agentlens

Zero-dependency, AI-agent-native web inspector. Semantic page understanding in < 500 tokens.

Built from scratch on Chrome DevTools Protocol. No Playwright. No Puppeteer. No runtime dependencies. Just Node.js builtins + Chrome.

Install

npm install agentlens-ai

That's it. No browser download step. Uses the Chrome already on your machine.

Quick Start

import { Browser } from "agentlens-ai/browser";
import { AgentPage } from "agentlens-ai/agent";

const browser = await Browser.launch();
const page = await browser.newPage();
const agent = new AgentPage(page);

// Understand the page in ~120 tokens
const digest = await agent.goto("https://myapp.com");
console.log(digest.text);
// Page: My App (myapp.com/login)
// Status: ready
// Suggested: fill 2 required fields
//
// [nav] Header: Home, About, Pricing
// [form] Login: 0/2 filled
//     Email *: empty
//     Password *: empty
// [hero] Welcome: CTA "Get Started"
//
// Actions: fill form | submit | navigate

// Act with intent — not element-level clicks
await agent.do("log in with [email protected] / secret123");

// Only what changed — not the whole page again
const delta = await agent.whatChanged();
console.log(delta.text);
// Navigated → /dashboard
// + [nav] Sidebar: Dashboard, Settings
// - [form] Login
// Suggested: click "View Tasks"

await browser.close();

Why

AI agents burn 90% of their context window trying to understand web pages. page.content() dumps 50,000 tokens of raw HTML. AgentLens returns ~120 tokens of structured signal.

| | Tokens | What you get | |---|--------|-------------| | page.content() | ~50,000 | Raw HTML noise | | agent.digest() | ~120 | Semantic components + suggested actions | | agent.whatChanged() | ~40 | Only the delta | | No change | 3 | "[no change]" |

Architecture

agentlens (zero npm dependencies)
├── browser/     WebSocket client, CDP client, Chrome launcher, BrowserPage
│                Built on: net, tls, crypto, http, child_process
├── agent/       Semantic digest, intent actions, delta tracking, blocker detection
│                Built on: browser/ + page.evaluate()
└── cli          Config scaffolding, doctor, session management

The only external requirement is Chrome/Chromium installed on the machine.

Agent API

import { AgentPage } from "agentlens-ai/agent";

agent.digest()           // Semantic page model — components, status, suggestions
agent.do(intent)         // High-level action — returns result + delta
agent.whatChanged()      // Only what changed since last check
agent.waitUntilReady()   // Smart wait — spinners, network, DOM stability
agent.dismissBlockers()  // Auto-close modals, cookie banners, overlays
agent.goto(url)          // Navigate + wait + digest
agent.screenshot(path)   // Viewport screenshot

Supported Intents

await agent.do("submit form");
await agent.do("navigate to Pricing");
await agent.do("log in with [email protected] / password");
await agent.do("search for enterprise plan");
await agent.do("fill form with {email: [email protected], name: John}");
await agent.do("dismiss blockers");
await agent.do("wait until ready");
await agent.do("scroll to Footer");
await agent.do("go back");

Browser API

Direct access to our CDP-based browser when you need lower-level control:

import { Browser } from "agentlens-ai/browser";

const browser = await Browser.launch({ headless: true });
const page = await browser.newPage();

await page.goto("https://example.com");
const title = await page.title();
await page.fill("#email", "[email protected]");
await page.click("button[type=submit]");
const value = await page.evaluate("document.title");
const screenshot = await page.screenshot({ path: "shot.png" });

await browser.close();

CLI

agentlens init              # scaffold config + example
agentlens doctor --fix      # auto-patch test config
agentlens clean             # clear observation log
agentlens summarize         # regenerate report
agentlens diff a.json b.json  # compare runs
agentlens ci                # generate CI workflow

Exports

| Import | What you get | |--------|-------------| | agentlens | Everything — AgentPage, Browser, BrowserPage, utilities | | agentlens/agent | AgentPage, digest, intents, deltas, blockers | | agentlens/browser | Browser, BrowserPage, CDP client, WebSocket client |

Agent Instructions

Add to your AI agent's system prompt:

Use agentlens for web inspection:
- import { Browser } from "agentlens-ai/browser"
- import { AgentPage } from "agentlens-ai/agent"
- agent.digest() for compact page understanding (< 500 tokens)
- agent.do(intent) for high-level actions
- agent.whatChanged() for delta-only updates
- Never call page.content() or innerHTML

Dependencies

runtime:  0
peer:     0
built on: node:net, node:tls, node:crypto, node:http,
          node:child_process, node:fs, node:os, node:path,
          node:events, node:url
requires: Chrome or Chromium installed on the machine

License

MIT