fusion/plugins/fusion-plugin-hermes-runtime

Hermes Runtime Plugin

Status: Experimental placeholder runtime (current behavior)

Provides a Hermes runtime plugin for Fusion. The plugin is active today for runtime registration/discovery and runtime selection via runtimeConfig.runtimeHint: "hermes".

What it does today

• Registers Hermes runtime metadata with the plugin system
• Exposes a runtime factory that returns a placeholder runtime object
• Emits hermes-runtime:loaded on plugin load
• Supports runtime routing with runtimeHint: "hermes"

Current behavior and limitations

This plugin currently provides registration + placeholder execution semantics.

• Runtime factory returns an object with:
  • runtimeId: "hermes"
  • version: "0.1.0"
  • status: "deferred"
  • message describing placeholder/deferred status
  • execute() function
• Calling execute() always throws a not-implemented error.
• Runtime creation itself does not throw.

Expected execution failure message includes:

Hermes runtime is not yet implemented. Full implementation deferred to FN-2264. See https://github.com/gsxdsm/fusion/issues/FN-2264

Installation

Option 1: Copy to plugins directory

cp -r fusion-plugin-hermes-runtime ~/.fusion/plugins/

Option 2: Install via CLI

fn plugin add ./plugins/fusion-plugin-hermes-runtime

Runtime routing (runtimeHint)

To route an agent to Hermes, set runtimeConfig.runtimeHint to "hermes":

{
  "name": "Hermes Executor",
  "role": "executor",
  "runtimeConfig": {
    "runtimeHint": "hermes"
  }
}

⚠️ With the current placeholder runtime, agent/session selection can target Hermes successfully, but runtime execute() will throw.

Source-of-truth metadata

manifest.json

{
  "id": "fusion-plugin-hermes-runtime",
  "name": "Hermes Runtime Plugin",
  "version": "0.1.0",
  "description": "Hermes AI runtime plugin for Fusion - provides AI agent execution runtime capabilities",
  "author": "Fusion Team",
  "homepage": "https://github.com/gsxdsm/fusion",
  "runtime": {
    "runtimeId": "hermes",
    "name": "Hermes Runtime",
    "description": "Experimental Hermes runtime integration for Fusion tasks (implementation deferred to FN-2264)",
    "version": "0.1.0"
  }
}

Runtime metadata (from src/index.ts)

• Runtime ID: hermes
• Name: Hermes Runtime
• Version: 0.1.0
• Description: Experimental Hermes runtime integration for Fusion tasks (implementation deferred to FN-2264)

Development

# Install dependencies
pnpm install

# Run plugin tests
pnpm --filter @fusion-plugin-examples/hermes-runtime test

# Build
pnpm build

Test coverage

The plugin tests validate:

• Manifest identity
• Runtime registration + metadata consistency
• Placeholder runtime return shape (status: "deferred")
• execute() failure semantics
• Hook behavior (onLoad, onUnload, event emission)

Exports

• default — plugin instance
• hermesRuntimeMetadata — runtime metadata object
• hermesRuntimeFactory — runtime factory
• HERMES_RUNTIME_ID — runtime ID constant ("hermes")

License

MIT