Request header value matches

Matches when the value of a specific request header matches a regular expression.

This condition inspects the value of a specified header sent in the request to determine if it matches a regular expression. It returns true if the named header contains a value that matches the defined pattern.

Configuration

  • Case sensitive: Whether to enable case sensitivity during the name and value comparison. When disabled, the condition performs a case-insensitive match for the header name and evaluates the pattern against all headers sent in the request that match that name.
  • Name: The exact name of the request header to inspect. This field is required and supports a maximum of 50 characters.
  • Pattern: The RE2 regular expression used to evaluate the header’s value. The condition returns true if the pattern matches the value of the specified header. This field is required and supports a maximum of 255 characters.

Measurement

The condition extracts all values for the specified header name from the incoming request and evaluates them against the configured pattern.

  • Match found: If any instance of the header matches the regular expression, the condition returns true.
  • No match found: If none of the header values match the pattern, the condition returns false.
  • Missing header: If the specified header is absent from the request, the condition returns false.

Last modified March 5, 2026