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HTTP Request

Overview​

The HTTP Request Traffic Policy action performs an outbound HTTP request to a target URL. You can use it to integrate with external services through internal endpoints or—if enabled—with external APIs.

Note: External requests are supported but disabled by default. Contact ngrok support to enable external access.

Configuration Reference​

The Traffic Policy configuration reference for this action.

Supported Phases​

on_http_request, on_http_response

Type​

http-request

Configuration Fields​

  • urlstringRequiredCEL

    The destination URL for the HTTP request.

  • methodenum

    The HTTP method to use for the request.

    • Possible enum values
    • GET (default)
    • PUT
    • POST
    • PATCH
    • DELETE
    • OPTIONS

  • query_paramslist of objectsCEL

    A list of query parameters to append to the URL. Each item is an object with the following structure:

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    This format supports CEL interpolation in both keys and values.

    Maximum: 32 entries. Key max length: 128 chars. Value max length: 8192 chars.

  • headersobjectCEL

    A map of HTTP headers to include in the request. Keys are header names and values are header values.

    Maximum: 10 entries.

  • bodystringCEL

    The body of the HTTP request. Supported on methods like POST, PUT, or PATCH.

  • max_redirectsint

    The maximum number of HTTP redirects to follow.

    Default is 10. The minimum allowed is 0. The maximum allowed is 100.

  • timeoutduration

    The maximum duration as a duration string to wait for the entire request (including retries and redirects).

    Default is 3s. The minimum allowed is 1s. The maximum allowed is 30s.

  • retry_conditionstringCEL

    A CEL expression evaluated after each failed attempt. If true, the request is retried (up to 3 times).

    • Supported retry variables
    • attempts (int): Total number of attempts so far
    • last_attempt.req: The last request object
    • last_attempt.res: The last response object (if any)
    • last_attempt.error: The error string (if any)

    Default: false

  • on_errorenum

    Determines how to proceed if the HTTP request fails.

    • Possible enum values
    • continue (default) – Proceed with remaining actions
    • halt – Stop processing the policy

Action Result Variables​

The following variables are made available for use in subsequent expressions and CEL interpolations after the action has run. Variable values will only apply to the last action execution, results are not concatenated.

  • actions.ngrok.http_request.error.codestring

  • actions.ngrok.http_request.error.messagestring

    Message for an error that occurred during the invocation of an action.

  • actions.ngrok.http_request.attemptsarray of objects

    A list of HTTP responses for each request attempt.

  • actions.ngrok.http_request.reqobject

    The HTTP request.

  • actions.ngrok.http_request.resobject

    The last attempted HTTP response. Unlike actions.ngrok.attempts[i] this variable also contains the response body.