Claude Sonnet 4 API

Access Claude Sonnet 4 from Anthropic using Puter.js AI API.

Get Started

Model Card

Claude Sonnet 4 is the May 2025 successor to Sonnet 3.7 with enhanced steerability and coding (72.7% SWE-bench). It excels at following complex instructions precisely and autonomous multi-feature app development with near-zero navigation errors.

Context Window

200K

tokens

Max Output

64,000

tokens

Input Cost

$3

per million tokens

Output Cost

$15

per million tokens

API Usage Example

Add Claude Sonnet 4 to your app with just a few lines of code.
No API keys, no backend, no configuration required.

<html>
<body>
    <script src="https://js.puter.com/v2/"></script>
    <script>
        puter.ai.chat("Explain quantum computing in simple terms", {
            model: "anthropic/claude-sonnet-4"
        }).then(response => {
            document.body.innerHTML = response.message.content;
        });
    </script>
</body>
</html>

View full documentation →

Get started with Puter.js

Add Claude Sonnet 4 to your app without worrying about API keys or setup.

Read the Docs View Tutorials