAX_VISIBLE_TASK_PAGE_SIZE + 1 <= 400.
+        // It passes validation and reaches the resolver.
+        let single_task = schema
+            .execute(format!(
+                "{{ tasks(limit: {MAX_VISIBLE_TASK_PAGE_SIZE}) {{ id }} }}"
+            ))
+            .await;
+        assert!(
+            !single_task
+                .errors
+                .iter()
+                .any(|e| e.message == "Query is too complex."),
+            "single-field tasks at the maximum page size must pass complexity validation: {:?}",
+            single_task.errors
+        );
+        assert!(
+            single_task
+                .errors
+                .iter()
+                .any(|e| e.message == GRAPHQL_DB_ERROR_MESSAGE),
+            "single-field tasks at the maximum page size must reach the resolver: {:?}",
+            single_task.errors
+        );
+
+        // Two-field selection has child_complexity 2, so the cost is
+        // 50 + MAX_VISIBLE_TASK_PAGE_SIZE + 2 <= 400.
+        // A request at the documented maximum stays reachable with multiple
+        // fields (the old multiplicative price rejected it at 450); it passes
+        // validation and reaches the resolver like the single-field case.
+        let multi_task = schema
+            .execute(format!(
+                "{{ tasks(limit: {MAX_VISIBLE_TASK_PAGE_SIZE}) {{ id status }} }}"
+            ))
+            .await;
+        assert!(
+            !multi_task
+                .errors
+                .iter()
+                .any(|e| e.message == "Query is too complex."),
+            "two-field tasks at the maximum page size must pass complexity validation: {:?}",
+            multi_task.errors
+        );
+        assert!(
+            multi_task
+                .errors
+                .iter()
+                .any(|e| e.message == GRAPHQL_DB_ERROR_MESSAGE),
+            "two-field tasks at the maximum page size must reach the resolver: {:?}",
+            multi_task.errors
+        );
+    }
+
+    #[tokio::test]
+    async fn two_repos_aliases_exceed_the_budget() {
+        // `repos` is priced as the full page it scans
+        // (50 + MAX_VISIBLE_REPO_PAGE_SIZE + child), so two `repos { name }`
+        // aliases cost 2 * 251 = 502 > 400 and the document is rejected before
+        // any resolver runs. If the price reverts to `50 + child_complexity`
+        // the aliases cost 2 * 51 = 102, validation passes, and the failure
+        // mode changes (resolver DB errors on the lazy pool): this test goes
+        // red on revert.
+        let schema = production_test_schema();
+        let response = schema
+            .execute("{ r0: repos { name } r1: repos { name } }")
+            .await;
+        assert_eq!(response.errors.len(), 1, "{:?}", response.errors);
+        assert_eq!(response.errors[0].message, "Query is too complex.");
+    }
+
+    #[tokio::test]
+    async fn seven_repos_page_aliases_exceed_the_budget() {
+        // `reposPage` is priced as the full corpus scan
+        // (50 + MAX_VISIBLE_REPO_PAGE_SIZE + child_complexity), so seven
+        // `reposPage(limit: 1) { nodes { name } }` aliases cost
+        // 7 * (50 + 200 + 2) = 1764 > 400 and the document is rejected
+        // before any resolver runs. Under the previous row-priced formula
+        // the same aliases cost 7 * (50 + 1 + 2) = 371, validation passes,
+        // and the failure mode changes (resolver DB errors on the lazy
+        // pool): this test goes red on revert. Eight aliases are rejected
+        // under both formulas, so seven is the load-bearing boundary.
+        let schema = production_test_schema();
+        let fields = (0..7)
+            .map(|n| format!("r{n}: reposPage(limit: 1) {{ nodes {{ name }} }}"))
+            .collect::<Vec<_>>()
+            .join(" ");
+        let response = schema.execute(format!("{{ {fields} }}")).await;
+        assert_eq!(response.errors.len(), 1, "{:?}", response.errors);
+        assert_eq!(response.errors[0].message, "Query is too complex.");
+    }
+
+    #[tokio::test]
+    async fn ref_updates_fixed_base_is_charged() {
+        // The 100 base in the refUpdates complexity formula charges for the
+        // collector's fixed work (loading the deduped repo set, the
+        // quarantined set, and the visibility rules, then walking up to 16
+        // keyset pages) even at limit: 1. Four aliases at limit: 1 cost
+        // 4 * (100 + 1 + 1) = 408 > 400 and must be rejected. If the base
+        // disappears, the cost drops to 4 * (1 + 1) = 8 and this test fails.
+        let schema = production_test_schema();
+        let fields = (0..4)
+            .map(|n| format!("r{n}: refUpdates(limit: 1) {{ repo }}"))
+            .collect::<Vec<_>>()
+            .join(" ");
+        let response = schema.execute(format!("{{ {fields} }}")).await;
+        assert_eq!(response.errors.len(), 1, "{:?}", response.errors);
+        assert_eq!(response.errors[0].message, "Query is too complex.");
+    }
+
+    #[derive(Clone, Copy)]
+    struct Nested;
+
+    #[Object]
+    impl Nested {
+        async fn child(&self) -> Nested {
+            Nested
+        }
+
+        async fn value(&self) -> i32 {
+            1
+        }
+    }
+
+    struct CountingQuery(Arc<AtomicUsize>);
+
+    #[Object]
+    impl CountingQuery {
+        async fn nested(&self) -> Nested {
+            self.0.fetch_add(1, Ordering::Relaxed);
+            Nested
+        }
+    }
+
+    #[tokio::test]
+    async fn query_depth_limit_accepts_fourteen_and_rejects_fifteen() {
+        let calls = Arc::new(AtomicUsize::new(0));
+        let schema = apply_query_limits(Schema::build(
+            CountingQuery(Arc::clone(&calls)),
+            EmptyMutation,
+            EmptySubscription,
+        ))
+        .finish();
+        let query_at_depth = |depth: usize| {
+            let selection = (2..depth).fold("value".to_string(), |selection, _| {
+                format!("child {{ {selection} }}")
+            });
+            format!("{{ nested {{ {selection} }} }}")
+        };
+
+        let accepted = schema.execute(query_at_depth(GRAPHQL_MAX_DEPTH)).await;
+
+        assert!(
+            accepted.errors.is_empty(),
+            "depth {GRAPHQL_MAX_DEPTH} should be accepted: {:?}",
+            accepted.errors
+        );
+        assert_eq!(calls.swap(0, Ordering::Relaxed), 1);
+
+        let rejected = schema.execute(query_at_depth(GRAPHQL_MAX_DEPTH + 1)).await;
+
+        assert_eq!(rejected.data, Value::Null);
+        assert_eq!(rejected.errors.len(), 1);
+        assert_eq!(rejected.errors[0].message, "Query is nested too deep.");
+        assert_eq!(calls.load(Ordering::Relaxed), 0);
+    }
+
+    #[tokio::test]
+    async fn production_schema_enforces_depth_limit() {
+        let schema = production_test_schema();
+        // Depth 14 is accepted through the production build_schema path.
+        let of_types_14 = (0..9).fold("name".to_string(), |acc, _| format!("ofType {{ {acc} }}"));
+        let query_14 =
+            format!("{{ __schema {{ types {{ fields {{ type {{ {of_types_14} }} }} }} }} }}");
+        let accepted = schema.execute(&query_14).await;
+        assert!(accepted.errors.is_empty(), "{:?}", accepted.errors);
+
+        // Construct an introspection query of depth 15 using __schema.
+        // 1: __schema
+        // 2: types
+        // 3: fields
+        // 4: type
+        // 5..14: ofType (10 times)
+        // 15: name
+        // Total depth = 15 > GRAPHQL_MAX_DEPTH (14).
+        let of_types = (0..10).fold("name".to_string(), |acc, _| format!("ofType {{ {acc} }}"));
+        let query = format!("{{ __schema {{ types {{ fields {{ type {{ {of_types} }} }} }} }} }}");
+
+        let rejected = schema.execute(&query).await;
+        assert_eq!(rejected.data, async_graphql::Value::Null);
+        assert_eq!(rejected.errors.len(), 1);
+        assert_eq!(rejected.errors[0].message, "Query is nested too deep.");
+    }
+
     /// Every `.map_err(` in the GraphQL query/mutation resolvers must route
     /// through the opaque helpers, or discard the error (`|_|`). Same source-
     /// scrape pattern as `api::authz_guard` (#255 review).

crates/gitlawb-node/src/graphql/mutation.rs

@@ -22,6 +22,7 @@ pub struct MutationRoot;
 
 #[Object]
 impl MutationRoot {
+    #[graphql(complexity = "50 + child_complexity")]
     async fn create_task(
         &self,
         ctx: &Context<'_>,
@@ -89,6 +90,7 @@ impl MutationRoot {
         Ok(AgentTaskType::from(stored))
     }
 
+    #[graphql(complexity = "50 + child_complexity")]
     async fn claim_task(
         &self,
         ctx: &Context<'_>,
@@ -126,6 +128,7 @@ impl MutationRoot {
         Ok(AgentTaskType::from(task))
     }
 
+    #[graphql(complexity = "50 + child_complexity")]
     async fn complete_task(
         &self,
         ctx: &Context<'_>,
@@ -177,6 +180,7 @@ impl MutationRoot {
         Ok(AgentTaskType::from(task))
     }
 
