Skip to content

feat: add reasoning_content support for OpenRouter chat completions#88

Merged
jpr5 merged 1 commit into
mainfrom
feat/openrouter-reasoning-content
Apr 7, 2026
Merged

feat: add reasoning_content support for OpenRouter chat completions#88
jpr5 merged 1 commit into
mainfrom
feat/openrouter-reasoning-content

Conversation

@AlemTuzlak

@AlemTuzlak AlemTuzlak commented Apr 7, 2026

Copy link
Copy Markdown
Contributor

Summary

  • Adds reasoning_content field to chat completions streaming (delta.reasoning_content) and non-streaming (message.reasoning_content) responses
  • Updates collapseOpenAISSE to extract reasoning_content from chat completions delta chunks for record-and-replay
  • OpenRouter models that support reasoning (DeepSeek, Claude via OpenRouter, etc.) return thinking tokens via this field — aimock previously only supported reasoning for the Responses API and Anthropic Messages API

What's included

This PR covers the aimock mock server side — emitting reasoning_content in /v1/chat/completions responses when a fixture has reasoning set. It does NOT cover any additional OpenRouter-specific behavior (e.g. reasoning_details, model routing, provider preferences). Those may need separate work.

Files changed

  • src/types.ts — added reasoning_content to SSEDelta and ChatCompletionMessage
  • src/helpers.ts — buildTextChunks and buildTextCompletion now accept and emit reasoning
  • src/server.ts — passes response.reasoning through to chat completions builders
  • src/stream-collapse.ts — extracts reasoning_content from chat completions deltas
  • Tests — 5 new tests covering streaming, non-streaming, absence, delta reconstruction, and stream-collapse

Test plan

  • Streaming: reasoning_content deltas emitted before content deltas
  • Streaming: reasoning_content deltas reconstruct full reasoning text
  • Streaming: content deltas still reconstruct full text
  • Streaming: no reasoning_content when fixture has no reasoning
  • Non-streaming: reasoning_content present in message
  • Non-streaming: reasoning_content absent when no reasoning
  • Stream-collapse: extracts reasoning_content from chat completions deltas
  • All 2034 existing tests still pass

🤖 Generated with Claude Code

@pkg-pr-new

pkg-pr-new Bot commented Apr 7, 2026 •
edited
Loading

Copy link
Copy Markdown

Open in StackBlitz

npm i https://pkg.pr.new/@copilotkit/aimock@88

commit: 66e61be

jpr5
jpr5 previously approved these changes Apr 7, 2026
View reviewed changes

@jpr5 jpr5 left a comment

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

PR Review Summary

Reviewed by 7 specialized agents (code-reviewer, silent-failure-hunter, test-analyzer, comment-analyzer, type-design-analyzer, test-file-reviewer, CI/packaging) across all 6 changed files.

Zero actionable findings — clean PR.

The implementation is straightforward and well-executed. reasoning_content is correctly threaded through the full pipeline:

  • Types (SSEDelta, ChatCompletionMessage): optional, not nullable — matches OpenRouter's wire format
  • Helpers (buildTextChunks, buildTextCompletion): reasoning chunks emitted before content (streaming), conditional spread for non-streaming — both correct
  • Server (handleCompletions): passes response.reasoning through to both builders — clean plumbing
  • Stream collapse (collapseOpenAISSE): extracts reasoning_content from deltas using the same defensive pattern as existing content extraction

Tests are solid — 8 new tests covering streaming ordering, content/reasoning reconstruction, absence cases, and stream-collapse extraction. Assertions are specific (exact string equality, index comparison for ordering), not weak.

One note

The branch is ~21 commits behind main (branched before v1.8.0). A rebase before merge would confirm no conflicts with the reasoning work that landed in PR #81.

🤖 Reviewed with Claude Code

@AlemTuzlak @jpr5
feat: add reasoning_content support for OpenRouter chat completions
66e61be 
OpenRouter returns reasoning via reasoning_content in the chat completions
message/delta format. This adds support for emitting and collapsing
reasoning_content in both streaming and non-streaming responses.
@jpr5
jpr5 force-pushed the feat/openrouter-reasoning-content branch from fc6a74c to 66e61be Compare April 7, 2026 21:38
@jpr5
jpr5 merged commit fd4bf4a into main Apr 7, 2026
18 checks passed
@jpr5
jpr5 deleted the feat/openrouter-reasoning-content branch April 7, 2026 22:12
@jpr5

jpr5 commented Apr 7, 2026

Copy link
Copy Markdown
Contributor

Thank you! 🙏

This was referenced Apr 8, 2026
Merged
Merged
Merged
jpr5 added a commit that referenced this pull request Apr 8, 2026
@jpr5
Release v1.9.0 (#97)
dbe574c 
## Summary

