# API Explorer of Explorers

> Search 2,500+ public APIs or summarise any OpenAPI spec: servers, auth, endpoints, changes. Search the APIs.guru OpenAPI directory for public APIs (titles, versions, categories, spec links), or paste/link an OpenAPI 3.x or Swagger 2 document (JSON or YAML) to get its servers, authentication schemes and scopes, a full endpoint table with auth per operation, tags, example coverage, schema count and documentation issues. Specs fetched by URL are snapshotted so the next run shows what changed (breaking or not).

Part of usefulweb.site (https://usefulweb.site/). Results are deterministic calculations from the inputs and the listed assumptions; the API returns exactly what the web page shows.

## Use it
- Human interface: https://apiexplorerofexplorers.usefulweb.site/ (interactive tool at https://apiexplorerofexplorers.usefulweb.site/tool)
- JSON API: POST https://apiexplorerofexplorers.usefulweb.site/api/v1/calculate with a JSON object of inputs (schema: https://apiexplorerofexplorers.usefulweb.site/api/v1/tool)
- OpenAPI: https://apiexplorerofexplorers.usefulweb.site/openapi.json
- MCP (Streamable HTTP): https://apiexplorerofexplorers.usefulweb.site/mcp - tool `api_explorer_of_explorers`

## Inputs
- mode (select): What do you want to do?
- query (text): Search for an API / provider - Search mode: matched against APIs.guru provider names (e.g. github.com, googleapis.com).
- specText (textarea): OpenAPI / Swagger document (JSON or YAML)
- specUrl (url): Or: URL of the spec - Public URL of a JSON/YAML spec (e.g. a specUrl from search results). Max 4 MiB.
- previousSpec (textarea): Optional: earlier version to compare with - Paste an older version of the same spec to list breaking and non-breaking changes.
- remember (boolean): Keep a snapshot of URL specs to show changes next time

## Method
- Directory search: provider names from https://api.apis.guru/v2/providers.json are ranked (exact, prefix, word, substring match); details for the top 5 providers come from https://api.apis.guru/v2/{provider}.json (title, version, categories, OpenAPI version, last update and spec links).
- Spec summary: servers (OpenAPI servers or Swagger schemes+host+basePath), securitySchemes/securityDefinitions with flows and scope counts, effective security per operation (operation-level overrides the global requirement; [] means public), tags with operation counts and component/definition schema count.
- Example coverage counts operations whose parameters, request bodies or responses carry example/examples (including examples on referenced schemas).
- Change detection uses the same direction-aware rules as the OpenAPI Diff Explorer; URL specs are fingerprinted with SHA-256 of their canonical JSON and the snapshot is kept under SHA-256(URL), so the next run reports changes since the last snapshot.