+    #[graphql(complexity = "50 + child_complexity")]
     async fn fail_task(
         &self,
         ctx: &Context<'_>,

crates/gitlawb-node/src/graphql/query.rs

@@ -1,57 +1,154 @@
 use async_graphql::{Context, Object, Result};
+use base64::{engine::general_purpose::URL_SAFE_NO_PAD, Engine};
 use std::sync::Arc;
 
-use crate::db::Db;
+use crate::api::events::MAX_VISIBLE_REF_UPDATES;
+use crate::db::{Db, RepoRecord, MAX_VISIBLE_REPO_PAGE_SIZE, MAX_VISIBLE_TASK_PAGE_SIZE};
 
-use super::types::{AgentTaskType, RefUpdateType, RepoType};
+use super::types::{AgentTaskType, RefUpdateType, RepoPageType, RepoType};
+
+fn repo_type(repo: RepoRecord) -> RepoType {
+    RepoType {
+        name: repo.name,
+        owner_did: repo.owner_did,
+        description: repo.description,
+        default_branch: repo.default_branch,
+        created_at: repo.created_at.to_rfc3339(),
+    }
+}
+
+fn repo_cursor(repo: &RepoRecord) -> String {
+    URL_SAFE_NO_PAD.encode(
+        serde_json::to_vec(&(&repo.owner_did, &repo.name))
+            .expect("a pair of strings is JSON serializable"),
+    )
+}
+
+fn parse_repo_cursor(cursor: &str) -> Result<(String, String)> {
+    // A position contains only public response fields, not a database id or
+    // authority. Every page re-evaluates visibility for the current caller.
+    if cursor.len() > 4096 {
+        return Err(async_graphql::Error::new("invalid repository cursor"));
+    }
+    let bytes = URL_SAFE_NO_PAD
+        .decode(cursor)
+        .map_err(|_| async_graphql::Error::new("invalid repository cursor"))?;
+    let position: (String, String) = serde_json::from_slice(&bytes)
+        .map_err(|_| async_graphql::Error::new("invalid repository cursor"))?;
+    // PostgreSQL text cannot contain NUL. Reject it as malformed input before
+    // binding either cursor component, rather than reporting a database error.
+    if position.0.contains('\0') || position.1.contains('\0') {
+        return Err(async_graphql::Error::new("invalid repository cursor"));
+    }
+    Ok(position)
+}
 
 pub struct QueryRoot;
 
 #[Object]
 impl QueryRoot {
+    // DB-backed roots carry a base cost so aliases consume the request budget
+    // even when each alias selects only one inexpensive response field.
+    // `repos` performs the same full corpus scan as a max-size `reposPage`
+    // (list_visible_repos_page with MAX_VISIBLE_REPO_PAGE_SIZE + 1), so it
+    // is priced as the full page it is, not as a cheap alias.
+    #[graphql(complexity = "50 + MAX_VISIBLE_REPO_PAGE_SIZE + child_complexity")]
+    /// Complete visible repository list, up to the documented maximum number
+    /// of entries. Larger lists must use reposPage; this field returns an
+    /// error instead of truncating silently.
     async fn repos(&self, ctx: &Context<'_>) -> Result<Vec<RepoType>> {
         let db = ctx.data_unchecked::<Arc<Db>>();
-        let repos = db
-            .list_all_repos_deduped()
-            .await
-            .map_err(crate::graphql::graphql_db_err)?;
-
-        // Apply the same "/" visibility gate the REST/per-repo endpoints use so
-        // this surface does not enumerate private repos (#97). The caller DID is
-        // threaded onto the context by optional_signature; absent = anonymous.
         let caller = ctx
             .data::<crate::auth::AuthenticatedDid>()
             .ok()
             .map(|d| d.0.as_str());
-        let ids: Vec<String> = repos.iter().map(|r| r.id.clone()).collect();
-        let rules_by_repo = db
-            .list_visibility_rules_for_repos(&ids)
+        let mut repos = db
+            .list_visible_repos_page(caller, None, MAX_VISIBLE_REPO_PAGE_SIZE + 1)
             .await
             .map_err(crate::graphql::graphql_db_err)?;
-
-        Ok(repos
-            .into_iter()
-            .filter(|r| {
-                let rules = rules_by_repo.get(&r.id).map(Vec::as_slice).unwrap_or(&[]);
-                crate::visibility::listable_at_root(rules, r.is_public, &r.owner_did, caller)
-            })
-            .map(|r| RepoType {
-                name: r.name,
-                owner_did: r.owner_did,
-                description: r.description,
-                default_branch: r.default_branch,
-                created_at: r.created_at.to_rfc3339(),
-            })
-            .collect())
+        if repos.len() > MAX_VISIBLE_REPO_PAGE_SIZE {
+            return Err(async_graphql::Error::new(format!(
+                "repository list exceeds {} entries; use reposPage with limit and after",
+                MAX_VISIBLE_REPO_PAGE_SIZE
+            )));
+        }
+        // Preserve the legacy activity ordering for complete, small lists.
+        repos.sort_by_key(|repo| std::cmp::Reverse(repo.updated_at));
+        Ok(repos.into_iter().map(repo_type).collect())
     }
 
+    /// Bounded visible repositories ordered by owner and name. Continue with
+    /// endCursor while hasNextPage is true. Pages are not a database snapshot.
+    // Every page sorts the full deduplicated corpus under COLLATE "C"
+    // (list_visible_repos_page documents the accepted O(total repos) bound),
+    // so the price charges the scan, not the emitted rows: a limit:1 page
+    // costs the same as a max-size page, the way `repos` is priced.
+    #[graphql(complexity = "50 + MAX_VISIBLE_REPO_PAGE_SIZE + child_complexity")]
+    async fn repos_page(
+        &self,
+        ctx: &Context<'_>,
+        #[graphql(
+            default = 50,
+            desc = "Page size from 1 to the documented maximum; other values are rejected."
+        )]
+        limit: i64,
+        after: Option<String>,
+    ) -> Result<RepoPageType> {
+        if !(1..=MAX_VISIBLE_REPO_PAGE_SIZE as i64).contains(&limit) {
+            return Err(async_graphql::Error::new(format!(
+                "limit must be between 1 and {}",
+                MAX_VISIBLE_REPO_PAGE_SIZE
+            )));
+        }
+        let after = after.as_deref().map(parse_repo_cursor).transpose()?;
+        let caller = ctx
+            .data::<crate::auth::AuthenticatedDid>()
+            .ok()
+            .map(|d| d.0.as_str());
+        let db = ctx.data_unchecked::<Arc<Db>>();
+        let mut repos = db
+            .list_visible_repos_page(
+                caller,
+                after
+                    .as_ref()
+                    .map(|(owner, name)| (owner.as_str(), name.as_str())),
+                limit as usize + 1,
+            )
+            .await
+            .map_err(crate::graphql::graphql_db_err)?;
+        let has_next_page = repos.len() > limit as usize;
+        repos.truncate(limit as usize);
+        let end_cursor = repos.last().map(repo_cursor);
+        Ok(RepoPageType {
+            nodes: repos.into_iter().map(repo_type).collect(),
+            has_next_page,
+            end_cursor,
+        })
+    }
+
+    // Complexity is additive with a base reflecting the collector's fixed scan:
+    // every request loads the full deduped repo set, the quarantined set, and
+    // the visibility rules, then walks up to max(limit, 2048) event rows past
+    // withheld ones, regardless of `limit`. A multiplicative price both
+    // undercharged limit:1 (51 for that fixed work) and made a request at the
+    // documented maximum unreachable (two fields at max limit cost 450 > 400).
+    //
+    // Decision on the collector floor (review #465, 3rd round): the up-to-2048
+    // walk is bounded constant overhead that does not scale with `limit`, so
+    // it is priced in the fixed base, not the limit term; the limit term
+    // prices only the emitted rows. Pricing the walk at face value in the base
+    // would put every refUpdates query over the 400 budget and make the field
+    // unusable, so the base prices that fixed scan as a lump sum instead.
+    #[graphql(
+        complexity = "100 + (limit.clamp(0, MAX_VISIBLE_REF_UPDATES) as usize) + child_complexity"
+    )]
     async fn ref_updates(
         &self,
         ctx: &Context<'_>,
         repo: Option<String>,
         #[graphql(
             default = 20,
-            desc = "Max 200; larger requests return the newest 200 rows (no continuation cursor)."
+            desc = "Requests above the documented maximum return the newest rows up to that maximum (no continuation cursor)."
         )]
         limit: i64,
     ) -> Result<Vec<RefUpdateType>> {
@@ -105,6 +202,14 @@ impl QueryRoot {
         Ok(resolved)
     }
 
