Live Browser Sandbox API

Free Public API

Lease isolated cloud Chromium browsers on demand via native Chrome DevTools Protocol (CDP) WebSocket.

Try in Live Web Tool

POSThttps://api.headless-lender.com/api/v1/sessions

Public: No Key Needed•Highest Free Quota: 1,000 Req/Mo + 10h Browsers (No Card Required)

Overview & Architecture

Connect autonomous AI agents (Browser-Use, Stagehand, LangChain), Playwright, or Puppeteer directly to leased cloud Chromium clusters. Inspect live interactive screencasts in real-time with sub-millisecond key verification.

Native Chrome DevTools Protocol (CDP) WebSocket connection

Interactive real-time screencast viewer

Stealth fingerprint spoofing (Canvas, WebGL, Audio)

Zero Docker management overhead

Playwright Execution & Valkey Caching Pipeline

Because this endpoint utilizes full headless Chromium rendering, dynamic JavaScript and single-page apps (SPAs) are executed completely before conversion:

1. Cold Scrape (Cache MISS)~800ms – 2.5s

Chromium initializes, fetches the URL, executes client JavaScript, resolves DOM mutations, and generates output.

2. Repeat Request (Cache HIT)~5ms – 15ms

Returned instantly from Valkey/Redis cache with header X-Lender-Cache: HIT (15-minute TTL).

Code Integration Examples

Instant Public Endpoint: Zero configuration, no API key needed. Want our highest free quota? Get 1,000 free requests/month + 10 hours of cloud browsers with a free key (No credit card required).

curl -X POST https://api.headless-lender.com/api/v1/sessions \
  -H "Content-Type: application/json" \
  -d '{
    "agentName": "Claude Computer Use Agent",
    "timeoutMinutes": 15,
    "stealth": true
  }'

Headers & Authentication Standard

1. Public Access (No Key)

No Authorization header required. Simply send a JSON POST request. Perfect for quick prototypes, small scripts, and low-volume scraping.

Content-Type: application/json

2. Free API Key (Highest Free Quota)

1,000 Req/Mo Free

Sign up in 10s with no credit card required. Unlocks 1,000 free monthly requests, 600 browser minutes (10 hours), 120 req/min burst limits, and cache-bypass controls.

Authorization: Bearer hl_live_your_api_key_here

Access Mode	Monthly Quota	Cloud Browser Time	Burst Limit	Credit Card	Action
Public Anonymous	Daily IP Allowance	5-min trial sandbox	10 req/min	None	Instant (No Setup)
Free Account (Highest Quota)	1,000 Req / Month	600 Mins (10 Hours)	120 req/min	Zero ($0 forever)	Claim Free Key →

Request Body Parameters

Field	Type	Required	Default	Description
agentName	string	optional	'Browser-Use AI Agent'	Label for the connecting client or agent.
sessionType	'interactive' \| 'ai_agent' \| 'test'	optional	'interactive'	Session allocation profile.
timeoutMinutes	number	optional	15	Session lease duration before auto-termination.
stealth	boolean	optional	true	Enable stealth fingerprint patches and bot bypass.
viewport	{ width, height }	optional	{ width: 1280, height: 800 }	Browser display dimensions.

Response Schema & Example

200 OK — application/jsonDuration: ~800ms (Cold) / ~8ms (Cached)

{
  "sessionId": "b8f1a234-9023-4c4b-8ea8-d8cf88d85c06",
  "status": "active",
  "wsEndpoint": "ws://127.0.0.1:3000/browser/b8f1a234-9023-4c4b-8ea8-d8cf88d85c06",
  "liveViewerUrl": "/dashboard/playground?sessionId=b8f1a234-9023-4c4b-8ea8-d8cf88d85c06",
  "agentName": "Browser-Use AI Agent",
  "durationSeconds": 0,
  "stealth": true
}

JS HTML Renderer