> ## 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.

# Update a guardrail

> Changes a guardrail's `name`, `modes`, `always_on`, or `settings`. `settings` is replaced whole, secrets included. The `type` cannot change. The instance must be `ready`; otherwise the request answers `409`.



## OpenAPI

````yaml /openapi/source/external/agent-gateway/agent-gateway.json patch /agent_gateways/{instance_id}/guardrails/{guardrail_id}
openapi: 3.1.0
info:
  version: 1.0.0
  title: Telnyx API
  x-latency-category: interactive
  x-endpoint-cost: light
  description: >-
    Agent Gateway authenticates, authorizes, and audits the requests agents send
    to models, tools, and other agents. Each gateway runs as a dedicated
    instance on the account's
    [*Network*](https://developers.telnyx.com/docs/network/overview). This API
    creates, lists, and deletes instances, and manages the keys, teams, spend
    logs, MCP servers, APIs, tool permissions, and guardrails on them. Each
    instance serves an OpenAI-compatible API at its `gateway_url`.
servers:
  - url: https://api.telnyx.com/v2
    description: Telnyx API v2
security:
  - bearerAuth: []
tags:
  - name: Agent Gateways
    description: Create, list, retrieve, and delete Agent Gateway instances.
  - name: Agent Gateway Keys
    description: Keys on an instance.
  - name: Agent Gateway Teams
    description: 'Teams on an instance: shared model lists, budgets, and rate limits.'
  - name: Agent Gateway Spend Logs
    description: The requests an instance served, with their cost.
  - name: Agent Gateway MCP Servers
    description: MCP servers on an instance, served to agents at one MCP endpoint.
  - name: Agent Gateway APIs
    description: REST APIs on an instance, served to agents as tools.
  - name: Agent Gateway Tool Permissions
    description: The MCP servers and tools a key or team may use.
  - name: Agent Gateway Guardrails
    description: Checks an instance runs on model and tool requests.
  - name: Agent Gateway Policies
    description: Named sets of guardrails an instance applies to requests.
  - name: Agent Gateway Policy Attachments
    description: Where an instance applies each policy.
paths:
  /agent_gateways/{instance_id}/guardrails/{guardrail_id}:
    patch:
      tags:
        - Agent Gateway Guardrails
      summary: Update a guardrail
      description: >-
        Changes a guardrail's `name`, `modes`, `always_on`, or `settings`.
        `settings` is replaced whole, secrets included. The `type` cannot
        change. The instance must be `ready`; otherwise the request answers
        `409`.
      operationId: UpdateAgentGatewayGuardrail
      parameters:
        - name: instance_id
          in: path
          required: true
          description: The Agent Gateway's `id`.
          schema:
            type: string
            format: uuid
          example: 32ce035d-3165-4031-b1a7-a7c0c259590a
        - name: guardrail_id
          in: path
          required: true
          description: The guardrail's `id`.
          schema:
            type: string
            format: uuid
          example: 9645e556-6532-4341-8cab-21b58cdef529
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/AgentGatewayGuardrailUpdate'
            examples:
              always_on:
                summary: Run on every request
                value:
                  always_on: true
      responses:
        '200':
          description: The updated guardrail
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/AgentGatewayGuardrailResponse'
              example:
                data:
                  id: 9645e556-6532-4341-8cab-21b58cdef529
                  name: mask-pii
                  modes:
                    - before_request
                  always_on: true
                  type: content_filter
                  settings:
                    patterns:
                      - name: us_ssn
                        action: mask
                      - name: email
                        action: mask
                    regexes: []
                    keywords: []
                    categories: []
                  created_at: '2026-10-28T17:07:48.905000Z'
                  updated_at: '2026-10-28T17:07:48.905000Z'
        '400':
          description: A name the instance already uses
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/TelnyxErrors'
              example:
                errors:
                  - code: '10012'
                    title: Duplicate resource
                    detail: Resource is a duplicate.
                    meta:
                      url: https://developers.telnyx.com/docs/overview/errors/10012
                    source:
                      pointer: /name
        '401':
          description: Unauthorized
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/TelnyxErrors'
              example:
                errors:
                  - code: '10009'
                    title: Authentication failed
                    detail: >-
                      The required authentication headers were either invalid or
                      not included in the request.
                    meta:
                      url: https://developers.telnyx.com/docs/overview/errors/10009
        '404':
          description: Not found
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/TelnyxErrors'
              example:
                errors:
                  - code: '10005'
                    title: Resource not found
                    detail: The requested resource or URL could not be found.
                    meta:
                      url: https://developers.telnyx.com/docs/overview/errors/10005
        '409':
          description: The instance is not `ready`
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/TelnyxErrors'
              example:
                errors:
                  - code: '99901'
                    title: Instance not ready
                    detail: The instance is not ready; its engine is not running.
