fix(oauth): release Anthropic refresh intent after a proven-unsent DNS failure

[lidge-jun]

Summary

Fixes the lockout in #6570: when an Anthropic OAuth token refresh failed DNS resolution before connecting, the durable refresh intent stayed behind. The next refresh then refused with OAuthLoginRequiredError and the account needed a fresh login, even after the network recovered.

• src/oauth/anthropic.ts: postJson treats a fetch rejection as "request never sent" only when no outbound proxy is configured, either at process startup or in the current environment, and the error is a structured code: "ENOTFOUND", syscall: "getaddrinfo" for the token URL's own hostname. It then throws AnthropicTokenError with requestNotSent: true and no HTTP status. Only the fetch call is inside that catch; body reads and parsing stay outside.
• The token exchange is pinned to a single HTTP/1.1 attempt with keepalive: false and redirect: "manual". On the pinned Bun 1.4.0, the HTTP/1 client retries pooled sockets only for idempotent methods, but the HTTP/2 client can retry a buffered body after REFUSED_STREAM. Disabling keep-alive and pinning HTTP/1.1 means that DNS error can't follow bytes already sent.
• A 3xx from the token endpoint is an unknown outcome: a 303 can follow a completed POST (RFC 9110 §15.4.4). It throws AnthropicTokenError with no HTTP status, so the intent is kept, and the unread body is cancelled.
• Bun keeps the proxy it saw at process start even after the environment changes. The release therefore also requires that no outbound proxy was configured at startup. src/lib/proxy-env.ts captures this once as startupOutboundProxyConfigured; src/config/proxy-env.ts, the only runtime writer of proxy keys, imports that module, so the snapshot is taken before any write on the CLI, server, and compiled-sidecar entry paths.
• src/oauth/index.ts: refreshAnthropicAccountWithLock handles that typed flag the same way it handles existing pre-dispatch evidence. It releases the intent through the existing generation-safe clearAnthropicRefreshIntentForKnownFailure(..., "pre-dispatch", ...) and invents no HTTP status. Terminal handling, ownership and stale-flight guards, and the definitive-rejection path are unchanged.
• Everything else keeps the replay guard: timeouts, redirects, unstructured or wrong-host DNS errors, DNS-shaped failures while reading a returned body, and any request with a proxy configured now or at startup.
• structure/providers/anthropic-account-pool.md documents the unsent-attempt rule and its transport assumptions; structure/transports/inventory.md documents the startup proxy snapshot.

This carries the local patch @atinseau posted on #6570 into current dev, hardened with the startup and current proxy guards, the HTTP/1.1 pin, and redirects treated as unknown outcomes. The commit includes their Co-authored-by trailer.

Refs #6570

Verification

The full local suite was intentionally not run, per maintainer instruction for this landing train; hosted CI at the exact head is the merge evidence.

Focused commands at 1c0e29a409 (Bun 1.4.0, macOS arm64):

• bun run typecheck — exit 0
• bun test tests/oauth/oauth-refresh.test.ts — 67 pass, 0 fail, run from two startup environments: once with all six outbound proxy keys removed before Bun starts, and once launched with HTTPS_PROXY=http://proxy.invalid:8080. The real-adapter block covers HTTP 503 recovery; 302 and 303 redirects keep the intent; timeout keeps the intent; invalid_grant requires reauth; wrong-host DNS, unstructured DNS text, and DNS-shaped body-read failure keep the intent; and a proxy configured now keeps the intent. Each case asserts the call count and the redirect/keepalive/protocol fetch options. Child processes cover startup state. One starts with no proxy keys, so structured token-host DNS releases the intent and the retry succeeds with two token calls. The others start with HTTPS_PROXY, so the intent is kept after the variable is deleted or emptied. The direct-DNS check is wired to fail if the release path is disabled, which I confirmed.
• bun test tests/oauth/oauth-anthropic-identity.test.ts — 53 pass
• bun test tests/adapters/anthropic/anthropic-hardening.test.ts — 10 pass
• bun test tests/lib/provider-egress.test.ts tests/lib/socks5-fetch.test.ts — 44 pass
• bun run structure:check, bun run privacy:scan, git diff --check — pass
• Transport probes on Bun 1.4.0 (reserved .invalid hosts and a local server only, no credentials, no token sent to Anthropic): an unresolvable host yields structured ENOTFOUND/getaddrinfo with the target hostname; HTTP and SOCKS proxy failures surface the proxy hostname or a SOCKS error without DNS fields; a pooled POST is not retried; redirect: "manual" returns the 3xx as a response without following it. An empty, credential-free POST to the token endpoint answers HTTP 400 directly, without redirecting.
• src/oauth/index.ts is 1992 lines (unchanged since the first commit; unbaselined, under the 2000 threshold); no new test files, so the layout registries are unchanged.

