Prelude Verification API

openapi: 3.0.3
info:
  title: Prelude Lookup Verification 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: Verification
  description: Create and check one-time passcode (OTP) verifications.
paths:
  /verification:
    post:
      operationId: createVerification
      tags:
      - Verification
      summary: Create or retry a verification
      description: Creates a new verification for a phone number or email address and dispatches a one-time passcode. If a non-expired verification already exists for the same target within the verification window, this endpoint performs a retry instead of creating a new verification.
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/CreateVerificationRequest'
      responses:
        '200':
          description: The created or retried verification.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Verification'
        '400':
          $ref: '#/components/responses/BadRequest'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '429':
          $ref: '#/components/responses/RateLimited'
  /verification/check:
    post:
      operationId: checkVerification
      tags:
      - Verification
      summary: Check a code
      description: Validates a one-time passcode submitted by an end user against an active verification for the given target.
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/CheckVerificationRequest'
      responses:
        '200':
          description: The verification check result.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/VerificationCheck'
        '400':
          $ref: '#/components/responses/BadRequest'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '429':
          $ref: '#/components/responses/RateLimited'
components:
  schemas:
    CheckVerificationRequest:
      type: object
      required:
      - target
      - code
      properties:
        target:
          $ref: '#/components/schemas/Target'
        code:
          type: string
          description: The one-time passcode submitted by the end user.
        psd2:
          type: object
          description: Transaction details for PSD2 (dynamic linking) verifications.
          properties:
            amount:
              type: string
            currency:
              type: string
            recipient:
              type: string
    VerificationCheck:
      type: object
      properties:
        id:
          type: string
          example: vrf_01jc0t6fwwfgfsq1md24mhyztj
        status:
          type: string
          enum:
          - success
          - failure
          - expired_or_not_found
          - transaction_missing
          - transaction_mismatch
        metadata:
          $ref: '#/components/schemas/Metadata'
        request_id:
          type: string
    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
    CreateVerificationRequest:
      type: object
      required:
      - target
      properties:
        target:
          $ref: '#/components/schemas/Target'
        options:
          type: object
          description: Optional verification settings.
          properties:
            template_id:
              type: string
            variables:
              type: object
              additionalProperties:
                type: string
            method:
              type: string
              enum:
              - auto
              - voice
            locale:
              type: string
            sender_id:
              type: string
            app_realm:
              type: object
              additionalProperties: true
            code_size:
              type: integer
            custom_code:
              type: string
            callback_url:
              type: string
              format: uri
            preferred_channel:
              type: string
              enum:
              - sms
              - rcs
              - whatsapp
              - viber
              - voice
            force_challenge:
              type: boolean
          additionalProperties: true
        signals:
          $ref: '#/components/schemas/Signals'
        metadata:
          $ref: '#/components/schemas/Metadata'
        dispatch_id:
          type: string
          description: Identifier of a dispatch created by the Prelude frontend SDK.
    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'
    Verification:
      type: object
      properties:
        id:
          type: string
          example: vrf_01jc0t6fwwfgfsq1md24mhyztj
        status:
          type: string
          enum:
          - success
          - retry
          - challenged
          - blocked
          - shadow_blocked
        method:
          type: string
          enum:
          - email
          - message
          - silent
          - voice
        reason:
          type: string
          description: Populated when status is blocked or shadow_blocked.
        channels:
          type: array
          description: Ordered sequence of delivery channels attempted.
          items:
            type: string
        silent:
          type: object
          additionalProperties: true
        risk_factors:
          type: array
          items:
            type: string
        metadata:
          $ref: '#/components/schemas/Metadata'
        request_id:
          type: string
    Metadata:
      type: object
      properties:
        correlation_id:
          type: string
          maxLength: 80
          description: A user-defined identifier to correlate this call with others.
    Error:
      type: object
      properties:
        code:
          type: string
        message:
          type: string
        type:
          type: string
        request_id:
          type: string
  responses:
    RateLimited:
      description: Too many requests.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
    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.'