cosmos by polarity lab

The browser surface of Cosmos MCP. Sends the pages you actually read into your Cosmos graph. Local filtering, no analytics.

cosmos by polarity lab is the browser-history connector for cosmos, the exocortex at cosmos.polarity-lab.com. it walks your chrome.history.search, filters out navigational noise client-side, and ships the pages that actually meant something into your personal knowledge graph. what gets sent - url, title, hostname, last-visit timestamp, visit count, and the static string "web" as source. that's the entire payload per page. - no page bodies, no cookies, no form data, no request headers, no tracking pixels. the network call carries exactly the fields above and nothing else. what gets filtered (locally, before the network call) - navigational noise, search-result URLs, untitled tabs, your own domains. filter rules live in the open at shared/filter-rules.json in the source repo. nothing leaves your machine without passing through this. how it runs - hourly background sync via chrome.alarms. installs with a 90-day lookback on first sync so the graph starts with the last quarter of your real reading, not a year-zero blank slate. subsequent syncs are incremental and idempotent. how to use it 1. open chrome://extensions and pin the cosmos icon. 2. go to cosmos.polarity-lab.com/connectors, mint an MCP key. 3. paste the key into the extension's options page. that's it. the cosmos MCP key lives in chrome.storage.local and is sent only as the X-MCP-Key header to cosmos.polarity-lab.com. no other endpoint is contacted. no analytics, no telemetry. permissions justification - history: read the browser history this extension is named after. the whole product is "your reading becomes your graph." - storage: hold the MCP key and the last-sync watermark. - alarms: schedule the hourly background sync. - host permission to cosmos.polarity-lab.com only. source code at github.com/teampolarity/cosmos-browser-extension.