You save a hundred articles a year. You write notes in three apps. You bookmark things you intend to read and never see again. The promise of the "second brain" is that all of this scattered knowledge becomes searchable, queryable, and useful. The reality for most tools is that your saved items go into a black hole.
What we actually built
Glassy Second Brain is not a marketing label. It is an indexed knowledge base that contains everything you save — bookmarks, notes, documents, voice transcripts, and your connected Obsidian vault files. Everything is embedded and indexed automatically. BM25 full-text search plus vector semantic search, merged with Reciprocal Rank Fusion. When you search, you get results ranked by relevance across both exact matching and meaning.
Query from Claude, Cursor, Windsurf, OpenCode, Hermes, Openclaw, Pi, or any MCP-compatible client
Here is the part that changes how you use your knowledge. The Glassy MCP server is built on the official
@modelcontextprotocol/sdk v2. It exposes forty-two tools on a self-hosted appliance
(thirty-seven on our cloud, where five tools stay appliance-only), four prompts, and nine resources.
Generate an MCP key in Settings, paste the config snippet into Claude Desktop, Cursor, Windsurf, OpenCode,
Hermes, Openclaw, Pi, or any MCP-compatible client, and ask questions about your entire corpus.
"What do I know about recursive neural networks?" "Summarize everything I saved about OAuth2 in the last
six months." Your AI assistant queries your actual knowledge base and returns real results with citations.
Four lanes, not one search box
A search engine answers a question. A second brain carries state, and that is what separates this from pasting context into a chat window:
- Memory. An agent saves durable memories as real notes — searchable, graph-linked, and scoped to that agent. It recalls the decision next session instead of asking again.
- Canvas. The one page type that can hold live content, with an embed policy that is written down and reported per surface.
- Approval. Agents ask before they act. The review queue shows each choice and its consequence, and the note carries the verdict.
- Pairing. A calendar event can dispatch a task; the result rides the event, lands in the activity feed, and can post itself back as a note.
Privacy by architecture
On your own machine your corpus stays there — only the specific query leaves, and that goes to your chosen AI assistant, not to us. On our cloud the corpus is indexed on our servers so the tools can read it, and the same rule holds: it is never training data, and we do not sell it. The MCP server has DNS-rebinding protection and tier-based rate limiting (120 tool calls an hour on Free, 1,200 on paid plans); on the self-hosted appliance there are no tool-call rate limits at all, because the only meter is your hardware.
How to start
Install the Glassy Capture extension. Save a few pages. Your Second Brain starts indexing immediately. Open Settings → MCP Keys, generate a key, and follow the config snippet for your agent. The whole setup takes under five minutes.