Functions let you transform values directly inside a request file without preprocessing. You call them inline using the syntax:
Arguments can be literal strings or variables: bearer(<api_token>).
Built-in functions
bearer(token)
Produces a Bearer <token> string. Use it in the Authorization header instead of writing the prefix manually.
Resolves to Authorization: Bearer abc123 when api_token=abc123 in your environment.
basicAuth(username, password)
Encodes the username and password as a Base64 Basic credential string. Use it in the Authorization header.
Resolves to Authorization: Basic dXNlcjpwYXNz (the Base64 encoding of user:pass).
join(...parts)
Concatenates any number of strings and variables together with no separator.
Resolves to X-Correlation-Id: req-42-abc when user_id=42 and session_id=abc.
readText(path)
Reads a file from disk and inlines its content as the request body. Useful for large JSON payloads or other text content you want to keep in a separate file.
readFile(path)
Reads a binary file from disk and attaches it as a form part in a multipart body. This function is only valid inside a form body — see Request body for usage.
readFile is used in @body form entries, not in headers. Using readFile in a form body automatically switches the content type to multipart/form-data if you haven’t set it explicitly.
Example: authenticated request with functions
This single request uses bearer() to format the token, join() to build a custom header value, and a variable inside a JSON body — all resolved at run time from the active environment.