> ## Documentation Index
> Fetch the complete documentation index at: https://docs.altahq.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Trigger an assistant call

> Triggers an outbound phone call from an AI assistant to the specified phone number.

<Note>
  See [Error](/api-reference/objects/error) for the error response format.
</Note>


## OpenAPI

````yaml POST /assistant/calls
openapi: 3.1.0
info:
  title: Alta API
  description: >-
    The Alta public API allows you to programmatically access and manage your
    campaigns, prospects, companies, persons, email messages, LinkedIn messages,
    calls, reps, tags, and trigger assistant calls.
  version: 1.0.0
servers:
  - url: https://api.altahq.com/v1
    description: Production
security:
  - bearerAuth: []
paths:
  /assistant/calls:
    post:
      tags:
        - Assistant
      summary: Trigger an assistant call
      description: >-
        Triggers an outbound phone call from an AI assistant to the specified
        phone number.
      operationId: triggerAssistantCall
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/TriggerAssistantCallRequest'
      responses:
        '200':
          description: Call triggered successfully
        '400':
          $ref: '#/components/responses/BadRequest'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '429':
          $ref: '#/components/responses/RateLimited'
components:
  schemas:
    TriggerAssistantCallRequest:
      type: object
      required:
        - assistantId
        - name
        - phoneNumber
      properties:
        assistantId:
          type: string
          description: The ID of the assistant to use for the call.
        name:
          type: string
          description: The name of the person being called.
        phoneNumber:
          type: string
          description: The phone number to call (E.164 format recommended).
        email:
          type: string
          description: The email address of the person being called.
        timezone:
          type: string
          description: The timezone of the person being called (e.g. `America/New_York`).
        data:
          type: object
          additionalProperties: true
          description: Custom data to pass to the assistant during the call.
        callTransfer:
          type: object
          required:
            - phoneNumber
          description: Call transfer configuration.
          properties:
            phoneNumber:
              type: string
              minLength: 2
              description: The phone number to transfer the call to.
            description:
              type: string
              description: Description of when/why to transfer.
            message:
              type: string
              description: Message to play to the prospect before transferring.
            messageToReceiver:
              type: string
              description: Message to play to the receiver when the call is transferred.
            transferSummaryPrompt:
              type: string
              description: Prompt to generate a summary for the transfer receiver.
            receiverMessageMode:
              type: string
              enum:
                - static
                - summary
              description: >-
                Whether to play a static message or an AI-generated summary to
                the receiver.
            showProspectPhoneOnTransfer:
              type: boolean
              description: >-
                Whether to show the prospect's phone number to the transfer
                receiver.
    Error:
      type: object
      required:
        - error
        - message
      properties:
        error:
          type: string
          description: Error type.
        message:
          type: string
          description: Human-readable error message.
  responses:
    BadRequest:
      description: The request body is invalid.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
          example:
            error: ValidationError
            message: Invalid request body
    Unauthorized:
      description: Authentication failed - invalid or missing API token.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
          example:
            error: Unauthorized
            message: Invalid API token
    RateLimited:
      description: >-
        Too many requests - you've exceeded the rate limit of 100 requests per
        minute.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
          example:
            error: TooManyRequests
            message: Rate limit exceeded. Please retry after 60 seconds.
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      description: >-
        API token authentication. Generate a token from the Alta dashboard and
        pass it as a Bearer token in the Authorization header.

````