Installing Custom MCP Servers
Install Model Context Protocol (MCP) servers not included in the recommended list. Register them via the Add Extension UI or delegate the setup to
@skill:tool-installer.
To use pre-configured presets, refer to Installing MCP with Extensions.
When to Use Custom MCP Servers
- NPM or
npxpackages and GitHub MCP repositories. - Custom local commands using
node,python, oruvx. - Remote HTTP or Server-Sent Events (SSE) MCP endpoints.
- Migrating MCP configurations from Cursor, VS Code, Windsurf, or Claude Desktop.
Method A — UI: Add Extension
- Navigate to Extensions → Tools in the sidebar.
- Click Add Extension.
- Complete the form fields and click Save.
Common Fields
- Name — Unique identifier (e.g.,
filesystem,my-search). Reserved built-in names are not allowed. - Description — Optional summary of server capabilities.
- Transport Type:
- stdio (Local Process) — Launches a process on your local system.
- HTTP (Remote Server) — Connects to a remote network endpoint.
stdio Configuration (Local Process)
| Field | Description | Example |
|---|---|---|
| Command | Executable binary name | npx, uvx, node, python |
| Arguments | Space-separated arguments | -y @modelcontextprotocol/server-filesystem /tmp |
| Environment Variables | Key-value pairs passed to the process | API keys and configuration secrets |
Example — Filesystem MCP:
- Name:
filesystem - Transport:
stdio - Command:
npx - Arguments:
-y @modelcontextprotocol/server-filesystem /path/to/folder
If npx or uv is missing, install the required runtimes using @skill:setup-wizard or the App Wizard.
HTTP Configuration (Remote Server)
| Field | Description |
|---|---|
| URL | Complete URL for the MCP endpoint |
| API Key / Token (Optional) | Automatically attached as Authorization: Bearer <token> |
| Custom Headers (Advanced) | Additional HTTP headers in JSON format |
| Enable SSE | Enables streaming for Server-Sent Events. Disable for stateless HTTP |
Steps After Saving
- Verify that the extension shows the Active status in the list.
- Permit access to the extension in your target Assistant settings if needed.
- Start a new session or send the next message to load the tools.
To modify or remove an extension, click Edit or Delete on the extension card.
Method B — Agent Setup: @skill:tool-installer
Instruct the agent in chat:
@skill:tool-installer
Register @modelcontextprotocol/server-everything in LibrAgent using npx.@skill:tool-installer
Import MCP server configurations from Cursor into LibrAgent.The tool installer skill handles:
- Direct registration from npm packages, GitHub repositories, or JSON configurations.
- Automatic configuration imports from Cursor, VS Code, Windsurf, and Claude Desktop.
For detailed procedures, refer to the bundled skill documentation in the Skills Guide.
Connect to an Assistant
Tools remain unavailable in chat until you enable them for your active assistant profile.
- Open Assistants and click Edit on your target assistant.
- In the tool permissions section, select the newly registered MCP server.
- Start or reload a session using that assistant profile.
Troubleshooting
| Symptom | Verification Steps |
|---|---|
| Server saved, but tools do not appear | Check if server is Active, permit tools in Assistant settings, and reload the session. |
command not found or npx failure | Run the App Wizard or prompt @skill:setup-wizard to install missing runtimes. |
| Startup timeout error | Increase timeout in Settings → Advanced → MCP Discovery Timeout. |
| Name registration rejected | The name conflicts with a built-in server. Choose a different name. |
| Preset requires an API key | Enter required keys in the extension configuration form before starting. |
Related Documentation
- Installing MCP with Extensions — Pre-configured extension presets
- 5-Minute Quickstart — App Wizard setup
- Troubleshooting Guide — General application recovery