+    // Complexity is additive: list_tasks is a single LIMIT-bounded query whose
+    // cost does not scale with the selected fields, so the price is the base
+    // plus the clamped limit plus the child fields. A multiplicative price
+    // made a request at the documented maximum unreachable (two fields at max
+    // limit cost 450 > 400).
+    #[graphql(
+        complexity = "50 + (limit.clamp(0, MAX_VISIBLE_TASK_PAGE_SIZE) as usize) + child_complexity"
+    )]
     async fn tasks(
         &self,
         ctx: &Context<'_>,
@@ -112,7 +217,7 @@ impl QueryRoot {
         assignee_did: Option<String>,
         #[graphql(
             default = 50,
-            desc = "Max 200; larger requests are clamped to 200 (no error). Negative values clamp to 0."
+            desc = "Requests above the documented maximum are clamped to it (no error). Negative values clamp to 0."
         )]
         limit: i64,
     ) -> Result<Vec<AgentTaskType>> {
@@ -120,7 +225,7 @@ impl QueryRoot {
         // Clamp before SQL: a negative LIMIT is a client fault that Postgres
         // rejects with 2201W, which would otherwise trip the opaque DB path
         // and write an error-level log on every probe (#250 review).
-        let limit = limit.clamp(0, 200);
+        let limit = limit.clamp(0, MAX_VISIBLE_TASK_PAGE_SIZE);
         let tasks = db
             .list_tasks(status.as_deref(), assignee_did.as_deref(), limit)
             .await
@@ -128,6 +233,7 @@ impl QueryRoot {
         Ok(tasks.into_iter().map(AgentTaskType::from).collect())
     }
 
+    #[graphql(complexity = "50 + child_complexity")]
     async fn task(&self, ctx: &Context<'_>, id: String) -> Result<Option<AgentTaskType>> {
         let db = ctx.data_unchecked::<Arc<Db>>();
         let t = db
@@ -141,12 +247,642 @@ impl QueryRoot {
 #[cfg(test)]
 mod tests {
     use crate::db::{Db, ReceivedRefUpdate, RepoRecord};
+    use base64::Engine;
     use chrono::Utc;
     use sqlx::PgPool;
     use std::sync::Arc;
 
     const OWNER: &str = "did:key:z6MkOwner";
 
