MobileBuildMCP Rendering and Streaming Review

Review guardrails for rendering boundaries, streaming fragments, and output modes.

Review scope

• Review-only by default.
• Do not edit product code unless the user explicitly requests implementation changes.

Files to inspect

• src/rendering/**
• src/types/domain-fragments.ts
• src/types/runtime-status.ts
• src/runtime/tool-invoker.ts
• src/runtime/__tests__/tool-invoker.test.ts
• xcodebuildmcp.com/app/docs/_content/architecture-rendering-output.mdx
• xcodebuildmcp.com/app/docs/_content/architecture-tool-lifecycle.mdx
• xcodebuildmcp.com/app/docs/_content/output-formats.mdx

Guardrails

• Tool handlers do not branch on CLI vs MCP output mode.
• Fragments represent progress, not final contract data.
• Final structured output remains canonical.
• Do not invent json/jsonl render strategies.
• Streaming tools emit typed fragments and one final structured result.
• Non-streaming tools do not emit unnecessary fragments.
• Keep ctx.emit and xcodebuild pipeline emitFragment contexts separate.
• Keep next-step rendering in runtime/rendering boundary.

Validation

• npm test -- src/runtime/__tests__/tool-invoker.test.ts
• npm run test:snapshots
• npm run typecheck
• npx skill-check .agents/skills/mobilebuildmcp-rendering-streaming-review