openapi: 3.1.0
info:
  title: Candid Essentials Lookup 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: Lookup
  description: Operations for retrieving lookup values and filter metadata.
paths:
  /lookup:
    get:
      operationId: listLookupFilters
      summary: List Lookup Filters
      description: Returns the list of available lookup filters (e.g., NTEE codes, states, subjects) supported by the Essentials API.
      tags:
      - Lookup
      responses:
        '200':
          description: A list of available lookup filters.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/LookupListResponse'
  /lookup/{filter_name}:
    get:
      operationId: getLookupByFilter
      summary: Get Lookup Values for Filter
      description: Returns the available lookup values for a named filter (e.g., states, NTEE codes, subjects).
      tags:
      - Lookup
      parameters:
      - name: filter_name
        in: path
        required: true
        description: Name of the lookup filter to retrieve values for.
        schema:
          type: string
      responses:
        '200':
          description: Lookup values for the requested filter.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/LookupListResponse'
        '404':
          $ref: '#/components/responses/NotFound'
  /lookup/{filter_name}/{key_or_value}:
    get:
      operationId: getLookupByFilterAndKey
      summary: Get Lookup Detail
      description: Returns the detail for a single lookup value within a filter, by key or value.
      tags:
      - Lookup
      parameters:
      - name: filter_name
        in: path
        required: true
        description: Name of the lookup filter.
        schema:
          type: string
      - name: key_or_value
        in: path
        required: true
        description: Key or value within the lookup filter to retrieve.
        schema:
          type: string
      responses:
        '200':
          description: A single lookup detail record.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/LookupItem'
        '404':
          $ref: '#/components/responses/NotFound'
components:
  responses:
    NotFound:
      description: The requested resource was not found.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
  schemas:
    LookupListResponse:
      type: object
      description: A response wrapping a list of lookup items.
      additionalProperties: true
    Error:
      type: object
      description: Generic error response.
      properties:
        code:
          type: string
        message:
          type: string
      additionalProperties: true
    LookupItem:
      type: object
      description: A single lookup item record.
      additionalProperties: true
  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