UmairPerwaiz•2mo ago

In the javascript node I am getting the error

PLease understand the below code : function encodeMimeMessageAsBase64Url(mimeContent) { // Ensure Buffer is available in your execution environment. // In Voiceflow's JavaScript steps, Buffer might not be available directly. // You might need to use browser-compatible methods like btoa and TextEncoder if this causes issues. const base64url = Buffer.from(mimeContent) .toString('base64') .replace(/+/g, '-') // Convert '+' to '-' .replace(///g, '') // Convert '/' to '' .replace(/=+$/, ''); // Remove trailing '=' return base64url; } // --- Example Usage --- // Compose MIME text email manually mimeMessage =

Content-Type: text/plain; charset="utf-8"
To: umairperwaizmalik1@gmail.com
From: cxboltagency@gmail.com
Subject: Test Subject

Hello Umair, this is a test email from Voiceflow!

; // Encode message using the new function rawMessage = encodeMimeMessageAsBase64Url(mimeMessage); // In Voiceflow, you would typically assign 'rawMessage' to a variable // that you've defined in your step, for example: // _.set('rawMessageVariable', rawMessage); if using _ for state management, // or simply if rawMessage is an output variable of your JavaScript step. console.log(rawMessage); // For testing outside Voiceflow to see the output Task: Please help me resolve the error

3 Replies

Tico | Voiceflow Assistant•2mo ago

It’s failing because the Buffer class is a Node-only global; the JavaScript Code step in Voiceflow runs in a sandboxed V8 runtime where Buffer isn’t exposed.
Replace the Buffer logic with a browser-compatible approach that Voiceflow’s runtime does support (TextEncoder + btoa). Drop this inside your JavaScript step (the variable mimeMessage must already exist in Voiceflow before this step runs):

/* Encode a MIME string as base64-url without using Buffer */

/* 1. UTF-8 → binary string */
const utf8Bytes = new TextEncoder().encode(mimeMessage);
let binary = '';
for (let i = 0; i < utf8Bytes.length; i++) {
  binary += String.fromCharCode(utf8Bytes[i]);
}

/* 2. binary → standard base64 */
let base64 = btoa(binary);

/* 3. base64 → base64-url (RFC 4648 §5) */
const rawMessage = base64
  .replace(/\+/g, '-')  // “+” → “-”
  .replace(/\//g, '_')  // “/” → “_”
  .replace(/=+$/, '');  // trim “=” padding

/* 4. save result to a Voiceflow variable that already exists */
rawMessageVar = rawMessage;      // <-- change to your output var name

/* Encode a MIME string as base64-url without using Buffer */

/* 1. UTF-8 → binary string */
const utf8Bytes = new TextEncoder().encode(mimeMessage);
let binary = '';
for (let i = 0; i < utf8Bytes.length; i++) {
  binary += String.fromCharCode(utf8Bytes[i]);
}

/* 2. binary → standard base64 */
let base64 = btoa(binary);

/* 3. base64 → base64-url (RFC 4648 §5) */
const rawMessage = base64
  .replace(/\+/g, '-')  // “+” → “-”
  .replace(/\//g, '_')  // “/” → “_”
  .replace(/=+$/, '');  // trim “=” padding

/* 4. save result to a Voiceflow variable that already exists */
rawMessageVar = rawMessage;      // <-- change to your output var name

What changed • TextEncoder is part of the standard ES API and is available in Voiceflow’s V8 runtime.
• btoa converts a binary string to base64.
• We manually transform the result into base64-url, which Gmail’s API expects. After this step the Voiceflow variable (rawMessageVar above) contains the correctly‐encoded value ready to pass to the Gmail API. That should clear the “Buffer is not defined” error.

UmairPerwaizOP•2mo ago

const utf8Bytes = new TextEncoder().encode(mimeMessage); let binary = ''; for (let i = 0; i < utf8Bytes.length; i++) { binary += String.fromCharCode(utf8Bytes[i]); } /* 2. binary → standard base64 / let base64 = btoa(binary); / 3. base64 → base64-url (RFC 4648 §5) / const rawMessage = base64 .replace(/+/g, '-') // “+” → “-” .replace(///g, '') // “/” → “” .replace(/=+$/, ''); // trim “=” padding / 4. save result to a Voiceflow variable that already exists */ rawMessageVar = rawMessage; // <-- change to your output var name I am executing the above code. but still I am getting error. Variables are defined in the voiceflow but still there is the error

W. Williams (SFT)•2mo ago

You can't use Buffer. In whatever you used to write that code, say that it will be run in the "V8 Isolate" runtime.

In the javascript node I am getting the error

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