Summary

• Problem: self-hosted Kimi/SGLang routes on openai-completions could emit streamed tool-call arguments in shapes the existing repair wrapper knows how to fix, but the runner only enabled that wrapper for anthropic-messages + Kimi.
• Why it matters: fragmented or malformed tool-call args could reach tool dispatch as empty or unusable objects, breaking the turn.
• What changed: renamed the stale Anthropic-only gate to shouldRepairMalformedToolCallArguments, kept the existing Kimi provider behavior, and additionally enabled the repair wrapper for openai-completions transports. Added focused guard tests and generalized the repair log wording.
• What did NOT change (scope boundary): this does not rewrite the repair algorithm itself, broaden the helper to every transport, or change tool-call ID handling.

Change Type (select all)

• Bug fix
• Feature
• Refactor required for the fix
• Docs
• Security hardening
• Chore/infra

Scope (select all touched areas)

• Gateway / orchestration
• Skills / tool execution
• Auth / tokens
• Memory / storage
• Integrations
• API / contracts
• UI / DX
• CI/CD / infra

Linked Issue/PR

• Closes [Bug]: openai-completions: Kimi/SGLang streamed tool-call arguments can arrive in a shape that breaks tool dispatch #69672
• Related Fix #67488: Handle Unicode smart quotes in tool call argument JSON #67551
• This PR fixes a bug or regression

Root Cause (if applicable)

• Root cause: the malformed-argument repair wrapper already existed, but run/attempt.ts only enabled it when params.model.api === "anthropic-messages" and the provider normalized to Kimi.
• Missing detection / guardrail: there was no direct test locking in the enablement gate itself, only wrapper-behavior tests once the wrapper was already active.
• Contributing context (if known): self-hosted Kimi/SGLang reports the problematic stream shape over openai-completions, so the repair path stayed dormant even though the runtime already had logic for this class of malformed stream.

Regression Test Plan (if applicable)

• Coverage level that should have caught this:
  • Unit test
  • Seam / integration test
  • End-to-end test
  • Existing coverage already sufficient
• Target test or file:
  • src/agents/pi-embedded-runner/run/attempt.tool-call-argument-repair.test.ts
  • src/agents/pi-embedded-runner/run/attempt.test.ts
• Scenario the test should lock in: Kimi on anthropic-messages still enables repair, openai-completions now enables repair even for non-Kimi provider ids, and unrelated transports remain off.
• Why this is the smallest reliable guardrail: the bug was in wrapper enablement, not in the repair parser itself.
• Existing test that already covers this (if any): src/agents/pi-embedded-runner/run/attempt.test.ts already covers the live wrapper behavior after enablement.
• If no new test is added, why not: N/A

User-visible / Behavior Changes

• Self-hosted openai-completions backends such as Kimi/SGLang now get the existing malformed streamed tool-call argument repair path, reducing empty-argument or unusable-argument tool dispatch failures.

Diagram (if applicable)

Before:
[self-hosted openai-completions stream] -> [wrapper gate off] -> [malformed args reach tool dispatch]

After:
[self-hosted openai-completions stream] -> [wrapper gate on] -> [existing repair wrapper normalizes args]

Security Impact (required)

• New permissions/capabilities? No
• Secrets/tokens handling changed? No
• New/changed network calls? No
• Command/tool execution surface changed? No
• Data access scope changed? No
• If any Yes, explain risk + mitigation: N/A

Repro + Verification

Environment

• OS: macOS
• Runtime/container: local pnpm workspace checkout
• Model/provider: self-hosted Kimi/SGLang on openai-completions; existing Kimi anthropic-messages path preserved
• Integration/channel (if any): N/A
• Relevant config (redacted): N/A

Steps

1. Run a model on openai-completions that streams fragmented tool-call arguments.
2. Observe the embedded runner stream wrapper selection in run/attempt.ts.
3. Verify the malformed-argument repair wrapper is now installed for that transport and existing repair tests remain green.

Expected

• The runner enables malformed tool-call argument repair for openai-completions and preserves existing Kimi behavior.

Actual

• Matches expected in local verification.

Evidence

• Failing test/log before + passing after
• Trace/log snippets
• Screenshot/recording
• Perf numbers (if relevant)

Human Verification (required)

• Verified scenarios:
  • pnpm check:changed
  • pnpm tsgo
  • pnpm test src/agents/pi-embedded-runner/run/attempt.tool-call-argument-repair.test.ts src/agents/pi-embedded-runner/run/attempt.test.ts
• Edge cases checked:
  • normalized Kimi provider ids still return true on anthropic-messages
  • openai-completions now returns true even when the provider id is not normalized to Kimi
  • openai-responses remains disabled
• What you did not verify:
  • live round-trip against a real external SGLang endpoint from this PR branch

Review Conversations

• I replied to or resolved every bot review conversation I addressed in this PR.
• I left unresolved only the conversations that still need reviewer or maintainer judgment.

Compatibility / Migration

• Backward compatible? Yes
• Config/env changes? No
• Migration needed? No
• If yes, exact upgrade steps: N/A

Risks and Mitigations

• Risk: enabling the wrapper for every openai-completions route is broader than a Kimi-only gate and could affect other OpenAI-compatible backends.
  • Mitigation: the wrapper already has targeted repair heuristics and existing tests remain green; unrelated non-openai-completions transports remain unchanged.
• Risk: future parser changes might regress the enablement contract again.
  • Mitigation: the new focused gate tests lock in the intended transport/provider matrix.