Guides

Browser Automation

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This guide walks through common browser automation patterns with Chaser.

Recommended client: Use rebrowser-puppeteer-core for Chaser browser sessions. It’s a drop-in replacement for puppeteer-core (identical API). We recommend it over both stock Puppeteer and Playwright because Chaser’s Chromium has C++ stealth patches that conflict with stock Puppeteer’s instrumentation hooks and Playwright’s lifecycle state machine. Raw CDP is also supported. Captcha solving is built into every browser session — no API keys or per-page setup.

Quick ephemeral scrape

The fastest path to a browser automation result — create a throwaway session, do the work, and move on:

$npm i rebrowser-puppeteer-core
1import puppeteer from "rebrowser-puppeteer-core";
2
3// Create an ephemeral browser session
4const res = await fetch("https://api.chaser.sh/v1/sessions", {
5  method: "POST",
6  headers: {
7    "Authorization": `Bearer ${process.env.CHASER_API_KEY}`,
8    "Content-Type": "application/json"
9  },
10  body: JSON.stringify({ session_type: "browser", ephemeral: true })
11});
12const session = await res.json();
13
14// Connect and automate
15const browser = await puppeteer.connect({ browserWSEndpoint: session.endpoints.control });
16const page = await browser.newPage();
17await page.goto("https://example.com");
18const title = await page.title();
19console.log(title);
20await browser.close();

Persistent browser workspace

When you need browser state (cookies, local storage) to persist across sessions:

$# Create a browser workspace once
$chaser workspaces create --session-type browser --name scraper --json
$
$# Boot sessions against it -- state carries over
$chaser browser --workspace scraper --json

This is also the recommended base for extension-driven automation, since uploaded browser extensions persist on the workspace disk alongside the browser profile. See Browser Extensions.

Queued browser jobs

For batch work, use the jobs API instead of managing sessions directly:

$# Scrape a URL
$curl -sS "$CHASER_API_URL/v1/jobs" \
>  -H "Authorization: Bearer $CHASER_API_KEY" \
>  -H "Content-Type: application/json" \
>  -d '{
>    "kind": "browser.scrape",
>    "input": {"url": "https://example.com", "selector": "h1"}
>  }' | jq
$
$# Execute sequential browser actions
$curl -sS "$CHASER_API_URL/v1/jobs" \
>  -H "Authorization: Bearer $CHASER_API_KEY" \
>  -H "Content-Type: application/json" \
>  -d '{
>    "kind": "browser.action",
>    "input": {
>      "session_id": "<session_id>",
>      "actions": [
>        {"method": "Page.navigate", "params": {"url": "https://example.com"}},
>        {"method": "Page.screenshot", "params": {}}
>      ]
>    }
>  }' | jq

MCP browser tool for agents

AI agents can use the browser MCP tool to automate browsers without managing CDP connections:

$# Step 1: Prepare a browser session
$curl -sS "$CHASER_API_URL/v1/mcp" \
>  -H "Authorization: Bearer $CHASER_API_KEY" \
>  -H "Content-Type: application/json" \
>  -d '{
>    "jsonrpc": "2.0", "id": 1,
>    "method": "tools/call",
>    "params": {
>      "name": "browser",
>      "arguments": {"ephemeral": true, "action": "prepare"}
>    }
>  }' | jq
$
$# Step 2: Discover available tools
$# (use the session_id from step 1)
$curl -sS "$CHASER_API_URL/v1/mcp" \
>  -H "Authorization: Bearer $CHASER_API_KEY" \
>  -H "Content-Type: application/json" \
>  -d '{
>    "jsonrpc": "2.0", "id": 2,
>    "method": "tools/call",
>    "params": {
>      "name": "browser",
>      "arguments": {"session_id": "<session_id>", "action": "discover"}
>    }
>  }' | jq
$
$# Step 3: Call a specific browser tool
$curl -sS "$CHASER_API_URL/v1/mcp" \
>  -H "Authorization: Bearer $CHASER_API_KEY" \
>  -H "Content-Type: application/json" \
>  -d '{
>    "jsonrpc": "2.0", "id": 3,
>    "method": "tools/call",
>    "params": {
>      "name": "browser",
>      "arguments": {
>        "session_id": "<session_id>",
>        "action": "call",
>        "method": "browser_navigate",
>        "params": {"url": "https://example.com"}
>      }
>    }
>  }' | jq

Proxy configuration

Pass a proxy selector when creating browser sessions to route traffic through residential or datacenter proxies:

$curl -sS "$CHASER_API_URL/v1/sessions" \
>  -H "Authorization: Bearer $CHASER_API_KEY" \
>  -H "Content-Type: application/json" \
>  -d '{"session_type": "browser", "ephemeral": true, "proxy": "us-residential"}' | jq