- **Per-test sequence isolation** via `X-Test-Id` header — each test
gets its own fixture match counters across all 12 HTTP + 3 WebSocket
handlers (#93)
- **Combined content + toolCalls** in fixture responses — new
`ContentWithToolCallsResponse` type across OpenAI Chat, Responses,
Anthropic Messages, and Gemini with stream collapse support (#92)
- **OpenRouter reasoning_content** support (#88)
- **Clean URLs** for docs site — all pages restructured as directories,
.html extensions removed from links
- Fix `web_search_call` items to use `action.query` matching real OpenAI
API (#89)
- Bump aimock-pytest to 0.3.0

## Version bumps
- `package.json`: 1.8.0 → 1.9.0
- `pyproject.toml`: 0.2.0 → 0.3.0
- `Chart.yaml` appVersion: 1.8.0 → 1.9.0
- `plugin.json` / `marketplace.json`: 1.8.0 → 1.9.0

## Test plan
- [x] All 2206 tests pass (including 80 new clean-URL validation tests)
- [x] Build passes
- [x] Prettier clean
- [ ] npm publish triggers automatically on merge via OIDC workflow
- [ ] Verify v1.9.0 appears on npm after merge

🤖 Generated with [Claude Code](https://claude.com/claude-code)
jpr5 added a commit that referenced this pull request Jul 15, 2026
@jpr5
feat: add reasoning_content support for OpenRouter chat completions (#88
9abacec 
)

## Summary

- Adds `reasoning_content` field to chat completions streaming
(`delta.reasoning_content`) and non-streaming
(`message.reasoning_content`) responses
- Updates `collapseOpenAISSE` to extract `reasoning_content` from chat
completions delta chunks for record-and-replay
- OpenRouter models that support reasoning (DeepSeek, Claude via
OpenRouter, etc.) return thinking tokens via this field — aimock
previously only supported reasoning for the Responses API and Anthropic
Messages API

## What's included

This PR covers the **aimock mock server** side — emitting
`reasoning_content` in `/v1/chat/completions` responses when a fixture
has `reasoning` set. It does NOT cover any additional
OpenRouter-specific behavior (e.g. `reasoning_details`, model routing,
provider preferences). Those may need separate work.

## Files changed

- `src/types.ts` — added `reasoning_content` to `SSEDelta` and
`ChatCompletionMessage`
- `src/helpers.ts` — `buildTextChunks` and `buildTextCompletion` now
accept and emit reasoning
- `src/server.ts` — passes `response.reasoning` through to chat
completions builders
- `src/stream-collapse.ts` — extracts `reasoning_content` from chat
completions deltas
- Tests — 5 new tests covering streaming, non-streaming, absence, delta
reconstruction, and stream-collapse

## Test plan

- [x] Streaming: reasoning_content deltas emitted before content deltas
- [x] Streaming: reasoning_content deltas reconstruct full reasoning
text
- [x] Streaming: content deltas still reconstruct full text
- [x] Streaming: no reasoning_content when fixture has no reasoning
- [x] Non-streaming: reasoning_content present in message
- [x] Non-streaming: reasoning_content absent when no reasoning
- [x] Stream-collapse: extracts reasoning_content from chat completions
deltas
- [x] All 2034 existing tests still pass

🤖 Generated with [Claude Code](https://claude.com/claude-code)
jpr5 added a commit that referenced this pull request Jul 15, 2026
@jpr5
Release v1.9.0 (#97)
5adcb59 
## Summary

- **Per-test sequence isolation** via `X-Test-Id` header — each test
gets its own fixture match counters across all 12 HTTP + 3 WebSocket
handlers (#93)
- **Combined content + toolCalls** in fixture responses — new
`ContentWithToolCallsResponse` type across OpenAI Chat, Responses,
Anthropic Messages, and Gemini with stream collapse support (#92)
- **OpenRouter reasoning_content** support (#88)
- **Clean URLs** for docs site — all pages restructured as directories,
.html extensions removed from links
- Fix `web_search_call` items to use `action.query` matching real OpenAI
API (#89)
- Bump aimock-pytest to 0.3.0

## Version bumps
- `package.json`: 1.8.0 → 1.9.0
- `pyproject.toml`: 0.2.0 → 0.3.0
- `Chart.yaml` appVersion: 1.8.0 → 1.9.0
- `plugin.json` / `marketplace.json`: 1.8.0 → 1.9.0

## Test plan
- [x] All 2206 tests pass (including 80 new clean-URL validation tests)
- [x] Build passes
- [x] Prettier clean
- [ ] npm publish triggers automatically on merge via OIDC workflow
- [ ] Verify v1.9.0 appears on npm after merge

🤖 Generated with [Claude Code](https://claude.com/claude-code)
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Reviewers

@jpr5 jpr5 jpr5 left review comments

Assignees

No one assigned

Labels

None yet

Projects

None yet

Milestone

No milestone

Development

Successfully merging this pull request may close these issues.

2 participants

@AlemTuzlak @jpr5