Opencode Fast Apply

opencode-fast-apply

OpenCode plugin for Fast Apply - High-performance code editing with OpenAI-compatible APIs.

Features

• Partial file editing - Only send relevant sections (50-500 lines), not entire files
• Smart context matching - Automatically finds and replaces code sections
• Token efficient - Save 80-98% tokens compared to full-file edits
• Lazy edit markers - Use // ... existing code ... for unchanged sections
• Multi-backend support - LM Studio, Ollama, OpenAI, any OpenAI-compatible endpoint
• Robust XML handling - Safely handles special characters and XML tags in code

Installation

npm install -g opencode-fast-apply

Configure your API endpoint:

# LM Studio (default)
export FAST_APPLY_URL="http://localhost:1234"
export FAST_APPLY_MODEL="fastapply-1.5b"
export FAST_APPLY_API_KEY="optional-api-key"

# Ollama
export FAST_APPLY_URL="http://localhost:11434"
export FAST_APPLY_MODEL="codellama:7b"

# OpenAI
export FAST_APPLY_URL="https://api.openai.com"
export FAST_APPLY_MODEL="gpt-4"
export FAST_APPLY_API_KEY="sk-your-key"

Add to OpenCode config (`~/.config/opencode/opencode.json`):

{
  "plugin": ["opencode-fast-apply"]
}

Restart OpenCode. The `fast_apply_edit` tool is now available.

Usage

// 1. Read relevant section (not entire file)
const content = await read("src/app.ts", { offset: 100, limit: 50 })

// 2. Edit with partial context
fast_apply_edit({
  target_filepath: "src/app.ts",
  original_code: content,  // Just 50 lines!
  code_edit: `// ... existing code ...
function updated() {
  return "modified";
}
// ... existing code ...`
})

**Key points:**

• Provide 50-500 lines of context around the area you want to change
• Include 2-5 lines before/after the target section
• Tool automatically finds and replaces that section in the full file
• No need to send entire file (saves tokens and improves speed)

Configuration

| Variable | Default | Description | |-