[jackjinke]

Summary

OpenCode Go can return a single Responses API reasoning item that contains both explicit plaintext (content[].type === "reasoning_text") and non-empty opaque state (encrypted_content). The extractor treated any opaque companion as a veto and dropped the portable plaintext, so the next DeepSeek tool-call continuation failed with:

400: The `reasoning_text` in the thinking mode must be passed back to the API.

Opaque-only reasoning from a previous provider could also hard-fail a direct cross-model replay instead of being dropped when the selected target could not transport it.

Fixes #10949 and #10959. Related: #10550, #10574.

Change

• extractReplayableResponsesReasoningText() (open-sse/services/reasoningInputPolicy.ts): explicit plaintext now wins over a coexisting opaque companion; opaque-only items are still never converted or exposed.
• applyReasoningInputPolicy(): mixed input is projected onto the target transport, and incompatible reasoning is dropped by default. Combos retain the explicit Skip strategy to fall through without mutating the request.
• Responses → Chat request translator: mixed items replay their plaintext companion; opaque-only items are dropped instead of throwing.
• Combo advanced settings retain Drop/Skip, with Drop as the default and without the warning text.

Test Plan

New regressions:

• Non-streaming extraction: mixed item preserves reasoning_content and caches for replay (tests/unit/reasoning-cache.test.ts)
• Streaming response.output_item.done: mixed item replays plaintext; opaque-only still emits nothing fabricated (tests/unit/translator-resp-openai-responses.test.ts)
• Policy projection: mixed input follows the target transport instead of rejecting, both directions (tests/unit/strip-reasoning-blobs-agentic-context-1599.test.ts)
• Request translator: mixed item replays its plaintext companion (tests/unit/translator-openai-responses-req.test.ts)
• Direct Responses and Chat replay drops incompatible opaque reasoning by default; Combo Skip still rejects the attempt for target fallthrough (tests/unit/chatcore-translation-paths.test.ts)

Legacy tests locking in the old direct mixed/opaque rejection behavior were flipped to the new contract.

Commands run:

# focused suites (all green)
npx cross-env DISABLE_SQLITE_AUTO_BACKUP=true node --import tsx/esm --import ./open-sse/utils/setupPolyfill.ts --import ./tests/_setup/isolateDataDir.ts --test --test-force-exit --test-concurrency=1 \
  tests/unit/reasoning-cache.test.ts \
  tests/unit/strip-reasoning-blobs-agentic-context-1599.test.ts \
  tests/unit/translator-resp-openai-responses.test.ts \
  tests/unit/translator-openai-responses-req.test.ts
# plus chatcore/combo/translator neighbor suites (all green)

# #10959 follow-up: 155 pass
npx cross-env DISABLE_SQLITE_AUTO_BACKUP=true node --import tsx/esm --import ./open-sse/utils/setupPolyfill.ts --import ./tests/_setup/isolateDataDir.ts --test --test-force-exit --test-concurrency=1 tests/unit/strip-reasoning-blobs-agentic-context-1599.test.ts tests/unit/translator-openai-responses-req.test.ts tests/unit/chatcore-translation-paths.test.ts tests/unit/combo-attempt-body-isolation-7847.test.ts

# full gate, excluding tests/unit/cli-serve-stop-command.test.ts per ~/OMNIROUTE_TESTS_SKIP_20128.txt
npm run test:coverage

Final coverage result (gate requires ≥60% each):

Metric	Result
Statements	84.02%
Branches	79.06%
Functions	87.25%
Lines	84.02%

Note: two pre-existing failures in vision-bridge-maxchars.test.ts / vision-compression-authoritative-capability-7237.test.ts are unrelated to this change (vision modality bridge settings, untouched here); coverage gate passed regardless.

[diegosouzapw]

Nice, tightly-scoped fix. I verified the mixed plaintext+opaque projection and the new drop-by-default flow: the reasoning tests pass locally (strip-reasoning 16/16, reasoning-cache + both Responses translators 140/140, and chatcore-translation-paths 75/75 on a clean run). One optional nit: the docstring on extractReplayableResponsesReasoningText (open-sse/services/reasoningInputPolicy.ts, before line 94) still says "a record carrying opaque state is never cross-converted," which now contradicts the #10949 behavior you're shipping (mixed plaintext IS projected and replayed). Consider rewording the first sentence so future readers don't misread the intent. No mandatory items from my review.