openapi: 3.0.3
info:
  title: Prelude Lookup Watch API
  description: 'Prelude is a phone and email verification, transactional messaging, phone number intelligence (lookup), and anti-fraud API - "the trust layer between your signups and your business." This document models Prelude''s public REST API v2 (base https://api.prelude.dev/v2) across four products: Verify (create / check one-time passcodes over SMS, WhatsApp, RCS, Viber, and voice), Notify (transactional messaging), Lookup / Intel (phone number intelligence - line type, carrier, ported / temporary flags, CNAM), and Watch (anti-fraud risk prediction and feedback). All requests authenticate with a Bearer API key (Authorization: Bearer YOUR_API_KEY) obtained from the Prelude dashboard under All Services > Configure > Keys. Endpoint paths and request / response schemas are grounded in the live Prelude documentation at docs.prelude.so as of 2026-07-11; the Watch events (dispatch-events) endpoint is modeled from documentation references and marked accordingly.'
  version: '2.0'
  contact:
    name: Prelude
    url: https://prelude.so
servers:
- url: https://api.prelude.dev/v2
  description: Prelude API v2
security:
- bearerAuth: []
tags:
- name: Watch
  description: Anti-fraud risk prediction and outcome feedback.
paths:
  /watch/predict:
    post:
      operationId: predictWatch
      tags:
      - Watch
      summary: Predict signup risk
      description: Scores a signup identifier (phone number or email address) as `legitimate` or `suspicious`, optionally using anti-fraud signals such as IP, device id, and device platform, plus a frontend SDK dispatch id.
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/PredictWatchRequest'
      responses:
        '200':
          description: The risk prediction.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/PredictWatchResponse'
        '400':
          $ref: '#/components/responses/BadRequest'
        '401':
          $ref: '#/components/responses/Unauthorized'
  /watch/feedback:
    post:
      operationId: sendWatchFeedback
      tags:
      - Watch
      summary: Send feedbacks about verifications
      description: Reports what actually happened in your verification flow (for example a verification started or completed) so Watch can update its counters and improve future predictions. Accepts up to 100 feedback items per request.
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/FeedbackWatchRequest'
      responses:
        '200':
          description: Feedback acknowledgement.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/FeedbackWatchResponse'
        '400':
          $ref: '#/components/responses/BadRequest'
        '401':
          $ref: '#/components/responses/Unauthorized'
  /watch/dispatch-events:
    post:
      operationId: dispatchWatchEvents
      tags:
      - Watch
      summary: Dispatch events
      description: Sends frontend interaction events (associated with a dispatch id from the Prelude frontend SDK) to Watch to enrich risk scoring. NOTE - this endpoint is referenced in the Prelude documentation but its full request / response schema was not published at review time; the request shape below is modeled and unconfirmed.
      x-modeled: true
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/DispatchEventsRequest'
      responses:
        '200':
          description: Events acknowledgement.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/FeedbackWatchResponse'
        '401':
          $ref: '#/components/responses/Unauthorized'
components:
  schemas:
    Signals:
      type: object
      description: Anti-fraud signals gathered from the end user's device / session.
      properties:
        ip:
          type: string
        device_id:
          type: string
        device_platform:
          type: string
          enum:
          - android
          - ios
          - web
        device_model:
          type: string
        os_version:
          type: string
        app_version:
          type: string
        user_agent:
          type: string
        ja4_fingerprint:
          type: string
        is_trusted_user:
          type: boolean
      additionalProperties: true
    DispatchEventsRequest:
      type: object
      description: Modeled request shape; the published documentation references this endpoint but did not include its full schema at review time.
      properties:
        dispatch_id:
          type: string
        events:
          type: array
          items:
            type: object
            additionalProperties: true
    FeedbackWatchResponse:
      type: object
      properties:
        status:
          type: string
          example: success
        request_id:
          type: string
    PredictWatchResponse:
      type: object
      properties:
        id:
          type: string
          description: The prediction identifier.
        prediction:
          type: string
          enum:
          - legitimate
          - suspicious
        risk_factors:
          type: array
          description: Present when prediction is suspicious.
          items:
            type: string
            enum:
            - behavioral_pattern
            - device_attribute
            - fraud_database
            - location_discrepancy
            - network_fingerprint
            - poor_conversion_history
            - prefix_concentration
            - suspected_request_tampering
            - suspicious_ip_address
            - temporary_phone_number
        request_id:
          type: string
    PredictWatchRequest:
      type: object
      required:
      - target
      properties:
        target:
          $ref: '#/components/schemas/Target'
        signals:
          $ref: '#/components/schemas/Signals'
        dispatch_id:
          type: string
          description: Identifier of a dispatch created by the Prelude frontend SDK.
        metadata:
          $ref: '#/components/schemas/Metadata'
    Target:
      type: object
      required:
      - type
      - value
      properties:
        type:
          type: string
          description: The kind of target identifier.
          enum:
          - phone_number
          - email_address
        value:
          type: string
          description: An E.164 formatted phone number or an email address.
          example: '+30123456789'
    Metadata:
      type: object
      properties:
        correlation_id:
          type: string
          maxLength: 80
          description: A user-defined identifier to correlate this call with others.
    FeedbackWatchRequest:
      type: object
      required:
      - feedbacks
      properties:
        feedbacks:
          type: array
          maxItems: 100
          items:
            type: object
            required:
            - target
            - type
            properties:
              target:
                $ref: '#/components/schemas/Target'
              type:
                type: string
                enum:
                - verification.started
                - verification.completed
              metadata:
                $ref: '#/components/schemas/Metadata'
    Error:
      type: object
      properties:
        code:
          type: string
        message:
          type: string
        type:
          type: string
        request_id:
          type: string
  responses:
    Unauthorized:
      description: Missing or invalid API key.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
    BadRequest:
      description: The request was invalid.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      description: 'Bearer API key passed as `Authorization: Bearer YOUR_API_KEY`. Obtain keys from the Prelude dashboard under All Services > Configure > Keys.'