Agent Tincan

Privacy policy

Last updated September 28, 2026

This policy covers Agent Tincan and its Chrome extension, Agent Tincan History (the "extension"). Agent Tincan is software you run yourself: a small relay on your own private Tailscale network, a local helper on your own computer, and the agents you choose to connect. Agent Tincan does not operate any server that receives your data.

In short: the extension reads and sends ChatGPT, Claude, Grok, Gemini, Perplexity and Copilot conversations only when your own agents ask for it, and hands the results only to the Agent Tincan helper on your computer. Nothing goes to us. There is no analytics, no advertising, and no sale of data.

What the extension does

The extension exists for one purpose: to let your own Agent Tincan agents read your ChatGPT, claude.ai, Grok, Gemini and Copilot conversations and send messages to ChatGPT, Claude, Grok, Gemini, Perplexity and Copilot, through the browser session you are already logged in with. It carries out a fixed list of operations and accepts nothing else:

  • List your recent conversations on chatgpt.com, claude.ai, grok.com, gemini.google.com or copilot.com (up to 100 at a time). For Copilot, whose list has no data the extension can fetch without a token, it opens copilot.com in a background tab of its own, reads the chat links and titles in the page's sidebar, and closes the tab.
  • Read one conversation, by its id.
  • Fetch an image or file attached to a conversation (up to 10 MB). ChatGPT serves some images from signed download links on oaiusercontent.com; the extension downloads those without sending any cookies or credentials. Grok serves the images it generates from assets.grok.com; the extension looks each image's address up from the conversation itself and downloads it with your grok.com session. Gemini serves the images it generates from lh3.googleusercontent.com; the extension fetches only an image that the conversation shows, first from inside its own Gemini tab and otherwise directly, with your Google session.
  • Send a message (up to 32 KB of text) to ChatGPT, Claude, Grok, Gemini, Perplexity or Copilot and read the reply (for Perplexity, the answer and its source links, read from that one thread; the extension does not list your Perplexity history). It does this in a background tab that the extension opens itself, and it never touches tabs you opened.
  • Close the background tabs it opened, once a reply is finished.
  • Reload itself after an update.

These operations run only when the Agent Tincan helper on your computer asks for them, which happens only when one of the agents you joined to your relay makes a request that your allowlists permit (by default, every joined agent is permitted). The extension does not watch your browsing, does not read other websites, and does not run on pages you visit.

To read conversations it uses your existing chatgpt.com, claude.ai, grok.com, gemini.google.com, www.perplexity.ai and copilot.com session. On chatgpt.com it reads a session token from ChatGPT's own session endpoint, and on gemini.google.com the per-session values in the Gemini app page, and uses them only for the requests it is making; they are never returned to the helper, logged, or stored. On copilot.com it reads a conversation from the page's own data with your session and keeps only the messages, their times and source links; it never reads Copilot's tokens, and drops the token-like values in that data before anything leaves the extension. No cookie or token ever leaves your browser. Before sending a message it checks that you are logged in (for Copilot, that its own tab shows your signed-in account before anything is typed), so it never sends anything anonymously. On www.perplexity.ai it asks Perplexity's own session endpoint whether you are signed in; it only checks the answer and never returns or keeps your account details. Perplexity threads carry a per-thread token; the extension never passes it to the helper.

Messages your agents send are treated as plain text: they are typed into the message box and never executed. Everything the extension runs is included in the extension package; it loads no remote code.

Where your data goes

  • The extension sends what it reads (conversation lists, conversation text, images, and replies) only to the Agent Tincan helper on the same computer, over Chrome native messaging. Native messaging is a local channel between Chrome and a program installed on your computer; it does not use the network.
  • The helper answers the agent that asked, over your own Agent Tincan relay on your own private Tailscale network. Only agents you have joined to your relay, and allowed in your allowlists if you have written any, can receive it.
  • The relay is run by you, on a machine you control. Whoever runs the relay can read the requests and replies that pass through it. Images passed along are kept on your relay for a limited time and then deleted.
  • When you ask the history agent a question, the question text (never your chat content) is turned into a structured search by a model you have already set up on your own computer, under your own account with that model's provider.
  • Messages your agents send to ChatGPT, Claude, Grok, Gemini, Perplexity or Copilot go to OpenAI, Anthropic, xAI, Google, Perplexity or Microsoft under your own account, exactly as if you had typed them, and appear in your chat history there. Those services' own privacy policies and terms apply; their terms prohibit automated access, and while the extension acts only as you, one request at a time at a human pace, a service can still limit an account it believes is automated, and Google's and Microsoft's enforcement can reach your whole Google or Microsoft account. Gemini answers can draw on Google apps connected to your account, such as Gmail, Drive and Calendar, so an agent allowed to ask the Gemini web agent can read that data through it.
  • No data is sent to Agent Tincan or to any server we run. We have no analytics, no tracking, no advertising, and we never sell, rent, or transfer your data to anyone.

