Cookie Sync

browserbase/cookie-sync

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.

44k tokens

context cost

the whole folder, loaded on every use

files

ships runnable scripts

copies elsewhere

how many repositories repackaged it

3669

stars on the repo

on the repository, not the skill itself

Install

one command, takes just this skill from the repository

npx skills add https://github.com/browserbase/skills --skill cookie-sync

What comes with it

172 159 bytes besides the instruction

EXAMPLES.md

LICENSE.txt

REFERENCE.md

package-lock.json

package.json

scripts/cookie-sync.mjs

What it tells the agent to use

found in the instruction text

Bash runs shell commands — read the instruction before connecting

The instruction itself

13 sections, as written by the author

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.

Verified browser mode

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

Enables Browserbase Identity with a Verified browser to improve access on protected sites. 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 --verified --proxy "San Francisco,CA,US"

Browsing Authenticated Sites

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

SESSION_JSON="$(browse cloud sessions create --context-id <ctx-id> --persist --keep-alive)"
SESSION_ID="$(echo "$SESSION_JSON" | jq -r .id)"
CONNECT_URL="$(echo "$SESSION_JSON" | jq -r .connectUrl)"

browse open https://mail.google.com --cdp "$CONNECT_URL"

The --persist flag on browse cloud sessions create saves any new cookies or state changes back to the context when the cloud session is released, 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
SESSION_JSON="$(browse cloud sessions create --context-id ctx_abc123 --persist --keep-alive)"
SESSION_ID="$(echo "$SESSION_JSON" | jq -r .id)"
CONNECT_URL="$(echo "$SESSION_JSON" | jq -r .connectUrl)"

browse open https://x.com/messages --cdp "$CONNECT_URL"
browse snapshot
browse screenshot
browse stop
browse cloud sessions update "$SESSION_ID" --status REQUEST_RELEASE

Reusing Contexts for Scheduled Jobs

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

Once (laptop open): Run cookie-sync → get a context ID
Scheduled jobs: Create a Browserbase session with browse cloud sessions create --context-id <ctx-id> --persist --keep-alive, then attach with browse open <url> --cdp <connectUrl> — no local Chrome needed
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 --verified and/or --proxy with a location near you

How to use it

Copy the folder

Take browserbase/cookie-sync from the repository into ~/.claude/skills for personal use, or into .claude/skills inside a project.

Check the name does not clash

The agent identifies a skill by the name field in its header. Two skills with the same name cannot sit side by side — one of them will be ignored.

Install what it needs

The instructions reference npm. Without those the skill loads but fails at the first command.