Offsend Browser Extension

Mask secrets before they reach ChatGPT, Claude, or Gemini.

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yy liao· 3mo ago
This is exactly what the market needs right now. Keep up the great work!
Zain Sheikh· 3mo ago
A local-first extension that scrubs secrets before they ever hit ChatGPT or Claude is exactly the guardrail most teams are missing right now. Does it let you define custom redaction patterns for internal token formats?
Simon Hudishkin[maker]· 3mo ago
Yes, if you paste a code block into the prompt editor, Offsend scans it as part of the prompt before it is sent. This includes things like configs, stack traces, JSON, .env snippets, API responses, and code blocks. They are treated as plain text. It does not scan uploaded files or attachments in the browser extension. Right now the extension focuses on copy-paste and typed prompts in ChatGPT, Claude, and Gemini. A version that can scan uploaded files is planned. Workflows with files and documents are being considered separately.
PDFops· 3mo ago
Masking prompts before they reach the model is the right layer for this — server-side DLP always misses the copy-paste path. Two things I'd want to know: (1) how does it decide what's a secret — fixed denylist, regex/entropy heuristics, or user-defined patterns? Entropy alone over-flags base64/UUIDs; a denylist misses the novel key format. (2) Is it one-way redaction, or does it re-map the placeholder back to the real value when the model echoes it? One-way is fine for pasting a config, but anything conversational needs the round-trip. Open-source + local is exactly how a tool like this earns trust — starring it.
Zain Sheikh· 3mo ago
Local-first scanning with no server-side analysis is exactly the right approach for keeping secrets out of AI chats - does it also cover pasted code blocks?

Offsend is a local-first browser extension that helps prevent sensitive data from leaking into AI chats. When you write or paste a prompt in ChatGPT, Claude, or Gemini, Offsend checks it locally in your browser before it is submitted. If it finds API keys, tokens, private keys, emails, phone numbers, IDs, card-like values, or other sensitive data, you can mask them before sending. Masked values are replaced with readable placeholders like {{API_KEY_1}} or {{EMAIL_1}}, so the prompt still makes sense without exposing the original data. You can also restore the original values later from encrypted, time-limited local mappings. Offsend is built for the everyday moment when developers paste logs, configs, stack traces, API responses, or internal data into AI tools and want one last safety check before pressing Send. What Offsend helps with: * Detect sensitive data before it reaches an AI chat * Mask secrets while keeping prompts readable * Replace sensitive values with stable placeholders like {{API_KEY_1}} * Restore original values when needed * Stay quiet when nothing sensitive is found * Warn you if protection may be degraded because a site changed its layout How it works: * Write or paste a prompt into ChatGPT, Claude, or Gemini * Press Enter or click Send * Offsend scans the prompt locally in your browser * If sensitive data is found, choose Mask, Send anyway, or Cancel * If nothing sensitive is found, the prompt is sent normally Local-first by design: * Prompt content is not uploaded for scanning * Offsend does not send prompts, detected values, findings, or browsing details to a server * There is no server-side analysis * There is no cloud account required The extension only uses the network for licensing, updates, and an optional anonymous active-install ping. That ping does not include prompt content, detected values, findings, or browsing details, and can be turned off. Offsend brings the same local-first approach from the desktop app and CLI to web AI chats. Learn more at https://offsend.io

AI Security Open Source Browser Extension

Offsend is a local-first browser extension that detects and masks secrets in prompts before they reach AI chat services.

for: Developers and teams who paste code, logs or data into AI chat tools.
pricing: free
license: Apache-2.0

Offsend/browser-extension 1 0TypeScriptupdated 24 days ago

works withChatGPTClaudeGeminiGrokPerplexityDeepSeek

Key features

6 features of Offsend Browser Extension

Local detection — Scans prompts in the browser without sending data to any server.
Automatic masking — Replaces detected secrets with readable placeholders like {{API_KEY_1}}.
Restore capability — Keeps encrypted, time-limited mappings to restore original values locally.
Custom rules — Add JavaScript regex patterns to detect organization-specific secrets.
Mode selection — Choose Warn, Auto-mask, or Block behavior when secrets are found.
Built-in detectors — Detect emails, phones, API keys, tokens, private keys, credit cards, IPs, UUIDs and more.

Use cases

Paste a stack trace containing API keys into ChatGPT without exposing them
Share a config file snippet with private tokens in Claude while keeping it readable
Review logs in Gemini and automatically mask any credit-card numbers before sending