review-pr

SMG PR Review

The Iron Law

NO REVIEW APPROVAL WITHOUT CHECKING ALL TOUCHED SUBSYSTEMS

If you haven't mapped the changed files to checklist sections, you cannot start reviewing.

The Hard Gate

Do NOT write review comments, approve, or provide feedback until you have: 1. Fetched the full diff 2. Listed every changed file 3. Mapped each file to the checklist sections below 4. Created a task for each applicable section

Process

1. FETCH: Get the PR diff (gh pr diff <number>)
2. MAP: List changed files → match to sections using the file-to-section table
3. TASK: Create one review task per matched section
4. CHECK: Work through each task, flag issues as blocker/suggestion/nit
5. ANTI-PATTERNS: Read @anti-patterns.md for the touched subsystems
6. SUMMARIZE: List all findings with severity and file:line citations

File-to-Section Mapping

Files Changed	Review Sections
crates/protocols/src/	1 (Layering), 3 (Worker Lifecycle)
model_gateway/src/config/	2 (Config Plumbing)
model_gateway/src/main.rs	2 (Config Plumbing)
model_gateway/src/service_discovery.rs	3 (Worker Lifecycle)
model_gateway/src/worker/, model_gateway/src/workflow/steps/local/	3 (Worker Lifecycle)
model_gateway/src/policies/	4 (Routing Policy)
model_gateway/src/routers/ (incl. anthropic/, gemini/, responses/, conversations/, grpc/)	1 (Layering), 4 (Routing Policy)
model_gateway/src/middleware/ (scheduler, tenant_resolution, rate limit)	1 (Layering), 10 (Architecture) — no dedicated section yet
crates/tool_parser/src/	5 (Parser Changes)
crates/reasoning_parser/src/	5 (Parser Changes)
crates/data_connector/src/	6 (Storage)
bindings/	2 (Config Plumbing)
Any file	7 (Error Handling), 8 (Testing), 9 (Code Quality)

Sections 7, 8, 9 always apply. Section 10 applies to PRs touching 3+ files or adding new types.

Review Checklist

1. Layering & Separation of Concerns

• No new fields in crates/protocols/ types that only one crate sets
• Config types at correct layer: user-facing → config/types.rs, runtime → module-specific
• No raw strings parsed at runtime — parse at boundary
• WASM/MCP concerns stay in their crates, not leaking into core

2. Config Plumbing

• BOTH to_router_config() AND to_server_config() in main.rs updated
• CLI flag has value_parser validation
• Default impl includes new fields
• #[serde(default, skip_serializing_if)] for backward compat
• Python bindings struct literals updated
• Go SDK updated if new types exposed

3. Worker Lifecycle & Label Pipeline

• New metadata flows through label pipeline (not parallel _override fields)
• Model ID resolution chain not bypassed
• WorkerSpec kept minimal at discovery time
• No post-hoc ModelCard mutation — inject via labels before build_model_card

4. Routing Policy

• Works for both HTTP and gRPC paths (SelectWorkerInfo)
• All state is Send + Sync (DashMap, Arc — no bare Mutex on hot paths)
• No .unwrap() on worker slices — handle empty list
• Circuit breaker checked: w.is_healthy() && w.circuit_breaker_can_execute()
• Policy implements LoadBalancingPolicy and is registered in policies/factory.rs with a PolicyConfig enum variant

5. Parser Changes (Tool / Reasoning)

• Implements full trait (all methods + reset)
• Streaming state correct (buffer, partial token detection, delta calc)
• Registered in ParserFactory with model pattern mapping
• Tests: single call, multiple calls, streaming at boundaries, invalid input

6. Storage / Data Connector

• Implements all required traits
• Schema migrations handled
• Hook system integration (audit, validation)
• Batch operations supported

7. Error Handling

• No unwrap() in production code
• Meaningful error messages with anyhow::Context
• Invalid config fails loudly — no silent fallback to None
• thiserror for domain errors, anyhow for wrapping

8. Testing

• Unit tests for new types/parsing including error cases
• Integration test for full flow
• Existing test struct literals updated with new fields
• E2E tests if user-facing behavior changes (in e2e_test/ — tests run sequentially with class-scoped backends)
• E2E test markers set: @pytest.mark.engine(...), @pytest.mark.gpu(count), @pytest.mark.model(...) as needed

9. Code Quality

• Conventional commit format
• DCO sign-off present
• No AI attribution
• cargo +nightly fmt --all clean
• cargo clippy --all-targets --all-features -- -D warnings clean
• Uses #[expect] with reason, not #[allow]
• tracing for logging, not println!

10. Architecture Smell Tests

• "If I remove K8s, does this change still make sense?" → shouldn't be in crates/protocols/
• "Can existing config overrides or labels achieve this?" → may be unnecessary
• "Does this compose with DP-aware mode, PD disagg, mesh HA?" → don't break existing
• "Is this Send + Sync safe under concurrent load?" → all routing state thread-safe
• "Did I check both HTTP and gRPC paths?" → dual-mode is easy to forget

See @anti-patterns.md for subsystem-specific anti-patterns.

Rationalization Prevention

Excuse	Reality
"This change is small, I can eyeball it"	Small changes cause the biggest bugs — the two-path config rule is a one-line omission.
"I know this code well"	Familiarity breeds blindness. Use the checklist.
"It's just a config change"	Config changes touch the most layers (CLI → types → main.rs → bindings). Check section 2.
"Tests pass so it's fine"	Tests don't catch layering violations, missing bindings, or one-path config bugs.

Red Flags — STOP

• About to approve without mapping files to sections
• Skipping a section because "it doesn't apply" without checking the mapping table
• No file:line citations in review comments
• Approving a config change without verifying both conversion paths
• Reviewing without fetching the actual diff first