plugin-manager-mcp

MCP server for deterministic harness plugin management inside the harness-plugins repository.

Install

npm install -g plugin-manager-mcp

Run

HARNESS_PLUGINS_ROOT=/path/to/harness-plugins plugin-manager-mcp

For a direct readiness check:

HARNESS_PLUGINS_ROOT=/path/to/harness-plugins plugin-manager-mcp --health

The server uses stdio transport and exposes these MCP tools:

• list_plugins
• show_status
• update_repo
• install_plugin
• sync_plugin
• sync_all
• sync_to_claude
• sync_to_opencode
• sync_to_codex

For OpenCode, set OPENCODE_CONFIG_ROOT to the OpenCode config directory if you do not want the default ~/.config/opencode.

OpenCode layout

sync_to_opencode writes global OpenCode plugins to ~/.config/opencode by default:

~/.config/opencode/
├── commands/<skill-name>.md
├── skills/<skill-name>/SKILL.md
└── plugins/<plugin-name>/
    ├── agents/
    ├── commands/
    ├── instructions/
    ├── profiles/
    ├── skills/
    └── opencode-plugin.json

The sync keeps the harness source as the authority and maps:

• skills/ to skills/
• agents/ to agents/
• README.md and other top-level markdown files to instructions/
• PROFILE.md to profiles/default.md
• OVERRIDES.md to profiles/overrides.md

OpenCode slash commands are thin wrappers that say Use the <skill-name> skill. so the original SKILL.md remains the source of truth.

Generated OpenCode skill and command names are namespaced as <plugin-name>__<skill-name> to avoid collisions across harnesses.

Example:

/minmos-harness__commit-mm

Update checks

The server checks the npm registry once per hour and writes update notices to stderr only, so stdout remains reserved for MCP protocol messages.

Disable update checks with:

PLUGIN_MANAGER_DISABLE_UPDATE_CHECK=1 plugin-manager-mcp