Skillselion developer resources
The public catalog, OpenAPI document, and MCP server that coding agents already use. There is no API-key portal and no billed sandbox — reads are same-origin and free.
Start here
- Read the map: /llms.txt and the typed spec at /openapi.json.
- Search the catalog:
GET /api/v1/listings?q=design&type=skill&limit=10 - Or install the MCP:
claude mcp add skillselion -- npx -y skillselion-mcp
Same-origin catalog reads
Browser and agent clients call the versioned prefix /api/v1/… on skillselion.com (/api/upstream/… is the unversioned alias). The Next.js proxy forwards to the Fly API and injects the server-side frontend secret. You do not send an API key. Send Accept: application/json and optional API-Version: 1. Errors are JSON with code, message, and resolution. Full API docs: /api-docs.
GET /api/v1/listings— search. Query params:q,semantic,type,types,category,owner,sort(installs|stars|trending),limit(1–2000),offset.GET /api/upstream/listings/{id}— one listing. Encode path-style ids.GET /api/upstream/listings/{id}/files— SKILL.md and bundled files.GET /api/upstream/catalog/stats— live totals (skills, MCP servers, installs).GET /api/upstream/meta— brand, disclaimer, last-updated.
Typed schemas and unique operationIds live in the OpenAPI spec. The RFC 9727 catalog is at /.well-known/api-catalog.
Skillselion MCP server
The published npm package is skillselion-mcp. It is the official machine interface named in llms.txt — three tools: search_skillselion, load_skill, top_skillselion.
claude mcp add skillselion -- npx -y skillselion-mcpLive handshake (initialize / tools/list): /.well-known/mcp. Product page: /skillselion-mcp.
What the CLI mention means
There is no separate skillselion CLI package on npm. The command in llms.txt is npx -y skillselion-mcp — that is the official interface. Install lines on listing pages such as npx skills add <owner/repo> are the upstream skills.sh / Agent Skills installer, not a Skillselion product.