anton-abyzov/plugins/specweave/skills/skill-gen

sw:skill-gen — Project-Specific Skill Generation

Project Overrides

Skill Memories: If .specweave/skill-memories/skill-gen.md exists, read and apply its learnings.

Generate project-local skills from recurring patterns detected across increment closures.

Overview

This skill reads .specweave/state/skill-signals.json, displays qualifying patterns (observed in 3+ increments), and generates SKILL.md files in .claude/skills/ using Anthropic's official skill-creator plugin.

Key principle: Skills are generated on-demand only. The signal detection and suggestion system runs passively — this skill is where the user actively decides what to codify.

Workflow

Step 1: Load Signals

SIGNALS_FILE=".specweave/state/skill-signals.json"
if [ ! -f "$SIGNALS_FILE" ]; then
  echo "No signals detected yet. Run a few increments with living docs enabled, then try again."
  exit 0
fi

Read skill-signals.json and load config for minSignalCount (default: 3).

Step 2: Display Qualifying Patterns

Filter signals where incrementIds.length >= minSignalCount. Display ALL qualifying patterns regardless of declined status (the user may reconsider).

For each qualifying signal, show:

• Pattern name and category
• Number of increments where observed
• Confidence score
• Evidence (file paths)
• Status: [suggested], [declined], [generated], or [new]

If no signals qualify: Print "No qualifying patterns found. Patterns need to be observed in at least {minSignalCount} increments."

Step 3: User Selects Pattern

Wait for the user to select a pattern by name or number. The user responds in natural language.

Step 4: Check Skill-Creator Plugin

Verify Anthropic's official skill-creator is available (local-first, then global fallback):

# Check local project copy first (auto-installed by specweave init)
SKILL_CREATOR_PATH=".claude/skills/skill-creator/SKILL.md"
if [ ! -f "$SKILL_CREATOR_PATH" ]; then
  # Fall back to global plugin cache
  SKILL_CREATOR_PATH=$(find ~/.claude/plugins/cache/claude-plugins-official/skill-creator -name "SKILL.md" -maxdepth 3 2>/dev/null | head -1)
fi
if [ -z "$SKILL_CREATOR_PATH" ]; then
  echo "ERROR: Anthropic's skill-creator plugin is not installed."
  echo "Install it via: claude install-skill https://github.com/anthropics/claude-code/tree/main/skill-creator"
  echo ""
  echo "The skill-creator is required to build tested, benchmarked skills."
  exit 1
fi

Step 5: Delegate to Skill-Creator

Slug dedup guard — before delegating, check if a skill with this slug already exists:

SKILL_SLUG="$SELECTED_PATTERN_SLUG"   # e.g. "error-handling"
SKILL_DIR=".claude/skills/$SKILL_SLUG"
if [ -d "$SKILL_DIR" ] && [ -f "$SKILL_DIR/SKILL.md" ]; then
  echo "Skill '$SKILL_SLUG' already exists at $SKILL_DIR/SKILL.md -- skipping generation."
  # Mark signal as generated in skill-signals.json and continue to next pattern
  exit 0
fi

Invoke the skill-creator with the selected pattern context:

1. Provide context to skill-creator:

   • Skill name: derive from pattern slug (e.g., project-error-handling)
   • Description: based on the signal's description and evidence
   • Purpose: codify the detected project convention
   • Evidence files: provide the file paths from signal evidence for the creator to read

2. Skill-creator workflow handles:

   • Writing SKILL.md with proper frontmatter
   • Creating evals/evals.json with test cases
   • Running with-skill vs without-skill benchmarks
   • Description optimization via run_loop.py

3. Output location: .claude/skills/{pattern-slug}/SKILL.md (project-local)

Step 6: Update Signal State

After successful generation:

signal.generated = true;
// Save updated store

Step 7: Summary

Print:

Generated project skill: .claude/skills/{pattern-slug}/SKILL.md

This skill will be active in future conversations for this project.
To test: start a new conversation and try a task related to {pattern-name}.
To remove: delete .claude/skills/{pattern-slug}/

Options

| Flag | Description | |------|-------------| | --refresh | Re-check all existing .claude/skills/ against current living docs for drift |

--refresh Mode

When --refresh is passed:

1. Read all .claude/skills/*.md files
2. Compare each against current living docs analysis
3. Report which skills may be stale
4. Offer to regenerate stale skills

Configuration

Controlled via .specweave/config.json:

{
  "skillGen": {
    "detection": "on-close",
    "suggest": true,
    "minSignalCount": 3,
    "declinedSuggestions": [],
    "maxSignals": 100
  }
}

| Field | Default | Description | |-------|---------|-------------| | detection | "on-close" | When to detect patterns: "on-close" or "off" | | suggest | true | Print suggestions on increment closure | | minSignalCount | 3 | Minimum increments for a pattern to qualify | | declinedSuggestions | [] | Pattern IDs permanently excluded from suggestions | | maxSignals | 100 | Maximum signals to retain |

Error Handling

• No signals file: Inform user to run increments with living docs
• No skill-creator: Print installation instructions
• Generation failure: Catch, log, and offer manual SKILL.md creation as fallback

When This Skill Activates

This skill activates when the user:

• Says "skill-gen", "generate skills", "create project skills"
• Says "codify patterns", "skill generation", "detected patterns"
• Responds to a suggestion printed during increment closure
• Runs sw:skill-gen explicitly

Resources

• Official Documentation