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+# 2026-07-29 — OpenAI Runtime Runs Unavailable
+
+- Status: Resolved
+- Severity: SEV-2
+- Window: 2026-07-29 16:31–20:37 UTC
+- Affected surface: OpenAI runtime
+- Public status update: https://mosoo.ai/status
+- Tracking PRs:
+  [#455](https://github.com/langgenius/mosoo/pull/455),
+  [#456](https://github.com/langgenius/mosoo/pull/456),
+  [#457](https://github.com/langgenius/mosoo/pull/457),
+  [#458](https://github.com/langgenius/mosoo/pull/458), and
+  [#459](https://github.com/langgenius/mosoo/pull/459)
+
+## Summary And Impact
+
+OpenAI Runtime users could submit a Run, but it failed before producing an
+assistant response. Depending on which release and sandbox state served the
+Run, users saw an inactive runtime, an OpenAI authentication failure, a generic
+502, or a runtime lifecycle maintenance error. Other runtime providers were not
+part of the confirmed impact.
+
+The number of affected users is unknown because the public production canary
+had not been activated. A user report first confirmed impact at 17:46 UTC.
+
+## Timeline
+
+- 16:31 — A production release enabled HTTPS interception for every sandbox.
+- 17:46 — A user report confirmed OpenAI Runtime Runs were failing.
+- 19:02 — HTTPS interception was limited to restricted-network sandboxes;
+  runtime startup recovered.
+- 19:37 — Codex app-server was configured to send OpenAI traffic through the
+  Mosoo LLM proxy.
+- 20:06 — Safe upstream failure logging reached production.
+- 20:08 — Production logs identified a Cloudflare-incompatible Fetch redirect
+  mode before any request reached OpenAI.
+- 20:18 — The proxy redirect fix reached production.
+- 20:27 — The checkpoint-directory repair reached production.
+- 20:34 — The affected Agent's sandbox automatically recovered from lifecycle
+  maintenance.
+- 20:37 — Recovery was confirmed by two successful production Runs on the
+  affected OpenAI Agent, including same-driver follow-up reuse.
+
+## Root Cause
+
+The incident combined four gaps along one production-only path:
+
+1. HTTPS interception was enabled for full-network sandboxes even though those
+   sandboxes did not receive an interception certificate, so the container
+   refused to start.
+2. Codex app-server requires `openai_base_url` configuration and does not use
+   the provisioned environment variable, so the Mosoo proxy grant was sent to
+   OpenAI as if it were an OpenAI key.
+3. The proxy used `redirect: "error"`. Bun accepted that mode, but Cloudflare
+   Workers rejects it before issuing the upstream request.
+4. Failed Runs left some pet sandboxes with stale session workspace records.
+   A missing workspace then made every checkpoint retry fail, keeping the
+   entire Agent in lifecycle maintenance.
+
+Unit and repository checks covered each component in isolation, but no active
+production canary exercised the complete OpenAI path through container startup,
+Codex app-server configuration, the Worker proxy, and sandbox recycling.
+
+## Detection And Response
+
+The incident was detected by a user report rather than the status surface.
+Production container logs identified the startup failure; a real OpenAI Run and
+temporary safe error logging then isolated the proxy failures. The status feed
+remained `unknown` because its production canary credentials and targets were
+not configured, which delayed detection and left the release freeze dependent
+on manual evidence.
+
+## Corrective Actions
+
+- [x] Runtime team — enable HTTPS interception only for limited-network
+      sandboxes — 2026-07-29
+- [x] Runtime team — configure Codex app-server with the Mosoo OpenAI proxy —
+      2026-07-29
+- [x] Runtime team — use the Cloudflare-supported manual redirect mode and keep
+      sanitized upstream failure logging — 2026-07-29
+- [x] Runtime team — make checkpoint targets exist before backup so stale
+      workspaces cannot wedge an Agent — 2026-07-29
+- [ ] Runtime team — activate all three public production canaries and verify
+      `/status.json` records real Runs — 2026-08-03
+- [ ] Runtime team — add a Worker-runtime proxy smoke test to catch platform
+      Fetch differences before deployment — 2026-08-07
+
+## Lessons
+
+Passing unit tests did not prove the production runtime path because Bun and
+Cloudflare implement different redirect modes, and the Driver's OpenAI
+configuration contract differs from ordinary environment-based SDKs. A release
+that changes sandbox boot or provider routing needs a real production Run as
+its acceptance check. The public status page also needs an active canary; an
+unconfigured `unknown` feed is not incident detection.