Callosium MCP Server - install, status & alternatives [2026]

01 · Install Callosium

before you install - you'll need

The README does not document required environment variables for a basic install.

Claude Code

claude mcp add callosium-callosium -- npx -y callosium

Claude Desktop / Cursor / VS Code - add to config

{
  "mcpServers": {
    "callosium-callosium": {
      "command": "npx",
      "args": [
        "-y",
        "callosium"
      ]
    }
  }
}

Same JSON for Cursor. For VS Code, rename the top-level key from `mcpServers` to `servers`.

Using another client? Same JSON, different key

Claude Desktop · mcpServers

Cursor · mcpServers

VS Code · servers

Windsurf · mcpServers

Zed · context_servers

Cline · mcpServers

Roo Code · mcpServers

Continue · mcpServers

LibreChat · mcpServers

Gemini CLI · mcpServers

Codex CLI · mcp_servers

Full setup guides: every client.

02 · Evidence

Security posture

What to check before giving this server access to your agent - from the registry, GitHub, and our own probes. We don't score safety; we show what's verifiable.

runs as local process (stdio) - runs on your machine with your user's permissions

repo age created 2026-07-25 - young repo, little track record yet

license Apache-2.0 - declared in the repository

npm package callosium - unscoped; check the name against the project README before installing

registry namespace io.github.callosium is GitHub-verified and matches the repo owner

03 · What Callosium can do

Prose above is summarized from the project's README and registry record - no invented capabilities.

Latest releases

desktop-v0.1.17 · 2026-08-01

Windows installer below. · Heads up: this installer isn't code-signed yet, so Windows SmartScreen will · warn you - and if you have Smart App Control on, it will block it outright. · To skip that, install with npm…

desktop-v0.1.16 · 2026-07-31

Windows installer below. · Heads up: this installer isn't code-signed yet, so Windows SmartScreen will · warn you - and if you have Smart App Control on, it will block it outright. · To skip that, install with npm…

04 · Who maintains Callosium

Callosium is maintained by callosium. It's the only MCP server we track from this author; the repo dates to Jul 2026.

05 · Facts

repository: github.com/callosium/callosium
website: https://callosium.com/
category: documentation - ranked #38 of 183 actively-maintained documentation servers as of 2026-08-25.
release cadence: 2 releases in the last 90 days (latest 2026-08-01)
registry: io.github.callosium/callosium (active, first published 2026-08-04)
packages: npm:callosium

06 · Callosium FAQ

What is Callosium?

One shared memory for every AI you use, in plain Markdown files you own. It runs locally over stdio via the published package.

Is Callosium still maintained?

Yes - as of 2026-08-25, its last commit was 2026-08-04 and it shipped 2 releases in the last 90 days. We re-verify nightly.

How do I install Callosium?

Run `npx -y callosium`. The README does not document required environment variables for a basic install. You can also paste the ready-made client config above.

Does Callosium run locally?

Yes - it's a stdio server: it runs on your machine (via npx) with your user's permissions. Your data stays local unless the server itself calls external APIs.

07 · Alternatives to Callosium

Alternatives to Callosium

Maintained documentation servers if Callosium isn't the fit.

Pairs well with

Servers that cover what Callosium doesn't - only shown when the pairing reason fits the companion.

More documentation MCP servers · Openzim MCP · Cashfree MCP · Prior · Chainstack · Clean Slice

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