Error Codes

When using API calls to the MiMo model, common error codes and solutions are as follows:

Error Code	Causes	Solutions
400 - Invalid Format	Invalid request format	Check if the JSON format is correct Check if all required parameters are included Check if parameter values are within the valid range Check if the message format meets the interface requirements Check if the model exists Check if the fields are entered correctly Check multimodal file input for compliance with format, size and other restrictions. Check if multimodal file input is publicly accessible In multi-turn conversations under thinking mode, the `reasoning_content` field must be fully passed back to the API.
401 - Authentication Fails	Missing or invalid API Key, or incorrect Authorization request header format API Key that mixes Token Plan and Pay-as-you-go API	Check if the API key and request header format are correct Check if a dedicated Base URL and API Key are used when using the Token Plan
402 - Insufficient Balance	Insufficient account balance	Check your account balance and recharge in a timely manner
403 - Forbidden Access	The service is currently not available in the current region, or the API Key has been restricted by risk control	Create a new API Key and pay attention to the security of input content
404 - Not Found	The requested endpoint or model does not support image input capability	Verify that the model / endpoint being used supports image input capability
421 - Content Filter	Content moderation and blocking	Avoid entering unsafe or sensitive content
429 - Too Many Requests	Requests are too frequent, or the quota of Token Plan has been exhausted	Implement exponential backoff and retry logic, or reduce the request frequency Upgrade the Token Plan package or switch to pay-as-you-go API
500 - Server Error	Our server encounters an issue	Please try again later, or contact us for resolution
503 - Server Overloaded	The server is overloaded due to high traffic	Please try again later

Update Time May 12, 2026