opencode-plugin-zooplankton

A lightweight global OpenCode plugin that injects ZooplanktonAI coding standards into every session via config.instructions and experimental.chat.system.transform.

What it does

Pushes instructions/coding-standards.md into OpenCode's instruction context on startup. No agents, no skills, no commands — just rules.

Current rules:

1. Skeleton-then-replace for large files — write a stub structure first, then fill in implementations chunk by chunk.
2. Prefer Edit over Write for existing files — use targeted find-and-replace instead of full file rewrites.
3. Prefer master over main — use master as the default branch name for new repos.

How it works

The plugin uses two complementary mechanisms to inject coding standards:

1. config hook — Pushes the path to instructions/coding-standards.md into config.instructions, so OpenCode loads it as a session-level instruction file (with the "Instructions from:" banner).

2. experimental.chat.system.transform hook — Appends the coding standards content directly into the system prompt array for every LLM call, including subagent calls. This ensures standards remain salient even in long multi-agent conversations where trailing instructions may be deprioritized.

Note: The experimental.chat.system.transform hook is an experimental OpenCode API (available since OpenCode ≥0.1) and may change in future versions.

Installation

Install globally so it applies to every project:

# In ~/.config/opencode/
npm install opencode-plugin-zooplankton

Add to ~/.config/opencode/opencode.json:

{
  "plugin": ["opencode-plugin-zooplankton"]
}

Adding rules

Edit instructions/coding-standards.md and bump the version in package.json, then republish.

Development

Requires Node.js >= 20.

git clone [email protected]:ZooplanktonAI/opencode-plugin-zooplankton.git
cd opencode-plugin-zooplankton
npm install
npm test