+    #[sqlx::test]
+    async fn repos_legacy_rejects_overflow_and_pages_reach_every_visible_repo(pool: PgPool) {
+        let db = db(pool).await;
+        let total = crate::db::MAX_VISIBLE_REPO_PAGE_SIZE + 5;
+        for index in 0..total {
+            let name = format!("repo-{index:03}");
+            db.create_repo(&repo(&name, OWNER, &name, true))
+                .await
+                .unwrap();
+        }
+        // The SQL helper itself must bound materialization, even for a caller
+        // accidentally requesting an unlimited page.
+        assert_eq!(
+            db.list_visible_repos_page(None, None, usize::MAX)
+                .await
+                .unwrap()
+                .len(),
+            crate::db::MAX_VISIBLE_REPO_PAGE_SIZE + 1
+        );
+        let schema = schema(db);
+        let legacy = anon(&schema, "{ repos { name } }").await;
+        assert_eq!(legacy.errors.len(), 1);
+        assert!(legacy.errors[0].message.contains("use reposPage"));
+        assert_eq!(legacy.data, async_graphql::Value::Null);
+
+        let mut cursor = None;
+        let mut names = Vec::new();
+        loop {
+            let response = schema.execute(
+                async_graphql::Request::new(
+                    "query($after: String) { reposPage(limit: 50, after: $after) { nodes { name } hasNextPage endCursor } }",
+                ).variables(async_graphql::Variables::from_json(serde_json::json!({"after": cursor}))),
+            ).await;
+            assert!(response.errors.is_empty(), "{:?}", response.errors);
+            let json = response.data.into_json().unwrap();
+            let page = &json["reposPage"];
+            let rows = page["nodes"].as_array().unwrap();
+            assert!(rows.len() <= 50);
+            names.extend(
+                rows.iter()
+                    .map(|row| row["name"].as_str().unwrap().to_owned()),
+            );
+            if !page["hasNextPage"].as_bool().unwrap() {
+                break;
+            }
+            let next = page["endCursor"].as_str().unwrap().to_owned();
+            assert_ne!(cursor.as_ref(), Some(&next));
+            cursor = Some(next);
+            assert!(names.len() <= crate::db::MAX_VISIBLE_REPO_PAGE_SIZE);
+        }
+        assert_eq!(
+            names,
+            (0..total)
+                .map(|index| format!("repo-{index:03}"))
+                .collect::<Vec<_>>()
+        );
+    }
+
+    #[sqlx::test]
+    async fn repos_legacy_accepts_exactly_the_visible_bound(pool: PgPool) {
+        let db = db(pool).await;
+        let base_time = Utc::now();
+        let total = crate::db::MAX_VISIBLE_REPO_PAGE_SIZE;
+        for index in 0..total {
+            let name = format!("repo-{index:03}");
+            let mut r = repo(&name, OWNER, &name, true);
+            // Anti-correlate updated_at with name, creation order, and index
+            // so only ordering by updated_at DESC can satisfy the expectation.
+            let offset = (index * 37) % total;
+            r.updated_at = base_time + chrono::Duration::seconds(offset as i64);
+            db.create_repo(&r).await.unwrap();
+        }
+        db.create_repo(&repo("hidden", OWNER, "hidden", false))
+            .await
+            .unwrap();
+        let response = anon(&schema(db), "{ repos { name } }").await;
+        assert!(response.errors.is_empty(), "{:?}", response.errors);
+        let repos = response.data.into_json().unwrap()["repos"]
+            .as_array()
+            .unwrap()
+            .clone();
+        assert_eq!(repos.len(), total);
+        let names: Vec<_> = repos.iter().filter_map(|r| r["name"].as_str()).collect();
+        assert!(
+            !names.contains(&"hidden"),
+            "hidden repo must be excluded from legacy repos response"
+        );
+        let mut expected_indices = (0..total).collect::<Vec<_>>();
+        expected_indices.sort_by_key(|&idx| std::cmp::Reverse((idx * 37) % total));
+        let expected_names: Vec<String> = expected_indices
+            .into_iter()
+            .map(|index| format!("repo-{index:03}"))
+            .collect();
+        assert_eq!(
+            names,
+            expected_names
+                .iter()
+                .map(|s| s.as_str())
+                .collect::<Vec<_>>(),
+            "legacy repos must retain activity ordering (most recently updated first)"
+        );
+    }
+
+    #[sqlx::test]
+    async fn repos_page_pagination_crosses_owner_boundary(pool: PgPool) {
+        let db = db(pool).await;
+        let owner1 = "did:key:z6MkaOwner1";
+        let owner2 = "did:key:z6MkbOwner2";
+        let earlier_owner = "did:web:example.com";
+        // This owner sorts first only after did:key normalization. Its name
+        // sorts past the first cursor, so an unqualified OR name predicate
+        // would incorrectly serve it again on the next page.
+        //
+        // Rows are inserted out of order and not in reverse asserted order.
+        // Assigned IDs do not track name order, and owner2 contains both
+        // "B-repo" and "a-repo" whose byte order (B < a) differs from their
+        // case-folded order (a < b), ensuring lower(d.name) cannot satisfy
+        // the keyset query. Sized to 6 entries so the last page is full-sized
+        // (limit 2), proving hasNextPage distinguishes a full terminal page.
+        db.create_repo(&repo("r5", owner2, "c-repo", true))
+            .await
+            .unwrap();
+        db.create_repo(&repo("r9", earlier_owner, "zz-repo", true))
+            .await
+            .unwrap();
+        db.create_repo(&repo("r3", owner2, "B-repo", true))
+            .await
+            .unwrap();
+        db.create_repo(&repo("r8", owner1, "z-repo", true))
+            .await
+            .unwrap();
+        db.create_repo(&repo("r2", owner1, "b-repo", true))
+            .await
+            .unwrap();
+        db.create_repo(&repo("r1", owner2, "a-repo", true))
+            .await
+            .unwrap();
+
+        let schema = schema(db);
+        let page1_resp = anon(
+            &schema,
+            "{ reposPage(limit: 2) { nodes { name ownerDid } hasNextPage endCursor } }",
+        )
+        .await;
+        assert!(page1_resp.errors.is_empty(), "{:?}", page1_resp.errors);
+        let p1 = page1_resp.data.into_json().unwrap()["reposPage"].clone();
+        assert_eq!(p1["hasNextPage"], true);
+        assert_eq!(
+            p1["nodes"],
+            serde_json::json!([
+                {"name": "zz-repo", "ownerDid": earlier_owner},
+                {"name": "b-repo", "ownerDid": owner1},
+            ])
+        );
+        let cursor = p1["endCursor"].as_str().unwrap();
+
+        let page2_query = format!(
+            "{{ reposPage(limit: 2, after: \"{cursor}\") {{ nodes {{ name ownerDid }} hasNextPage endCursor }} }}"
+        );
+        let page2_resp = anon(&schema, &page2_query).await;
+        assert!(page2_resp.errors.is_empty(), "{:?}", page2_resp.errors);
+        let p2 = page2_resp.data.into_json().unwrap()["reposPage"].clone();
+        assert_eq!(p2["hasNextPage"], true);
+        assert_eq!(
+            p2["nodes"],
+            serde_json::json!([
+                {"name": "z-repo", "ownerDid": owner1},
+                {"name": "B-repo", "ownerDid": owner2},
+            ])
+        );
+        let cursor = p2["endCursor"].as_str().unwrap();
+        let page3_query = format!(
+            "{{ reposPage(limit: 2, after: \"{cursor}\") {{ nodes {{ name ownerDid }} hasNextPage endCursor }} }}"
+        );
+        let page3_resp = anon(&schema, &page3_query).await;
+        assert!(page3_resp.errors.is_empty(), "{:?}", page3_resp.errors);
+        let p3 = page3_resp.data.into_json().unwrap()["reposPage"].clone();
+        assert_eq!(p3["hasNextPage"], false);
+        assert_eq!(
+            p3["nodes"],
+            serde_json::json!([
+                {"name": "a-repo", "ownerDid": owner2},
+                {"name": "c-repo", "ownerDid": owner2},
+            ])
+        );
+    }
+
+    #[sqlx::test]
+    async fn repos_page_at_documented_maximum_distinguishes_terminal_page(pool: PgPool) {
+        let db = db(pool).await;
+        let total = crate::db::MAX_VISIBLE_REPO_PAGE_SIZE;
+        for index in 0..total {
+            let name = format!("repo-{index:03}");
+            db.create_repo(&repo(&name, OWNER, &name, true))
+                .await
+                .unwrap();
+        }
+        let schema = schema(db.clone());
+        let query =
+            format!("{{ reposPage(limit: {total}) {{ nodes {{ name }} hasNextPage endCursor }} }}");
+        let resp200 = anon(&schema, &query).await;
+        assert!(resp200.errors.is_empty(), "{:?}", resp200.errors);
+        let p200 = resp200.data.into_json().unwrap()["reposPage"].clone();
+        assert_eq!(p200["hasNextPage"], false);
+        let nodes200 = p200["nodes"].as_array().unwrap().clone();
+        assert_eq!(nodes200.len(), total);
+
+        // Adding row 201 keeps page 1 content identical while flipping hasNextPage to true.
+        let name201 = format!("repo-{total:03}");
+        db.create_repo(&repo(&name201, OWNER, &name201, true))
+            .await
+            .unwrap();
+        let resp201 = anon(&schema, &query).await;
+        assert!(resp201.errors.is_empty(), "{:?}", resp201.errors);
+        let p201 = resp201.data.into_json().unwrap()["reposPage"].clone();
+        assert_eq!(p201["hasNextPage"], true);
+        assert_eq!(p201["nodes"], p200["nodes"]);
+        assert_eq!(p201["endCursor"], p200["endCursor"]);
+    }
+
+    #[sqlx::test]
+    async fn repos_page_visibility_matches_the_shared_gate(pool: PgPool) {
+        use crate::db::VisibilityMode;
+        let db = db(pool).await;
+        let reader = "did:key:zReader";
+        for (id, public) in [
+            ("open", true),
+            ("private", false),
+            ("root-deny", true),
+            ("root-reader", false),
+            ("subtree", true),
+            ("root-tie", true),
+            ("odd-star", true),
+            ("malformed-readers", true),
+            ("non-array-readers", true),
+            ("non-string-reader", true),
+            ("quarantined", true),
+        ] {
+            db.create_repo(&repo(id, OWNER, id, public)).await.unwrap();
+        }
+        // Canonical and mirror copies must still collapse before pagination.
+        db.create_repo(&repo("z6MkOwner/open", "z6MkOwner", "open", true))
+            .await
+            .unwrap();
+        db.create_repo(&repo(
+            "other-method",
+            "did:web:z6MkOwner",
+            "other-method",
+            false,
+        ))
+        .await
+        .unwrap();
+        db.set_repo_quarantine("quarantined", true).await.unwrap();
+        for (id, glob, readers) in [
+            ("root-deny", "/", vec![]),
+            ("root-reader", "/**", vec![reader.to_owned()]),
+            ("subtree", "/secret/**", vec![]),
+            ("root-tie", "/", vec![reader.to_owned()]),
+            ("root-tie", "/**", vec![]),
+            ("odd-star", "/*", vec![]),
+            ("malformed-readers", "/", vec![]),
+            ("non-array-readers", "/", vec![]),
+            ("non-string-reader", "/", vec![]),
+        ] {
+            db.set_visibility_rule(id, glob, VisibilityMode::B, &readers, OWNER)
+                .await
+                .unwrap();
+        }
+        // The typed setter cannot create malformed JSON, but existing TEXT rows
+        // can contain it. Such a rule must deny this repo, not abort the page.
+        // All three deny arms of the reader_dids predicate are pinned here:
+        // (a) invalid JSON, (b) valid JSON that is not an array, (c) an array
+        // containing a non-string member. The Rust gate parses reader_dids as
+        // Vec<String> with unwrap_or_default(), so (b) and (c) also fail to
+        // parse and deny; the SQL CASE must agree on every shape.
+        let rows = sqlx::query("UPDATE visibility_rules SET reader_dids = $1 WHERE repo_id = $2")
+            .bind("not JSON")
+            .bind("malformed-readers")
+            .execute(db.pool())
+            .await
+            .unwrap();
+        assert_eq!(rows.rows_affected(), 1);
+        let rows = sqlx::query("UPDATE visibility_rules SET reader_dids = $1 WHERE repo_id = $2")
+            .bind("\"just-a-string\"")
+            .bind("non-array-readers")
+            .execute(db.pool())
+            .await
+            .unwrap();
+        assert_eq!(rows.rows_affected(), 1);
+        // The named reader is listed, but the non-string member poisons the
+        // whole list: both sides must still deny them.
+        let rows = sqlx::query("UPDATE visibility_rules SET reader_dids = $1 WHERE repo_id = $2")
+            .bind("[\"did:key:zReader\", 42]")
+            .bind("non-string-reader")
+            .execute(db.pool())
+            .await
+            .unwrap();
+        assert_eq!(rows.rows_affected(), 1);
+        let all = db.list_all_repos_deduped().await.unwrap();
+        for caller in [
+            None,
+            Some(OWNER),
+            Some("z6MkOwner"),
+            Some(reader),
+            Some("zReader"),
+            Some("did:web:z6MkOwner"),
+        ] {
+            let mut expected = Vec::new();
+            for record in &all {
+                let rules = db.list_visibility_rules(&record.id).await.unwrap();
+                if crate::visibility::listable_at_root(
+                    &rules,
+                    record.is_public,
+                    &record.owner_did,
+                    caller,
+                ) {
+                    expected.push(record.id.clone());
+                }
+            }
+            expected.sort();
+            let mut actual = db
+                .list_visible_repos_page(caller, None, usize::MAX)
+                .await
+                .unwrap()
+                .into_iter()
+                .map(|record| record.id)
+                .collect::<Vec<_>>();
+            actual.sort();
+            assert_eq!(actual, expected, "caller {caller:?}");
+        }
+        let schema = schema(db);
+        for caller in [None, Some("did:key:zUnauthorized")] {
+            let query = "{ repos { name } }";
+            let response = match caller {
+                None => anon(&schema, query).await,
+                Some(caller) => authed(&schema, query, caller).await,
+            };
+            assert!(response.errors.is_empty(), "{:?}", response.errors);
+            let mut names: Vec<String> = response.data.into_json().unwrap()["repos"]
+                .as_array()
+                .unwrap()
+                .iter()
+                .map(|repo| repo["name"].as_str().unwrap().to_owned())
+                .collect();
+            names.sort();
+            assert_eq!(names, ["odd-star", "open", "subtree"]);
+        }
+        let query = "{ reposPage(limit: 1) { nodes { name ownerDid } hasNextPage endCursor } }";
+        let response = anon(&schema, query).await;
+        assert!(response.errors.is_empty(), "{:?}", response.errors);
+        let json = response.data.into_json().unwrap();
+        let page = &json["reposPage"];
+        assert_eq!(
+            page["nodes"],
+            serde_json::json!([{"name": "odd-star", "ownerDid": OWNER}])
+        );
+        assert_eq!(page["hasNextPage"], true);
+        let cursor = super::parse_repo_cursor(page["endCursor"].as_str().unwrap()).unwrap();
+        assert_eq!(cursor, (OWNER.to_owned(), "odd-star".to_owned()));
+        assert!(!json.to_string().contains("private"));
+        assert!(!json.to_string().contains("quarantined"));
+
+        // Route-level check with unauthorized authenticated caller:
+        // Excludes private, quarantined, and root-deny repos, matching anonymous behavior.
+        let all_query = "{ reposPage(limit: 50) { nodes { name } hasNextPage } }";
+        let unauth_response = authed(&schema, all_query, "did:key:zUnauthorized").await;
+        assert!(
+            unauth_response.errors.is_empty(),
+            "{:?}",
+            unauth_response.errors
+        );
+        let unauth_json = unauth_response.data.into_json().unwrap();
+        let unauth_names: Vec<&str> = unauth_json["reposPage"]["nodes"]
+            .as_array()
+            .unwrap()
+            .iter()
+            .filter_map(|n| n["name"].as_str())
+            .collect();
+        assert_eq!(unauth_names, vec!["odd-star", "open", "subtree"]);
+        let unauth_str = unauth_json.to_string();
+        assert!(!unauth_str.contains("private"));
+        assert!(!unauth_str.contains("quarantined"));
+        assert!(!unauth_str.contains("root-deny"));
+        assert!(!unauth_str.contains("root-reader"));
+        assert!(!unauth_str.contains("root-tie"));
+
+        // Reader caller gets root-reader and root-tie, but still excludes private, quarantined, root-deny.
+        let reader_response = authed(&schema, all_query, reader).await;
+        assert!(
+            reader_response.errors.is_empty(),
+            "{:?}",
+            reader_response.errors
+        );
+        let reader_json = reader_response.data.into_json().unwrap();
+        let reader_names: Vec<&str> = reader_json["reposPage"]["nodes"]
+            .as_array()
+            .unwrap()
+            .iter()
+            .filter_map(|n| n["name"].as_str())
+            .collect();
+        assert_eq!(
+            reader_names,
+            vec!["odd-star", "open", "root-reader", "subtree"]
+        );
+        let reader_str = reader_json.to_string();
+        assert!(!reader_str.contains("private"));
+        assert!(!reader_str.contains("quarantined"));
+        assert!(!reader_str.contains("root-deny"));
+        assert!(!reader_str.contains("root-tie"));
+    }
+
+    #[sqlx::test]
+    async fn repos_page_rechecks_cursor_authority_and_exact_boundary(pool: PgPool) {
+        let db = db(pool).await;
+        let visible = repo("visible", OWNER, "a-visible", true);
+        db.create_repo(&visible).await.unwrap();
+        db.create_repo(&repo("hidden", OWNER, "z-private", false))
+            .await
+            .unwrap();
+        let schema = schema(db);
+        let first = anon(
+            &schema,
+            "{ reposPage(limit: 1) { nodes { name } hasNextPage endCursor } }",
+        )
+        .await;
+        assert!(first.errors.is_empty());
+        let first = first.data.into_json().unwrap();
+        assert_eq!(first["reposPage"]["hasNextPage"], false);
+        let query = format!(
+            "{{ reposPage(limit: 1, after: \"{}\") {{ nodes {{ name }} hasNextPage endCursor }} }}",
+            super::repo_cursor(&visible)
+        );
+        let owner = authed(&schema, &query, OWNER).await;
+        assert!(owner.errors.is_empty());
+        assert_eq!(
+            owner.data.into_json().unwrap()["reposPage"]["nodes"][0]["name"],
+            "z-private"
+        );
+        let anon = anon(&schema, &query).await;
+        assert!(anon.errors.is_empty());
+        assert_eq!(
+            anon.data.into_json().unwrap()["reposPage"],
+            serde_json::json!({
+                "nodes": [], "hasNextPage": false, "endCursor": null
+            })
+        );
+        let unauth = authed(&schema, &query, "did:key:zUnauthorized").await;
+        assert!(unauth.errors.is_empty());
+        assert_eq!(
+            unauth.data.into_json().unwrap()["reposPage"],
+            serde_json::json!({
+                "nodes": [], "hasNextPage": false, "endCursor": null
+            })
+        );
+    }
+
+    #[tokio::test]
+    async fn repos_page_rejects_nul_cursors_before_database_access() {
+        let pool = sqlx::postgres::PgPoolOptions::new()
+            .connect_lazy("postgres://localhost/unused")
+            .unwrap();
+        let schema = schema(Arc::new(Db::for_testing(pool)));
+        for position in [("did:key:zOwner\0", "repo"), ("did:key:zOwner", "repo\0")] {
+            let cursor = super::URL_SAFE_NO_PAD.encode(serde_json::to_vec(&position).unwrap());
+            let query = format!("{{ reposPage(after: \"{cursor}\") {{ hasNextPage }} }}");
+            let response =
+                tokio::time::timeout(std::time::Duration::from_secs(1), anon(&schema, &query))
+                    .await
+                    .expect("invalid cursors must be rejected without accessing the database");
+            assert_eq!(response.errors.len(), 1);
+            assert_eq!(response.errors[0].message, "invalid repository cursor");
+            assert_eq!(response.data, async_graphql::Value::Null);
+        }
+        let position = ("did:key:zOwner", "repo");
+        let cursor = super::URL_SAFE_NO_PAD.encode(serde_json::to_vec(&position).unwrap());
+        assert_eq!(
+            super::parse_repo_cursor(&cursor).unwrap(),
+            (position.0.to_owned(), position.1.to_owned())
+        );
+    }
+
+    #[tokio::test]
+    async fn repos_page_rejects_invalid_inputs_before_database_access() {
+        let pool = sqlx::postgres::PgPoolOptions::new()
+            .connect_lazy("postgres://localhost/unused")
+            .unwrap();
+        let schema = schema(Arc::new(Db::for_testing(pool)));
+        let over_max = crate::db::MAX_VISIBLE_REPO_PAGE_SIZE + 1;
+        let expected_limit_message = format!(
+            "limit must be between 1 and {}",
+            crate::db::MAX_VISIBLE_REPO_PAGE_SIZE
+        );
+        // Each input pins its own rejection message: the loop must not accept
+        // either message for every query, or a misattributed message (e.g. the
+        // limit arm returning "invalid repository cursor") stays invisible.
+        for (query, expected_message) in [
+            (
+                "{ reposPage(limit: 0) { hasNextPage } }".to_owned(),
+                expected_limit_message.clone(),
+            ),
+            (
+                "{ reposPage(limit: -1) { hasNextPage } }".to_owned(),
+                expected_limit_message.clone(),
+            ),
+            (
+                format!("{{ reposPage(limit: {over_max}) {{ hasNextPage }} }}"),
+                expected_limit_message.clone(),
+            ),
+            (
+                "{ reposPage(after: \"invalid!\") { hasNextPage } }".to_owned(),
+                "invalid repository cursor".to_owned(),
+            ),
+        ] {
+            let response =
+                tokio::time::timeout(std::time::Duration::from_secs(1), anon(&schema, &query))
+                    .await
+                    .unwrap();
+            assert_eq!(response.errors.len(), 1);
+            assert_eq!(
+                response.errors[0].message, expected_message,
+                "wrong rejection message for query: {query}"
+            );
+        }
+        // Valid base64 and valid cursor JSON: only the length guard rejects it.
+        let oversized = super::URL_SAFE_NO_PAD
+            .encode(serde_json::to_vec(&("did:key:reader", "a".repeat(3100))).unwrap());
+        assert!(oversized.len() > 4096);
+        assert!(serde_json::from_slice::<(String, String)>(
+            &super::URL_SAFE_NO_PAD.decode(&oversized).unwrap()
+        )
+        .is_ok());
+        assert!(super::parse_repo_cursor(&oversized).is_err());
+    }
+
+    #[tokio::test]
+    async fn parse_repo_cursor_rejects_wrong_shape_json() {
+        // Valid base64 and valid JSON, but not a (String, String) pair: the
+        // wrong-shape arm must report "invalid repository cursor", exactly,
+        // before any database access.
+        let pool = sqlx::postgres::PgPoolOptions::new()
+            .connect_lazy("postgres://localhost/unused")
+            .unwrap();
+        let schema = schema(Arc::new(Db::for_testing(pool)));
+        for payload in [
+            serde_json::json!(["only-one"]),
+            serde_json::json!(["a", "b", "c"]),
+            serde_json::json!({"owner": "x", "name": "y"}),
+            serde_json::json!(42),
+            serde_json::json!(["a", 1]),
+        ] {
+            let cursor = super::URL_SAFE_NO_PAD.encode(serde_json::to_vec(&payload).unwrap());
+            let err = super::parse_repo_cursor(&cursor).unwrap_err();
+            assert_eq!(err.message, "invalid repository cursor");
+            let query = format!("{{ reposPage(after: \"{cursor}\") {{ hasNextPage }} }}");
+            let response =
+                tokio::time::timeout(std::time::Duration::from_secs(1), anon(&schema, &query))
+                    .await
+                    .expect("wrong-shape cursors must be rejected without accessing the database");
+            assert_eq!(response.errors.len(), 1);
+            assert_eq!(response.errors[0].message, "invalid repository cursor");
+            assert_eq!(response.data, async_graphql::Value::Null);
+        }
+    }
+
+    #[tokio::test]
+    async fn longest_repo_name_cursor_round_trips() {
+        // #465 4th round: a cursor the server emits must always parse back.
+        // Repo names are bounded at the create/fork/mirror write paths, so the
+        // longest admissible name must produce a cursor under the 4096-byte
+        // parse limit.
+        let name = "a".repeat(crate::db::MAX_REPO_NAME_LEN);
+        let record = repo("long", OWNER, &name, true);
+        let cursor = super::repo_cursor(&record);
+        assert!(
+            cursor.len() <= 4096,
+            "emitted cursor must stay under the parse limit: {}",
+            cursor.len()
+        );
+        assert_eq!(
+            super::parse_repo_cursor(&cursor).unwrap(),
+            (OWNER.to_owned(), name)
+        );
+    }
+
+    /// A negative refUpdates(limit) must be accepted and clamped to zero rows,
+    /// like tasks(limit: -1): the complexity formula's `limit.clamp(0, ...)`
+    /// prices it at the floor and the shared collector returns before any
+    /// database access. Mirrors tasks_negative_limit_clamped.
+    #[tokio::test]
+    async fn ref_updates_negative_limit_clamped() {
+        let pool = sqlx::postgres::PgPoolOptions::new()
+            .connect_lazy("postgres://localhost/unused")
+            .unwrap();
+        let schema = schema(Arc::new(Db::for_testing(pool)));
+        let resp = tokio::time::timeout(
+            std::time::Duration::from_secs(1),
+            anon(&schema, "{ refUpdates(limit: -1) { repo } }"),
+        )
+        .await
+        .expect("negative limit must clamp without accessing the database");
+        assert!(
+            resp.errors.is_empty(),
+            "negative limit must clamp, not fail: {:?}",
+            resp.errors
+        );
+        assert_eq!(count(&resp), 0);
+    }
+
+    /// The mirror write path binds peer-supplied names verbatim, so it must
+    /// enforce the same bound as the local write paths: an overlong peer name
+    /// would otherwise make reposPage emit an unparseable cursor. The
+    /// rejection happens before any database access.
+    #[tokio::test]
+    async fn mirror_repo_rejects_overlong_name() {
+        let pool = sqlx::postgres::PgPoolOptions::new()
+            .connect_lazy("postgres://localhost/unused")
+            .unwrap();
+        let db = Db::for_testing(pool);
+        let name = "b".repeat(crate::db::MAX_REPO_NAME_LEN + 1);
+        let err = db
+            .upsert_mirror_repo("z6MkLong", &name, "/tmp/long", None, false)
+            .await
+            .unwrap_err();
+        assert!(
+            err.to_string().contains("exceeds"),
+            "unexpected error: {err}"
+        );
+    }
+
     async fn db(pool: PgPool) -> Arc<Db> {
         let db = Db::for_testing(pool);
         db.run_migrations().await.unwrap();
@@ -475,12 +1211,13 @@ mod tests {
         assert_eq!(count_tasks(&resp), 0);
     }
 
