A Claude Code plugin that turns skill creation, discovery, iteration, and optimization into a skill itself — a meta-system for skills.
Claude Code skills solve "how to codify workflows into reusable slash commands." But three gaps remain:
| Gap | skill-forge's Answer |
|---|---|
| Don't know when to create a skill | Auto-detects complex tasks, proactively asks |
| Don't know if a skill is well-written | Built-in 4-dimension evaluator, won't save below threshold |
| Don't know if a skill will actually trigger | Dedicated description optimization phase, eval-driven |
Via CLI (recommended):
npm install -g @nekocode/skill-forge
skill-forge installOr manually in Claude Code (installs to user-global scope):
/plugin marketplace add nekocode/skill-forge
/plugin install skill-forge
Run skill-forge doctor to verify your environment.
| Command | What it does |
|---|---|
/scan [prompt] | Scan project for skill opportunities. Optional prompt as focus hint |
/create <prompt> | Create a new skill from prompt. Name auto-derived |
/improve <prompt> | Iterate existing skill from prompt. Target matched from registry |
/rename <old> <new> | AI-driven skill rename — updates dir, SKILL.md body, workspace, registry |
Auto mode: After complex tasks (5+ tool calls), the Stop hook detects the pattern and offers to create a skill — no manual invocation needed.
- Hermes Agent — Autonomous creation with concrete trigger conditions; patch over rewrite
- planning-with-files — File system as persistent working memory (context window = RAM, files = disk)
- Anthropic skill-creator — Eval-driven quality: description is a separate optimization problem, 20-case trigger evals, explain why not just what
- DSPy — All internal prompts (evaluation, improvement guidance) are self-optimized: structured FP/FN failure analysis, directional improvement, eval-driven variant selection
External content (grep/glob/read output) goes to .skill-forge/insights.md (low trust, hooks don't read it). Only after validation does content get promoted to .skill-forge/draft.md (high trust, injected by hooks). This prevents prompt injection amplification. Workspace lives at project-local ./.skill-forge/ — outside .claude/ entirely, so write permissions don't need the trust-boundary exemption and Python/shell both resolve the same absolute path without any slug-translation step.
New skills are assembled in .skill-forge/staging/<name>/ (SKILL.md, scripts/, CHANGELOG, .opt/). finalize_skill.py then runs shutil.copytree in a subprocess to move the tree into .claude/skills/<name>/ — bypassing Claude's tool permission layer, which would otherwise prompt on any Write into a not-yet-real skill dir (empty dirs fail the trust-boundary exemption until a SKILL.md lands). Improve mode uses the same staging path: init_improve.py copies the live skill into staging, Claude edits there, and finalize --mode update rmtree's the target and copies staging back atomically.
Skill-scoped hooks (SKILL.md frontmatter) — only active when skill-forge is engaged. All four run via one Python entrypoint (hook_draft_inject.py / skill_check.py) for cross-platform consistency:
UserPromptSubmit— Inject draft header into attention windowPreToolUse— Small draft-head dump before Read/Glob/Grep/Bash (goal-drift guard)PostToolUse— Nudge draft update after Write/EditStop— Check for unprocessed skill opportunities (skipped when a draft is active, to prevent self-looping)
Global hooks (hooks/hooks.json, auto-registered by plugin system):
SessionStart— Reset counters + inject skill inventoryPostToolUse— Tool counting + registry update on SKILL.md writesStop— Detect complex workflows, trigger auto modePreCompact— Mark compact state to prevent false positivesUserPromptSubmit— Keyword matching for skill creation prompts
Complex task completed
-> Stop hook / manual invocation
-> scan -> create (draft -> research -> SKILL.md -> eval >= 6/8)
-> .claude/skills/<name>/SKILL.md
-> improve (diagnose -> content patch / trigger eval loop -> changelog + version bump)
-> repeat after real usage
On each new session, skill_catchup.py scans the previous session's JSONL for uncaptured complex tasks (5+ tool calls after last draft write). Solves "forgot to save as skill yesterday."
| Dimension | Max | Checks |
|---|---|---|
| Trigger quality | 3 | Complex scenarios? Pushy coverage? Do NOT use? Under 250 chars? |
| Step clarity | 3 | Concrete actions per step? Explains why, not just what? |
| Completeness | 2 | Prerequisites / verification / notes? |
| Discriminability | bonus | Assertions pass both with and without skill -> no discriminability, rewrite |
Minimum score to save: 6/8.
- Complex scenarios, not simple verbs — "Use when adding a new REST endpoint that requires route registration, Zod schema, test file, and index.ts update" not "Generate API endpoints"
- Pushy coverage — Cover cases where users won't name the skill explicitly
- Do NOT use when — Prevent trigger overlap with related skills
The skill-forge CLI provides terminal-based plugin management without entering a Claude Code session.
npm install -g @nekocode/skill-forge| Command | What it does |
|---|---|
skill-forge install | Install plugin (project scope embeds files, user scope uses plugin system) |
skill-forge uninstall | Uninstall plugin |
skill-forge list | Print skill registry for current project |
skill-forge rm <name> [...] | Remove skills (--force to skip confirmation) |
skill-forge doctor | Diagnose environment (claude CLI, plugin, Python, project structure) |
skill-forge init | Initialize .claude/skills/ with empty registry |
skill-forge sync | Sync embedded plugin to latest release (project scope) |
skill-forge upgrade | Upgrade CLI to latest npm version |
| Feature | Hand-written SKILL.md | Anthropic skill-creator | skill-forge |
|---|---|---|---|
| Auto-discover opportunities | - | - | scan |
| Content quality evaluation | - | eval viewer | 4-dim evaluator |
| Description trigger optimization | - | run_loop.py | improve |
| Persistent working memory | - | - | draft/insights files |
| Cross-session memory | - | - | catchup.py |
| Scoped hooks (no global pollution) | - | - | frontmatter hooks |
| Injection defense | - | - | dual-file isolation |
| Self-iteration | - | - | improve skill-forge |