openapi: 3.1.0
info:
  title: Candid Essentials Lookup Search API
  description: The Candid Essentials API provides core nonprofit search and lookup over Candid's database of U.S. nonprofits. It supports search by name, EIN, location, NTEE code, organization size, and other criteria, and returns summary records suitable for autocompletes, lookups, and basic-verification flows. Multiple versions (v1-v4) are available with POST search and GET lookup variants.
  version: v4
  contact:
    name: Candid Developer Support
    url: https://developer.candid.org/
  termsOfService: https://developer.candid.org/
servers:
- url: https://api.candid.org/essentials
  description: Candid Essentials API production server
security:
- apiKeyAuth: []
tags:
- name: Search
  description: Operations for searching the Candid nonprofit database.
paths:
  /v4:
    post:
      operationId: searchEssentialsV4
      summary: Search Essentials v4
      description: Search Candid's database of U.S. nonprofits using the v4 search endpoint, supporting flexible filters and faceted search.
      tags:
      - Search
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/SearchRequest'
      responses:
        '200':
          description: Search results
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/SearchResponse'
        '400':
          $ref: '#/components/responses/BadRequest'
        '401':
          $ref: '#/components/responses/Unauthorized'
  /v3:
    post:
      operationId: searchEssentialsV3
      summary: Search Essentials v3
      description: Search Candid's database of U.S. nonprofits using the v3 search endpoint.
      tags:
      - Search
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/SearchRequest'
      responses:
        '200':
          description: Search results
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/SearchResponse'
  /v2:
    post:
      operationId: searchEssentialsV2
      summary: Search Essentials v2
      description: Search Candid's database of U.S. nonprofits using the v2 search endpoint.
      tags:
      - Search
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/SearchRequest'
      responses:
        '200':
          description: Search results
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/SearchResponse'
  /v1:
    post:
      operationId: searchEssentialsV1
      summary: Search Essentials v1
      description: Search Candid's database of U.S. nonprofits using the v1 search endpoint.
      tags:
      - Search
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/SearchRequest'
      responses:
        '200':
          description: Search results
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/SearchResponse'
components:
  schemas:
    SearchResponse:
      type: object
      description: A generic search response object returned by Essentials endpoints.
      additionalProperties: true
    SearchRequest:
      type: object
      description: A generic search request object accepted by Essentials search endpoints.
      additionalProperties: true
    Error:
      type: object
      description: Generic error response.
      properties:
        code:
          type: string
        message:
          type: string
      additionalProperties: true
  responses:
    Unauthorized:
      description: Authentication credentials are missing or invalid.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
    BadRequest:
      description: The request was malformed or contained invalid parameters.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
  securitySchemes:
    apiKeyAuth:
      type: apiKey
      in: header
      name: Subscription-Key
      description: Candid subscription key required to call the Essentials API.
externalDocs:
  description: Candid Developer Documentation
  url: https://developer.candid.org/reference/welcome
x-generated-from: https://developer.candid.org/reference/welcome
x-generated-by: claude-crawl-2026-05-08