§9 optional revocation denylist (todo §9); closes the documented ~10m role/session lag for security-critical revoke, off by default (REVOCATION_DENYLIST, zero hot-path cost + zero behaviour change when off). New pure src/denylist.ts (createDenylist({ttlSec})): an in-memory, auto-evicting Map<sub, revokedAt> — revoke(sub) records now, isRevoked(sub, iat) rejects a subject's tokens minted at/before the revoke (iat <= revokedAt; missing iat fails closed), so a fresh re-login (iat after the revoke) passes while a downgrade lands immediately. Entries self-evict after REVOCATION_TTL_SEC (default 900 ≥ the 10m tokenizer TTL + skew), so it stays a bounded cache like JWKS — no database, Keto stays off the hot path. Wired: jwt-middleware.ts takes the denylist in VerifyOptions and throws TokenError(expired) on a revoked sub, so resolveSession routes it through the existing §4 re-mint (live session → fresh post-revoke JWT with current Keto roles; dead/deactivated → cleared cookie). app.ts merges it into authOptions (the same resolveSession hot-path call) and hands a bound revoke to the Users + Roles admin deps; admin-users.ts revokes on deactivate/delete, admin-roles.ts revokes a direct user: member on assign/unassign (a group:/whole-role change is transitive → left to lag, documented). server.ts builds it only when the toggle is on. Tests-first: denylist.test.ts (iat semantics, cutoff-advance, TTL eviction), jwt-middleware.test.ts (revoked→expired→re-mint, fresh passes), config.test.ts (toggle + posint TTL), app.test.ts (hot-path reject + fresh-login pass; admin deactivate/role-assign/unassign record the revoke). Stability-reviewer on the diff: APPROVE, no Critical/High/Medium (addressed its one Low). Per the §9 security-headers precedent, covered by unit + app-HTTP integration (no new browser E2E — no new user-facing page). README (Auth trade-off + new "Instant revoke" subsection, config table, Layout) updated. typecheck + 317 units green.

src/config.test.ts

@@ -21,6 +21,15 @@ test("loads dev defaults when the environment is empty", () => {
   assert.equal(c.hydraAdminUrl, "http://hydra:4445");
   assert.match(c.csrfSecret, /dev-insecure/);
   assert.equal(c.jwtClockSkewSec, 60); // default exp/nbf leeway for Kratos↔web clock drift
+  assert.equal(c.revocationDenylist, false); // instant-revoke is opt-in (§9)
+  assert.equal(c.revocationTtlSec, 900); // ≥ tokenizer TTL (10m) + skew
+});
+
+test("REVOCATION_DENYLIST: opt-in toggle (off by default) + REVOCATION_TTL_SEC must be a positive integer", () => {
+  assert.equal(loadConfig({ REVOCATION_DENYLIST: "true" }).revocationDenylist, true);
+  assert.throws(() => loadConfig({ REVOCATION_DENYLIST: "on" }), /REVOCATION_DENYLIST/);
+  assert.equal(loadConfig({ REVOCATION_TTL_SEC: "1200" }).revocationTtlSec, 1200);
+  for (const v of ["0", "-1", "1.5", "abc"]) assert.throws(() => loadConfig({ REVOCATION_TTL_SEC: v }), /REVOCATION_TTL_SEC/);
 });
 
 test("JWKS_URL defaults to the committed Kratos tokenizer signing key, not an http endpoint", () => {