Silent Send

A browser extension (Chrome + Firefox) that intercepts personal information and substitutes it with user-defined replacements before sending to AI services.

Supported services

Service	Domains	Status
Claude	claude.ai, claude.ai/code	Tested
ChatGPT	chatgpt.com, chat.openai.com	Untested
Grok	grok.x.ai, x.com/i/grok	Untested
Gemini	gemini.google.com	Untested
OpenWebUI	localhost, 127.0.0.1, or custom domain	Untested

Note: Only Claude has been tested so far. The other services have API interception patterns defined but may need adjustments. PRs welcome.

How it works

1. You fill in your Identity — name, email, username, computer name, phone
2. Smart patterns auto-catch variations — jsmith@macbook-pro, John's, /home/jsmith, 555.123.4567
3. Secret scanner auto-redacts credentials — API keys, tokens, passwords, SSNs, credit cards (zero config)
4. You type normally — you see your real text while composing
5. On send, it swaps — the extension intercepts the API request and replaces real values with substitutes
6. Badge shows count — the extension icon shows how many substitutions were made
7. Reveal mode — translates AI responses back to your real data, right in the chat window

Smart pattern examples

You type	What gets sent
jsmith@macbook-pro	ademo@mycomputer
anyone@gmail.com	anon@example.com (catch-all)
John Smith	Alex Demo
Smith, John	Demo, Alex
John's code	Alex's code
/home/jsmith/project	/home/ademo/project
~jsmith	~ademo
C:\Users\jsmith	C:\Users\ademo
(555) 123-4567	(555) 000-0000
555.123.4567	(555) 000-0000
macbook-pro	mycomputer

Secret scanner (automatic, no configuration needed)

You type	What gets sent
sk-proj-abc123xyz789...	[REDACTED-OPENAI-KEY]
sk-ant-api01-xyz...	[REDACTED-ANTHROPIC-KEY]
ghp_xxxxxxxxxxxxxxxxxxxx	[REDACTED-GITHUB-TOKEN]
AKIAIOSFODNN7EXAMPLE	[REDACTED-AWS-KEY]
sk_live_abc123...	[REDACTED-STRIPE-KEY]
AIzaSyxxxxxxxxxxxxxxxxx	[REDACTED-GOOGLE-KEY]
glpat-xxxxxxxxxxxx	[REDACTED-GITLAB-TOKEN]
xoxb-xxx-xxx-xxx	[REDACTED-SLACK-TOKEN]
Bearer eyJhbGciOi...	Bearer [REDACTED]
password=MyS3cret!	password=[REDACTED]
api_key=abcdef123456...	api_key=[REDACTED]
postgres://user:pass@host	postgres://REDACTED:REDACTED@host
-----BEGIN RSA PRIVATE KEY-----	[REDACTED-PRIVATE-KEY]
123-45-6789	[REDACTED-SSN]
4111 1111 1111 1111	[REDACTED-CARD]

How to verify it's working

• Badge count on the extension icon shows substitutions per page
• Activity tab in the popup shows a timestamped log of every substitution
• Test tab in the popup lets you type text and see the before/after diff live
• Reveal mode (eye icon) toggles showing real vs substitute data in responses
• Browser DevTools → Console shows [Silent Send] Substituted N value(s) messages

Installation

Prerequisites

• Git
• Node.js v18 or newer (needed for Firefox signing only)

Step 1: Get the code

Open a terminal (Terminal on Mac, Command Prompt or PowerShell on Windows, any terminal on Linux) and run:

git clone https://github.com/outis1one/silent-send.git
cd silent-send

This downloads the extension code to a silent-send folder on your computer.

Chrome

1. Open chrome://extensions/ in Chrome
2. Enable Developer mode (toggle in the top right corner)
3. Click Load unpacked
4. Navigate to the silent-send folder you cloned and select it
5. Navigate to any supported AI site — the extension icon appears in your toolbar

That's it for Chrome. No build step, no account, no store, no fees.

Firefox (signed, persistent)

Firefox requires extensions to be cryptographically signed before it will permanently install them. Mozilla provides free signing — no store listing, no review process, no fees. You just need a free Firefox account.

