Node.js Http2ServerRequest.rawTrailers Method

Last Updated : 23 Jul, 2026

The http2ServerRequest.rawTrailers property in Node.js returns the raw trailing headers of an incoming HTTP/2 request as an array. It preserves the original order and casing of the trailer fields received from the client.

  • It provides the trailer fields as an array.
  • It preserves the original order and casing of trailer headers.
  • It is useful when working with HTTP/2 trailer metadata.

Syntax:

request.rawTrailers

Where

  • request: An instance of the Http2ServerRequest object.
  • rawTrailers: A read-only property that returns the raw trailing headers of the incoming HTTP/2 request as an array.

Return Value: This method returns the raw request/response trailer keys and values exactly as they were received.

Example 1:

JavaScript 
// Node.js program to demonstrate the
// Http2ServerRequest.rawTrailers method

const http2 = require('http2');
const fs = require('fs');

// Private key and public certificate for access
const options = {
  key: fs.readFileSync('private-key.pem'),
  cert: fs.readFileSync('public-cert.pem'),
};

// Request and response handler
const http2Handlers = (request, response) => {

  // Getting rawTrailers of http2 
  // by using request.rawTrailers method
  const auth = request.rawTrailers;
  console.log( auth)
};

// Creating and initializing server
// by using http2.createServer() method
const server = http2.createServer(options, http2Handlers);

server.on('stream', (stream, requestrawTrailers) => {
  stream.respond({ ':status': 200, 'content-type': 
  'text/plain' });
  stream.write('hello ');

  // Getting all information of this http2stream object
  // by using state method
  const status = stream.state;

  stream.end("priority weight : " + status.weight);

  // Stopping the server
  // by using the close() rawTrailers
  server.close(() => {
    console.log("server destroyed");
  })
});

server.listen(8000);

// Creating and initializing client
// by using tls.connect() rawTrailers
const client = http2.connect('http://localhost:8000');

const req = client.request({ 
  ':method': 'GET', ':path': '/'});

req.on('response', (responserawTrailers) => {
  console.log("status : " 
  + responserawTrailers[":status"]);
});

req.on('data', (data) => {
  console.log('Received: %s ',
  data.toString().replace(/(\n)/gm,""));
});

req.on('end', () => {
  client.close(() => {
    console.log("client destroyed");
  })
});

Output:

[]
status : 200
Received: hello
Received: priority weight : 16
client destroyed
server destroyed

Example 2:

JavaScript 
// Node.js program to demonstrate the
// Http2ServerRequest.rawTrailers method

const http2 = require('http2');
const fs = require('fs');

// Private key and public certificate for access
const options = {
  key: fs.readFileSync('private-key.pem'),
  cert: fs.readFileSync('public-cert.pem'),
};

// Request and response handler
const http2Handlers = (request, response) => {

  // Getting rawTrailers of http2 
  // by using request.rawTrailers method
  const auth = request.rawTrailers;
  console.log("AUTH: ", auth)
  response.end( "raw trailers :- ", auth)
};

// Creating and initializing server
// by using http2.createServer() method
const server = http2.createServer(options, http2Handlers);

server.on('stream', (stream, requestHeaders) => {

   // Getting all information of this http2stream object
   // by using state method
   const status = stream.state;

   stream.end("The sum weight of all Http2Stream : " + 
   status.sumDependencyWeight);

  // Stopping the server
  // by using the close() method
  server.close(() => {
    console.log("server destroyed");
  })
});

server.listen(8000);

// Creating and initializing client
// by using tls.connect() method
const client = http2.connect('http://localhost:8000');

const req = client.request({ 
  ':method': 'GET', ':path': '/' });

req.on('data', (data) => {
  console.log('Received: %s ',
  data.toString().replace(/(\n)/gm,""));
});

req.on('end', () => {
  client.close(() => {
    console.log("client destroyed");
  })
});

Output:

AUTH:  []
Received: raw trailers :-  
client destroyed
server destroyed

Use Cases of http2ServerRequest.rawTrailers

  • Accessing raw trailer headers received from the client.
  • Preserving the original order and casing of trailer fields.
  • Processing HTTP/2 trailer metadata.
  • Logging or debugging trailing headers.

Reference: https://nodejs.org/dist/latest-v12.x/docs/api/http2.html#http2_request_rawtrailers

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