Sift Labels API

openapi: 3.2.0
info:
  title: Sift Labels API
  description: Sift is a digital trust and safety platform that uses machine learning to detect and prevent online fraud and abuse - payment fraud, account takeover, account abuse, content abuse, and promotion abuse.
  version: '2026-07-12'
  contact:
    name: Sift Developer Documentation
    url: https://developers.sift.com/docs
  x-modeled: true
  x-modeled-by: API Evangelist
  x-modeled-sources:
  - https://developers.sift.com/docs
  - https://developers.sift.com/docs/curl/apis-overview
  - https://github.com/SiftScience/sift-python
servers:
- url: https://api.sift.com
  description: Sift production API (single public host)
security:
- apiKeyBasic: []
tags:
- name: Labels
  description: Legacy API for labeling users to train models.
paths:
  /v205/users/{user_id}/labels:
    parameters:
    - $ref: '#/components/parameters/UserId'
    post:
      operationId: applyLabel
      tags:
      - Labels
      summary: Apply a label (legacy)
      description: Labels a user as good or bad for a given abuse type to train Sift's models. Legacy - Sift recommends the Decisions API for new integrations.
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/Label'
      responses:
        '200':
          description: The label was accepted.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/EventResponse'
        '401':
          $ref: '#/components/responses/Unauthorized'
    delete:
      operationId: removeLabel
      tags:
      - Labels
      summary: Remove a label (legacy)
      description: Removes a previously applied label from a user.
      parameters:
      - name: abuse_type
        in: query
        required: false
        description: The abuse type of the label to remove.
        schema:
          type: string
      responses:
        '200':
          description: The label was removed.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/EventResponse'
        '401':
          $ref: '#/components/responses/Unauthorized'
components:
  schemas:
    Label:
      type: object
      description: Legacy label payload (modeled from documented examples).
      required:
      - $api_key
      - $is_bad
      - $abuse_type
      properties:
        $api_key:
          type: string
        $is_bad:
          type: boolean
          description: true labels the user as bad (fraudulent) for the abuse type.
        $abuse_type:
          type: string
          enum:
          - payment_abuse
          - account_abuse
          - account_takeover
          - content_abuse
          - promotion_abuse
          - legacy
        $description:
          type: string
        $source:
          type: string
        $analyst:
          type: string
    AbuseScore:
      type: object
      properties:
        score:
          type: number
          format: float
          minimum: 0
          maximum: 1
          description: Score expressed 0-1 in the API payload; presented as 0-100 in the console.
        reasons:
          type: array
          items:
            type: object
            properties:
              name:
                type: string
              value:
                type: string
              details:
                type: object
                additionalProperties: true
    EventResponse:
      type: object
      description: Modeled response envelope for event and label ingestion.
      properties:
        status:
          type: integer
          description: 0 indicates the event was accepted.
        error_message:
          type: string
        time:
          type: integer
          format: int64
        request:
          type: string
        score_response:
          $ref: '#/components/schemas/ScoreResponse'
    ApiError:
      type: object
      description: Modeled error envelope. Sift returns a numeric status and error_message.
      properties:
        status:
          type: integer
          description: Sift status code (0 indicates success; non-zero indicates an error).
        error_message:
          type: string
        time:
          type: integer
          format: int64
    ScoreResponse:
      type: object
      description: Sift Score response (modeled). Scores range 0-100; higher is riskier. The scores object is keyed by abuse type, each carrying a score and reason codes.
      properties:
        status:
          type: integer
        error_message:
          type: string
        user_id:
          type: string
        scores:
          type: object
          additionalProperties:
            $ref: '#/components/schemas/AbuseScore'
          description: Keyed by abuse type - payment_abuse, account_abuse, account_takeover, content_abuse, promotion_abuse.
        latest_labels:
          type: object
          additionalProperties: true
  responses:
    Unauthorized:
      description: Missing or invalid API key.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ApiError'
  parameters:
    UserId:
      name: user_id
      in: path
      required: true
      description: The unique identifier for the user, URL-encoded.
      schema:
        type: string
  securitySchemes:
    apiKeyBasic:
      type: http
      scheme: basic
      description: HTTP Basic authentication using your Sift REST API key as the username and an empty password. Ingestion APIs (Events, Score, Labels) also accept the key as $api_key in the JSON request body. Account-scoped APIs (Decisions, Workflows, PSP Merchant Management) require your numeric Account ID in the path in addition to the API key.