AI Playground

Chat with any Claude model using your own API key. Streaming, system prompts, effort control and live cost — your key and chats never touch our servers.

API key

Anthropic API key

Remember on this device Stored in this browser's localStorage. Only enable on a personal, trusted device.

Get a key ↗

🔒 Requests go straight from your browser to api.anthropic.com.

Model

ModelBest default — top quality at a lower price · $4.00/$20.00 per 1M tokensEffortHigher effort = deeper thinking, more tokens. Use low for quick chats.Max output tokensRefusal fallback If the model declines, the API automatically retries on a fallback model.

Tools (MCP)

Give Claude tools via MCP Claude can call tools on remote MCP servers — maths, time zones, hashes, cron, model pricing and more from our free server, or your own.

System prompt

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Connect your Claude API key

Your key is sent only from your browser directly to api.anthropic.com — never to our servers. You pay Anthropic directly for what you use.

Anthropic API key

Remember on this device Stored in this browser's localStorage. Only enable on a personal, trusted device.

Get a key ↗

Tip: create a dedicated key with a low monthly spend limit for browser use.

Connect your Claude API key

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