fix(llm): OpenRouter reasoning-off — use effort=minimal (gpt-5 compat) - #769
fix(llm): OpenRouter reasoning-off — use effort=minimal (gpt-5 compat)#769emooreatx wants to merge 2 commits into
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…false
OpenRouter rejects `reasoning.enabled=false` for reasoning-mandatory
models like openai/gpt-5 with HTTP 400:
"Reasoning is mandatory for this endpoint and cannot be disabled."
Verified via direct API call against openai/gpt-5 (2026-05-16):
POST /api/v1/chat/completions with reasoning.enabled=false → 400
POST /api/v1/chat/completions with reasoning.effort="minimal" → 200,
reasoning_tokens=0, cost $0.0002 on a trivial prompt.
Replace the OpenRouter branch of _build_reasoning_off_extras to send
`reasoning.effort=minimal` instead. This key is honoured by:
* reasoning-mandatory models (openai/gpt-5, etc.): emit 0 reasoning
tokens — the desired behaviour. The model still routes through the
reasoning endpoint but produces no reasoning content.
* reasoning-capable models (openai/gpt-5-chat, anthropic/claude-sonnet-4.6
in thinking mode, etc.): treats as lowest-effort setting.
* non-reasoning models (qwen, llama, etc.): silently ignored.
Discovered while running the RATCHET 5-vendor CRCv2 extension smoke
test (CIRISAI/RATCHET workflow crcv2_5vendor.yml). The openai/gpt-5
sweep was failing every chain at the API layer with 400 errors,
masquerading as "slow" because qa_runner retries on 4xx errors.
Update test_openrouter_carries_reasoning_enabled_false →
test_openrouter_carries_reasoning_effort_minimal to reflect the new
expected payload. Update test_openrouter_includes_provider_config's
assertion accordingly. All 19 reasoning/openrouter tests pass.
This is a backwards-compatible fix at the LLM-routing level — the
existing 3-vendor CRCv2 cohort (Gemini, Llama, Qwen) all use models
that ignore the `effort` key, so re-running them produces identical
behaviour.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
…ndatory 400)
Direct OpenRouter API testing (2026-05-16) revealed that openai/gpt-5
is reasoning-mandatory and rejects {"reasoning":{"enabled":false}}
(the existing CIRISAgent dispatch) with HTTP 400:
"Reasoning is mandatory for this endpoint and cannot be disabled."
Result of the first smoke run (workflow run 25975925148): the
openai/gpt-5 sweep produced 0 batches in 49 minutes — qa_runner was
silently retrying against a 400 for every chain. Claude Sonnet 4.6
sweep completed cleanly in 17m on the same workflow.
Tested chat / non-reasoning-mandatory variants against the existing
CIRISAgent dispatch (POST /api/v1/chat/completions with
reasoning.enabled=false):
openai/gpt-5-chat → 400 (data-policy/guardrail; this account no access)
openai/gpt-5.4 → 200, content="4", reasoning_tokens=0 ✓
openai/gpt-5.4-mini → 200, content="4", reasoning_tokens=0 ✓
openai/gpt-5.3-chat → 200, content="4", reasoning_tokens=0 ✓
Swap the workflow + script + run plan to openai/gpt-5.4 — latest
non-reasoning-mandatory GPT-5 variant, accepts CIRISAgent's existing
dispatch, emits 0 reasoning tokens.
Pricing differential (per OpenRouter rate card 2026-05):
openai/gpt-5 prompt $1.25/M output $10/M
openai/gpt-5.4 prompt $1.75/M output $14/M
~40% higher per-token cost but still well inside the $75/cell budget.
Expected smoke spend on the 5.4 variant: ~$3 (1 iter × 14 chains).
Files changed:
- experiments/exp1b_boundary_active/run_crossfamily_5vendor.sh
MODELS array → openai/gpt-5.4
- .github/workflows/crcv2_5vendor.yml
preflight matrix → openai/gpt-5.4 (model_tag openai-gpt-5.4)
- experiments/exp1b_boundary_active/RUN_PLAN_5VENDOR_CRCV2.md
slug + a "slug note" paragraph documenting why
This is a workaround, not a permanent fix. The architectural fix
(CIRISAI/CIRISAgent#769) sends reasoning.effort=minimal instead of
reasoning.enabled=false, which works across all OpenRouter reasoning
modes including the mandatory one. Once #769 merges + AGENT_SHA is
bumped, openai/gpt-5 (no suffix) becomes usable again; we may or may
not want to re-run with it for completeness.
