> ## Documentation Index > Fetch the complete documentation index at: https://developers.telnyx.com/llms.txt > Use this file to discover all available pages before exploring further. # SIP UAC registration status > Check whether a UAC connection is registered with its external SIP provider. Supply the UAC connection's `connection_id`. ## OpenAPI ````yaml /openapi/playground/sip-registration-status/uac.json get /sip_registration_status openapi: 3.0.0 info: version: 1.0.0 x-latency-category: responsive x-endpoint-cost: light title: SIP UAC registration status description: >- Check whether a UAC connection is registered with its external SIP provider. Supply the UAC connection's `connection_id`. contact: email: support@telnyx.com servers: - url: https://api.telnyx.com/v2 description: Telnyx API v2 security: - bearerAuth: [] paths: /sip_registration_status: get: tags: - UAC Connections summary: SIP UAC registration status description: >- Check whether a UAC connection is registered with its external SIP provider. Supply the UAC connection's `connection_id`. operationId: GetUacRegistrationStatus parameters: - name: credential_type in: query required: true description: Credential type to check. schema: type: string enum: - uac_external_credential default: uac_external_credential example: uac_external_credential - name: connection_id in: query required: true description: UAC connection ID. schema: type: string example: '1234567890' responses: '200': description: Registration status payload content: application/json: schema: $ref: '#/components/schemas/SipRegistrationStatus' examples: uac_credential: summary: UAC external credential - registered value: connection_id: '1234567890' connection_name: FreePBX UAC 1002 credential_type: uac_external_credential credential_username: useralice12345 registered: true sip_registration_status: registered last_registration_response: 200 OK sip_registration_details: auth_retries: 0 expires: 1780404431 uptime: 1780401551699908 next_action_at: 1780414482 failures: 0 sip_uri_user_host: 1002@192.0.2.10 '400': description: >- Missing or invalid query parameters. Returned when `credential_type` is unsupported, or when the identifier required for the chosen `credential_type` (`connection_id` or `username`) is missing. '401': description: Missing or invalid API key '403': description: >- The connection or credential exists but is not owned by the authenticated account '404': description: >- No connection or credential matches the supplied identifier, or it has no known registration components: schemas: SipRegistrationStatus: type: object properties: connection_id: type: string description: Identifier of the connection associated with the credential. connection_name: type: string description: Human-readable connection name. credential_type: type: string description: The credential type that was looked up. enum: - uac_external_credential - telephony_credential - sip_credential_connection credential_username: type: string description: SIP username used for the registration. registered: type: boolean description: True if the endpoint is currently registered. sip_registration_status: type: string description: Human-readable registration status derived from the registrar state. enum: - unregistering - connection_disabled - standby - failed - trying - registered - unknown last_registration_response: type: string nullable: true description: SIP response from the last registration attempt. example: 200 OK sip_registration_details: type: object description: >- Detailed registration information reported by the registrar. The populated fields depend on `credential_type`: UAC external credentials report `auth_retries`, `uptime`, `next_action_at`, `failures`, and `sip_uri_user_host`; telephony credentials and SIP credential connections report `ua_ip`, `ua_port`, `transport`, and `last_modified`. All types report `expires`, but its unit differs by `credential_type` — see that field. properties: auth_retries: type: integer description: >- Number of authentication retries on the last attempt (uac_external_credential). expires: type: integer description: >- When the current registration expires. The unit depends on `credential_type`: for `uac_external_credential` this is a Unix timestamp (seconds since epoch) of the next scheduled re-registration; for `telephony_credential` and `sip_credential_connection` this is the registration lifetime in seconds as negotiated with the registrar (the `Expires` value, defaulting to 3600 when the endpoint sends none). uptime: type: integer description: >- Registration uptime reported by the registrar (uac_external_credential). next_action_at: type: integer description: >- Unix timestamp of the next scheduled registration action (uac_external_credential). failures: type: integer description: >- Count of consecutive registration failures (uac_external_credential). sip_uri_user_host: type: string description: >- SIP URI user@host of the registered contact (uac_external_credential). ua_ip: type: string description: >- IP address of the registered user agent (telephony_credential and sip_credential_connection). ua_port: type: integer description: >- Port of the registered user agent (telephony_credential and sip_credential_connection). transport: type: string description: >- Transport used for the registration, e.g. UDP/TCP/TLS (telephony_credential and sip_credential_connection). last_modified: type: string description: >- Timestamp when the registration was last modified (telephony_credential and sip_credential_connection). securitySchemes: bearerAuth: type: http scheme: bearer ````