unity-csharp-editing

Unity C# Script Editing

A guide for efficient editing, searching, and refactoring of Unity C# scripts.

Quick Start

1. Initialize Code Index

On first use or when the index is outdated, build the index first:

// Check index status
mcp__unity-mcp-server__get_index_status()

// Build index (first time only, may take a few minutes)
mcp__unity-mcp-server__build_index()

2. Basic Reading Flow

// Get symbol list in file
mcp__unity-mcp-server__get_symbols({
  path: "Assets/Scripts/Player.cs"
})

// Get specific symbol details
mcp__unity-mcp-server__find_symbol({
  name: "PlayerController",
  kind: "class",
  exact: true
})

// Read code
mcp__unity-mcp-server__read({
  path: "Assets/Scripts/Player.cs",
  startLine: 10,
  endLine: 50
})

3. Basic Editing Flow

// Small changes (within 80 characters) → snippet
mcp__unity-mcp-server__edit_snippet({
  path: "Assets/Scripts/Player.cs",
  instructions: [{
    operation: "replace",
    anchor: { type: "text", target: "if (health < 0)" },
    newText: "if (health <= 0)"
  }]
})

// Large changes (method body) → structured
mcp__unity-mcp-server__edit_structured({
  path: "Assets/Scripts/Player.cs",
  symbolName: "PlayerController/TakeDamage",
  operation: "replace_body",
  newText: "{\n    health -= damage;\n    OnDamaged?.Invoke(damage);\n}"
})

Core Concepts

Code Index

unity-mcp-server provides a code index via built-in C# LSP. Output is 5x more compact than standard tools, optimizing LLM context.

Tool	Purpose	Comparison
find_symbol	Symbol search	5x smaller output
find_refs	Reference search	3x smaller output
search	Code search	Instant response

namePath (Symbol Path)

Symbols are identified by hierarchical path within file:

// Simple class
PlayerController

// Nested member
PlayerController/TakeDamage
PlayerController/health

// Deep nesting
OuterClass/InnerClass/Method