        '422':
          description: A field fails validation
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/TelnyxErrors'
              example:
                errors:
                  - code: '10027'
                    title: Unprocessable Entity
                    detail: The type does not run in one of these modes.
                    meta:
                      url: https://developers.telnyx.com/docs/overview/errors/10027
                    source:
                      pointer: /modes
        '502':
          description: The instance's engine did not answer
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/TelnyxErrors'
              example:
                errors:
                  - code: '99903'
                    title: Engine unavailable
                    detail: The instance's engine did not answer; try again shortly.
      x-codeSamples:
        - lang: JavaScript
          source: >-
            import Telnyx from 'telnyx';


            const client = new Telnyx({
              apiKey: process.env['TELNYX_API_KEY'], // This is the default and can be omitted
            });


            const AgentGatewayGuardrail = await
            client.agentGateways.guardrails.update('instance_id',
            'guardrail_id', {
              name: 'name',
            });


            console.log(AgentGatewayGuardrail.data);
        - lang: Python
          source: |
            import os
            from telnyx import Telnyx

            client = Telnyx(
                api_key=os.environ.get("TELNYX_API_KEY"),  # This is the default and can be omitted
            )
            agent_gateway_guardrail = client.agent_gateways.guardrails.update(
                instance_id="instance_id",
                guardrail_id="guardrail_id",
                name="name",
            )
            print(agent_gateway_guardrail.data)
        - lang: Go
          source: "package main\n\nimport (\n\t\"context\"\n\t\"fmt\"\n\n\t\"github.com/team-telnyx/telnyx-go\"\n\t\"github.com/team-telnyx/telnyx-go/option\"\n)\n\nfunc main() {\n\tclient := telnyx.NewClient(\n\t\toption.WithAPIKey(\"My API Key\"),\n\t)\n\tguardrail, err := client.AgentGateways.Guardrails.Update(\n\t\tcontext.TODO(),\n\t\t\"instance_id\",\n\t\t\"guardrail_id\",\n\t\ttelnyx.AgentGatewayGuardrailUpdateParams{\n\t\t\tName: telnyx.String(\"name\"),\n\t\t},\n\t)\n\tif err != nil {\n\t\tpanic(err.Error())\n\t}\n\tfmt.Printf(\"%+v\\n\", guardrail.Data)\n}\n"
        - lang: Java
          source: >-
            package com.telnyx.sdk.example;


            import com.telnyx.sdk.client.TelnyxClient;

            import com.telnyx.sdk.client.okhttp.TelnyxOkHttpClient;

            import
            com.telnyx.sdk.models.agentGateways.guardrails.GuardrailUpdateParams;


            public final class Main {
                private Main() {}

                public static void main(String[] args) {
                    TelnyxClient client = TelnyxOkHttpClient.fromEnv();

                    GuardrailUpdateParams params = GuardrailUpdateParams.builder()
                        .name("name")
                        .build();
                    var response = client.agentGateways().guardrails().update("instance_id", "guardrail_id", params);
                }
            }
        - lang: Ruby
          source: >-
            require "telnyx"


            telnyx = Telnyx::Client.new(api_key: "My API Key")


            agent_gateway_guardrail =
            telnyx.agent_gateways.guardrails.update("instance_id",
            "guardrail_id", name: "name")


            puts(agent_gateway_guardrail)
        - lang: PHP
          source: >-
            <?php


            require_once dirname(__DIR__) . '/vendor/autoload.php';


            use Telnyx\Client;

            use Telnyx\Core\Exceptions\APIException;


            $client = new Client(apiKey: getenv('TELNYX_API_KEY') ?: 'My API
            Key');


            try {
              $agent_gateway_guardrail = $client->agentGateways->guardrails->update(
                'instance_id',
                'guardrail_id',
                name: 'name',
              );

              var_dump($agent_gateway_guardrail);
            } catch (APIException $e) {
              echo $e->getMessage();
            }
        - lang: CLI
          source: |-
            telnyx agent-gateways:guardrails update \
              --api-key 'My API Key' \
              --instance-id 32ce035d-3165-4031-b1a7-a7c0c259590a \
              --guardrail-id 9645e556-6532-4341-8cab-21b58cdef529 \
              --name name
components:
  schemas:
    AgentGatewayGuardrailUpdate:
      type: object
      additionalProperties: false
      description: The fields to change. `settings` is replaced whole, secrets included.