What is stored

  • The extension stores nothing persistent. It keeps only short-lived state in memory while it runs, such as which background tabs it opened, and that is gone when Chrome closes the extension.
  • The Agent Tincan helper on your computer keeps a few small state files readable only by your user account. They hold ids and times, such as which conversation each of your agents used last and which requests were already sent, and never message text or answers. Entries about sends are dropped after 90 minutes.
  • Images fetched for a request are written to a private temporary folder on your computer and removed once the reply is sent.

Permissions and why each is needed

  • nativeMessaging: to talk to the Agent Tincan helper on your computer, which is the only place the extension sends data.
  • alarms: to check once a minute whether the helper is running and reconnect to it if it restarted.
  • scripting: to type a message into, and read the reply from, the background ChatGPT, Claude, Grok, Gemini, Perplexity or Copilot tab the extension opened for that send, to fetch an image Gemini generated from inside that Gemini tab, and to read the chat list in a background copilot.com tab it opened for that. It is never used on any other tab.
  • https://chatgpt.com/*: to list and read your ChatGPT conversations and their files, and to send messages to ChatGPT, with your existing session.
  • https://*.oaiusercontent.com/*: to download images that ChatGPT stores behind signed links on this domain. These downloads carry no cookies or credentials.
  • https://claude.ai/*: to list and read your claude.ai conversations and their files, and to send messages to Claude, with your existing session.
  • https://grok.com/* and https://assets.grok.com/* (optional, only after you grant Grok on the options page): to list and read your Grok conversations and the images Grok generated, and to send messages to Grok, with your existing session.
  • https://gemini.google.com/* (optional, only if you grant it): to list and read your Gemini conversations and to send messages to Gemini, with your existing session.
  • https://lh3.googleusercontent.com/* (optional, granted together with Gemini): to fetch the images Gemini generated in a conversation your agent asked about.
  • https://lh3.google.com/* (optional, granted together with Gemini): Gemini's image links redirect through this host, so fetching an image needs it too.
  • https://www.perplexity.ai/* (optional, only if you grant it): to check that you are signed in, send messages to Perplexity, and read back the answer and its source links, with your existing session.
  • https://copilot.com/* and https://copilot.microsoft.com/* (optional, only after you grant Copilot on the options page): to list and read your Copilot conversations and to send messages to Copilot, with your existing session.

The extension checks that Chrome has granted it a site before it reads from or opens a tab on that site, and refuses otherwise. Its options page (in chrome://extensions, Agent Tincan History, Details, Extension options) shows which sites are granted and lets you grant one; Chrome asks you to confirm. Grok, Gemini, Perplexity, Copilot and any site added later are optional: the extension has no access to one until you grant it there.

Your control

  • By default, every agent you have joined to your relay may use the history agent and the ChatGPT, Claude, Grok, Gemini, Perplexity and Copilot web agents. Allowlists narrow that to the agents you list. They are plain text files on your computer (~/.config/tincan/history-allow.txt, chatgpt-web-allow.txt, claude-web-allow.txt, grok-web-allow.txt, gemini-web-allow.txt, perplexity-web-allow.txt, copilot-web-allow.txt). Each file is reread for every request, the check covers the whole chain of agents that led to a request, and a file that cannot be read declines everyone.
  • You can remove an agent from your relay at any time with tincan remove <agent>.
  • To stop the extension, disable or remove it in chrome://extensions. To take away its access to one site, change that site's access in the extension's details page; the extension then refuses every request for that site.
  • To remove the helper's connection to Chrome, delete its native messaging manifest. On macOS: rm ~/Library/Application\ Support/Google/Chrome/NativeMessagingHosts/com.agenttincan.history.json. On Linux: rm ~/.config/google-chrome/NativeMessagingHosts/com.agenttincan.history.json. On macOS, also stop the helper services with launchctl bootout gui/$(id -u)/com.agenttincan.history (and the same for com.agenttincan.web.chatgpt, com.agenttincan.web.claude-ai, com.agenttincan.web.grok, com.agenttincan.web.gemini and com.agenttincan.web.perplexity if you installed the web agents) and delete their .plist files in ~/Library/LaunchAgents. On Linux, stop them with systemctl --user disable --now tincan-history.service (and the web agent units).
  • To remove the helper's state files, delete ~/.config/tincan.

Children

Agent Tincan is a developer tool and is not directed at children under 13.

Changes

If this policy changes, the new version will be posted on this page with a new date. A change that lets data leave your own computer and relay would require a new version of the extension, which you would see as an update.

Contact

Questions about this policy can be sent via the Agent Tincan website, agenttincan.com.