Security review (OAuth refresh boundary)

An independent review of 85903a3ce0 returned REQUEST-CHANGES with two findings. (P1) Manual redirects made a 3xx status-bearing, so the existing cleanup released the intent although a 303 can follow a completed POST. (P2) The current-environment proxy check missed Bun's retained startup proxy. Both are fixed in cbbef21ae8. A second independent review of the full diff at cbbef21ae8 returned APPROVE-WITH-NITS with no blockers. It confirmed that only a proven-unsent DNS failure releases the intent; that terminal handling, generation-safe cleanup, and ownership and stale-flight guards are unchanged; that no secrets are logged; and that the startup snapshot is taken before any runtime proxy write on every entry path. Its one nit, cancelling the unread redirect body, is applied in 4eb332be3b.

@Ingwannu's review at 4eb332be3b found the direct-DNS regression depended on the runner's startup proxy state. 1c0e29a409 moves that case into a child process started without proxy keys and changes only the test file. A delta review of 4eb332be3b..1c0e29a409 returned APPROVE: production code and docs are byte-identical, the child keeps the isolated homes, and no in-process case depends on startup proxy state. It passed 67/67 from proxy-free, HTTPS_PROXY, and ALL_PROXY startup environments.

Checklist

• Scope stays focused and avoids unrelated cleanup.
• Docs or release notes were updated when needed.
• Security-sensitive changes were reviewed for secrets, auth, and unsafe defaults.

Summary by CodeRabbit

• Bug Fixes
  • Improved Anthropic credential refresh handling so a token request that fails with a confirmed token-host DNS lookup failure, when no outbound proxy is configured, can be retried safely without treating credentials as rejected.
  • Redirects and other uncertain network failures continue to preserve refresh safeguards and prevent potentially unsafe retries.
• Documentation
  • Clarified how startup and current proxy settings affect whether a failed token request is considered safe to retry.

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• tests/oauth/oauth-refresh.test.ts

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📝 Walkthrough

Walkthrough

Anthropic token requests now use explicit HTTP/1.1 settings and proxy-state checks to classify certain token-host DNS failures as unsent. Refresh-intent cleanup uses that classification. Tests cover retry, intent retention, and reauthentication outcomes.

Changes

Anthropic refresh intent handling

Layer / File(s)	Summary
Classify token-request transport outcomes src/lib/proxy-env.ts, src/oauth/anthropic.ts, structure/transports/inventory.md, structure/providers/anthropic-account-pool.md	startupOutboundProxyConfigured captures proxy configuration at module load. postJson disables keep-alive and automatic redirects. A matching token-host DNS failure is marked as unsent only when startup and current proxy settings permit it. The documentation describes these conditions and the intent-release boundary.
Apply transport outcomes to refresh intents src/oauth/index.ts, tests/oauth/oauth-refresh.test.ts	Refresh-intent cleanup uses pre-dispatch for an Anthropic token error marked as not sent. Tests cover HTTP errors, redirects, DNS failures, timeouts, response-body failures, invalid grants, and startup or current proxy configuration.

Priority: ➖ Normal

Estimated code review effort: 3 (Moderate) | ~25 minutes

Change: Bug fix

Sequence Diagram(s)

sequenceDiagram
  participant OAuthRefresh
  participant postJson
  participant fetch
  participant IntentCleanup
  OAuthRefresh->>postJson: Submit token request
  postJson->>fetch: Send HTTP/1.1 request without redirects
  fetch-->>postJson: Return response or transport failure
  postJson-->>OAuthRefresh: Return response or raise token error
  OAuthRefresh->>IntentCleanup: Select cleanup reason from outcome

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Merge Risk: ⚪ Minimal · up to 1c0e2

No actionable issue remains from this review; the change is mergeable after normal checks.

