Evolution

This skill makes the skills library evolve based on real development signals without auto-editing skills. The default output is a patch suggestion only.

Why it exists (solving "too passive")

Default hooks can only "log events" without automatically consolidating experience into skills.

The goal of this skill is to turn retrospectives into a fixed closing action:

At the end of each "big task", spend 60 seconds on Q&A confirmation: whether to optimize skills and which areas to prioritize
When user chooses "yes to optimize", use skill-improver to generate minimal patch suggestions based on real run artifacts (still no auto-editing of skill library)

Default strategy

Capture context and failures into run artifacts
Generate evolution candidates
Use skill-improver to propose a minimal patch
Human reviews and applies the patch

Global hooks (recommended)

Hooks live in: ~/.claude/skills/skill-evolution/hooks/

Add to your global settings (or project settings) so hooks run automatically.

Example (merge into ~/.claude/settings.json or <project>/.claude/settings.json):

Evolution settings

Configure behavior via ~/.claude/skills/skill-evolution/hooks/settings.json:

{
  "min_fail_count": 2,
  "ignore_tool_errors": true,
  "noise_filters": {
    "ignore_patterns": [
      "typescript: type.*already exists",
      "eslint:.*no-unused-vars.*react",
      "prettier:.*prettier-ignore"
    ],
    "max_failures_per_run": 20,
    "recent_only": true,
    "recent_window_minutes": 60
  },
  "output_format": {
    "summary_only": false,
    "include_context": true,
    "include_recent_failures": 20,
    "sort_by": "frequency"
  }
}

Settings explanation:

min_fail_count: Minimum occurrences of a single error type before generating a candidate
ignore_tool_errors: Whether to ignore tool-level errors (vs user code errors)
noise_filters.ignore_patterns: List of regex patterns to ignore
max_failures_per_run: Maximum failures to record per session (prevent explosion)
recent_only: Only look at failures within recent time window
recent_window_minutes: Only count failures within the last N minutes
output_format: Controls evolution-candidates.md output format

{
  "hooks": {
    "PreToolUse": [
      {
        "matcher": "Bash|Write|Edit",
        "hooks": [
          {
            "type": "command",
            "command": "bash ~/.claude/skills/skill-evolution/hooks/pre-tool.sh"
          }
        ]
      }
    ],
    "PostToolUse": [
      {
        "matcher": "Bash",
        "hooks": [
          {
            "type": "command",
            "command": "bash ~/.claude/skills/skill-evolution/hooks/post-bash.sh \"$TOOL_OUTPUT\" \"$EXIT_CODE\""
          }
        ]
      },
      {
        "matcher": "Write|Edit",
        "hooks": [
          {
            "type": "command",
            "command": "bash ~/.claude/skills/skill-evolution/hooks/post-tool.sh \"$TOOL_OUTPUT\" \"$EXIT_CODE\""
          }
        ]
      }
    ],
    "Stop": [
      {
        "matcher": "",
        "hooks": [
          {
            "type": "command",
            "command": "bash ~/.claude/skills/skill-evolution/hooks/session-end.sh"
          }
        ]
      }
    ]
  }
}

Run artifacts

Hooks write to project-local run folders:

<project-root>/runs/evolution/<run_id>/
  logs/
    events.jsonl
    failures.jsonl
    state.json
    context.json
  evolution-candidates.md
  evolution-review.md

run_id is stored in <project-root>/runs/evolution/.current so all hooks in a session write to the same run.

Evolution checkpoint (default action at end of big tasks)

When you have just completed a "deliverable big task" (e.g., you have already written final.md or filled the run’s tasks.md Delivery summary), you must do a brief retrospective when closing, and give the choice to the user.

In the conversation, ask only 3 questions (prefer multiple choice to reduce cost):

Do you want to optimize skills based on this run?
- A. Yes, propose a patch now (recommend using skill-improver first to generate minimal patch)
- B. Record the issue first, optimize later
- C. Not needed
What was the biggest blocker this time?
- A. Missing input/context fields (need clearer I/O contracts)
- B. Unclear plan/granularity too large (need to split or clarify validation steps)
- C. Environment/dependency/command issues (need scripting or fixed commands)
- D. UI/design iterations (need clearer design-system or UI subtask splitting)
- E. External service/permissions/configuration (need clearer confirmation points and verification)
- F. Other (explain in one sentence)
Which direction do you want to prioritize for optimization?
- A. I/O contracts: Fix artifact names, fields, paths
- B. Index/summary: Less context, better resume navigation (proposal/tasks)
- C. Scripts/templates: Turn repetitive steps into deterministic scripts
- D. Confirmation points: Reduce risky actions, confirm earlier/more clearly

Execution rules:

If user chooses 1A: Immediately run skill-improver, only give run_dir path as input (don't paste logs into conversation)
If user chooses 1B: Write "blocker + desired optimization direction" to evolution-review.md (or corresponding workflow run's final.md / tasks.md), process collectively next time
If user chooses 1C: Don't interrupt, just end (but still keep run artifacts for future retrospectives)

When to evolve (Ship Faster focus)

Next.js upgrade or migration issue solved
Guardrails problem fixed (lint/typecheck/build)
Supabase error or migration pattern learned
Stripe setup or billing flow resolved
Vercel deploy or GitHub CI issue resolved
AI SEO setup or indexing issue solved

How to evolve

Hooks create evolution-candidates.md + evolution-review.md with the latest signals.
At the end of a big task, ask the 3 checkpoint questions (above) and let the user decide.
If user chooses to evolve: run skill-improver with the best run_dir (the workflow run_dir is usually better than evolution run_dir).
Apply the patch manually and re-validate skills.

Example event

{"ts":"2026-01-11T12:00:00Z","event":"post-bash","category":"build","exit_code":1,"summary":"next build failed: Module not found","artifacts":["logs/failures.jsonl"]}

Outputs

evolution-candidates.md (auto-generated)
evolution-review.md (auto-generated, includes the 3 questions)
Suggested patch from skill-improver (manual apply)

No skills are edited automatically.