Step 1: Create a free Firefox account

1. Go to https://accounts.firefox.com/ and sign up (or sign in if you have one already)
2. This is the same account used for Firefox Sync — you may already have one

Step 2: Generate your signing keys

1. Go to https://addons.mozilla.org/developers/addon/api/key/
2. Sign in with your Firefox account
3. You'll see two values on that page:
   • JWT issuer — looks like user:12345678:901
   • JWT secret — a long string of random characters
4. You need both of these. Copy them or keep the page open.

Step 3: Install dependencies and save your signing keys

In your terminal, inside the silent-send folder:

Mac / Linux:

npm install
cp .env.example .env

Windows (Command Prompt):

npm install
copy .env.example .env

Now open the .env file in any text editor (Notepad, VS Code, etc.) and replace the placeholder values with the two values from step 2:

WEB_EXT_API_KEY="user:12345678:901"
WEB_EXT_API_SECRET="your-jwt-secret-here"

Save and close the file.

Step 4: Build and sign

All platforms (Mac, Linux, Windows with Git Bash):

npm run sign:firefox

The sign script reads your .env file automatically — no need to source it. First-time signing can take 1-5 minutes while Mozilla validates and approves the extension. Subsequent signs are usually faster. When done, you'll find a signed .xpi file in dist/firefox-signed/.

Windows (Command Prompt — if not using Git Bash):

node -e "require('fs').readFileSync('.env','utf8').split('\n').forEach(l=>{const[k,v]=l.split('=');if(k&&v)process.env[k.trim()]=v.trim().replace(/^\"|\"$/g,'')})" && npm run sign:firefox

Windows (PowerShell):

Get-Content .env | ForEach-Object { if ($_ -match '^(.+?)=(.*)$') { [Environment]::SetEnvironmentVariable($matches[1], $matches[2].Trim('"')) } }
npm run sign:firefox

Step 5: Install

• Drag the .xpi file into any Firefox window, or
• Firefox menu → File → Open File → select the .xpi
• Click Add when prompted

Done. The extension is permanently installed — survives restarts, updates, everything. You only need to re-sign if you update to a newer version of Silent Send.

Firefox (temporary, no signing needed)

If you just want to try it out quickly:

Mac / Linux:

npm install && npm run run:firefox

Windows:

npm install && npm run run:firefox

This opens Firefox with the extension pre-loaded. Resets when Firefox closes — useful for testing.

Custom domains (OpenWebUI, etc.)

If you run OpenWebUI or another AI service on a custom domain (not localhost), go to Options → Custom Domains and add your domain (e.g. https://ai.myserver.com). The extension will activate on those domains too.

For Chrome, you'll need to also grant the extension permission to access the new domain via chrome://extensions/ → Silent Send → Details → Site access.

Architecture

manifest.json           — Chrome extension manifest (Manifest V3)
manifest.firefox.json   — Firefox variant (adds gecko ID for signing)
build.sh                — Copies the right manifest to dist/{chrome,firefox}/
src/
  background/
    service-worker.js   — Badge management, logging coordination
  content/
    injector.js         — Content script (isolated world) — loads config, bridges messaging
    content.js          — Page script (main world) — hooks fetch(), does substitution
    content.css         — Visual indicators (highlights, reveals)
  popup/
    popup.html/css/js   — Quick access: identity, mappings, activity, test mode
  options/
    options.html/css/js — Full mapping management, import/export, settings, custom domains
  lib/
    substitution-engine.js — Core explicit find/replace logic
    smart-patterns.js   — Auto-detection of emails, names, usernames, hostnames, phones, paths
    secret-scanner.js   — Auto-detection of API keys, tokens, passwords, SSNs, credit cards
    storage.js          — Browser storage wrapper
    browser-polyfill.js — Chrome/Firefox API compatibility

Privacy

• All data stays local in browser storage
• No external servers, no telemetry, no analytics
• The extension only activates on supported AI sites (and any custom domains you add)
• Your real identity data never leaves your machine