OpenCode Model Announcer Plugin

This plugin automatically injects the current model name into the chat context. This helps the LLM know exactly which model it is (e.g., google/gemini-3-pro-high or anthropic/claude-opus-4-5-thinking) without needing to ask the user or hallucinating.

Features

• Automatic Announcement: Injects a synthetic message part into every user prompt turn.
• Context Awareness: Seen only by the LLM, invisible in the TUI history.
• Zero Configuration: Just load the plugin and it works.

Installation

npm install @ramarivera/opencode-model-announcer

Or add it to your ~/.config/opencode/opencode.json:

{
  "plugin": ["@ramarivera/opencode-model-announcer"]
}

How it Works

The plugin hooks into experimental.chat.messages.transform. Right before the messages are sent to the AI provider, it:

1. Finds the last user message.
2. Resolves the friendly model name (e.g., "Claude 3.5 Sonnet") using the OpenCode SDK.
3. Prepends a system-level announcement to the user's message:

[SYSTEM: CURRENT_MODEL_ANNOUNCEMENT - The current model being used is: {friendlyName} ({provider}/{model}). Use this information to tailor your responses if necessary.]

🤖 This content was generated with AI assistance using Claude Opus 4.5.

Note: Ironically, this README was generated when the project started, and I was actually using Gemini 3 Pro, not Claude Opus 4.5. With this plugin, the model would have known its true identity, and this disclaimer would have been accurate. This is exactly the problem I'm aiming to solve.

Disclaimer

This is a community plugin and is not officially affiliated with, endorsed by, or sponsored by OpenCode or SST.