-    /// #255: ceiling of the tasks(limit) clamp must be held (schema promises Max 200).
+    /// #255: ceiling of the tasks(limit) clamp must be held (schema promises the
+    /// documented maximum).
     #[sqlx::test]
-    async fn tasks_limit_ceiling_clamped_to_200(pool: PgPool) {
+    async fn tasks_limit_ceiling_clamped_to_max(pool: PgPool) {
         let db = db(pool).await;
         let now = Utc::now().to_rfc3339();
-        for i in 0..201 {
+        for i in 0..crate::db::MAX_VISIBLE_TASK_PAGE_SIZE + 1 {
             db.create_task(&crate::db::AgentTask {
                 id: format!("task-ceil-{i}"),
                 repo_id: None,
@@ -501,7 +1238,49 @@ mod tests {
         }
         let schema = schema(db);
         let resp = anon(&schema, "{ tasks(limit: 5000) { id } }").await;
-        assert_eq!(count_tasks(&resp), 200, "limit above 200 must clamp to 200");
+        assert_eq!(
+            count_tasks(&resp),
+            crate::db::MAX_VISIBLE_TASK_PAGE_SIZE as usize,
+            "limit above the maximum must clamp to MAX_VISIBLE_TASK_PAGE_SIZE"
+        );
+    }
+
+    /// A limit above MAX_VISIBLE_REF_UPDATES must reach the resolver clamped,
+    /// not be rejected: the complexity formula clamps the priced limit (so the
+    /// document passes validation) and the shared collector clamps the rows
+    /// (so at most MAX_VISIBLE_REF_UPDATES come back). Removing the formula
+    /// clamp prices the raw limit and rejects the document; removing the
+    /// collector clamp returns unbounded rows. Mirrors
+    /// tasks_limit_ceiling_clamped_to_max.
+    #[sqlx::test]
+    async fn ref_updates_limit_ceiling_clamped_to_max(pool: PgPool) {
+        use crate::api::events::MAX_VISIBLE_REF_UPDATES;
+        let db = db(pool).await;
+        db.create_repo(&repo("r1", OWNER, "widget", true))
+            .await
+            .unwrap();
+        let total = MAX_VISIBLE_REF_UPDATES as usize + 1;
+        for i in 0..total {
+            let mut row = ref_row(&format!("ceil{i}"), "z6MkOwner/widget");
+            row.timestamp = format!("2026-07-01T10:{:02}:{:02}+00:00", i / 60, i % 60);
+            db.insert_ref_update(&row).await.unwrap();
+        }
+        let schema = schema(db);
+        let query = format!(
+            "{{ refUpdates(limit: {}) {{ repo }} }}",
+            MAX_VISIBLE_REF_UPDATES + 4800
+        );
+        let resp = anon(&schema, &query).await;
+        assert!(
+            resp.errors.is_empty(),
+            "limit above the maximum must clamp, not fail: {:?}",
+            resp.errors
+        );
+        assert_eq!(
+            count(&resp),
+            MAX_VISIBLE_REF_UPDATES as usize,
+            "limit above the maximum must clamp to MAX_VISIBLE_REF_UPDATES"
+        );
     }
 
