Claude Opus API

Add Claude Opus, Anthropic's most capable model line, to your app. Access every Opus model through a single API with Puter.js — no API keys, no backend.

Get Started Read Tutorial

// npm install @heyputer/puter.js
import { puter } from '@heyputer/puter.js';

puter.ai.chat("Explain quantum computing in simple terms", {
    model: "anthropic/claude-opus-4-7"
}).then(response => {
    console.log(response.message.content);
});

<html>
<body>
    <script src="https://js.puter.com/v2/"></script>
    <script>
        puter.ai.chat("Explain quantum computing in simple terms", {
            model: "anthropic/claude-opus-4-7"
        }).then(response => {
            document.body.innerHTML = response.message.content;
        });
    </script>
</body>
</html>

The Opus API for Frontier Intelligence

Frontier Reasoning

Opus leads on multidisciplinary reasoning benchmarks, handling complex, multi-step problems that smaller models can't.

Best-in-Class Coding

Claude Opus tops agentic coding evaluations, making it ideal for autonomous agents and large-scale refactoring.

1M-Token Context

Fit entire codebases, long documents, and extended conversations into a single context window of up to one million tokens.

Adaptive Thinking

Tune the thinking budget and effort level to balance depth against speed, with extended reasoning for the hardest tasks.

Vision & PDF Input

Send images and PDFs alongside text. Opus reads high-resolution visuals for document analysis and vision-heavy pipelines.

Long-Horizon Agents

Built for autonomous, long-running work with tool calling and file-based memory across multi-step agentic loops.

Claude Opus Models Compared

Every Claude Opus model available through Puter.js, with context, output limits, and per-million-token pricing. Click a model for full specs and examples.

Model	Context	Max Output	Input / 1M	Output / 1M
Claude Opus 4.7 `anthropic/claude-opus-4-7`	1M	128K	$5	$25
Claude Opus 4.7 Fast `anthropic/claude-opus-4.7-fast`	1M	128K	$30	$150
Claude Opus 4.6 `anthropic/claude-opus-4-6`	1M	128K	$5	$25
Claude Opus 4.6 Fast `anthropic/claude-opus-4.6-fast`	1M	128K	$30	$150
Claude Opus 4.5 `anthropic/claude-opus-4-5`	200K	64K	$5	$25
Claude Opus 4.1 `anthropic/claude-opus-4-1`	200K	32K	$15	$75
Claude Opus 4 `anthropic/claude-opus-4`	200K	32K	$15	$75

Which Claude Opus Model Should You Use?

Pick the Claude Opus model that fits your workload — capability, latency, or cost.

Most capable

Claude Opus 4.7

Claude Opus 4.7 is Anthropic's most capable model line, built for complex reasoning and agentic coding, with a 1M-token context window. Use it as your default for complex, high-stakes work.

View Claude Opus 4.7 →

Lowest latency

Claude Opus 4.7 Fast

Claude Opus 4.7 Fast runs the same intelligence with up to 2.5x faster output. Reach for it in interactive, real-time, and live-coding workflows where response speed matters.

View Claude Opus 4.7 Fast →

Proven & cost-aware

Claude Opus 4.6

Other versions like Claude Opus 4.6 stay available for pinned, reproducible deployments and cost-sensitive workloads that don't need the very latest model.

View Claude Opus 4.6 →

Use Claude Opus in Seconds

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

// npm install @heyputer/puter.js
import { puter } from '@heyputer/puter.js';

puter.ai.chat("Explain quantum computing in simple terms", {
    model: "anthropic/claude-opus-4-7"
}).then(response => {
    console.log(response.message.content);
});

<html>
<body>
    <script src="https://js.puter.com/v2/"></script>
    <script>
        puter.ai.chat("Explain quantum computing in simple terms", {
            model: "anthropic/claude-opus-4-7"
        }).then(response => {
            document.body.innerHTML = response.message.content;
        });
    </script>
</body>
</html>

View full documentation →

How Claude Opus Performs

Claude Opus 4.7 on standard evaluations, scored by Artificial Analysis.

Artificial Analysis

Intelligence Index

57.3

Better than 99% of tracked models

Artificial Analysis

Coding Index

52.5

Better than 98% of tracked models

See full Claude Opus 4.7 benchmarks →

Frequently Asked Questions

What is the Claude Opus API?

The Claude Opus API gives you access to Anthropic's most capable model line, built for complex reasoning and agentic coding — including Claude Opus 4.7 — through Puter.js. You can call any Claude Opus model from your app with no API keys and no backend.

Is the Claude Opus API free?

Yes, it is free for you as the developer when you use it through Puter.js. With the User-Pays model, each of your users covers their own usage through their Puter account, so you can ship Claude Opus-powered apps at no cost to you.

Which Claude Opus model should I use?

Start with Claude Opus 4.7 as your default. Choose Claude Opus 4.7 Fast when you need lower latency for interactive workflows. Other versions like Claude Opus 4.6 suit pinned, cost-aware deployments.

How much does Claude Opus cost?

Claude Opus 4.7 is priced at $5 per million input tokens and $25 per million output tokens at the API level. Through Puter.js it is free for developers under the User-Pays model.

What is the context window of Claude Opus?

Claude Opus 4.7 supports a context window of 1M tokens and can generate up to 128K tokens in a single response.

Do I need an API key?

No. Puter.js handles authentication and infrastructure for you, so you can use the Claude Opus API without any API key, an Anthropic account, a server, or any configuration.

Does it work with React / Vue / Vanilla JS / Node / etc.?

Yes — the Claude Opus API through Puter.js works with any JavaScript framework, Node.js, or plain HTML. Just include the library and start building.

Related Resources

Learn how to use Claude Opus and other models with Puter.js.