cURL

Overview

You can use ModelStack directly with cURL or any HTTP client. No SDK required — just make standard HTTP requests.

Chat Completion

curl https://api.modelstack.cc/v1/chat/completions \
  -H "Authorization: Bearer your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "claude-sonnet-4-5",
    "messages": [
      {"role": "system", "content": "You are a helpful assistant."},
      {"role": "user", "content": "What is ModelStack?"}
    ]
  }'

With Parameters

curl https://api.modelstack.cc/v1/chat/completions \
  -H "Authorization: Bearer your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "gpt-4o",
    "messages": [
      {"role": "user", "content": "Explain quantum computing in 3 sentences."}
    ],
    "temperature": 0.5,
    "max_tokens": 200
  }'

Streaming

Add "stream": true to get Server-Sent Events:

curl https://api.modelstack.cc/v1/chat/completions \
  -H "Authorization: Bearer your_api_key" \
  -H "Content-Type: application/json" \
  -N \
  -d '{
    "model": "claude-sonnet-4-5",
    "messages": [
      {"role": "user", "content": "Write a haiku about programming."}
    ],
    "stream": true
  }'

The -N flag disables cURL’s output buffering, allowing you to see streamed tokens in real time.

List Models

curl https://api.modelstack.cc/v1/models \
  -H "Authorization: Bearer your_api_key"

Using Different Models

Simply change the model field to switch providers:

# Anthropic Claude
curl https://api.modelstack.cc/v1/chat/completions \
  -H "Authorization: Bearer your_api_key" \
  -H "Content-Type: application/json" \
  -d '{"model": "claude-sonnet-4-5", "messages": [{"role": "user", "content": "Hello!"}]}'

# OpenAI GPT-4o
curl https://api.modelstack.cc/v1/chat/completions \
  -H "Authorization: Bearer your_api_key" \
  -H "Content-Type: application/json" \
  -d '{"model": "gpt-4o", "messages": [{"role": "user", "content": "Hello!"}]}'

# Google Gemini
curl https://api.modelstack.cc/v1/chat/completions \
  -H "Authorization: Bearer your_api_key" \
  -H "Content-Type: application/json" \
  -d '{"model": "gemini-2.5-pro", "messages": [{"role": "user", "content": "Hello!"}]}'

Using Environment Variables

Set your API key as an environment variable to avoid repeating it:

export MODELSTACK_API_KEY="your_api_key"

curl https://api.modelstack.cc/v1/chat/completions \
  -H "Authorization: Bearer $MODELSTACK_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "claude-sonnet-4-5",
    "messages": [{"role": "user", "content": "Hello!"}]
  }'

Pretty-Printing JSON

Pipe the output through jq for formatted JSON:

curl -s https://api.modelstack.cc/v1/chat/completions \
  -H "Authorization: Bearer your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "claude-sonnet-4-5",
    "messages": [{"role": "user", "content": "Hello!"}]
  }' | jq .

Extracting Just the Response Text

curl -s https://api.modelstack.cc/v1/chat/completions \
  -H "Authorization: Bearer your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "claude-sonnet-4-5",
    "messages": [{"role": "user", "content": "Hello!"}]
  }' | jq -r '.choices[0].message.content'

Getting Started

Models

Billing & Credits

Dashboard

SDKs & Integration

IDE & CLI Integrations

Overview

Chat Completion

With Parameters

Streaming

List Models

Using Different Models

Using Environment Variables

Pretty-Printing JSON

Extracting Just the Response Text

​Overview

​Chat Completion

​With Parameters

​Streaming

​List Models

​Using Different Models

​Using Environment Variables

​Pretty-Printing JSON

​Extracting Just the Response Text

Overview

Chat Completion

With Parameters

Streaming

List Models

Using Different Models

Using Environment Variables

Pretty-Printing JSON

Extracting Just the Response Text