skill-creator

Give an AI agent a link to an OpenAPI spec, GraphQL schema, or MCP server and get back a ready-to-use Agent Skill with wrapper scripts, references, and usage notes.

Instead of pasting API docs into every chat, install one slash command and let your agent create reusable command-line skills for the tools your team uses.

Install

Requires Node.js ^22.22.2 || ^24.15.0 || >=26.0.0 (Node 26 is used in CI).

Install the /skill-creator command and companion improvement skill with npx:

npx @asnd/skill-creator command install --agent pi --scope global

This installs:

~/.pi/agent/prompts/skill-creator.md
~/.pi/agent/skills/skill-creator-improvement/

For a project-local command and improvement skill:

npx @asnd/skill-creator command install --agent pi --scope project

Skip the companion skill if you only want the prompt command:

npx @asnd/skill-creator command install --agent pi --scope global --no-improvement-skill

Other supported agents include claude-code, codex, cursor, opencode, gemini-cli, github-copilot, cline, and windsurf.

npx @asnd/skill-creator command install --agent claude-code --scope project

Use it

Open your agent and run /skill-creator with the source you want to turn into a skill.

/skill-creator https://example.com/openapi.json

That is the normal flow: provide the spec/server/schema link, answer any missing install questions, and the agent creates the skill for you.

More examples:

/skill-creator --spec https://example.com/openapi.json --name youtube --agent pi --scope project
/skill-creator --graphql https://api.example.com/graphql --graphql-schema https://example.com/schema.graphql --name pokeapi
/skill-creator --mcp https://mcp.example.com/mcp --name context7
/skill-creator --mcp-stdio "npx -y @example/mcp-server" --name example-mcp

What it creates

A generated skill looks like this:

.pi/skills/youtube/
├── SKILL.md
├── scripts/
│   └── youtube
└── references/
    └── openapi-spec-MM-DD-YYYY.json

Future agents can then use simple commands instead of reading API docs from scratch:

./scripts/youtube commands list
./scripts/youtube commands search videos
./scripts/youtube commands help <command>
./scripts/youtube run --pretty <command> <flags>

Generated scripts use npx -y @asnd/skill-creator internally, so consumers do not need a global install.

Skill improvement loop

Generated skills are tracked in ~/.skill-creator/lock.json. The companion skill-creator-improvement skill helps agents improve generated skills during real use. When the agent discovers a reusable gotcha, custom field, corrected command pattern, or faster workflow, it updates the generated skill's ## Gotchas section directly.

The improvement skill only works on skills tracked in the lock file, so it avoids touching skills that were not generated by skill-creator. Its description is refreshed after generation to include every tracked generated skill name, making the agent more likely to activate it after using those skills.

flowchart TD
    A[User runs<br/>npx @asnd/skill-creator command install] --> B[Install /skill-creator prompt command]
    A --> C[Install skill-creator-improvement skill]
    B --> D[User invokes /skill-creator with API/MCP/GraphQL source]
    D --> E[Agent researches source]
    E --> F[Agent runs<br/>skill-creator generate]
    F --> G[Generated skill files]
    F --> H[Write/Update ~/.skill-creator/lock.json entry]
    G --> I[Agent refines SKILL.md]
    I --> J[Agent smoke tests wrapper]
    J --> K[Final generated skill]
    K --> L[Future agent uses generated skill]
    L --> M{Reusable learning found?}
    M -- No --> L
    M -- Yes --> N[Invoke skill-creator-improvement]
    N --> O[Check lock.json<br/>Was this skill generated by skill-creator?]
    O -- No --> P[Do not modify skill]
    O -- Yes --> Q[Patch SKILL.md Gotchas / examples]
    Q --> R[Future use is faster and more reliable]
    R --> L

Runtime CLI usage

Generated scripts delegate to the same runtime CLI. You can also call it directly for one-off discovery or API calls:

npx @asnd/skill-creator --spec ./openapi.yaml commands list
npx @asnd/skill-creator --spec ./openapi.yaml commands help <command>
npx @asnd/skill-creator --spec ./openapi.yaml run --pretty <command> <flags>

npx @asnd/skill-creator --graphql https://api.example.com/graphql commands list
npx @asnd/skill-creator --mcp https://mcp.example.com/mcp commands list
npx @asnd/skill-creator --mcp-stdio "npx -y @example/mcp-server" commands list

Common runtime flags:

| Flag | Purpose | | ----------------------------------------- | ----------------------------------------------------------------- | | --auth-header 'Header:env:NAME' | Read a secret from an environment variable; repeatable. | | --auth-header 'Header:file:/path/token' | Read a secret from a file; repeatable. | | --base-url URL | Override the OpenAPI server URL. | | --graphql-schema FILE\|URL | Use SDL or introspection JSON instead of endpoint introspection. | | --transport auto\|streamable\|sse | Select MCP HTTP transport; auto tries Streamable HTTP then SSE. | | --include, --exclude, --methods | Filter discovered commands. | | --fields, --selection-depth | Control GraphQL response selection. | | --stdin | Read JSON object input from stdin. | | --pretty, --raw, --head N | Control output formatting and size. | | --cache-key, --cache-ttl, --refresh | Control cached specs, schemas, and MCP tool lists. |

Remote OpenAPI specs, GraphQL introspection results, and MCP tool lists are cached under ~/.cache/skill-creator by default. Override with SKILL_CREATOR_CACHE_DIR when needed.

Shell usage

If you want to generate a skill directly from the shell or CI, use the same package with npx:

npx @asnd/skill-creator generate \
  --template openapi \
  --name youtube \
  --spec https://example.com/openapi.json \
  --agent pi \
  --scope project

GraphQL and MCP are supported too:

npx @asnd/skill-creator generate \
  --template graphql \
  --name pokeapi \
  --graphql https://api.example.com/graphql \
  --graphql-schema ./schema.graphql \
  --agent pi \
  --scope project

npx @asnd/skill-creator generate \
  --template mcp-http \
  --name context7 \
  --mcp https://mcp.example.com/mcp \
  --agent pi \
  --scope project

npx @asnd/skill-creator generate \
  --template mcp-stdio \
  --name example-mcp \
  --mcp-stdio "npx -y @example/mcp-server" \
  --agent pi \
  --scope project

Useful generation flags:

--script <script-name>
--auth-header 'Header:env:ENV_NAME'
--base-url <url>
--description '<specific skill activation description>'
--force
--no-test
--yes

Development

pnpm install
pnpm typecheck
pnpm test
pnpm lint
pnpm fmt:check
pnpm build

CI runs validation on Node 26.

Why use it?

• One command turns API sources into reusable agent skills.
• Specs and schemas are saved as references, so future runs are reproducible.
• Wrapper scripts expose discoverable commands with commands list, commands search, and commands help.
• Secrets stay in environment variables or files, not in generated docs.
• Future agents get focused instructions, gotchas, and safe usage patterns instead of a giant pasted spec.

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