     fn count_tasks(resp: &async_graphql::Response) -> usize {

crates/gitlawb-node/src/graphql/subscription.rs

@@ -20,6 +20,7 @@ impl SubscriptionRoot {
     /// `if announce` block, `api/repos.rs`). This is a single-point invariant —
     /// any new sender to `ref_update_tx` MUST be `announce`-gated, or private-repo
     /// ref metadata leaks here to unauthenticated subscribers (#112/#114 class).
+    #[graphql(complexity = "50 + child_complexity")]
     async fn ref_updates(
         &self,
         ctx: &Context<'_>,
@@ -46,6 +47,7 @@ impl SubscriptionRoot {
         })
     }
 
+    #[graphql(complexity = "50 + child_complexity")]
     async fn task_events(
         &self,
         ctx: &Context<'_>,

crates/gitlawb-node/src/graphql/types.rs

@@ -11,6 +11,14 @@ pub struct RepoType {
     pub created_at: String,
 }
 
+#[derive(SimpleObject)]
+pub struct RepoPageType {
+    pub nodes: Vec<RepoType>,
+    pub has_next_page: bool,
+    /// Position after the last returned visible repository; null for an empty page.
+    pub end_cursor: Option<String>,
+}
+
 #[derive(SimpleObject, Clone)]
 pub struct AgentTaskType {
     pub id: String,

crates/gitlawb-node/src/ipfs_pin.rs

@@ -2638,6 +2638,7 @@ mod tests {
     /// type probe carries its oid on stdin rather than in argv, so an oid appears in
     /// the log only once an object has already got past its probe, and a healthy
     /// object costs two invocations to a faulting one's one.
+    #[cfg(unix)]
     fn objects_attempted(log: &std::path::Path) -> usize {
         std::fs::read_to_string(log)
             .unwrap_or_default()

crates/gitlawb-node/src/pinata.rs

@@ -912,6 +912,7 @@ mod tests {
     /// probe carries its oid on stdin rather than in argv, so an oid appears in the log only
     /// once an object has already got past its probe, and a healthy object costs two
     /// invocations to a faulting one's one.
+    #[cfg(unix)]
     fn objects_attempted(log: &std::path::Path) -> usize {
         std::fs::read_to_string(log)
             .unwrap_or_default()

crates/gitlawb-node/src/sync.rs

@@ -1330,6 +1330,18 @@ mod tests {
         .await;
     }
 
+    /// Use a rooted path without a Windows drive prefix in the remote fixture.
+    /// The destination still resolves on the temp directory's current drive,
+    /// while the remote's relative path contains no illegal colon component.
+    fn absolute_slug_path(path: &Path) -> String {
+        assert!(path.is_absolute());
+        path.components()
+            .filter(|part| !matches!(part, std::path::Component::Prefix(_)))
+            .collect::<std::path::PathBuf>()
+            .to_string_lossy()
+            .replace('\\', "/")
+    }
+
     #[sqlx::test]
     async fn process_batch_rejects_slug_escaping_repos_dir(pool: PgPool) {
         // The verified escape from #272: `PathBuf::join` discards everything
@@ -1345,12 +1357,13 @@ mod tests {
         // fails on but leaves the parent it created, so assert on both.
         let outside = TempDir::new().unwrap();
         let escape_dir = outside.path().join("nest");
-        let slug = format!("a/{}/escape", escape_dir.display());
+        let escape_path = absolute_slug_path(&escape_dir);
+        let slug = format!("a/{escape_path}/escape");
         let escape_target = escape_dir.join("escape.git");
 
         // Serve the composed URL for real, so a run without the guard genuinely
         // clones outside the root rather than merely failing at git.
-        let rel = format!("a{}/escape", escape_dir.display());
+        let rel = format!("a{escape_path}/escape");
         let (_remote, peer_url) = rooted_remote(&[&rel]);
 
         let did = "did:key:z6MkAttacker";
@@ -1470,6 +1483,7 @@ mod tests {
     // ── canonical containment before the git call (issue #272) ───────────────
 
     /// Every ref in `repo`, as one string, for a before/after comparison.
+    #[cfg(unix)]
     fn refs_of(repo: &Path) -> String {
         let out = Command::new("git")
             .args(["-C", repo.to_str().unwrap(), "for-each-ref"])
@@ -1802,6 +1816,7 @@ mod tests {
     /// starvation tests is fixed rather than dependent on how fast the loop
     /// runs. Two rows enqueued in the same microsecond would otherwise order
     /// arbitrarily.
+    #[cfg(unix)]
     async fn enqueue_at(db: &Db, pool: &PgPool, repo: &str, did: &str, enqueued_at: &str) {
         enqueue(db, repo, did).await;
         sqlx::query("UPDATE sync_queue SET enqueued_at = $1 WHERE repo = $2")
@@ -1995,7 +2010,8 @@ mod tests {
 
         let outside = TempDir::new().unwrap();
         let escape_dir = outside.path().join("nest");
-        let slug = format!("a/{}/gitlawb-probe", escape_dir.display());
+        let escape_path = absolute_slug_path(&escape_dir);
+        let slug = format!("a/{escape_path}/gitlawb-probe");
         let escape_target = escape_dir.join("gitlawb-probe.git");
 
