How Sendra keeps request scripts sandboxed
Request scripts are useful when a request needs a little logic before it is sent or after a response comes back. They also create an important boundary: what should a script be allowed to reach from inside an API request file?
The script only sees the request and response
Sendra registers no functions, types, packages, or modules into its embedded
interpreter. The only Sendra-shaped values available to a script are request
and response, made up of strings, integers, and arrays. There is no helper
that can access the filesystem or make a network call.
That small surface is easier to reason about than a list of capabilities that must be audited and secured. The interpreter does not get a Sendra-powered way to reach the outside world in the first place.
Close off the interpreter's other doors
The default Rhai module resolver can load .rhai files from disk, so Sendra
removes import at compile time. eval is disabled too. It is not a
filesystem or network capability, but disabling it means scripts are checked
before the request is sent instead of being dynamically compiled during the
run.
Each script also has a ten-million-operation limit. That turns an accidental
while true into a named error instead of a process that hangs indefinitely.
It is a backstop for mistakes, not a defense against a hostile script; request
files are part of the project being run.
Keep script output out of JSON results
print, debug, and script errors go to stderr, alongside Sendra's progress
and error messages. That keeps stdout available for the single JSON document
promised by --json. If a script prints and then throws, its output remains
available to explain the failure.
The choice of output stream belongs to each front end. sendra-core returns
the script's printed lines and its verdict without printing anything itself;
the CLI decides to put those lines on stderr. The TUI does not run these hooks,
so the same output decision does not apply there.
See Scripting for the fields and hook order, and the interactive TUI reference for what the TUI supports.