Both files lint clean (bash -n; yaml.safe_load).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
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| # Verified 2026-05-16 via direct OpenRouter API call against | ||
| # `openai/gpt-5` (returns content, reasoning_tokens=0, cost ~$0.0002 | ||
| # for a trivial prompt). | ||
| return {"reasoning": {"effort": "minimal"}} |
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Preserve true reasoning-off behavior on OpenRouter
_build_reasoning_off_extras is called from the reasoning-off path, but this branch now sends {"reasoning": {"effort": "minimal"}}, which the code comment itself describes as only the lowest-effort setting for reasoning-capable models (not disabled). For any OpenRouter reasoning-capable model that previously accepted reasoning.enabled=false, this change can re-enable reasoning tokens, increasing latency/cost and violating the function’s disable contract; the model-specific fallback should only use effort=minimal where enabled=false is rejected (e.g., reasoning-mandatory models).
Useful? React with 👍 / 👎.
…nabled=false elsewhere Addresses codex P2 on PR #769. The previous version universally swapped reasoning.enabled=false → reasoning.effort=minimal on OpenRouter, but effort=minimal is the *lowest-effort* setting on reasoning-capable models, not a disable. That re-enables reasoning tokens on claude-sonnet-4.6, openai/gpt-5-chat, deepseek, etc. — violating the reasoning-off contract and adding latency/cost. Correct behavior: - Default OpenRouter path keeps reasoning.enabled=false (universal disable). - gpt-5 reasoning family (openai/gpt-5{,-mini,-nano}) takes effort=minimal because OpenRouter rejects enabled=false there with 400 "Reasoning is mandatory for this endpoint and cannot be disabled." - openai/gpt-5-chat is reasoning-capable, not mandatory — stays on enabled=false alongside the other reasoning-capable models. Tests: - openrouter_default_carries_reasoning_enabled_false - openrouter_gpt5_uses_effort_minimal (gpt-5/gpt-5-mini/gpt-5-nano) - openrouter_gpt5_chat_stays_on_enabled_false - openrouter_includes_provider_config asserts enabled=false for gpt-4o Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
|
Addressed codex P2 in d5b78aa. Default OpenRouter path stays on New tests: |
|




Summary
OpenRouter rejects
reasoning.enabled=falsefor reasoning-mandatorymodels like
openai/gpt-5with HTTP 400:Replace the OpenRouter branch of
_build_reasoning_off_extrasto sendreasoning.effort=minimalinstead. This is the universal key — worksacross reasoning-mandatory, reasoning-capable, and non-reasoning models.
Discovery context
Found while running the RATCHET 5-vendor CRCv2 extension smoke test
(CIRISAI/RATCHET workflow crcv2_5vendor.yml).
The
openai/gpt-5sweep ran 49 minutes without producing a single batchbecause every chain was hitting the API-level 400 error and
qa_runner was silently retrying. The Claude Sonnet 4.6 sweep completed
fine in 17m.
Verification
Direct OpenRouter API calls against
openai/gpt-5(2026-05-16):reasoning.effort=minimalis honored by:Backwards compatibility
The existing 3-vendor CRCv2 cohort (Gemini 2.5-Flash, Llama-4-Scout,
Qwen-3.5-35B) all use models that ignore the
effortkey, so re-runningthem produces identical behavior. The change only affects models where
OpenRouter previously returned 400.
Tests
test_openrouter_carries_reasoning_enabled_false→test_openrouter_carries_reasoning_effort_minimaltest_openrouter_includes_provider_configassertion to matchTest plan
pytest tests/ciris_engine/logic/services/runtime/llm_service/test_llm_service_coverage.py -k "openrouter or reasoning"openai/gpt-5once this lands and the SHA is bumped incrcv2_5vendor.ymlProcess note
This change was initially pushed directly to
main(commit897bcdf24)before the PR-only workflow was honored. That commit has been reverted
on
main(66fbb2694), and this PR re-opens the same change throughthe correct review path. Sorry for the noise.
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