Seq.App.HttpRequest

Send events and notifications from Seq to a remote HTTP/REST/Webhook endpoint. Requires Seq 2021.4 or better.

Getting started

Install the app under Settings > Apps. The app package id is Seq.App.HttpRequest.

Visit the Seq documentation for detailed information about installing and configuring Seq Apps.

Configuration

Instances of the app support the following properties.

Property	Description	Default
URL	The target URL. This is a template based on event properties, for example, https://api.example.com/notify?to={Email}. Placeholders in templates will be URI-encoded.
Method	The HTTP method to use.	POST
Body	The request body to send.
Body is a template	Whether to treat the body as a template based on event properties, for example New request from: {Email}, or to send the body as-is.	false
Media Type	Media type describing the body.
Authentication Header	An optional Name: Value header, stored as sensitive data, for authentication purposes.
Other Headers	Additional headers to send with the request, one per line in Name: Value format.
Extended Error Diagnostics	Whether or not to include outbound request bodies, URLs, etc., and response bodies when requests fail.	false

Template language

The URL and body settings are templates that use braces to insert data from the event or notification that is being received by the app.

• Event and notification properties are inserted using {Name}
• Built-in properties use CLEF names, for example, the timestamp is @t, message is @m, and level is @l
• Braces are escaped by doubling: {{ for an opening brace, and }} for closing
• Substitutions can use most Seq query language expressions: {1 + 2}, {Round(Price, 2)}, etc.

To send a well-formed JSON payload based on event properties, construct a Seq object literal, and place it between spaced braces. For example:

{ {
   Timestamp: @t,
   Source: 'Seq',
   Contact: { Name: CompanyName, Type: 'Company' }
} }

This example will result in request bodies resembling:

{
  "Timestamp": "2021-09-15T06:33:21.432",
  "Source": "Seq",
  "Contact": {
    "Name": "Datalust Pty Ltd",
    "Type": "Company"
  }
}

Templates support repetition, conditionals, and many other features. For a more complete language reference, see the Serilog.Expressions README.

Development

To run the app locally, without installing the package into Seq, use Run.ps1 in the repository root. This requires seqcli on the path.

This will stream events from a Seq instance at http://localhost:5341, and send HTTP requests to http://localhost:5050. Modify the script to specify different app settings.

To easily inspect your generated HTTP requests, check out Webhook.site.

Acknowledgements

Templating support is based on code from Serilog.Expressions.