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

# Create a SIP client

> Register a plain SIP client for your domain. Returns the client's SIP URI and a generated `password`, shown ONCE and never returned again. Provide a `username` (a room-style name, optionally suffixed with `.<number>`); supply your own `password` or let one be generated. An optional `expires_in_seconds` sets a TTL after which the client is removed automatically - omit it for a long-lived client. Subject to a per-domain client limit.



## OpenAPI

````yaml POST /sip-clients
openapi: 3.0.3
info:
  title: Daily API
  description: |-
    The Daily REST API offers the ability to manage the following: 
    - Overall Domain Configuration
    - Individual Room creation and config management 
    - Meeting token creation and validation
    - Recording and compositing management 
    - Meeting analytics
    - Logs and metrics
    - Real-time presence

    Please reach out to help@daily.co if we can help with anything
  version: 1.1.1
  contact:
    name: Daily
    url: https://docs.daily.co
    email: help@daily.co
servers:
  - url: https://api.daily.co/v1
security:
  - bearerAuth: []
paths:
  /sip-clients:
    post:
      tags:
        - dialin
      summary: /sip-clients
      description: >-
        Register a plain SIP client for your domain. Returns the client's SIP
        URI and a generated `password`, shown ONCE and never returned again.
        Provide a `username` (a room-style name, optionally suffixed with
        `.<number>`); supply your own `password` or let one be generated. An
        optional `expires_in_seconds` sets a TTL after which the client is
        removed automatically - omit it for a long-lived client. Subject to a
        per-domain client limit.
      operationId: CreateSipClient
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              required:
                - username
              properties:
                username:
                  type: string
                  description: >-
                    SIP username: letters, digits, '-' and '_' (a room name),
                    optionally followed by .<number> (e.g. myroom.0). Up to 64
                    chars. Must be unique within your domain.
                  example: myroom.0
                password:
                  type: string
                  description: >-
                    Optional. 12-64 chars with at least one letter and one
                    digit. If omitted, a password is generated and returned once
                    in the response.
                expires_in_seconds:
                  type: integer
                  description: >-
                    Optional TTL in seconds (60-2592000). The client is removed
                    automatically after it elapses. Omit for a long-lived
                    client.
      responses:
        '200':
          description: The created SIP client. `password` is returned only here.
          content:
            application/json:
              schema:
                type: object
                properties:
                  username:
                    type: string
                  domain:
                    type: string
                    example: examplecorp.sip-us.daily.co
                  sip_uri:
                    type: string
                    example: sip:myroom.0@examplecorp.sip-us.daily.co
                  password:
                    type: string
                  expires_at:
                    type: string
                    format: date-time
                    nullable: true
        '400':
          $ref: '#/components/responses/400'
        '403':
          description: The domain's SIP client limit has been reached.
        '409':
          description: A SIP client with that username already exists in the domain.
      security:
        - bearerAuth: []
components:
  responses:
    '400':
      description: '400'
      content:
        application/json:
          schema:
            type: object
            properties:
              error:
                type: string
              info:
                type: string
          examples:
            Result:
              value:
                error: invalid-request-error
                info: missing required field
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer

````

This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.