# OpenAI / ChatGPT Setup
Connect to OpenAI's API for GPT-4o, GPT-4, and other models.
## Prerequisites
- [OpenAI API key](https://platform.openai.com/api-keys)
## Configuration
```bash
export OPENAI_API_KEY=sk-...
```
## Usage with Chasm
```bash
# Interactive chat with GPT-4o
chasm run chatgpt --model gpt-4o
# Use a different model
chasm run chatgpt --model gpt-4-turbo
# GPT-3.5 for faster, cheaper responses
chasm run chatgpt --model gpt-3.5-turbo
```
## Available Models
| `gpt-4o` | 128K | General purpose, vision |
| `gpt-4-turbo` | 128K | Complex reasoning |
| `gpt-3.5-turbo` | 16K | Fast, cost-effective |
| `o1` | 200K | Deep reasoning |
## Browser Extension
Chasm's browser extension can also capture sessions from [chatgpt.com](https://chatgpt.com):
1. Install the Chasm browser extension
2. Navigate to chatgpt.com
3. Click the Chasm icon to export the current conversation
## Tips
- Sessions are saved locally — your API key never leaves your machine
- Use `chasm harvest run --providers openai` to import ChatGPT web sessions
- Token usage is tracked per session for cost analysis