Fboss Review Agent Skill

FBOSS Review

Overview

Multi-reviewer code review for FBOSS diffs. Subsumes general review (/review-diff functionality) plus FBOSS-specific domain expertise.

Scope

Currently fboss/ only. TODO: extend to configerator/source/neteng/fboss, neteng/netcastle, neteng/fboss.

IMPORTANT: No Auto-Posting

All findings are shown to the user only. Never post to Phabricator automatically.

Review Workflow

Step 1: Identify Changes

• Run sl status and sl diff to get changed files
• If user specifies a diff number, fetch diff details via mcp__plugin_meta_mux__get_phabricator_diff_details

Step 2: Determine Applicable FBOSS Reviewers

• Files in agent/, SwSwitch, HwSwitch -> Agent Reviewer (#6)
• Files in fsdb/, thrift_cow/ -> FSDB/thrift_cow Reviewer (#7)
• Files in platform/, config, sensor/fan -> Platform Reviewer (#8)
• Files in sai/, hw/sai/, SDK -> SAI/SDK Reviewer (#9)
• Test files or coverage-affecting changes -> Testing Reviewer (#10)
• Changes spanning SwSwitch + HwSwitch, new SwitchState fields, new counters, BUCK dependency/target changes, new client infrastructure, or 3+ directory scope -> Architect Reviewer (#11)

Step 3: Dispatch Reviewers in Parallel

Use Agent tool (sonnet model) to dispatch all applicable reviewers simultaneously:

• Generic reviewers 1-5: ALWAYS dispatch. Use personas from references/generic-reviewers.md.
• FBOSS reviewers 6-10: Dispatch ONLY if their area is touched.
• Each reviewer receives: full diff content + their persona instructions.
• FBOSS reviewers additionally load patterns from ../fboss-code-standards/references/<area>-patterns.md.

| # | Reviewer | Focus | Patterns File |

|---|----------|-------|---------------|

| 1 | Reliability | Error handling, RAII, logging, timeout/retry, graceful degradation | - |

| 2 | Engineering / Performance | Algorithmic complexity, unnecessary copies, lock contention, modern C++ | - |

| 3 | Code Quality | Readability, modularity, duplication, API design | ../fboss-code-standards/references/general-patterns.md |

| 4 | Summary & Test Plan | Title accuracy, summary completeness, test plan adequacy, diff coherence | - |

| 5 | Silent Failure Finder | Logic errors, lossy conversions, race conditions, silent data loss | - |

| 6 | Agent Architecture | Mono/multi-switch, state management, warmboot, HwSwitch/SwSwitch boundary | ../fboss-code-standards/references/agent-patterns.md |

| 7 | FSDB & thrift_cow | State/Stats duality, COW node safety, subscriptions, build time | ../fboss-code-standards/references/thrift-cow-fsdb-patterns.md |

| 8 | Platform & Config | Platform services, JSON configs, startup order, OSS sync | ../fboss-code-standards/references/platform-config-patterns.md |

| 9 | SAI/SDK Integration | SAI API usage, object lifecycle, vendor SDK compat, attributes | ../fboss-code-standards/references/sai-sdk-patterns.md |

| 10 | Testing Standards | Coverage, naming, fixtures, NSDB impact, HW test patterns | ../fboss-code-standards/references/testing-patterns.md |

| 11 | FBOSS Architect | Cross-cutting design: layering, state derivability, abstraction, code org, infra reuse | references/fboss-specific-reviewers.md |

Step 4: Verification

Dispatch a single verifier agent (loads references/verifier.md) to:

• Deduplicate findings across reviewers
• Calibrate confidence scores
• Filter false positives
• Threshold: only report findings with confidence >= 0.7

Step 5: Present Findings

Output a structured report:

| File:Line | Reviewer | Severity | Issue | Confidence |
|-----------|----------|----------|-------|------------|

Never post findings to Phabricator.

When to Load References

| Topic | Action |

|-------|--------|

| Generic reviewer personas | Read references/generic-reviewers.md |

| Verification/dedup logic | Read references/verifier.md |

| FBOSS-specific reviewer personas | Read references/fboss-specific-reviewers.md |

| Adding/modifying reviewers | Read references/contributing.md |