Frequently asked questions

How do I switch models?

Change the model parameter in your request; the rest of the code stays the same. For example, replace deepseek-v4-flash with claude-sonnet-5 or gpt-5.6-sol. See Models (the Model Catalog) in the console for available IDs.

Which programming languages are supported?

Yomi API follows the OpenAI API standard, so languages covered by OpenAI SDKs can be used directly: Python, JavaScript/TypeScript, Java, C#/.NET, Go, Ruby, PHP and others. Any language capable of HTTPS requests can also call the REST API directly.

How do I check my balance and usage?

Sign in to the console and open the User Center. Dashboard shows your balance and spending overview; Usage shows token usage and charges by model, with filters for API key and date.

How do I choose a model quickly?

• General chat: claude-sonnet-5, deepseek-v4-flash
• Deep reasoning: claude-opus-4-8, gpt-5.5
• Coding: gpt-5.6-terra, deepseek-v4-pro
• Multimodal and long context: gpt-5.6-sol, kimi-k3

See Billing and concurrency for more complete recommendations by use case.

Why does Responses API return previous_response_id is only supported on Responses WebSocket v2？

This means the request includes previous_response_id. The current HTTP endpoint does not support saving server-side conversation state through this field. Remove it and maintain the full conversation history in your client as described below.

How can I fix it?

Use stateless calls (officially called manually manage conversation state): remove previous_response_id and send the complete conversation history in each request's input, including the model's previous output items. Removing the field without sending the history loses the conversation context.

Which use cases are affected?

• Normal Codex conversations and resume (local rollout replay) are unaffected.
• Remote conversation compaction with compact, Agents SDK conversation chaining and other features relying on server-side state trigger this error.
• If the source is unclear, give the error and a request to switch to stateless mode to an AI to help update your own code. If an agent tool generates the request itself, disable its conversation chaining or state settings, or use a tool that does not depend on them.

What should I do if I have a problem?

• Review the API reference and check the endpoint address and parameters.
• Check common configuration issues: whether base_url points to https://api.yomiapi.com/v1, the key is valid and the balance is sufficient.
• Contact support: Email [email protected].