Effect-TS Code Review

Orchestrate a multi-agent review of code changes against Effect-TS best practices.

Workflow

Step 1: Discover Changed Files

Run git diff --name-only main...HEAD to find all changed files on the current branch. If that fails (e.g., on main), fall back to git diff --name-only HEAD~1 or git diff --name-only for unstaged changes.

List the changed files for the user.

Step 2: Categorize Files

Split files into categories:

• Backend Effect files: .ts files NOT ending in .test.ts, NOT config files (.config.ts, tsconfig, etc.), NOT UI component library directories
• Test files: .test.ts files
• UI files: .tsx files
• Skip: .md, .json, .yml, .css, config files, generated files

Step 3: Launch Sub-Agents in Parallel

Based on which categories have files, launch the appropriate agents using the Agent tool. Launch all applicable agents in a single message for maximum parallelism.

If backend Effect files exist, launch these 4 agents in parallel:

• effect-primitives-reviewer — checks Effect primitives (Array, Match, Option, forEach, no try/catch, no async/await, Layer not Effect.provide)
• branded-types-reviewer — checks branded type usage for all entity IDs
• otel-reviewer — checks tracing setup (Effect.fn trace names, annotateCurrentSpan, structured logging)
• error-reviewer — checks error definitions and handling (Schema.TaggedError, catchTag, rich context)
• typescript-reviewer — checks TypeScript patterns (no as any, prefer satisfies over as, no manual type annotations on inferred types)

If test files exist, launch:

• test-coverage-reviewer — checks @effect/vitest patterns and assesses coverage gaps

If UI files exist, launch:

• ui-reviewer — checks component library usage, accessibility, layout, brand consistency

For each agent, provide the prompt:

Review the following files for [agent's specialty]. Read each file and produce a structured report with Critical/Warning/Info findings.

Files to review:

• [list of file paths]

Also review the reference guide at references/[relevant-reference].md (relative to this skill) for the detailed checklist.

Step 4: Unified Report

After all agents complete, compile results into a single report:

# Effect Review Report

## Effect Primitives
[agent output]

## Branded Types
[agent output]

## OTEL / Observability
[agent output]

## Error Handling
[agent output]

## TypeScript Patterns
[agent output]

## Test Coverage
[agent output]

## UI Quality
[agent output]

---

## Summary

| Category | Critical | Warning | Info |
|----------|----------|---------|------|
| Primitives | X | Y | Z |
| Branded Types | X | Y | Z |
| OTEL | X | Y | Z |
| Errors | X | Y | Z |
| TypeScript | X | Y | Z |
| Tests | X | Y | Z |
| UI | X | Y | Z |
| **Total** | **X** | **Y** | **Z** |

**Verdict**: PASS / NEEDS WORK / FAIL

**Score: X/10**

• PASS: 0 critical findings
• NEEDS WORK: 1-3 critical findings
• FAIL: 4+ critical findings

Scoring (0-10)

After compiling all findings, assign an overall score from 0 to 10:

• 10: Perfect — no findings at all, exemplary Effect-TS code
• 9: Excellent — only minor info-level suggestions
• 8: Great — a few warnings, no criticals
• 7: Good — several warnings but no criticals
• 6: Acceptable — 1 critical or many warnings
• 5: Needs work — 2-3 criticals
• 4: Below standard — 4-5 criticals
• 3: Poor — 6+ criticals or fundamental pattern violations
• 2: Very poor — majority of code ignores Effect patterns
• 1: Minimal compliance — almost no Effect patterns followed
• 0: No compliance — entirely non-Effect code submitted as Effect code

Display the score prominently at the end of the report.

Reference Files

Detailed checklists with codebase-specific examples:

• references/effect-primitives.md — Effect Array, Match, Option, forEach, Schema, Layer
• references/branded-types.md — Branded type usage and known types list
• references/otel-patterns.md — Tracing, span annotations, structured logging
• references/error-patterns.md — Schema.TaggedError, catchTag, error context
• references/typescript-patterns.md — No as any, prefer satisfies over as, no manual type annotations
• references/test-patterns.md — @effect/vitest, it.layer, coverage assessment
• references/effect-atom-patterns.md — Effect-Atom React patterns, queries, mutations, Result.builder