         // Two things this fixture must get right or the test is green for the
@@ -2006,7 +2022,7 @@ mod tests {
         // run without the guard genuinely clones outside the root instead of
         // just failing at git. Db::upsert_peer cannot seed this row: it gates on
         // is_public_http_url, which rejects file://.
-        let rel = format!("a{}/gitlawb-probe", escape_dir.display());
+        let rel = format!("a{escape_path}/gitlawb-probe");
         let (_remote, peer_url) = rooted_remote(&[&rel]);
         let did = "did:key:z6MkAttacker";
         seed_local_peer(&pool, did, &peer_url).await;

crates/gitlawb-node/src/test_git_shim.rs

@@ -0,0 +1,75 @@
+//! Native Git fixtures shared by timing tests on Unix and Windows.
+
+use std::ops::Deref;
+use std::path::{Path, PathBuf};
+use std::sync::OnceLock;
+
+/// The fixture delays or hangs in its own process, so the production watchdog
+/// can terminate it without depending on a shell or descendant process support.
+pub(super) enum Behavior<'a> {
+    Delay(u64),
+    Hang,
+    HangOid(&'a str),
+    HangRepo(&'a str),
+    LogTypes(&'a Path),
+}
+
+pub(super) struct GitShim {
+    _directory: tempfile::TempDir,
+    executable: PathBuf,
+}
+
+impl Deref for GitShim {
+    type Target = Path;
+
+    fn deref(&self) -> &Path {
+        &self.executable
+    }
+}
+
+pub(super) fn create(name: &str, behavior: Behavior<'_>) -> GitShim {
+    static COMPILED: OnceLock<tempfile::TempDir> = OnceLock::new();
+    let compiled = COMPILED.get_or_init(|| {
+        let directory = tempfile::tempdir().expect("native Git fixture directory");
+        let source = directory.path().join("git_shim.rs");
+        std::fs::write(&source, include_str!("../tests/fixtures/git_shim.rs"))
+            .expect("write native Git fixture source");
+        let executable = directory
+            .path()
+            .join(format!("git-shim{}", std::env::consts::EXE_SUFFIX));
+        let output =
+            std::process::Command::new(std::env::var_os("RUSTC").unwrap_or_else(|| "rustc".into()))
+                .arg("--edition=2021")
+                .arg("-Dwarnings")
+                .arg(&source)
+                .arg("-o")
+                .arg(executable)
+                .output()
+                .expect("compile native Git fixture with the installed Rust toolchain");
+        assert!(
+            output.status.success(),
+            "{}",
+            String::from_utf8_lossy(&output.stderr)
+        );
+        directory
+    });
+    let directory = tempfile::Builder::new()
+        .prefix(name)
+        .tempdir()
+        .expect("Git fixture instance");
+    let file_name = format!("git-shim{}", std::env::consts::EXE_SUFFIX);
+    let executable = directory.path().join(&file_name);
+    std::fs::copy(compiled.path().join(file_name), &executable).expect("copy native Git fixture");
+    let config = match behavior {
+        Behavior::Delay(milliseconds) => format!("delay\n{milliseconds}"),
+        Behavior::Hang => "hang\n".to_owned(),
+        Behavior::HangOid(oid) => format!("hang-oid\n{oid}"),
+        Behavior::HangRepo(repo) => format!("hang-repo\n{repo}"),
+        Behavior::LogTypes(path) => format!("log-types\n{}", path.display()),
+    };
+    std::fs::write(directory.path().join("config"), config).expect("configure native Git fixture");
+    GitShim {
+        _directory: directory,
+        executable,
+    }
+}

crates/gitlawb-node/src/test_support.rs

@@ -28,6 +28,9 @@ use gitlawb_core::identity::Keypair;
 use crate::auth::AuthenticatedDid;
 use crate::state::AppState;
 
+#[path = "test_git_shim.rs"]
+mod git_shim;
+
 /// Build an [`AppState`] over a real, migrated Postgres pool (from `#[sqlx::test]`).
 /// Runs the schema migrations first, because the per-test database starts empty.
 ///
@@ -559,11 +562,12 @@ mod tests {
     /// #174 (SC1, load-bearing): a saturated READ pool must NOT shed an
     /// authenticated push — the write pool is a separate budget. Read pool at zero,
     /// write pool with capacity: the push proceeds PAST admission (it then errors on
-    /// the placeholder DB, but crucially it is not a 503). Route git-receive-pack
+    /// the closed DB, with db_unavailable rather than overloaded). Route git-receive-pack
     /// back to the read pool and this goes red — that is the isolation proof.
     #[tokio::test]
     async fn git_receive_pack_not_shed_by_exhausted_read_pool() {
         let mut state = test_state_lazy();
+        state.db.pool().close().await;
         // Read pool exhausted as if a flood of anonymous clones held every slot.
         state.git_read_semaphore = Arc::new(tokio::sync::Semaphore::new(0));
         // Write pool keeps its default capacity from test_state_lazy.
@@ -585,10 +589,13 @@ mod tests {
             .await
             .unwrap();
 
-        assert_ne!(
-            resp.status(),
-            StatusCode::SERVICE_UNAVAILABLE,
-            "an exhausted READ pool must not shed a push — the write pool is a separate budget (#174)"
+        assert_eq!(resp.status(), StatusCode::SERVICE_UNAVAILABLE);
+        let bytes = axum::body::to_bytes(resp.into_body(), 1024).await.unwrap();
+        let body: serde_json::Value = serde_json::from_slice(&bytes).unwrap();
+        assert_eq!(
+            body["error"],
+            crate::error::DB_UNAVAILABLE_CODE,
+            "the push must clear admission and reach the deliberately closed database"
         );
     }
 
@@ -11195,14 +11202,10 @@ mod tests {
         seed_legacy_pin(&pool, &bare, &fx.public_oid, Some(&repo.id)).await;
 
         // A git that takes 300ms per invocation (the read makes two: type, then content).
-        let slow_git = std::env::temp_dir().join(format!("gl-slow-git-{short}"));
-        std::fs::write(&slow_git, "#!/bin/sh\nsleep 0.3\nexec git \"$@\"\n").expect("write shim");
-        #[cfg(unix)]
-        {
-            use std::os::unix::fs::PermissionsExt;
-            std::fs::set_permissions(&slow_git, std::fs::Permissions::from_mode(0o755))
-                .expect("chmod shim");
-        }
+        let slow_git = git_shim::create(
+            &format!("gl-slow-git-{short}"),
+            git_shim::Behavior::Delay(300),
+        );
 
         let ticks = std::sync::Arc::new(AtomicUsize::new(0));
         let ticker = {
@@ -12149,19 +12152,6 @@ mod tests {
         );
     }
 
-    /// Write an executable `git` stand-in and return its path.
-    fn write_git_shim(name: &str, script: &str) -> std::path::PathBuf {
-        let path = std::env::temp_dir().join(name);
-        std::fs::write(&path, script).expect("write the git shim");
-        #[cfg(unix)]
-        {
-            use std::os::unix::fs::PermissionsExt;
-            std::fs::set_permissions(&path, std::fs::Permissions::from_mode(0o755))
-                .expect("chmod the git shim");
-        }
-        path
-    }
-
     /// F6 scenario 1 (#173 round 13): one hung candidate must not starve the rows behind
     /// it in the same pass. `DiscoveryCtx` is loaded once per pass, so before the per-row
     /// slice every source-less row in a pass shared ONE deadline: the first row's wedged
@@ -12201,23 +12191,9 @@ mod tests {
 
         // The type stage feeds the oid on STDIN (`cat-file --batch-check`) and the
         // content stage puts it in argv, so the stand-in has to look in both places.
-        let git_bin = write_git_shim(
+        let git_bin = git_shim::create(
             &format!("gl-hung-git-{short}"),
-            &format!(
-                "#!/bin/sh\n\
-                 if [ \"$2\" = \"--batch-check\" ]; then\n\
-                 \x20 oid=$(cat)\n\
-                 \x20 case \"$oid\" in\n\
-                 \x20   {hung_oid}) sleep 30; exit 1 ;;\n\
-                 \x20 esac\n\
-                 \x20 printf '%s\\n' \"$oid\" | git \"$@\"\n\
-                 \x20 exit $?\n\
-                 fi\n\
-                 case \"$*\" in\n\
-                 \x20 *{hung_oid}*) sleep 30; exit 1 ;;\n\
-                 esac\n\
-                 exec git \"$@\"\n"
-            ),
+            git_shim::Behavior::HangOid(&hung_oid),
         );
 
         let stats = tokio::time::timeout(
@@ -12302,10 +12278,7 @@ mod tests {
 
         // Wedges on every invocation, so no row can ever be repaired and the only
         // question left is what each one COSTS.
-        let git_bin = write_git_shim(
-            &format!("gl-spent-git-{short}"),
-            "#!/bin/sh\nsleep 30\nexit 1\n",
-        );
+        let git_bin = git_shim::create(&format!("gl-spent-git-{short}"), git_shim::Behavior::Hang);
 
         let stats = tokio::time::timeout(
             std::time::Duration::from_secs(60),
@@ -12909,10 +12882,7 @@ mod tests {
             seed_legacy_pin(&pool, &src, oid, None).await;
         }
 
