fix: preserve Responses tool call correlation IDs

[jan-kubica]

Summary

• use the Responses call_id as the canonical tool-call correlation ID
• preserve the distinct output-item id as provider metadata
• replay both identifiers during stateless server-tool follow-up requests
• apply the same protocol handling to OpenAI and OpenRouter Responses adapters

Root cause

Responses function calls carry two opaque identifiers with different roles: output-item id is referenced by streamed argument events, while call_id pairs the call with its function_call_output. The adapters keyed stream state by the output-item ID and also exposed that value as the tool-call ID, which discarded the actual correlation ID.

When the provider returned different values, the agent loop sent the output-item ID as function_call_output.call_id. The follow-up request could no longer correlate the tool result with the original call.

Tests

• add a two-turn OpenRouter server-tool regression test with deliberately distinct item and call IDs

• verify the follow-up request preserves both IDs before and after SDK serialization

• update OpenAI Responses coverage to assert call_id correlation and output-item metadata

• include OpenRouter Responses in the tool-calling E2E matrix

• pnpm test:pr

• targeted Playwright openrouter-responses — tool-calling scenario (1 passed)

Summary by CodeRabbit

• Bug Fixes

  • Preserved Responses output item IDs and function call IDs across server tool round trips.
  • Improved streaming tool-call event correlation with consistent toolCallId handling and retained tool-call names.
  • Ensured subsequent tool-call requests include the correct identifiers when converting for later turns.

• Tests

  • Updated streaming and request-mapping assertions for revised tool-call correlation semantics.
  • Added coverage for distinct item vs function-call IDs across multi-turn interactions.
  • Expanded E2E support matrix to include the OpenRouter Responses provider where applicable.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: 41b23a0f-51d8-4458-b2bc-0c9aa29e73b2

📥 Commits

Reviewing files that changed from the base of the PR and between 922159a and a00829e.

📒 Files selected for processing (2)

• packages/ai-openrouter/src/adapters/responses-text.ts
• packages/ai-openrouter/tests/openrouter-responses-adapter.test.ts

🚧 Files skipped from review as they are similar to previous changes (2)

• packages/ai-openrouter/tests/openrouter-responses-adapter.test.ts
• packages/ai-openrouter/src/adapters/responses-text.ts

---

📝 Walkthrough

Walkthrough

The Responses adapters now preserve output item IDs separately from function call IDs, use canonical call IDs for AG-UI tool events, and replay both identifiers in subsequent server-tool requests. Tests, exports, Changesets metadata, and E2E provider support are updated.

Changes

Responses tool-call identity

Layer / File(s)	Summary
Identity metadata contracts and state wiring packages/openai-base/src/adapters/responses-text.ts, packages/ai-openrouter/src/adapters/responses-text.ts, packages/*/src/message-types.ts, packages/*/src/index.ts	Adds typed metadata for Responses output item IDs and tracks separate call ID, item ID, name, and lifecycle state.
Streaming tool-call event correlation packages/openai-base/src/adapters/responses-text.ts, packages/ai-openrouter/src/adapters/responses-text.ts	Uses canonical call IDs for TOOL_CALL_START, TOOL_CALL_ARGS, and TOOL_CALL_END, while preserving output item IDs in event metadata across normal and backfill paths.
Server tool replay and validation packages/openai-base/src/adapters/responses-text.ts, packages/ai-openrouter/src/adapters/responses-text.ts, packages/*/tests/*, .changeset/fuzzy-pandas-call.md, testing/e2e/src/lib/feature-support.ts	Maps preserved item IDs to outbound function-call id fields, validates two-turn server-tool replay, updates expectations, and enables OpenRouter Responses E2E coverage.

Estimated code review effort: 4 (Complex) | ~45 minutes

Sequence Diagram(s)

sequenceDiagram
  participant ResponsesStream
  participant ResponsesTextAdapter
  participant ServerTool
  participant NextResponsesRequest
  ResponsesStream->>ResponsesTextAdapter: Emit function call with item ID and call ID
  ResponsesTextAdapter->>ServerTool: Emit tool events correlated by call ID
  ServerTool->>ResponsesTextAdapter: Return tool result
  ResponsesTextAdapter->>NextResponsesRequest: Replay function call item ID and output call ID

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🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and concisely summarizes the main change: preserving Responses tool call correlation IDs.
Description check	✅ Passed	The description covers the change, root cause, and tests, though it omits the template's checklist and release impact sections.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
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.

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Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@packages/ai-openrouter/src/adapters/responses-text.ts`:
- Around line 1161-1168: Update the output_item.added backfill around
toolCallMetadata and the output_item.done backfill in
packages/ai-openrouter/src/adapters/responses-text.ts#L1161-L1168 and
`#L1281-L1288`: initialize metadata.name with an empty-string fallback when
item.name is missing, and only update an existing name when both metadata.name
is absent and item.name is truthy. Preserve valid names and satisfy the
StreamedFunctionCallMetadata string contract at both sites.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: b38e706c-aabd-4520-9ef4-c475e9ce27a9

📥 Commits

Reviewing files that changed from the base of the PR and between 5fcaf90 and 922159a.

📒 Files selected for processing (9)

• .changeset/fuzzy-pandas-call.md
• packages/ai-openrouter/src/adapters/responses-text.ts
• packages/ai-openrouter/src/index.ts
• packages/ai-openrouter/src/message-types.ts
• packages/ai-openrouter/tests/openrouter-responses-adapter.test.ts
• packages/openai-base/src/adapters/responses-text.ts
• packages/openai-base/src/index.ts
• packages/openai-base/tests/responses-text.test.ts
• testing/e2e/src/lib/feature-support.ts