Security Architecture Review

Security architecture risk: 🔵 Low · up to 1c0e2

The change is narrowly scoped and preserves conservative handling of uncertain refresh outcomes. No new security flaw was established, but safe retry depends on transport behavior that was not independently demonstrated.

Retained concerns
No architecture-level concerns identified.

Security review details

Security Blast Radius

• inferred — The changed decision affects Anthropic account refresh attempts and their local persisted replay guards. If the non-dispatch assumption were false, releasing a guard could permit reuse of an already consumed refresh token and consequent account revocation. The inspected evidence does not establish that runtime failure sequence or an attacker-controlled way to induce it.

Trust Boundaries and Controls

• observed — The cleanup owner accepts the adapter's typed requestNotSent assertion as authority to release intent, rather than trusting error text or an HTTP response body. Attempt, account, generation, and flight matching constrain cleanup so it cannot intentionally delete a replacement or foreign intent through this path.

Hardening Proposals

• proposed — Preserve repeatable transport-level evidence for the exact supported runtime showing that this POST configuration cannot emit the classified DNS failure after dispatch. Revalidate that invariant when changing runtime versions, fetch wrappers, or proxy behavior.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 3 functions across 4 files.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly summarizes the main change: releasing the Anthropic refresh intent after a DNS failure proves the token request was not sent.

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[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-10-04T15:06:22.337042Z	4eb332b	Draft marked ready

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Reviewed commit: 4eb332be3b

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Actionable comments posted: 1

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Inline comments:
Review comments at @tests/oauth/oauth-refresh.test.ts:
- Around line 618-619: Update the direct-DNS scenario setup around the proxyKeys
cleanup so startupOutboundProxyConfigured begins false, rather than relying on
deleting proxy variables after startup state is initialized; use a child process
with proxy keys removed at launch or an isolated startup-state fixture. Keep the
separate startup-proxy subprocess tests unchanged.

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📥 Commits

Reviewing files that changed from the base of the PR and between 584b92a and 4eb332b.

📒 Files selected for processing (6)

• src/lib/proxy-env.ts
• src/oauth/anthropic.ts
• src/oauth/index.ts
• structure/providers/anthropic-account-pool.md
• structure/transports/inventory.md
• tests/oauth/oauth-refresh.test.ts

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[Ingwannu]

P2 — Isolate the direct-DNS regression from the process's startup proxy state (tests/oauth/oauth-refresh.test.ts:618-646). Confirmed against exact head 4eb332b.

startupOutboundProxyConfigured is captured during module evaluation before this scenario deletes proxy variables. With HTTPS_PROXY set at process startup, production correctly preserves the refresh intent; the direct scenario nevertheless requires the intent to be absent at line 646. This is a valid test-reliability blocker, not evidence that the production startup-proxy guard should be loosened.

Independent Linux/Bun 1.4.0 reproduction, synthetic fetches only:

• Startup HTTPS_PROXY=http://proxy.invalid:8080: bun test tests/oauth/oauth-refresh.test.ts --test-name-pattern 'structured token-host DNS' — 0 pass, 1 fail, 66 filtered, exit 1 at the pending-intent assertion; peak memory 65.4 MiB.
• Separate fresh proxy-free startup (all six outbound proxy keys removed before Bun starts), same command/head — 1 pass, 0 fail, 66 filtered, 12 assertions, exit 0.
  Both ran sequentially as ubuntu with CPUQuota=75%, MemoryHigh=1280M, MemoryMax=1536M, swap=0, TasksMax=64, IOWeight=20, nice=10, RuntimeMaxSec=120 and bounded 5s stop, fresh private homes. All fetches in the selected case are mocked; no real account/provider/native call. Protected real-home snapshots remained unchanged and the owned units ended.

