API Overview - ModelStack

Base URL

All API requests are made to:

https://api.modelstack.cc

OpenAI-Compatible Format

ModelStack follows the OpenAI API format, so you can use any existing OpenAI SDK or HTTP client. Just change the base URL and API key.

Available Endpoints

Method	Endpoint	Description
`POST`	`/v1/chat/completions`	Create a chat completion
`GET`	`/v1/models`	List available models

Authentication

All requests require an API key passed via the Authorization header:

Authorization: Bearer your_api_key

API keys are created and managed from your dashboard.

Request Format

All requests use JSON. Set the Content-Type header:

Content-Type: application/json

Response Format

Responses follow the OpenAI response format:

{
  "id": "chatcmpl-abc123",
  "object": "chat.completion",
  "created": 1699000000,
  "model": "claude-sonnet-4-5",
  "choices": [
    {
      "index": 0,
      "message": {
        "role": "assistant",
        "content": "Hello! How can I help you?"
      },
      "finish_reason": "stop"
    }
  ],
  "usage": {
    "prompt_tokens": 10,
    "completion_tokens": 15,
    "total_tokens": 25
  }
}

Streaming

ModelStack supports Server-Sent Events (SSE) streaming. Set "stream": true in your request body to receive incremental responses.

Rate Limits

Rate limits depend on your subscription plan:

Plan	Rate Limit
Starter	15 RPM
Pro	40 RPM
Max	60 RPM

When you exceed your rate limit, requests return a 429 Too Many Requests error.

​Base URL

​OpenAI-Compatible Format

​Available Endpoints

​Authentication

​Request Format

​Response Format

​Streaming

​Rate Limits