opencode-interceptor

A lightweight OpenCode plugin that bridges the gap between Claude Code-native GSD workflow features and OpenCode.

Features

@ File Resolution

Resolves @path/to/file.md references inside skill files, replacing them with <resolved> XML blocks containing the file content. Works with:

• Relative paths (@./refs/notes.md, @references/notes.md)
• Absolute paths (@/home/user/docs/notes.md, @C:/Users/...)
• Recursive resolution (up to 5 levels deep)
• Circular reference detection
• Code block awareness (refs inside ``` fences are skipped)
• Cross-platform path support (Windows backslash and forward slash)

@! Script Execution

Executes @!path/to/script.sh references and inlines the script's stdout as a <resolved path="..." type="exec"> block. Useful for dynamically generating content from command output.

Hook Bridge

Executes Claude Code-compatible hook scripts from ~/.claude/settings.json:

• PreToolUse -- runs before a tool executes; exit code 2 blocks the tool
• PostToolUse -- runs after a tool executes; informational, cannot block
• Stop -- runs on session idle (fire-and-forget in OpenCode)

Hook scripts receive JSON on stdin with session_id, cwd, hook_event_name, tool_name, and tool_input.

Config Loading

Reads opencode.json for hook configuration:

• gsd-bridge-hooks-enabled (flat key, preferred)
• gsd.hooks (nested key, fallback)

Skill Pre-resolution

On session start, pre-resolves all skill files so @ references are resolved before any skill tool call.

Installation

npm

// opencode.json
{
  "plugin: ["opencode-interceptor"]
}

Local

Copy plugins/gsd-bridge.ts and plugins/resolver.ts to your project, then:

// opencode.json
{
  "plugins": ["plugins/gsd-bridge.ts"]
}

Enable hooks:

{
  "gsd-bridge-hooks-enabled": true
}

Configuration

Create ~/.claude/settings.json to define hooks:

{
  "hooks": {
    "PreToolUse": [
      {
        "matcher": "Bash|Edit|Write",
        "hooks": [
          { "type": "command", "command": "/path/to/pre-hook.sh" }
        ]
      }
    ],
    "PostToolUse": [
      {
        "matcher": "Read",
        "hooks": [
          { "type": "command", "command": "/path/to/post-hook.sh" }
        ]
      }
    ],
    "Stop": [
      {
        "hooks": [
          { "type": "command", "command": "/path/to/stop-hook.sh" }
        ]
      }
    ]
  }
}

Limitations

• No custom tool dispatch: Local .ts plugins only receive event hooks, not function calls. Only the skill tool namespace works. See docs/model-routing.md for details.
• Stop hooks are fire-and-forget: session.idle cannot re-activate the agent in OpenCode, so Stop hooks cannot trigger agent continuation.
• Depth limit: @ resolution stops at 5 levels of recursion to protect against circular references.
• Missing files are skipped: Unresolvable @ refs are left as-is in the output.

License

MIT. Portions derived from oh-my-openagent (MIT/Apache-2.0).