[maxmad64bis]

Base-red inherited: #14547

Summary

When several keyless accounts share one connection pool, every retry leaves through the same pool member, so each attempt after a 429 hits the same refused address on providers whose quota is bucketed by egress address. After this change a per-address 429 asks the connection pool for another member for the next attempt. Orders, never excludes: an exhausted pool keeps the current behavior, and a resolver answer for the member the request already egressed through is ignored silently. Opt-in via OPENCODE_POOL_RESELECT (default off); with the flag off the rotation is exactly the plain rotation.

Related Issues

Related to #14620 (merged: the shared capture context this PR reads the resolver through is now on the base)
Related to #13578 (merged refusal-memory mechanism this follows up per attempt)
Related to #13657 (stop/park 429 semantics this preserves)

Validation

• Change type: routing
• Focused tests: tests/unit/opencode-429-pool-reselect.test.ts 6/6 GREEN on the rebuilt head 3705c946 + flag guards 58/58
• npm run lint — ESLint on the touched files is clean (exit 0 with frozen suppressions); the full run is red on the base (🔴 Release branch not green: release/v3.8.51 #14547)
• Reconciled with the current active release base; focused checks rerun afterward (rev-list HEAD..upstream/release/v3.8.51 = 0 @ 3705c946, single commit, post-fix(sse): share applied proxy capture across duplicated fetch modules #14620 merge)
• Production-code changes include a new or updated automated test in this PR

Tests Added Or Updated

• tests/unit/opencode-429-pool-reselect.test.ts (6 cases: re-selects after per-address 429, keeps the member for non-bucketed providers, null resolver keeps behavior, flag-off inert, same-member answer ignored without logging, mixed fleets keep dedicated proxies; 6/6 GREEN on the rebuilt head)
• Replayed neighbors on the rebuilt head: feature-flags-settings + server-owned-tool-loop-flag 58/58

Coverage Notes

Unit tests cover the change (open-sse/executors/opencode.ts 429 arm): re-selection on the retry path, provider allowlist gate, null-exhausted fallback, flag-off path, same-member ignore, and the mixed-fleet guard. No coverage movement beyond the new test.

Reviewer Notes

• Post-fix(sse): share applied proxy capture across duplicated fetch modules #14620 rebuild: the branch is now one commit (3705c946) on the release tip (7d23bcf8); the parent symbol (APPLIED_PROXY_CONTEXT_KEY / getAppliedProxyContext in open-sse/utils/proxyFetch.ts, merged via fix(sse): share applied proxy capture across duplicated fetch modules #14620) is on the base, and this PR consumes it through the new currentAppliedProxySink().reselectPoolMember reader. The stacked-on banner is dropped.
• File-size rebaselined with operator approval (_rebaseline_2026_09_24_14659_pool_reselect_per_attempt_growth): own growth opencode.ts 1301->1355 (+54), proxyFetch.ts 1294->1311 (+17), chat.ts 2563->2564 (+1), chatHelpers.ts 1258->1303 (+45); additive, flag-off inert, covered by the new test. The chatcore-compression-integration test-size flag cites a file outside this PR.
• Reds qualified as inherited (§12): check-api-typecheck cites only auggie.ts / projectCombo.ts, both outside this PR (diff on them is empty); check-env-doc-sync cites DEEP_HEALTH_CHECK_ENABLED, also outside this PR and present on the tip; check-mutation-test-coverage --strict and the full lint run stay red on the base (🔴 Release branch not green: release/v3.8.51 #14547).

Maintainer rework (merge-batch 2026-09-24)

• fix(sse): share applied proxy capture across duplicated fetch modules #14620 (the stacked dependency) is merged and this branch was already rebased on it; merged the current release/v3.8.51 tip into the branch (real merge, contributor commit untouched).
• Conflicts resolved keeping both sides: OPENCODE_POOL_RESELECT sits next to the new STREAM_READINESS_STALL_RETRY flag (definitions, wrapper, ENVIRONMENT.md), the flag-count assertions go to 79, and the per-attempt dispatch now goes through the tip's headersWaitDispatch while still running under account.proxy ?? reselectedProxy.
• file-size-baseline.json: own growth re-measured after the merge (opencode.ts 1338→1392, proxyFetch.ts 1334→1351, chat.ts 2567→2568) under a dated annotation. eslint-suppressions.json: pruned two suppressions that no longer occur (tightening only; the pre-commit hook refused the merge otherwise).
• Red→green: tests/unit/opencode-429-pool-reselect.test.ts fails 1/6 with the base opencode.ts (the re-selection case; the other five are guard cases that must keep today's behavior) and passes 6/6 on this head.
• Focused suites (6 files, 98 tests) green except the known inherited flake opencode-proxy-refusal-memory.test.ts › "a connection without configured accounts never touches the memory", which also fails intermittently on the base tip. typecheck:core 0 errors, check:open-sse-typecheck 0 errors, eslint clean on touched files, check:env-doc-sync and check-file-size OK.

[diegosouzapw]

Good follow-up to #14655/#14657's per-address quota theme, from the account-rotation side this
time — re-selecting a live pool member (never forcing) after a per-address 429 when the account
has no proxy of its own, gated behind OPENCODE_POOL_RESELECT with the stop/park-ending exits
placed correctly before the reselection point. The 270-line test file with 6 RED-then-GREEN cases
looks solid. This is stacked on #14620 as noted — merging that one first, then this.