Free · Public · Read-only

Catalog API

Query the Sigistry catalog of verified Claude Code plugins and portable skills over plain HTTP and JSON. The same data the site and the MCP server use, described by an OpenAPI 3.1 spec so you can wire it into a custom GPT, a code generator, or any tool that speaks OpenAPI. No key, no signup.

https://sigistry.com/v1/openapi.json

Prefer MCP? The same catalog is a read-only MCP server at sigistry.com/mcp.

Endpoints

Base URL https://sigistry.com. Every route is a GET, returns JSON, and carries Cache-Control: public, max-age=300.

GET/v1/plugins

List and search plugins. Query: q (keyword), category, limit, offset.

GET/v1/plugins/{id}

One plugin by id, with its full verification object (per-check results).

GET/v1/verified/{id}

The security-audit record for one plugin: status, checks, badge, pinned commit.

GET/v1/skills

List and search verified skills. Query: q, plugin, limit, offset.

GET/v1/skills/{name}

One skill by name, including the full portable SKILL.md source.

GET/v1/categories

Every plugin category with its count, plus the total.

GET/v1/openapi.json

The OpenAPI 3.1 spec for this API.

Example

Search for database plugins:

Request
curl https://sigistry.com/v1/plugins?q=database
Response
{
  "total": 1,
  "count": 1,
  "limit": 50,
  "offset": 0,
  "plugins": [
    {
      "id": "sql-safety-net",
      "name": "SQL Safety Net",
      "category": "database",
      "installCommand": "/plugin install sql-safety-net@sigistry",
      "verificationStatus": "verified"
    }
  ]
}

MCP or REST?

Two ways into the same catalog. Pick the one your tool already speaks.

MCP server

Model Context Protocol over Streamable HTTP at sigistry.com/mcp. Best for agents with native MCP support (Claude Code, Claude Desktop). Tools for search, detail, categories, skills, and local verification.

REST API

Plain HTTP and JSON under /v1, described by OpenAPI 3.1. Best for custom GPTs, code generators, dashboards, and anything that ingests a spec rather than MCP.

Frequently asked questions

Is the API free and does it need a key?

Yes, free, and no. It is a public, read-only, authless API over data that is already public. There is no signup, no token, and no per-key rate limit. Please be reasonable with request volume; responses are cacheable for five minutes.

What is the difference between the API and the MCP server?

Same catalog data, two shapes. The MCP server (sigistry.com/mcp) speaks the Model Context Protocol over Streamable HTTP, ideal for agents like Claude Code that natively support MCP. The REST API speaks plain HTTP and JSON and is described by OpenAPI, which is what custom GPTs, code generators, and most integration tools expect. Use whichever your tool consumes.

Can I use it as a custom GPT action?

Yes. Point your GPT action or tool at the OpenAPI document at https://sigistry.com/v1/openapi.json and it can call the endpoints directly. The spec is OpenAPI 3.1.

How fresh is the data?

The catalog and verification results are read from the marketplace repository and cached about five minutes, so a newly merged or re-verified plugin appears within roughly that window.

What does verificationStatus mean?

verified means the plugin passed the eight-check security methodology; listed means it is in the registry but not audited; stale means it was verified at a pinned commit the repo has since moved past; failed means an audit check failed; unknown means there is no record. Detail endpoints return the full per-check breakdown.

Build on the catalog

Point your tool at https://sigistry.com/v1/openapi.json and start querying verified plugins and skills.

Browse the catalog