STRING, read-only.

Available inall subroutines.

The request body. Using this variable for binary data will truncate at the first null character. Limited to 8KB in size.

Exceeding the limit results in the req.body variable being blank. If this happens it can be detected with the following VCL:

if (std.atoi(req.http.Content-Length) > 0 && std.strlen(req.body) == 0 && req.method == "POST") {
// Body has been truncated

The variable req.postbody is an alias for req.body.