Sessioner

Export & import full browser sessions — cookies, localStorage, sessionStorage, IndexedDB — with automatic cross-domain discovery.

Install | Usage | How It Works

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Sessioner is a Firefox extension that lets you clone your logged-in session from one browser to another. Export your account state on Browser A, import it on Browser B, and you're logged in without re-authenticating.

It passively monitors network requests to automatically discover related domains (APIs, CDNs, auth providers) so you never miss a cookie.

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🔍 What Gets Captured

Data Type	Method	Scope
🍪 Cookies	browser.cookies API (includes httpOnly)	Domain + all discovered subdomains
📦 localStorage	Content script	Origin
📋 sessionStorage	Content script	Origin
🗄️ IndexedDB	Content script (full schema + records)	Origin

All data is saved as a single .json file.

📡 Passive Domain Tracking

Most sites talk to multiple domains — APIs, auth servers, CDNs. Sessioner's DomainTracker passively monitors webRequest traffic to build a live map of every domain each site communicates with.

When you export, cookies are captured for all discovered domains, not just the one in your URL bar.

example.com → api.example.com, auth.example-cdn.com, cdn.example.io, ...

• 🔄 Learns automatically as you browse — no configuration needed
• 💾 Persisted across browser restarts (30-day TTL)
• 🏷️ Visible in the popup as domain tags

📥 Installation

⚠️ Requires a Firefox variant that allows unsigned extensions (e.g. Firefox Developer Edition, Firefox Nightly, or unbranded builds). Set xpinstall.signatures.required to false in about:config.

1. Download the latest sessioner-*.zip from Releases
2. Open Firefox → about:addons (or Ctrl+Shift+A)
3. Click the ⚙️ gear icon → "Install Add-on From File..."
4. Select the downloaded .zip file

🚀 Usage

Export

1. Navigate to the site you want to export
2. Click the Sessioner icon in the toolbar
3. Click Export Session → saves a .json file

Import

1. On another browser/profile, navigate to the same site
2. Click Sessioner → Import Session (opens a dedicated import page)
3. Select or drag & drop the .json file
4. Refresh the page — you should be logged in

⚙️ How It Works

Export Flow

Popup click → Background script →
  1. Cookies: browser.cookies API for all discovered domains
  2. Storage: content script reads localStorage + sessionStorage
  3. IndexedDB: content script exports full schema + records
  4. Download: single .json file

Import Flow

Import page → reads .json → stores in browser.storage.local →
  Background script →
    1. Cookies: browser.cookies.set() per cookie
    2. Storage: content script writes localStorage + sessionStorage
    3. IndexedDB: navigate to clean page → inject content script →
       import DBs with no lock conflicts → navigate back

IndexedDB Lock Handling

Sites (especially SPAs) hold IndexedDB connections open. Sessioner handles this by:

1. ↗️ Navigating the tab to a minimal same-origin page (releases all JS/IDB connections)
2. 💉 Injecting the content script early (document_start)
3. ✅ Running IDB import with zero competing connections
4. ↩️ Navigating back to the original URL

Service worker databases (workbox-*) are automatically skipped — they're infrastructure, not user data.

🔐 Security Warning

Exported session files contain sensitive authentication data (session tokens, cookies, API keys). Treat them like passwords.

• ❌ Don't share export files publicly
• 🗑️ Delete them after use
• ☁️ Don't store them unencrypted in cloud storage

🔑 Permissions

Permission	Why
cookies	Read/write cookies (including httpOnly)
tabs	Get active tab URL, navigate for IDB import
activeTab	Access current tab
downloads	Save export file
storage	Persist domain tracker + import data transfer
webRequest	Passive domain discovery
<all_urls>	Content scripts + cookie access on any site

🛠️ Development

# Lint with web-ext
npx web-ext lint --source-dir .

# Run in Firefox with auto-reload
npx web-ext run --source-dir .

Requirements: Firefox 109+ · Manifest V2 · No build step

📄 License

MIT