How can I prevent 500 errors and excessive workflow runs during n8n chat widget initialization?

Below is some guidance on how to address these two issues when embedding chats using @n8n/chat.

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1. Avoiding the 500 Error on Initialization

The initial webhook call is made before the user sends a message, so the payload may not include a prompt (or may lack an action flag such as sendMessage). As a result, your workflow’s AI agent may error when it doesn’t find the expected input. Instead of merely filtering later in your workflow (with an IF node), you have two options:

• Early Check and Early Exit:
  At the very beginning of your workflow, add a node (for example, a Function node or IF node) that examines the inbound payload. Check if the expected parameter (e.g. the user prompt or a specific metadata flag) is missing or set to a default state. If so, simply return a benign response (or even use the Respond to Webhook node with an empty payload) to end the workflow execution without calling the AI agent.

  For example, using a Function node you could do:

  JAVASCRIPTCopied
  // Check if a valid user prompt is present
  if (!items[0].json.prompt || items[0].json.action !== 'sendMessage') {
    return [{ json: { message: 'No user message, skipping AI execution.' } }];
  }
  
  // Else continue normally
  return items;

• Client-Side Signal:
  Instead of letting the chat widget automatically call your webhook on page load, you can pass an extra metadata flag through the createChat call. When you create the widget, include a key that distinguishes an initialization call (for example, action: "init") so that your workflow ignores it. Then, only when the widget later calls with action "sendMessage" do you proceed with the AI processing.

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2. Preventing Unnecessary Workflow Executions on High-Traffic Pages

If the widget automatically makes an initialization request on every page load, these request can quickly add up and consume your execution allowance. There are two approaches to mitigate this:

• Use the “Require Button Click to Start Chat” Option (Hosted Chat):
  If you’re using n8n’s hosted chat interface, enable the “Require Button Click to Start Chat” option. This setting ensures that the chat session (and webhook call) only begins when the user explicitly clicks to start the conversation rather than on every page load.

• Delay Widget Instantiation on the Client Side (Embedded Chat):
  When using the embedded chat mode, you could change your client-side logic so that createChat is only called when the user takes an action (such as clicking a “Chat now” button). This way, the initialization request that triggers a workflow run won’t occur until there’s genuine user intent.

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By either returning early from the workflow when no prompt is detected or modifying the client-side behavior (or both), you can avoid triggering the AI agent on initialization requests and reduce unnecessary workflow runs. This should address your 500 errors and help prevent consuming runtime executions due to high page traffic.

Let me know if you have any further questions on configuring these options.