FreJun Teler Voice / Calls (legacy) API

Deprecated endpoints kept for backwards compatibility. Prefer the **Voice / Calls** endpoints for all new integrations.

Operations 1

POST /api/v1/calls/initiate (Deprecated) Initiate a call #

Work with this as data

Every API here is available over the APIs.io API and to AI agents over MCP.

MCP server

One button, every client — Claude, Cursor, VS Code and the rest.

https://apis.io/mcp

Tools for apis

7 MCP tools reach this
  • find_apisBrowse and filter every API in the catalog.
  • get_api_artifactsOne API's artifacts, grouped by type.
  • get_openapiThe primary OpenAPI for this API.
  • find_similar_apisAPIs that look like this one.
  • apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.
  • resolveTurn a domain, URL or GitHub org into the provider it belongs to.
  • find_cohortsEvery scored population of providers in the catalog.
All 92 tools →

Call it yourself

curl for this page
This API
curl "https://apis.io/api/v1/apis/frejun-teler-voice-calls-legacy-api"
All apis
curl "https://apis.io/api/v1/apis?limit=25"

Discovery needs no key. Ratings and market analysis are Pro.

Get an API key

Free tier, no form to fill in. Signing in shares your email address with us — we store it to create your key and to recognise you if you sign in with another provider. See our Privacy Policy and Terms.

A second provider on the same verified email joins the account you already have.

OpenAPI Specification

frejun-teler-voice-calls-legacy-api-openapi.yml Raw ↑
openapi: 3.2.0
info:
  title: Teler API Reference Voice / Calls (legacy) API
  summary: Programmable voice infrastructure for AI agents.
  description: 'The Teler API lets you place and control programmable voice calls, stream live

