Cherry Studio

Add Onefast API to the Cherry Studio desktop AI client and use every model with one key.

Add a provider

Open Cherry Studio → "Settings" (bottom left) → "Model Provider".
Click "Add" at the bottom and fill in:
- Provider Name: anything, e.g. Onefast API
- Provider Type: OpenAI
In the new provider, fill in:
- API Key: your sk- key
- API Host: https://api.onefast.ai
Click "Manage" (or fetch the model list), select the models you need (GPT, Claude, Gemini, DeepSeek and more are all listed) and save.
Click "Check" to test the connection. Once it succeeds, you can pick these models in chats.

Cherry Studio appends /v1/chat/completions to the API host automatically, so do not add /v1 yourself. If you entered https://api.onefast.ai/v1 and get a 404, remove the /v1.

Want Claude's native features?

Add another provider with type Anthropic, set the API host to https://api.onefast.ai as well, and add only Claude models. This lets you use native features such as extended thinking.

Image generation

In "Paintings", choose the OpenAI-compatible provider and select gpt-image-2.5 or a Gemini image model.

Getting started

Overview — Onefast API gives you GPT, Claude, Gemini, DeepSeek, Qwen and other leading models with one API key, compatible with the OpenAI, Anthropic and Gemini native protocols.
Quickstart — Create an API key and send your first request with cURL, Python or Node.js.
Authentication — How to send your API key, how to choose a group, and the quota, model and IP limits you can set on a key.
Groups & billing — What groups (routes) are, how prices are calculated, and when you aren't charged.

Text & chat

Chat completions (OpenAI-compatible) — Call any text model — GPT, Claude, Gemini, DeepSeek, Qwen and more — with the OpenAI Chat Completions format.
Responses API — OpenAI's next-generation Responses endpoint, used by default by Codex CLI and similar tools.
Claude Messages (Anthropic native) — Call Claude with Anthropic's official Messages API, with full native support for extended thinking, prompt caching, tool use and more.
Gemini native API — Call Gemini models with Google's official generateContent API, compatible with the Google GenAI SDK and Gemini CLI.
Tools & reasoning — Function calling, structured output, and controlling reasoning (thinking) for GPT, Claude and Gemini.
Prompt caching — Long prefixes you send repeatedly (system prompts, documents, tool definitions) can hit the cache, cutting input cost and latency significantly.

Images, video & audio

Image generation — Call GPT Image, Gemini (Nano Banana) and other image models with the OpenAI Images format, at 1K / 2K / 4K.
Video generation — Video runs as an async task — submit → poll status → download the result. Supports Seedance, Wan, Grok Imagine, HappyHorse, Gemini Omni and more.
Audio & embeddings — Text-to-speech (TTS), speech recognition (ASR) and text embeddings.

Client integrations

Claude Code — Use Onefast API in Claude Code, Anthropic's official command-line coding assistant.
Codex CLI — Use Onefast API in Codex CLI, OpenAI's official command-line coding assistant.
Gemini CLI — Use Onefast API in Gemini CLI, Google's official command-line assistant.
Cherry Studio — Add Onefast API to the Cherry Studio desktop AI client and use every model with one key.
Other clients & frameworks — Setup notes for common tools such as Cursor, Cline / Roo Code, LangChain, Dify and LobeChat.

Reference

API reference — Parameters, examples and live testing for every endpoint. Download the OpenAPI file to import into Postman / Apifox.
Model catalog — Every available model with live prices. When you're logged in, it shows all groups available to your account and their prices.
Errors — Error response formats, what common HTTP status codes mean and how to handle them.
FAQ — Frequently asked questions about integration, billing and choosing models.