# Magnitude
URL: /integrations/magnitude

---
title: Magnitude
sidebarTitle: Magnitude
description: Turn natural-language prompts into typed browser actions and structured outputs.
llm: true
---

Magnitude is a TypeScript browser-agent framework that turns natural-language prompts into typed actions. The Steel integration runs Magnitude's planning loop on a Steel cloud browser, so you can drive a real session from prompts and end with structured outputs validated against a schema.

Good fit for research-style flows that mix navigation and extraction.

### Requirements

*   **Steel API Key**: Active Steel subscription
*   **Anthropic API Key**: Magnitude's default planning model
*   **Node.js**: v20+

### Connect Steel to Magnitude

Pass Steel's CDP URL into Magnitude's `startBrowserAgent` config:

```typescript Typescript -wc
import { startBrowserAgent } from "magnitude-core";
import { Steel } from "steel-sdk";

const client = new Steel({ steelAPIKey: STEEL_API_KEY });
const session = await client.sessions.create({});

const agent = await startBrowserAgent({
  url: "https://github.com/steel-dev/leaderboard",
  llm: {
    provider: "anthropic",
    options: { model: "claude-sonnet-4-6", apiKey: ANTHROPIC_API_KEY },
  },
  browser: { cdp: `${session.websocketUrl}&apiKey=${STEEL_API_KEY}` },
});
```

Full runnable starter: [Steel + Magnitude recipe →](/cookbook/magnitude)

### FAQ

### Do I need to change my existing Magnitude code to use Steel?

No — add `browser: { cdp: ... }` to your `startBrowserAgent` config and Magnitude's planning loop runs on the Steel cloud browser. Prompts, typed actions, and structured outputs work as before.

### How do I connect Magnitude to a Steel browser session?

Create a session with `client.sessions.create()`, then set `browser.cdp` in the `startBrowserAgent` config to the session's `websocketUrl` with your `apiKey` appended.

### Does Magnitude work with Steel's proxies, stealth mode, and CAPTCHA solving?

Yes — configure them when creating the session (e.g. `useProxy`, `solveCaptcha`, `stealthConfig` on `sessions.create()`). Magnitude just connects to the resulting CDP endpoint.

### Which model does Magnitude use for planning?

Anthropic is Magnitude's default planning provider — the example configures `llm: { provider: "anthropic", options: { model: "claude-sonnet-4-6" } }`. You need an Anthropic API key plus Node.js 20+.


### Resources

*   [Magnitude documentation](https://docs.magnitude.run/) – Concepts, agent APIs, and examples
*   [Steel Sessions API reference](/api-reference) – Programmatic session control for Steel browsers
*   [Steel Discord](https://discord.gg/steel-dev) – Get help and share what you build