io.github.juw12/cairn
Cairn
Is the Cairn MCP server down? No. It answered initialize and tools/list in the probe of 2026-11-14.
Second brain as plain Markdown in your repo: search, notes, capture, journal, task queue.
alive probed 2026-11-14
13tools
2.0ktokens in Claude Opus 5.5
1.0 %of Claude's 200k window
0.8×the median server
103 msto initialize
3 msto list tools
- Bundle
- https://github.com/juw12/cairn/releases/download/mcp-v1.0.0/cairn.mcpb (MCPB, for a client that installs bundles; probed in a container with the network off)
- Host
- github.com
- Reports itself as
- cairn 1.0.0
- Capabilities
- prompts, resources, tools
- Instructions
- 515 characters
- Of a 1M window
- 0.2 % of a 1M context window
- Count
- 2.0k tokens in Claude Opus 5.5, exact, measured 2026-11-14. With the Claude Code prefix mcp__…__ on each tool name: 2.1k. The o200k_base estimate is 1.1k. Counted again when the tool definitions change. Method.
- Repository
- https://github.com/juw12/cairn
- Website
- https://github.com/juw12/cairn
- Registry
- active, updated 2026-11-13 · registry entry
Most expensive tools
The Claude column scales the o200k estimate of each tool by this server's ratio of exact to estimate, 1.77×.
| Tool | ≈ Claude tokens | o200k estimate | Share of this server |
|---|---|---|---|
| update_note | 278 | 157 | 14 % |
| search | 218 | 123 | 11 % |
| capture | 202 | 114 | 10 % |
| precedent_brief | 200 | 113 | 10 % |
| precedent_log | 198 | 112 | 10 % |
Compare this server with others.
More servers
Other registry entries on github.com, the ones next to this name; all of them.
- Orbit io.github.justinwilliames/braze-lifecycle-mcp · not found
- Orbit io.github.justinwilliames/orbit-for-claude · not found
- Orbit io.github.justinwilliames/orbit-lifecycle-mcp · not found
- JustRouting MCP Server io.github.justrouting/justrouting · install failed
- precedent io.github.juw12/precedent · alive
- io.github.kKEo/memors · install failed
- io.github.kKEo/memory-find · install failed
- io.github.kOlapsis/gofact · crashed on start
Servers that mention cairn.
- Chaparral Software MCP com.chapsoft/mcp · alive
- Cairn — keep your agent's daily build streak (public trail + badge) dev.workers.notdown-app.cairn/daily-build-streak-accountability-tracker · alive
- Cairn.ink Memory ink.cairn/memory · needs auth
- WEE WiLDS Booking com.weewilds/booking · alive
- Cairn com.cairnsafe/cairn · alive
- Cairn Commons io.github.cairncommons/cairn-commons · alive
- Cairn Remembers io.github.CairnRemembers/cairn-remembers · alive
- Cairn io.github.luckyjackluo/cairn · crashed on start
Badge for the README
The result of the latest probe, the tool count and the token cost. The feed has an entry for every probe that changed them.
A mail when this server changes
Stops answering, comes back, tool set or cost changes. One confirmation mail first, a stop link in every mail.
For the publisher
- The server answers initialize and tools/list. Nothing to fix.