opencode-morph-fast-apply

OpenCode plugin for Morph Fast Apply - 10x faster code editing with lazy edit markers.

Features

• 10,500+ tokens/sec code editing via Morph's Fast Apply API
• Lazy edit markers (// ... existing code ...) - no exact string matching needed
• Unified diff output with context for easy review
• Graceful fallback - suggests native edit tool on API failure

Installation

1. Clone the repository

git clone https://github.com/JRedeker/opencode-morph-fast-apply.git ~/dev/oc-plugins/morph-fast-apply
cd ~/dev/oc-plugins/morph-fast-apply
npm install

2. Set your Morph API key

Get an API key at morphllm.com/dashboard, then add to your shell profile:

export MORPH_API_KEY="sk-your-key-here"

3. Add the plugin to your OpenCode config

Add to your global config (~/.config/opencode/opencode.json):

{
  "plugin": [
    "/path/to/morph-fast-apply"
  ],
  "instructions": [
    "/path/to/morph-fast-apply/MORPH_INSTRUCTIONS.md"
  ]
}

Or in a project-local .opencode/config.json:

{
  "plugin": [
    "~/dev/oc-plugins/morph-fast-apply"
  ],
  "instructions": [
    "~/dev/oc-plugins/morph-fast-apply/MORPH_INSTRUCTIONS.md"
  ]
}

4. Restart OpenCode

The morph_edit tool will now be available.

Usage

The LLM can use morph_edit for efficient partial file edits:

morph_edit({
  target_filepath: "src/auth.ts",
  instructions: "Add error handling for invalid tokens",
  code_edit: `// ... existing code ...
function validateToken(token) {
  if (!token) {
    throw new Error("Token is required");
  }
  // ... existing code ...
}
// ... existing code ...`
})

When to use morph_edit vs edit

Situation	Tool	Reason
Small, exact replacement	edit	Fast, no API call
Large file (500+ lines)	morph_edit	Handles partial snippets
Multiple scattered changes	morph_edit	Batch efficiently
Whitespace-sensitive	morph_edit	Forgiving with formatting

Configuration

Variable	Default	Description
MORPH_API_KEY	(required)	Your Morph API key
MORPH_API_URL	https://api.morphllm.com	API endpoint
MORPH_MODEL	morph-v3-fast	Model (morph-v3-fast, morph-v3-large, auto)
MORPH_TIMEOUT	30000	Request timeout in ms

How It Works

1. Reads the original file content
2. Sends <instruction>, <code>, and <update> to Morph API
3. Morph intelligently merges the lazy edit markers with original code
4. Writes the merged result back to the file
5. Returns a unified diff showing what changed

Contributing

Contributions welcome! This plugin could potentially be integrated into OpenCode core.

License

MIT