feat(ai-gateway): map custom LLM thought content

[chrarnoldus]

Summary

• add a validated thought_content_mapping property path to custom LLM configuration
• expose only response-safe transform settings to the response pipeline
• move marked streamed delta content into reasoning_content while preserving unmarked deltas

Testing

• pnpm --filter web exec jest --runInBand --forceExit --runTestsByPath src/lib/ai-gateway/experiments/build-direct-provider.test.ts src/lib/rewriteModelResponse.test.ts src/app/api/openrouter/[...path]/route.test.ts
• pnpm --filter web typecheck

[kilo-code-bot]

Code Review Summary

Status: No Issues Found | Recommendation: Merge

Executive Summary

Incremental review of commit 78e55ef ("require nullable transform fields"): ProviderResponseTransforms.thoughtContentMapping is now required-but-nullable and the rewriteModelResponse responseTransforms parameter lost its default; the sole production caller (route.ts:1037) and all Provider constructions already pass explicit values, the only ProviderResponseTransforms object literal (build-direct-provider.ts:206) always includes the property, consumption remains null-safe via optional chaining, and all test call sites pass an explicit argument — no runtime, security, or type-consistency issues introduced.

Files Reviewed (3 files)

• apps/web/src/lib/ai-gateway/providers/types.ts
• apps/web/src/lib/rewriteModelResponse.ts
• apps/web/src/lib/rewriteModelResponse.test.ts

Previous Review Summaries (3 snapshots, latest commit 9a9614b)

Current summary above is authoritative. Previous snapshots are kept for context only.

Previous review (commit 9a9614b)

Status: No Issues Found | Recommendation: Merge

Executive Summary

Incremental review of commit 9a9614b ("require response transform argument"): the responseTransforms parameter of rewriteModelResponse_ChatCompletions is now required-but-nullable, the sole production call chain (rewriteModelResponse → line 885) passes it explicitly, consumption remains null-safe via optional chaining, and all test call sites were updated with an explicit fifth argument — no runtime, security, or memory-leak issues introduced.

Files Reviewed (2 files)

• apps/web/src/lib/rewriteModelResponse.ts
• apps/web/src/lib/rewriteModelResponse.test.ts

Previous review (commit 4c6b7ad)

Status: No Issues Found | Recommendation: Merge

Executive Summary

Incremental review of the responseTransforms type refactor (optional undefined → required null): all Provider constructions (6 provider definitions, direct-BYOK, build-direct-provider, and both test mocks) now set responseTransforms: null, the rewriteModelResponse/rewriteModelResponse_ChatCompletions signatures default to null with unchanged falsy optional-chaining consumption, and the updated tests assert the new null behavior — runtime semantics are fully preserved and no memory-leak surface was introduced.

Files Reviewed (8 files)

• apps/web/src/app/api/openrouter/[...path]/route.test.ts
• apps/web/src/lib/ai-gateway/experiments/build-direct-provider.ts
• apps/web/src/lib/ai-gateway/experiments/build-direct-provider.test.ts
• apps/web/src/lib/ai-gateway/providers/get-provider.ts
• apps/web/src/lib/ai-gateway/providers/provider-definitions.ts
• apps/web/src/lib/ai-gateway/providers/types.ts
• apps/web/src/lib/ai-gateway/providers/upstream-request.generation.test.ts
• apps/web/src/lib/rewriteModelResponse.ts

Previous review (commit a33dd92)

Status: No Issues Found | Recommendation: Merge

Reviewed the thought-content-mapping feature end to end: the property path is schema-validated (rejecting __proto__/constructor/prototype and empty segments), read-only at traversal time, exposed as an optional provider transform, and applied only to streamed chat-completions deltas as described; the broadened per-choice loop and optional signature parameters are backwards compatible, and no memory-leak surface (intervals, listeners, retained buffers) was introduced.

Files Reviewed (8 files)

• apps/web/src/app/api/openrouter/[...path]/route.ts
• apps/web/src/app/api/openrouter/[...path]/route.test.ts
• apps/web/src/lib/ai-gateway/experiments/build-direct-provider.ts
• apps/web/src/lib/ai-gateway/experiments/build-direct-provider.test.ts
• apps/web/src/lib/ai-gateway/providers/types.ts
• apps/web/src/lib/rewriteModelResponse.ts
• apps/web/src/lib/rewriteModelResponse.test.ts
• packages/db/src/schema-types.ts

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_{Reviewed by kimi-k3 · Input: 25.3K · Output: 2.5K · Cached: 94.2K}

_{Review guidance: REVIEW.md from base branch main}