LibreChat/api/server
Danny Avila 738003b220
🛡️ fix: Prevent silent crash from unhandled MCP OAuth reconnect rejections (#12812)
* 🛡️ fix: Install global `unhandledRejection` handler

Node 15+ terminates the process by default when a promise rejection goes
unhandled. Under MCP OAuth reconnect storms and streamable-HTTP transport
resets, fire-and-forget async paths can emit transient rejections (ECONNRESET,
token refresh races) that would otherwise silently kill the server — no
uncaught exception log, no OOM signal. Register a listener so these paths log
and the process keeps serving other requests.

Refs: #12078

* 🔧 fix: Guard MCP OAuth reconnect fire-and-forget calls

`OAuthReconnectionManager.tryReconnect` awaits `getServerConfig` outside its
inner try/catch, so a rejection from the registry (or any throw before the
guarded block) would escape the fire-and-forget `void` call sites and
propagate as an unhandled rejection — the failure mode behind the silent
crashes reported in #12078. Route both call sites through a `safeTryReconnect`
wrapper that attaches a terminal `.catch` so unexpected rejections are
surfaced via the logger instead.

Refs: #12078

* 🧹 fix: Address review findings on MCP OAuth reconnect crash fix

- Move `getServerConfig` inside `tryReconnect`'s try/catch so the registry
  rejection path is handled by the inner cleanup (the structural root cause
  behind the silent crash). The outer `safeTryReconnect` wrapper remains as
  defense-in-depth.
- Extract the failed-reconnect cleanup as a private `cleanupOnFailedReconnect`
  method and invoke it from `safeTryReconnect`'s catch as well, so any
  rejection that does escape the inner try (e.g. a future regression) still
  resets tracker state instead of leaving the server stuck in `active` for
  the full `RECONNECTION_TIMEOUT_MS` window.
- Update the regression test to assert tracker state is cleaned up
  (`isActive` cleared, `isFailed` set, `disconnectUserConnection` called) so
  it can detect the stale-state failure mode it was meant to guard against.
- Forward non-Error rejection reasons as-is in the global handler so
  structured payloads like `{ code: "ECONNRESET", errno: -104 }` survive
  instead of being collapsed to "[object Object]" by `String()`.

Refs: #12078, review of #12812

* 🚑 fix: Restore fail-fast on boot rejection in primary server entry

`startServer()` was invoked bare in `api/server/index.js`. Before installing
the global `unhandledRejection` handler, a startup rejection (`connectDb`,
`getAppConfig`, `performStartupChecks`) terminated the process via Node's
default — Kubernetes / the orchestrator restarted the pod immediately.

After the handler was added, the same rejection was caught and logged, then
the process kept running half-initialized (no HTTP listener) until the
liveness probe eventually timed out — slow, indirect recovery instead of a
fast restart.

Wrap `startServer()` with the same `.catch(() => process.exit(1))` pattern
already used in `experimental.js` so boot failures fail-fast.

Refs: #12078, codex review of #12812

* 🚑 fix: Fail-fast on post-listen init failure in both server entries

The `app.listen` callback in `index.js` and `experimental.js` is async and
awaits `initializeMCPs`, `initializeOAuthReconnectManager`, and
`checkMigrations`. The callback's promise is detached from
`startServer().catch(...)` (the outer catch only sees errors that occurred
before `app.listen` was called), so without explicit handling those init
rejections used to terminate the process via Node's default and now would
be swallowed by the new `unhandledRejection` handler — leaving the HTTP
server listening (and passing liveness probes) while MCP / OAuth / migration
state is broken.

Wrap the post-listen init block in a try/catch that logs and calls
`process.exit(1)` so initialization failures stay fail-fast.

Refs: #12078, codex review of #12812
2026-04-24 23:18:49 -07:00
..
controllers 🧹 fix: Clean Up Orphaned Agent File Stubs After Deletion (#12781) 2026-04-22 11:35:48 -07:00
middleware ⚡ refactor: Short-Circuit Config Override Resolution (#12553) 2026-04-07 22:38:08 -04:00
routes 🔐 fix: Restore Tenant Context in MCP OAuth Callback (#12782) 2026-04-22 14:05:51 -07:00
services 🧹 fix: Clean Up Orphaned Agent File Stubs After Deletion (#12781) 2026-04-22 11:35:48 -07:00
utils 🏗️ refactor: Remove Redundant Caching, Migrate Config Services to TypeScript (#12466) 2026-03-30 16:49:48 -04:00
cleanup.js 🧹 refactor: Tighten Config Schema Typing and Remove Deprecated Fields (#12452) 2026-03-29 01:10:57 -04:00
experimental.js 🛡️ fix: Prevent silent crash from unhandled MCP OAuth reconnect rejections (#12812) 2026-04-24 23:18:49 -07:00
index.js 🛡️ fix: Prevent silent crash from unhandled MCP OAuth reconnect rejections (#12812) 2026-04-24 23:18:49 -07:00
index.spec.js 🚦 fix: 404 JSON Responses for Unmatched API Routes (#11976) 2026-02-27 22:49:54 -05:00
socialLogins.js 🔐 feat: Admin Auth Support for SAML and Social OAuth Providers (#12472) 2026-03-30 22:49:44 -04:00