Amplitude Identify API

openapi: 3.1.0
info:
  title: Amplitude Attribution Annotations Identify API
  description: The Amplitude Attribution API allows developers to send attribution campaign events to Amplitude from ad networks, attribution providers, or custom marketing tools. It associates users with the campaigns, channels, and creatives that drove their acquisition or re-engagement. This API is used to enrich Amplitude user profiles with marketing attribution data for campaign performance analysis and ROI measurement.
  version: '2'
  contact:
    name: Amplitude Support
    url: https://amplitude.com/contact
  termsOfService: https://amplitude.com/terms
servers:
- url: https://api2.amplitude.com
  description: Amplitude US Production Server
- url: https://api.eu.amplitude.com
  description: Amplitude EU Production Server
security: []
tags:
- name: Identify
  description: User identification and property update operations
paths:
  /identify:
    post:
      operationId: identifyUser
      summary: Amplitude Identify a User
      description: Set or update user properties for a specific user without sending an event. Supports operations including set, setOnce, add, append, prepend, unset, and remove on user properties. The request can be sent as form data or JSON.
      tags:
      - Identify
      requestBody:
        required: true
        content:
          application/x-www-form-urlencoded:
            schema:
              $ref: '#/components/schemas/IdentifyRequestForm'
          application/json:
            schema:
              $ref: '#/components/schemas/IdentifyRequestBody'
      responses:
        '200':
          description: Success
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/IdentifyResponse'
              examples:
                identifyUser200Example:
                  summary: Default identifyUser 200 response
                  x-microcks-default: true
                  value:
                    code: 100
                    server_upload_time: 1718153645993
                    events_ingested: 100
        '400':
          description: Bad request - missing required fields or invalid data
        '429':
          description: Too many requests - rate limit exceeded
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
components:
  schemas:
    IdentifyRequestForm:
      type: object
      required:
      - api_key
      - identification
      properties:
        api_key:
          type: string
          description: The API key for the Amplitude project.
        identification:
          type: string
          description: A JSON-encoded string or array of JSON-encoded identification objects containing user_id or device_id and user_properties.
    IdentifyRequestBody:
      type: object
      required:
      - api_key
      - identification
      properties:
        api_key:
          type: string
          description: The API key for the Amplitude project.
        identification:
          type: array
          description: An array of identification objects containing user_id or device_id and user_properties.
          items:
            $ref: '#/components/schemas/Identification'
    Identification:
      type: object
      properties:
        user_id:
          type: string
          description: A readable ID specified by you. Required unless device_id is present.
        device_id:
          type: string
          description: A device-specific identifier. Required unless user_id is present.
        user_properties:
          $ref: '#/components/schemas/UserPropertyOperations'
    IdentifyResponse:
      type: object
      properties:
        code:
          type: integer
          description: The HTTP status code of the response.
          example: 200
        server_upload_time:
          type: integer
          format: int64
          description: The time the server received the request in milliseconds since epoch.
        events_ingested:
          type: integer
          description: The number of identify operations successfully processed.
    UserPropertyOperations:
      type: object
      description: An object containing user property operations. Each key is an operation type and the value is an object of property names to values.
      properties:
        $set:
          type: object
          description: Set the value of a user property. If the property already exists, the value is overwritten.
          additionalProperties: true
        $setOnce:
          type: object
          description: Set the value of a user property only if it has not already been set. Useful for properties like initial_referrer.
          additionalProperties: true
        $add:
          type: object
          description: Increment a numeric user property by the specified value.
          additionalProperties:
            type: number
        $append:
          type: object
          description: Append a value or values to a list user property.
          additionalProperties: true
        $prepend:
          type: object
          description: Prepend a value or values to a list user property.
          additionalProperties: true
        $unset:
          type: object
          description: Remove a user property by setting its value to the string $unset.
          additionalProperties: true
        $remove:
          type: object
          description: Remove a value from a list user property.
          additionalProperties: true
externalDocs:
  description: Amplitude Attribution API Documentation
  url: https://amplitude.com/docs/apis/analytics/attribution