    audio to AI agents, and observe everything that happens on a call in real time.'
  contact:
    name: Teler support
    email: support@frejun.com
  version: 0.1.0
servers:
- url: https://api.frejun.ai
  description: Production
security:
- ApiKeyAuth: []
tags:
- name: Voice / Calls (legacy)
  description: Deprecated endpoints kept for backwards compatibility. Prefer the **Voice / Calls** endpoints for all new integrations.
paths:
  /api/v1/calls/initiate:
    post:
      tags:
      - Voice / Calls (legacy)
      summary: (Deprecated) Initiate a call
      description: '**Deprecated.** Use `POST /api/v1/voice/calls/initiate` (Voice / Calls) instead. This path is kept only for backwards compatibility and will be removed in a future version.'
      operationId: initiate_call_legacy
      deprecated: true
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/CallInitiateRequest'
      responses:
        '202':
          description: The call was accepted and is being placed.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/CallInitiateResponse'
        '403':
          description: The `x-api-key` header is missing or invalid.
          content:
            application/json:
              example:
                success: false
                message: Invalid API Key.
              schema:
                $ref: '#/components/schemas/ErrorResponse'
        '422':
          description: The request body or query parameters failed validation.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ValidationErrorResponse'
        '502':
          description: Teler could not reach the call-control service.
          content:
            application/json:
              example:
                success: false
                message: The call could not be initiated. Please try again.
              schema:
                $ref: '#/components/schemas/ErrorResponse'
        '504':
          description: The call could not be initiated in time.
          content:
            application/json:
              example:
                success: false
                message: The call could not be initiated in time. Please try again.
              schema:
                $ref: '#/components/schemas/ErrorResponse'
components:
  schemas:
    ErrorResponse:
      properties:
        success:
          type: boolean
          title: Success
          description: Always `false` on an error response.
          default: false
        message:
          type: string
          title: Message
          description: Human-readable description of what went wrong. Safe to show to a user.
        code:
          anyOf:
          - type: string
          - type: 'null'
          title: Code
          description: Stable, machine-readable error code. Present on business-rule errors (e.g. `transfer_in_progress`). Branch on this, not on `message`.
        type:
          anyOf:
          - type: string
          - type: 'null'
          title: Type
          description: Error category (e.g. `invalid_state`). Present on some conflict errors.
      type: object
      required:
      - message
      title: ErrorResponse
      description: Standard error envelope returned for all non-validation errors.
      example:
        message: The requested call was not found.
        success: false
    ValidationFieldError:
      properties:
        loc:
          items: {}
          type: array
          title: Loc
          description: Path to the offending field, e.g. `["body", "to_number"]`.
        msg:
          type: string
          title: Msg
          description: Human-readable explanation of the problem.
        type:
          type: string
          title: Type
          description: Programmatic error type, e.g. `string_pattern_mismatch`.
      type: object
      required:
      - loc
      - msg
      - type
      title: ValidationFieldError
      description: One field-level problem within a `422` validation error.
    CallInitiateResponse:
      properties:
        message:
          type: string
          title: Message
          description: Human-readable confirmation message.
        data:
          $ref: '#/components/schemas/CallInitiateData'
          description: Details of the accepted call.
      type: object
      required:
      - message
      - data
      title: CallInitiateResponse
      example:
        data:
          from_number: '+14155552671'
          id: cs_01JQ8Z9K7M3N2P4R5S6T7V8W9X
          record: true
          status_callback_url: https://yourapp.com/callback
          to_number: '+14155559876'
        message: Call initiated successfully
    CallInitiateData:
      properties:
        id:
          type: string
          title: Id
          description: Identifier of the newly created call (`cs_` prefix).
        from_number:
          type: string
          title: From Number
          description: The number the call is placed from.
        to_number:
          type: string
          title: To Number
          description: The number being dialed.
        status_callback_url:
          type: string
          maxLength: 2083
          minLength: 1
          format: uri
          title: Status Callback Url
          description: Where status webhooks will be delivered.
        record:
          type: boolean
          title: Record
          description: Whether the call is being recorded.
      type: object
      required:
      - id
      - from_number
      - to_number
      - status_callback_url
      - record
      title: CallInitiateData
    ValidationErrorResponse:
      properties:
        success:
          type: boolean
          title: Success
          description: Always `false`.
          default: false
        message:
          type: string
          title: Message
          description: Always `"Validation Error"` for this response.
          default: Validation Error
        errors:
          items:
            $ref: '#/components/schemas/ValidationFieldError'
          type: array
          title: Errors
          description: One entry per field that failed validation.
      type: object
      required:
      - errors
      title: ValidationErrorResponse
      description: Returned with `422` when the request fails schema validation.
      example:
        errors:
        - loc:
          - body
          - to_number
          msg: String should match pattern '^\+\d{7,15}$'
          type: string_pattern_mismatch
        message: Validation Error
        success: false
    CallInitiateRequest:
      properties:
        from_number:
          type: string
          maxLength: 16
          minLength: 8
          pattern: ^\+\d{7,15}$
          title: From Number
          description: The number to place the call from, in E.164 format. Must be a number you own.
        to_number:
          type: string
          maxLength: 16
          minLength: 8
          pattern: ^\+\d{7,15}$
          title: To Number
          description: The destination number to dial, in E.164 format.
        flow_url:
          type: string
          maxLength: 2083
          minLength: 1
          format: uri
          title: Flow Url
          description: HTTPS URL Teler fetches when the call connects to obtain the call flow that drives the call.
        status_callback_url:
          type: string
          maxLength: 2083
          minLength: 1
          format: uri
          title: Status Callback Url
          description: HTTPS URL that receives status webhooks for the lifetime of the call.
        record:
          type: boolean
          title: Record
          description: Whether to record the call. Defaults to `true`.
          default: true
      type: object
      required:
      - from_number
      - to_number
      - flow_url
      - status_callback_url
      title: CallInitiateRequest
      example:
        flow_url: https://example.com/flows/123
        from_number: '+14155552671'
        record: true
        status_callback_url: https://yourapp.com/callback
        to_number: '+14155559876'
  securitySchemes:
    ApiKeyAuth:
      type: apiKey
      in: header
      name: x-api-key
      description: Your secret account API key. Create one in the Teler dashboard.