Hello, We are currently encountering issues with our assistants: All calls are stopped after the first message and we have the following error : pipeline-error-xai-400-bad-request-validation-failed Regards

Hi there! 👋 I understand you're facing an issue with your assistants where calls are stopping after the first message with the error "pipeline-error-xai-400-bad-request-validation-failed". While I can't diagnose your specific implementation without more details, I can definitely help explain what this error means and suggest some troubleshooting steps! Based on the information I've found, this error indicates a validation failure in your tool definitions. The "400 bad request" part suggests that the request sent to the server was malformed or invalid in some way. ## Possible causes: 1. Validation error in tool definitions - There appears to be an issue with how your tools are defined or configured. 2. Incorrect variable handling - The variable name in the API request might not match what the Vapi assistant expects, or the variable might not be correctly serialized in the request. 3. Model compatibility issues - The model you're using might not support function calling, similar to how some errors occur with models like "deepseek-reasoner". 4. Configuration problems with

firstMessage

and

firstMessageMode

- Incorrect settings here can cause calls to terminate after the first message. 5. Assistant ID configuration - There might be an issue with how the assistant ID is configured on your phone number. ## Troubleshooting steps: 1. Check your tool definitions for any validation errors or formatting issues. 2. Review variable handling in your API requests to ensure proper formatting and serialization. 3. Verify model compatibility with the functions you're trying to use. 4. Check your assistant configuration, particularly the

firstMessage

and

firstMessageMode

settings: ```javascript const assistant = { // ... other configurations ... firstMessage: "Hello! I'm your AI assistant. How may I help you today?", firstMessageMode: "assistant-speaks-first", // or use one of the other supported modes };

Hey! To help track down this issue, could you share: - The call ID This would really help us figure out what went wrong!

Hello, here: 39271573-2100-471b-8288-01aa8ab48ed6

Marking this ticket as Solved ✅