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
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 →
Resources
- Magnitude documentation – Concepts, agent APIs, and examples
- Steel Sessions API reference – Programmatic session control for Steel browsers
- Steel Discord – Get help and share what you build