Function API only Updated 23 Oct 2026

`getHeader(name)`

Reads a header value from the request.

Parameters

namestringrequired

The name of the header to read.

Returns

The header value as a string, or an array when the header has several values. null when the request does not have the header. Throws if the name is empty.

Example

Normal JavaScript, running in the browser or on the Docly™ server.

// Retrieve the 'If-Modified-Since' header from the request
let ifModifiedSinceHeader = docly.getHeader("If-Modified-Since");

// Write value to output
write(ifModifiedSinceHeader);