FactReason Search API

The Search API from FactReason — 1 operation(s) for search.

GitHub OpenAPI

Operations 1

GET /api/v1/search/semantic Search the catalogue by natural-language intent #

Work with this as data

Every API here is available over the APIs.io API and to AI agents over MCP.

MCP server

One button, every client — Claude, Cursor, VS Code and the rest.

https://apis.io/mcp

Tools for apis

7 MCP tools reach this
  • find_apisBrowse and filter every API in the catalog.
  • get_api_artifactsOne API's artifacts, grouped by type.
  • get_openapiThe primary OpenAPI for this API.
  • find_similar_apisAPIs that look like this one.
  • apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.
  • resolveTurn a domain, URL or GitHub org into the provider it belongs to.
  • find_cohortsEvery scored population of providers in the catalog.
All 92 tools →

Call it yourself

curl for this page
This API
curl "https://apis.io/api/v1/apis/factreason-com:factreason-com-search-api"
All apis
curl "https://apis.io/api/v1/apis?limit=25"

Calls without X-API-Key need no key. Calls with it need a paid plan — get a key.

Get an API key

Free tier, no form to fill in. Signing in shares your email address with us — we store it to create your key and to recognise you if you sign in with another provider. See our Privacy Policy and Terms.

A second provider on the same verified email joins the account you already have.

OpenAPI Specification

factreason-com-search-api-openapi.yml Raw ↑
openapi: 3.2.0
info:
  title: FactReason Agent Search API
  version: 2.1.0
  description: Public access, discovery, correction, and paid reference-data routes. Catalogue results remain protected by Bearer-key or x402 authorization.
servers:
- url: https://factreason.com
security:
- bearerAuth: []
tags:
- name: Search
paths:
  /api/v1/search/semantic:
    get:
      summary: Search the catalogue by natural-language intent
      description: 'Paid: $0.003 per successful query (tier `semantic_search`). Misses, HTTP 304 revalidations and rate-limited requests are never billed.'
      parameters:
      - name: q
        in: query
        required: true
        schema:
          type: string
        description: Intent, e.g. `3.3V ARM MCU with SPI`
      - name: limit
        in: query
        required: false
        schema:
          type: integer
          minimum: 1
          maximum: 100
      responses:
        '200':
          description: 'Authorized result, or an unbilled miss with `found: false` and nearest matches'
        '304':
          description: Cached revalidation. Never billed.
        '402':
          description: Payment required. Carries x402 requirements and key-creation routes only — never any part of the requested record, and identical for a hit and a miss.
        '429':
          description: Rate limited. Never billed; honour `Retry-After`.
      tags:
      - Search
      operationId: getApiV1SearchSemantic
      x-operation-id-source: derived
components:
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      description: FactReason API key
externalDocs:
  description: FactReason documentation
  url: https://factreason.com/docs