Agent-Skills.md

Agent Skills: Cookie Sync — Local Chrome → Browserbase Context

Sync cookies from local Chrome to a Browserbase persistent context so the browse CLI can access authenticated sites. Use when the user wants to browse as themselves, sync cookies, or log into sites via Browserbase.

UncategorizedID: browserbase/agent-browse/cookie-sync

Repository

browserbase/agent-browse
browserbase
47039

Install this agent skill to your local

pnpm dlx add-skill https://github.com/browserbase/skills/tree/HEAD/skills/cookie-sync

Skill Files

Browse the full folder contents for cookie-sync.

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skills/cookie-sync/SKILL.md

Skill Metadata

Name
cookie-sync
Description
Sync cookies from local Chrome to a Browserbase persistent context so the browse CLI can access authenticated sites. Use when the user wants to browse as themselves, sync cookies, or log into sites via Browserbase.

Cookie Sync — Local Chrome → Browserbase Context

Exports cookies from your local Chrome and saves them into a Browserbase persistent context. After syncing, use the browse CLI to open authenticated sessions with that context.

Supports domain filtering (only sync cookies you need) and context reuse (refresh cookies without creating a new context).

Prerequisites

  • Chrome (or Chromium, Brave, Edge) with remote debugging enabled
  • If your browser build exposes chrome://flags/#allow-remote-debugging, enable it and restart the browser
  • Otherwise, launch with --remote-debugging-port=9222 --user-data-dir=/tmp/chrome-debug and set CDP_URL=ws://127.0.0.1:9222
  • At least one tab open in Chrome
  • Node.js 22+
  • Environment variable: BROWSERBASE_API_KEY

Setup

Install dependencies before first use:

cd .claude/skills/cookie-sync && npm install

Usage

Basic — sync all cookies

node .claude/skills/cookie-sync/scripts/cookie-sync.mjs

Creates a persistent context with all your Chrome cookies. Outputs a context ID.

Filter by domain — only sync specific sites

node .claude/skills/cookie-sync/scripts/cookie-sync.mjs --domains google.com,github.com

Matches the domain and all subdomains (e.g. google.com matches accounts.google.com, mail.google.com, etc.)

Refresh cookies in an existing context

node .claude/skills/cookie-sync/scripts/cookie-sync.mjs --context ctx_abc123

Re-injects fresh cookies into a previously created context. Use this when cookies have expired.

Advanced stealth mode

node .claude/skills/cookie-sync/scripts/cookie-sync.mjs --stealth

Enables Browserbase's advanced stealth mode to reduce bot detection. Recommended for sites like Google that fingerprint browsers.

Residential proxy with geolocation

node .claude/skills/cookie-sync/scripts/cookie-sync.mjs --proxy "San Francisco,CA,US"

Routes through a residential proxy in the specified location. Format: "City,ST,Country" (state is 2-letter code). Helps match your local IP's geolocation so auth cookies aren't rejected.

Combine flags

node .claude/skills/cookie-sync/scripts/cookie-sync.mjs --domains github.com,google.com --stealth --proxy "San Francisco,CA,US"

Browsing Authenticated Sites

After syncing, use the browse CLI with the context ID:

browse open https://mail.google.com --context-id <ctx-id> --persist

The --persist flag saves any new cookies or state changes back to the context, keeping the session fresh for next time.

Full workflow example:

# Step 1: Sync cookies for Twitter
node .claude/skills/cookie-sync/scripts/cookie-sync.mjs --domains x.com,twitter.com
# Output: Context ID: ctx_abc123

# Step 2: Browse authenticated Twitter
browse open https://x.com/messages --context-id ctx_abc123 --persist
browse snapshot
browse screenshot
browse stop

Reusing Contexts for Scheduled Jobs

Contexts persist across sessions, making them ideal for scheduled/recurring tasks:

  1. Once (laptop open): Run cookie-sync → get a context ID
  2. Scheduled jobs: Use browse open <url> --context-id <ctx-id> --persist — no local Chrome needed
  3. Re-sync as needed: When cookies expire, run cookie-sync again with --context <ctx-id> to refresh

Troubleshooting

  • "No DevToolsActivePort found" → Enable chrome://flags/#allow-remote-debugging if your browser build exposes it, or launch with --remote-debugging-port=9222 and set CDP_URL=ws://127.0.0.1:9222
  • "No open page targets found" → Open at least one tab in Chrome
  • "WebSocket error" → Chrome may be hung; force quit and reopen it
  • Cookies expired in context → Re-run cookie-sync with --context <id> to refresh
  • Auth rejected by site → Try adding --stealth and/or --proxy with a location near you