---
title: "Update an FQDN authentication"
method: PATCH
path: "/fqdn_connections/{fqdn_connection_id}/fqdn_authentication"
tags: ["FQDN Connections"]
---

# Update an FQDN authentication

`PATCH /fqdn_connections/{fqdn_connection_id}/fqdn_authentication`

## Request

- Base URL: `https://api.telnyx.com/v2`
- URL: `https://api.telnyx.com/v2/fqdn_connections/{fqdn_connection_id}/fqdn_authentication`
- Auth: HTTP bearer

Updates the FQDN authentication strategy for a specific FQDN connection.

## Path parameters

- `fqdn_connection_id` string, required

## Request body

- UpdateFqdnAuthenticationRequest
  - `user_name` string: The username for authentication.
  - `password` string: The password for authentication.
  - `ip_authentication_method` 'token' | 'p-charge-info': The IP authentication method.
  - `fqdn_outbound_authentication` 'ip-authentication' | 'credential-authentication': The outbound authentication type.
  - `webhook_url` string, uri: The webhook URL for authentication events.
  - `failover_url` string, uri: The failover webhook URL.
  - `txt_name` string: The TXT record name for Microsoft Teams SBC DNS verification.
  - `txt_value` string: The TXT record value for Microsoft Teams SBC DNS verification.
  - `txt_ttl` integer: The TTL for the TXT record.

## Response `200`

Successful response with the updated FQDN authentication.

- object
  - `data` FqdnAuthentication
    - `id` string: Identifies the resource.
    - `record_type` string: Identifies the type of the resource.
    - `connection_id` string: The ID of the FQDN connection this authentication strategy belongs to.
    - `user_name` string: The username for authentication.
    - `password` string: The password for authentication. For primary accounts created on or after September 8, 2026, this password is returned as `********`. The password is returned in full on create, and on update only when that update changed the password. Accounts created before September 8, 2026 are unaffected.
    - `ip_authentication_method` 'token' | 'p-charge-info': The IP authentication method.
    - `fqdn_outbound_authentication` 'ip-authentication' | 'credential-authentication': The outbound authentication type.
    - `webhook_url` string, uri: The webhook URL for authentication events.
    - `failover_url` string, uri: The failover webhook URL.
    - `microsoft_teams_sbc` boolean: Whether the connection is a Microsoft Teams SBC.
    - `txt_name` string: The TXT record name for Microsoft Teams SBC DNS verification.
    - `txt_value` string: The TXT record value for Microsoft Teams SBC DNS verification.
    - `txt_ttl` integer: The TTL for the TXT record.

## Other responses

- `401`: Unauthorized
- `403`: The user doesn't have the required permissions to perform the requested action.
- `404`: The requested resource doesn't exist.
- `409`: Conflict. Another update to this connection is still in progress. Wait and retry the request later.
- `422`: The request was well-formed but was unable to be followed due to semantic errors.

## Changes

- **2026-10-15** `a72569d69430`: 1 info
  - endpoint added

[Operation history](https://skmtc.dev/team-telnyx/apis/telnyx-api/changes/fqdn_connections/:fqdn_connection_id/fqdn_authentication/patch.md)

---

[API](https://skmtc.dev/team-telnyx/apis/telnyx-api.md) - [All operations](https://skmtc.dev/team-telnyx/apis/telnyx-api/llms.txt) - [OpenAPI document](https://skmtc.dev/team-telnyx/apis/telnyx-api/revisions/0f17b8167873?raw)