Browser Extension Privacy Policy

Summary

• Your conversations never leave your browser. The extension reads your AI conversations on claude.ai, chatgpt.com and gemini.google.com and records each answer as a step of a verifiable evidence run. What is transmitted to Sigill are SHA-256 digests — fingerprints that identify content without revealing it — and a small signed record per step that carries those digests, never the content.
• You sign in with Sigill; nothing else about you is collected. The extension holds a sign-in token for one permission — recording conversations for your organisation. It holds no API key, never reads your sigill.ai session, and never records your name, email address or platform account in an evidence record.
• Nothing is sold or shared. No analytics, no tracking, no advertising identifiers, no third-party data transfers. The extension talks to exactly one service: api.sigill.ai.

What the extension collects

These are the categories we declare in the Chrome Web Store, with what each one actually means here:

• Personal communications and website content. The text of your AI conversations (your prompts and the assistant's answers) on the three supported platforms, read in your browser so they can be hashed. Files you attach and files the AI generates are hashed in your browser. The content is used only to compute SHA-256 digests; it is never transmitted and never stored by the extension.
• Authentication information. When you choose Sign in with Sigill, a sign-in window opens on sigill.ai; you sign in there and approve the extension. The extension then holds an access token (valid one hour) and a refresh token (renewed on use, valid 30 days), stored on the device and sent only to api.sigill.ai. They allow exactly one thing: recording conversations for your organisation. Disconnecting in the extension, or under Settings → Settings → Connectors on sigill.ai, ends them. The extension never reads credentials for any site, including sigill.ai.
• User activity (network monitoring). The extension works by observing the network responses that claude.ai, chatgpt.com and gemini.google.com send to your own browser — that is how it captures a conversation turn exactly as the platform produced it. Observation is read-only (requests and responses are never modified) and limited to those three sites. The extension has no access to any other website you visit.

Exactly what leaves your browser

Each network call the extension makes, exhaustively:

• Sign-in — the standard OAuth exchange with api.sigill.ai (authorization code, PKCE verifier, an installation identifier and the label "Browser extension"), and token renewal.
• Sealing — for each step of a run, the SHA-256 digest of the step's evidence record and the digests of its objects (prompt, attached files, answer), sent to api.sigill.ai to be sealed and timestamped.
• Indexing — the signed evidence record of each step, so the run appears under Evidence in your organisation on sigill.ai. A record holds: the step type and time, the assistant service (for example claude.ai), the model identifier the platform reported, random identifiers for the run and its objects, a one-way reference to the conversation (a truncated hash — not the platform's conversation ID), and digests. It never holds conversation content, file names, your name or email address, or the platform's conversation or message IDs.
• Generated-file hashing — when you download a file the AI produced, the extension may fetch that same file once more from the AI platform's own download URL in order to hash it. The bytes are hashed in memory and discarded; only the digest is sent, as part of the evidence record.

There are no analytics or telemetry calls of any kind. What api.sigill.ai keeps — the signed evidence records and seal-operation metadata, and for how long — is described in the main privacy policy.

Where data is stored, and for how long

• In the extension's local storage on the device: the sealed evidence records of your runs (digests and signatures, no content), a short index that lets the extension show its badge next to recorded answers, the sign-in tokens, and your choice of seal certificate. Nothing is synced by the extension.
• In sync storage, which your browser may replicate across your own signed-in profile: only your platform on/off switches.
• Local data remains until you press Clear log or uninstall the extension. Records from versions before 0.6 (which kept conversation text in a local log) stay on your device, read-only and exportable, until you clear them.
• On sigill.ai: the signed evidence records of the steps, under your organisation (see the main privacy policy for retention). Clearing the extension's local log does not remove them; they are managed in Sigill.

Why each permission is requested

• claude.ai, chatgpt.com, gemini.google.com — observing conversation turns on the supported platforms, and displaying the evidence badge.
• api.sigill.ai — sign-in, sealing and indexing.
• identity — opening the Sign in with Sigill window and receiving its answer. It gives the extension no access to your browser or Google account.
• storage / unlimitedStorage — the local evidence records.
• alarms — closing conversations that have been idle for 30 minutes, and retrying indexing.
• downloads — detecting when you download an AI-generated file so its digest can be recorded. Downloads that are not attributable to a supported AI platform are ignored entirely and never recorded.

What the extension does not do

• No collection of browsing history, location, health, financial or payment data.
• No keystroke logging; no reading of any website other than the three supported AI platforms.
• No transmission of conversation content, file content or file names.
• No sale of data, no transfer to third parties, no advertising or analytics, no use of data for any purpose beyond producing your evidence records.
• No modification of the AI platforms' traffic — observation is strictly read-only.

Legal basis and your rights (GDPR)

Processing happens on your device at your instruction; the legal basis for the sealing and indexing calls to Sigill is the performance of the service you signed up for (Art. 6(1)(b) GDPR). Because your conversation content never reaches Sigill, access and deletion of local records are actions you perform locally (export, clear log). For data Sigill holds server-side — your account, the signed evidence records and seal-operation metadata — the rights and contact points in the main privacy policy apply. Complaints may be directed to Datatilsynet (the Norwegian Data Protection Authority) or your local supervisory authority.

Changes and contact

Material changes to this policy are versioned on this page and noted in the extension's release notes. Version 1.0 (2 July 2026) described v0.5, which used an API key, read the sigill.ai session to show your organisation and recorded your email address as the actor. Questions and corrections: contact@sigill.ai.