      properties:
        name:
          type: string
          pattern: ^[A-Za-z0-9_.-]{1,100}$
          description: >-
            A name, unique on the instance. A request names it in its
            `guardrails` field.
        modes:
          type: array
          minItems: 1
          items:
            type: string
            enum:
              - before_request
              - during_request
              - after_request
              - logging_only
              - before_tool_request
              - during_tool_request
              - after_tool_request
          description: When the guardrail runs. Each type runs in some modes only.
        always_on:
          type: boolean
          default: false
          description: >-
            `true` runs the guardrail on every request, and a request cannot
            turn it off. `false` runs it on the requests that name it.
        settings:
          type: object
          additionalProperties: true
          description: >-
            The type's settings. `content_filter`: `patterns` (prebuilt patterns
            by name, such as `us_ssn` or `email`), `regexes`, `keywords`, and
            `categories` (such as `prompt_injection`), each with an `action` of
            `block` or `mask`. `tool_permission`: `rules` (`id`, `tool_name`,
            `tool_type`, `decision`, `argument_patterns`), a `default` decision,
            and `on_denied` (`block` or `rewrite`). `model_judge`: a `model` on
            the instance and weighted `criteria` (`name`, `description`,
            `weight`, the weights summing to 100). `custom_code`: `code`
            defining `apply_guardrail(inputs, request_data, input_type)`.
            `lakera`: `api_key`, `project_id`, `api_base`. `presidio`:
            `analyzer_url`, `anonymizer_url`, `entities` (entity name to `block`
            or `mask`), `language`. `bedrock`: `guardrail_id`, `version`,
            `region`, and `access_key_id` with `secret_access_key`, or
            `role_name`. `azure_content_safety`: `api_key`, `endpoint`,
            `severity` (0 to 7). Provider secrets are write-only.
    AgentGatewayGuardrailResponse:
      type: object
      required:
        - data
      properties:
        data:
          $ref: '#/components/schemas/AgentGatewayGuardrail'
    TelnyxErrors:
      type: object
      properties:
        errors:
          type: array
          items:
            $ref: '#/components/schemas/TelnyxError'
    AgentGatewayGuardrail:
      type: object
      required:
        - id
        - name
        - modes
        - always_on
        - type
        - settings
        - created_at
        - updated_at
      properties:
        id:
          type: string
          format: uuid
          description: Identifies the guardrail.
        name:
          type: string
          description: What a request names in its `guardrails` field.
        modes:
          type: array
          items:
            type: string
            enum:
              - before_request
              - during_request
              - after_request
              - logging_only
              - before_tool_request
              - during_tool_request
              - after_tool_request
          description: When the guardrail runs.
        always_on:
          type: boolean
          description: Whether it runs on every request.
        type:
          type: string
          enum:
            - content_filter
            - tool_permission
            - model_judge
            - custom_code
            - lakera
            - presidio
            - bedrock
            - azure_content_safety
        settings:
          type: object
          additionalProperties: true
          description: >-
            The type's settings. `content_filter`: `patterns` (prebuilt patterns
            by name, such as `us_ssn` or `email`), `regexes`, `keywords`, and
            `categories` (such as `prompt_injection`), each with an `action` of
            `block` or `mask`. `tool_permission`: `rules` (`id`, `tool_name`,
            `tool_type`, `decision`, `argument_patterns`), a `default` decision,
            and `on_denied` (`block` or `rewrite`). `model_judge`: a `model` on
            the instance and weighted `criteria` (`name`, `description`,
            `weight`, the weights summing to 100). `custom_code`: `code`
            defining `apply_guardrail(inputs, request_data, input_type)`.
            `lakera`: `api_key`, `project_id`, `api_base`. `presidio`:
            `analyzer_url`, `anonymizer_url`, `entities` (entity name to `block`
            or `mask`), `language`. `bedrock`: `guardrail_id`, `version`,
            `region`, and `access_key_id` with `secret_access_key`, or
            `role_name`. `azure_content_safety`: `api_key`, `endpoint`,
            `severity` (0 to 7). Provider secrets are write-only. Responses
            leave the secrets out.
        created_at:
          type:
            - string
            - 'null'
          format: date-time
        updated_at:
          type:
            - string
            - 'null'
          format: date-time
    TelnyxError:
      type: object
      properties:
        code:
          type: string
        title:
          type: string
        detail:
          type: string
        source:
          type: object
          properties:
            pointer:
              type: string
            parameter:
              type: string
        meta:
          type: object
          properties:
            url:
              type: string
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      description: Telnyx API key

````