MCP Mode & AI Agent Integration

Manage instance profiles and packages through the Trident CLI's Model Context Protocol tools.

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What is MCP?

The Model Context Protocol (MCP) is a standard for AI agents to interact with external tools. Polymerium's CLI (trident) can run as an MCP server, exposing 30+ tools that AI agents can call directly.

An agent can create instances, inspect and add packages, select versions, and export modpacks through these tools. Deployment and launch remain desktop or CLI commands; snapshots are created in the desktop app.

Starting the MCP Server

trident --mcp

This starts a local MCP server over stdio. Install the trident CLI separately, then connect an MCP client to it.

Configuration for AI Clients

Claude Desktop

Add to your claude_desktop_config.json:

{
  "mcpServers": {
    "polymerium": {
      "command": "trident",
      "args": ["--mcp"]
    }
  }
}

Cursor

Add as an MCP tool server in Cursor's settings, pointing to trident --mcp.

Other Clients

Any client that supports MCP over stdio can connect. The server speaks the standard MCP protocol.

Available Tools (30+)

Instance Tools

Tool	Description
`instance_list`	List all instances
`instance_inspect`	View instance details
`instance_create`	Create a new instance
`instance_delete`	Delete an instance
`instance_unlock`	Unlock an imported instance's source binding
`instance_reset`	Clear the Run Directory (`build/`); data not already in Local Data (`persist/`) is lost
`instance_export`	Export instance as a modpack
`instance_import`	Import a modpack file
`instance_install`	Install a repository modpack as a new instance

Package Tools

Tool	Description
`package_list`	List installed packages
`package_search`	Search CurseForge / Modrinth for packages
`package_add`	Add a package by Pref
`package_inspect`	View package details
`package_enable` / `package_disable`	Toggle packages
`package_dependency_list`	List a package's dependencies
`package_dependent_list`	List installed packages in this instance that depend on a package
`package_version_list`	List available versions
`package_version_set`	Pin a specific version

Loader Tools

Tool	Description
`loader_list`	List supported mod loaders
`loader_version_list`	List available loader versions
`loader_get` / `loader_set`	Get or set the loader

Config Tools

Tool	Description
`config_get` / `config_set`	Read/write configuration
`config_list` / `config_unset`	List or remove config keys

Account Tools

Tool	Description
`account_list`	List accounts
`account_add_offline`	Add an offline account
`account_remove`	Remove an account

Repository Tools

Tool	Description
`repository_list`	List configured repositories
`repository_status`	Check repository connectivity
`repository_add` / `repository_remove`	Add or remove repositories

Native Patch Tools

Tool	Description
`patch_list`	List an instance's imported and user patches
`patch_set_enabled`	Enable or disable a patch
`patch_move`	Reorder a patch within its layer

Example: Build a Package List

These calls use the tool names and required parameters exposed by the current server:

instance_create(name="Performance", version="1.21.1",
                loader="net.fabricmc:0.16.10", identity="perf-pack")
package_search(query="sodium", repository="modrinth")
package_add(pref="pref://modrinth/aC3cM3Vq", instance="perf-pack")

The search result supplies the Pref for the package you choose. The added reference is saved in the profile; use the desktop app or trident instance build --instance perf-pack to deploy it. To take a snapshot before changing versions, use the desktop app first.

Limitations

MCP runs locally over stdio. It does not expose deployment, game launch, snapshot creation, or Microsoft account sign-in tools.
A package tool changes profile data; it does not install game files until you deploy.
CLI account settings are separate from desktop accounts. Both hosts can access the same instances, so avoid editing an instance from both at the same time.

MCP Mode & AI Agent Integration

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