Cairn.ink Memory — Claude Code MCP server: setup and overview
Preserves context across AI sessions while attaching submitted source snippets to every saved record. Useful when preferences change over time.
claude mcp add --transport http memory https://cairn.ink/api/mcpWhat Cairn.ink Memory does
Cairn.ink Memory passes project decisions and instructions across separate AI sessions using the Model Context Protocol. Rather than collecting untraceable conversational logs, it pairs each memory with a Source Receipt containing the exact submitted text. You can inspect that original fragment later, adjust the record to match fresh project rules, or erase it from active context.
The basic operations run without contacting model APIs. Saving, viewing source receipts, revising entries, and dropping stale preferences remain model-free. However, semantic search across stored entries requires an OpenAI API key, which transmits selected text to that vendor.
You can run the memory layer locally or through a hosted endpoint. The local developer preview keeps records inside an SQLite database and operates without a Cairn account. Connecting to the shared service relies on https://cairn.ink/api/mcp and hosted authentication. Node 22.16 or higher is mandatory for running the setup installer.
What it helps with
- persist project guidelines across separate assistant sessions
- verify the exact source quote behind a stored decision
- modify outdated instructions without wiping past records
- drop obsolete preferences from active context recall
Example prompts for the agent
- Remember that this project uses Vitest instead of Jest for unit tests
- Inspect the source receipt for my report format preference
- Update the report guideline to require detailed summaries
How to install Cairn.ink Memory
Platform CLI: remote server
claude mcp add --transport http memory https://cairn.ink/api/mcpPlatform CLI: remote server
codex mcp add cairnink-memory --url https://cairn.ink/api/mcpConfig file
{
"mcpServers": {
"cairnink-memory": {
"url": "https://cairn.ink/api/mcp"
}
}
}Config file
{
"servers": {
"cairnink-memory": {
"type": "http",
"url": "https://cairn.ink/api/mcp"
}
}
}Platform CLI: remote server
gemini mcp add -t http cairnink-memory https://cairn.ink/api/mcpStep by step, with commands for each platform: How to add an MCP server to Claude Code, Codex, Cursor, VS Code, Gemini CLI and more
Questions about Cairn.ink Memory
How do I install Cairn.ink Memory in Claude Code?
Run claude mcp add --transport http cairnink-memory https://cairn.ink/api/mcp in your terminal. For automated setup across supported CLIs, execute npx @cairn-ink/memory setup on Node 22.16 or newer.
What is a Source Receipt in Cairn.ink Memory?
It is the raw snippet submitted when saving or editing a preference. It lets you inspect what text created the entry, though it is not a full chat transcript.
Is an OpenAI key required to use Cairn.ink Memory?
Saving, inspecting, editing, and dropping memories work offline without an AI model. An OpenAI API key is needed only when enabling semantic recall across past entries.