Please run the direct-DNS case in a child started without proxy variables (or an explicitly isolated startup-state fixture), preserving the separate startup-proxy cases. Validate from both startup environments and resolve the corresponding still-valid advisory threads, then refresh exact-head CI. Hosted green in a proxy-free runner does not cover this counterexample. This scoped correctness request does not claim an independent OAuth-boundary review, waive that duty, or authorize a new scan.

[lidge-jun]

@Ingwannu Thanks for the reproduction. Fixed in 1c0e29a, which changes only tests/oauth/oauth-refresh.test.ts; production code and docs are unchanged from 4eb332be3b.

The structured token-host DNS case no longer runs in the test process. It runs in a child process launched with all six outbound proxy keys removed. It asserts startupOutboundProxyConfigured === false, requestNotSent, a cleared intent, and a successful retry with two token calls and the pinned fetch options. The two startup-proxy cases use the same spawn helper and still launch with HTTPS_PROXY set, then delete or empty it, so the intent is kept. The production startup-proxy guard is unchanged.

Validation at 1c0e29a409 used only the focused file, never the suite:

• Launch with all outbound proxy keys removed: bun test tests/oauth/oauth-refresh.test.ts, 67 pass, 0 fail.
• Launch with HTTPS_PROXY=http://proxy.invalid:8080: same file, 67 pass, 0 fail.
• An independent delta reviewer also ran it with an ALL_PROXY startup: 67 pass.
• With the release path temporarily disabled in postJson, the new direct-DNS case fails 0/1, so it does detect the behavior.
• bun run typecheck passes.

The connector and CodeRabbit threads on this point are resolved. Exact-head CI is running at 1c0e29a409.

[Ingwannu]

The test-reliability blocker in my review 5406885843 is fixed at 1c0e29a. The direct-DNS case now starts a child with all six proxy keys removed before module evaluation; separate startup-proxy/deleted/empty cases keep their own startup snapshots. Production OAuth/proxy code is byte-identical to the previously reviewed 4eb332b head.

Independent Linux/Bun 1.4.0 validation with the parent launched under HTTPS_PROXY=http://proxy.invalid:8080: bun test tests/oauth/oauth-refresh.test.ts --test-name-pattern 'Anthropic real-adapter transport intent' — 12 pass, 0 fail, 55 filtered, 86 assertions, exit 0. Covers direct-DNS retry, startup/current proxy retention, 302/303 redirects, 503, timeout, invalid_grant, wrong-host/unstructured/body-read failures. Every provider response was synthetic; no real token/provider call.

Sequential ubuntu execution, exact-head worktree, fresh private HOME/CODEX_HOME/OPENCODEX_HOME/TMPDIR, CPUQuota75%, MemoryHigh1280M/MemoryMax1536M, swap0, Tasks64, IOWeight20, nice10, RuntimeMax120/stop5s. Peak memory72.2MiB; unit ended, protected real-home snapshots unchanged. I am withdrawing only that reproduced test blocker. This is not an approving OAuth-boundary review or merge decision: current-head CI37215099026 has now completed success, and the required independent boundary-review/attribution duties remain.

Withdrawn: the specific startup-proxy test-isolation P2 is fixed at 1c0e29a and independently passed 12 synthetic transport-intent tests under a proxied parent. This dismisses only review 5406885843's test blocker, not a whole-PR/auth-boundary approval; current-head CI remains pending.

[lidge-jun]

Maintainer integration (lidge-jun, dev only) — 2026-10-04 landing train, lane L2.

• Head: 1c0e29a
• CI at this head: runs 37215099026 (Cross-platform CI), 37215212759 (enforce-target); every executed job passed.
• Review: fixes [Bug]: Anthropic OAuth DNS failure leaves a durable intent and permanently requires re-login #6570 carrying atinseau's patch (Co-authored-by); DNS-only intent release with proven-unsent evidence; security review APPROVE + delta APPROVE; Ingwannu P2 test isolation fixed and re-reviewed.
• Full local suite intentionally not run per maintainer instruction; hosted CI is the evidence.
• scripts/ci/assert-mergeable-review.sh --maintainer-integration: OK.