Available in all subroutines.

Returns the given URL with the given parameter name and value appended to the end of the query string. The parameter name and value will be URL-encoded when added to the query string.


set req.url = querystring.add(req.url, "foo", "bar");

Try it out

querystring.add is used in the following code examples. Examples apply VCL to real-world use cases and can be deployed as they are, or adapted for your own service. See the full list of code examples for more inspiration.

Click RUN on a sample below to provision a Fastly service, execute the code on Fastly, and see how the function behaves.

No-origin RUM logging

Collect and aggregate log data submitted from browsers directly into S3 or another log store without having to handle the traffic at your origin.

Manipulate query string

Add, remove, and sort querystring parameters.