@silicaos/mcp

Model Context Protocol server for Silica. Lets Claude Code (and any MCP client) operate on a Silica workspace as a Yjs peer — features, tasks, slot docs, activity notes.

Install in any project

Once you've signed in to the Silica desktop app at least once, register the server in your project's MCP config:

{
  "mcpServers": {
    "silica": {
      "command": "npx",
      "args": ["-y", "@silicaos/mcp"]
    }
  }
}

Locations:

• Claude Code: ~/.claude.json top-level mcpServers (global) or <repo>/.mcp.json (per-repo)
• Cursor: ~/.cursor/mcp.json or <repo>/.cursor/mcp.json
• Any other MCP-compatible client: see its docs for the equivalent file

No cwd, no monorepo checkout, no per-project install. npx pulls the bundle and runs it.

One-command setup

Even faster than hand-editing config files: from inside a target repo,

npx -y @silicaos/mcp install

This will:

• Pick (or prompt for) which workspace to bind this directory to
• Detect Claude Code (.claude/) and Cursor (.cursor/) and merge the silica entry into .mcp.json and/or .cursor/mcp.json
• Drop a .silica.json so the MCP can resolve the workspace fast
• Register the directory with your workspace so the desktop app sees it
• Append a Silica block to AGENTS.md (only if the file exists)

Options:

| Flag | Effect | |---|---| | --workspace ws_xxx | Pin a specific workspace_id | | --client claude\|cursor\|all | Restrict which client configs get touched | | --global | Write to ~/.claude.json (Claude Code) / ~/.cursor/mcp.json (Cursor) instead of per-repo | | --no-agents-md | Skip the AGENTS.md append | | --force | Overwrite an existing .silica.json | | --dry-run | Compute changes, print diff, write nothing |

Reverse with:

npx -y @silicaos/mcp uninstall

Authentication

The server reads your Clerk JWT from ~/.config/silica/credentials, written by the Silica desktop app on every successful sign-in. If the file is missing or expired, sign in to the desktop app again to refresh it.

Workspace resolution

In order of priority:

1. SILICA_WORKSPACE_ID environment variable
2. .silica.json at the project root containing { "workspace_id": "ws_..." }
3. Auto-detect: matches cwd against the local_path of any directory connected to one of your workspaces (set via Settings → Connected directories in the desktop app)

Tools

• list_features({ in_motion?: boolean }) — list features in the workspace
• create_feature({ title }) — create a feature
• list_tasks({ feature_id }) — list tasks for a feature
• create_task({ feature_id, title, description? }) — append a task
• complete_task({ task_id, completed? }) — toggle completion
• read_slot({ slot_id }) — read a slot doc as Markdown
• update_slot({ slot_id, markdown }) — replace a slot doc (V1: lossy on rich structure; high-fidelity edits live in the desktop TipTap editor)
• append_note({ feature_id, text }) — append an activity entry

V1 limitations

• Token expiry: the server reads the token at connect; if a long session outlives the JWT, the WS client auto-reconnects on close. If ~/.config/silica/credentials itself goes stale, sign in to the desktop app again.
• Slot serialization: Markdown round-trip loses some rich-text structure. Use the desktop editor for fidelity-critical edits.

Developing in this monorepo

For working on the MCP server itself:

pnpm --filter @silicaos/mcp dev        # run from source via tsx
pnpm --filter @silicaos/mcp build      # bundle to dist/ with tsup
pnpm --filter @silicaos/mcp typecheck  # tsc --noEmit

If you want to point Claude Code at the in-repo source (instead of npm), register:

{
  "mcpServers": {
    "silica-dev": {
      "command": "pnpm",
      "args": ["--silent", "--filter", "@silicaos/mcp", "dev"],
      "cwd": "/absolute/path/to/Silica"
    }
  }
}

Publishing

The package is published from dist/. prepublishOnly builds. Workflow:

cd apps/mcp
pnpm version patch        # or minor / major
pnpm publish --access public

Tag-based CI publish is TBD.