-        let git_bin = write_git_shim(
-            &format!("gl-starve-git-{short}"),
-            "#!/bin/sh\nsleep 30\nexit 1\n",
-        );
+        let git_bin = git_shim::create(&format!("gl-starve-git-{short}"), git_shim::Behavior::Hang);
 
         tokio::time::timeout(
             std::time::Duration::from_secs(120),
@@ -12980,9 +12950,9 @@ mod tests {
         let (raw_cid, provider_cid) = seed_legacy_pin(&pool, &src, &fx.public_oid, None).await;
 
         // Wedges only inside the position-nine repo, which the sweep enters by cwd.
-        let git_bin = write_git_shim(
+        let git_bin = git_shim::create(
             &format!("gl-mid-git-{short}"),
-            "#!/bin/sh\ncase \"$(pwd)\" in\n  */midcand9.git) sleep 30; exit 1 ;;\nesac\nexec git \"$@\"\n",
+            git_shim::Behavior::HangRepo("midcand9.git"),
         );
 
         let first = tokio::time::timeout(
@@ -13144,19 +13114,9 @@ mod tests {
 
         let log = std::env::temp_dir().join(format!("gl-ali-log-{short}"));
         let _ = std::fs::remove_file(&log);
-        let git_bin = write_git_shim(
+        let git_bin = git_shim::create(
             &format!("gl-ali-git-{short}"),
-            &format!(
-                "#!/bin/sh\n\
-                 if [ \"$2\" = \"--batch-check\" ]; then\n\
-                 \x20 oid=$(cat)\n\
-                 \x20 printf '%s %s\\n' \"$oid\" \"$(basename $(pwd))\" >> {log}\n\
-                 \x20 printf '%s\\n' \"$oid\" | git \"$@\"\n\
-                 \x20 exit $?\n\
-                 fi\n\
-                 exec git \"$@\"\n",
-                log = log.display()
-            ),
+            git_shim::Behavior::LogTypes(&log),
         );
 
         let mut traversal = crate::ipfs_pin::DiscoveryTraversalState::default();

crates/gitlawb-node/tests/fixtures/git_shim.rs

@@ -0,0 +1,59 @@
+use std::io::{Read, Write};
+use std::process::{Command, Stdio};
+use std::time::Duration;
+
+fn main() -> std::io::Result<()> {
+    let executable = std::env::current_exe()?;
+    let config = std::fs::read_to_string(executable.parent().unwrap().join("config"))?;
+    let (mode, parameter) = config.split_once('\n').unwrap_or((&config, ""));
+    let args: Vec<_> = std::env::args_os().skip(1).collect();
+    if mode == "delay" {
+        std::thread::sleep(Duration::from_millis(parameter.parse().unwrap()));
+    }
+    let batch = args.get(1).is_some_and(|arg| arg == "--batch-check");
+    let input = if batch {
+        let mut bytes = Vec::new();
+        std::io::stdin().read_to_end(&mut bytes)?;
+        Some(bytes)
+    } else {
+        None
+    };
+    let cwd = std::env::current_dir()?;
+    let hang = mode == "hang"
+        || (mode == "hang-repo" && cwd.file_name().is_some_and(|name| name == parameter))
+        || (mode == "hang-oid"
+            && (args.iter().any(|arg| arg == parameter)
+                || input
+                    .as_ref()
+                    .is_some_and(|bytes| String::from_utf8_lossy(bytes).trim() == parameter)));
+    if hang {
+        std::thread::sleep(Duration::from_secs(30));
+        std::process::exit(1);
+    }
+    if mode == "log-types" && batch {
+        let mut log = std::fs::OpenOptions::new()
+            .create(true)
+            .append(true)
+            .open(parameter)?;
+        writeln!(
+            log,
+            "{} {}",
+            String::from_utf8_lossy(input.as_ref().unwrap()).trim(),
+            cwd.file_name().unwrap().to_string_lossy()
+        )?;
+    }
+    let mut child = Command::new("git")
+        .args(&args)
+        .stdin(if input.is_some() {
+            Stdio::piped()
+        } else {
+            Stdio::inherit()
+        })
+        .stdout(Stdio::inherit())
+        .stderr(Stdio::inherit())
+        .spawn()?;
+    if let Some(bytes) = input {
+        child.stdin.take().unwrap().write_all(&bytes)?;
+    }
+    std::process::exit(child.wait()?.code().unwrap_or(1));
+}

docs/RUN-A-NODE.md

@@ -8,6 +8,7 @@ Step-by-step guide to staking $GITLAWB, registering your node on-chain, and earn
 
 - A wallet with at least **10,000 $GITLAWB** (minimum stake) plus a small amount of ETH on Base for gas
 - Docker or Rust 1.91+ (for running the node process)
+- PostgreSQL 16+ — the node uses `pg_input_is_valid`, which exists only on PostgreSQL 16 and later. The bundled `docker-compose.yml` pins `postgres:16-alpine`; if you supply your own `DATABASE_URL`, the server must be 16+.
 - A public HTTP URL (your-host.com) — can be a VPS, Fly.io app, or anything reachable. A Fly.io config is provided at `infra/fly/fly.toml` (deploy from the repo root with `fly deploy -c infra/fly/fly.toml`)
 
 ---

docs/graphql-pagination.md

@@ -0,0 +1,76 @@
+# GraphQL repository pagination
+
+`repos` returns the complete visible repository list when it contains at most
+200 entries. Larger lists return a GraphQL error directing the caller to
+`reposPage`; they are never silently truncated.
+
+Use `reposPage` for larger lists:
+
+```graphql
+query Repositories($after: String) {
+  reposPage(limit: 50, after: $after) {
+    nodes {
+      name
+      ownerDid
+    }
+    hasNextPage
+    endCursor
+  }
+}
+```
+
+Start with `after: null`. When `hasNextPage` is true, pass the returned
+`endCursor` as `after` on the next request. Stop when `hasNextPage` is false.
+An empty page has a null `endCursor`. The default limit is 50 and the maximum
+page size is 200; limits below 1 or above 200 are rejected (see Query budgets
+below). Malformed cursors, including decoded owner or name strings containing
+NUL, return `invalid repository cursor` before database access.
+
+Pages are ordered by normalized owner DID and repository name. Visibility and
+mirror deduplication are applied in the database before limiting the page;
+hidden and quarantined repositories do not occupy page slots or create a
+continuation signal. Cursors contain a position from the last returned visible
+repository, not a permission grant. Each request checks the current caller's
+visibility independently. Keep the same caller while traversing a list.
+Malformed reader lists in a repository's root visibility rule deny access to
+non-owners for that repository while other visible repositories remain listable.
+
+Pagination is not a snapshot: concurrent renames, ownership changes, or visibility
+changes can alter subsequent pages. Treat cursors as opaque and restart from the
+first page when a fresh complete traversal is needed. Small legacy `repos`
+queries retain their activity ordering.
+
+## Query budgets
+
+Every GraphQL document is validated against two budgets before any resolver
+runs. Both apply per document (per request), not per client: `/graphql` has
+no per-caller rate limiting, so a rejected document can always be retried
+smaller. The constants live in `crates/gitlawb-node/src/graphql/mod.rs`.
+
+- **Complexity budget: 400 per document** (`GRAPHQL_MAX_COMPLEXITY`). Each
+  root field carries a base cost plus the clamped page size plus the selected
+  child fields:
+  - `repos`: 50 + `MAX_VISIBLE_REPO_PAGE_SIZE` + child fields. `repos`
+    always scans the full visible corpus, so it is priced as the full page
+    it is.
+  - `reposPage`: 50 + `MAX_VISIBLE_REPO_PAGE_SIZE` + child fields. Every
+    page request sorts the full deduplicated corpus, so the price does not
+    depend on `limit`: seven `reposPage(limit: 1)` aliases cost the same as
+    seven max-size pages.
+  - `refUpdates`: 100 + clamped `limit` (`MAX_VISIBLE_REF_UPDATES`) + child
+    fields. The 100 base covers the collector's fixed scan (the deduplicated
+    repo set, the quarantined set, the visibility rules, and the bounded
+    up-to-2048-row walk past withheld rows); the limit term prices only the
+    rows returned.
+  - `tasks`: 50 + clamped `limit` (`MAX_VISIBLE_TASK_PAGE_SIZE`) + child
+    fields.
+  - `task`, mutations, subscriptions: 50 + child fields.
+
+  A document whose total exceeds 400 is rejected with
+  `Query is too complex.` before any resolver runs, so an over-budget
+  document needs fewer aliases or fewer child fields. A smaller `limit` does
+  not help `reposPage` or `repos`: both are priced at the full
+  `MAX_VISIBLE_REPO_PAGE_SIZE` scan regardless of `limit`.
+
+- **Depth cap: 14 per document** (`GRAPHQL_MAX_DEPTH`). Documents nested
+  deeper than 14 selections are rejected with `Query is nested too deep.`