INTEGER, read-only.

Available in all subroutines.

Version of the service VCL currently loaded.

Try it out

req.vcl.version 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.

Configuration version discrepancy detection

Detect situations when a shield server might have a different version of your code than the edge server, and avoid errors that this might cause.