ue-codegraph-mcp

MCP server for indexing and querying Unreal Engine C++ codebases.

Indexes your UE project's Source/ directory into a local SQLite database and exposes 15 MCP tools so Claude Code can answer questions about call graphs, class structure, #include dependencies, and Blueprint-exposed symbols — without reading raw files every time.

Features

• Call graph analysis — find all callers of a function, trace call chains from A → B

• Class analysis — methods, fields, base classes, UE macros (UCLASS, UPROPERTY, UFUNCTION)

• Blueprint exposure — list all BlueprintCallable functions and BlueprintReadWrite properties

• #include dependency graph — what a file includes, and what includes it (transitive support)

• Symbol search — FTS5 full-text search across 40k+ symbols with prefix matching

• Incremental indexing — re-indexes only changed files (hash + mtime based)

• Standalone CLI — use ue-graph commands directly from the terminal without Claude

Prerequisites

Node.js 22 LTS is required. Odd-numbered "Current" releases (v23, v25, etc.) are incompatible with tree-sitter's native bindings and will fail to parse files.

Installation

1. Install Node.js 22 LTS

Download from https://nodejs.org (click the LTS tab) or use winget:

winget install OpenJS.NodeJS.LTS

2. Run setup.bat

cd C:\path\to\ue-codegraph-mcp
.\setup.bat

setup.bat will:

1. Verify Node.js 22 LTS

2. Install node-gyp globally (needed for native module builds)

3. Run npm install (builds tree-sitter and better-sqlite3 from source)

4. Run npm link to register the ue-graph CLI globally

5. Optionally index your project and generate mcp.json

If the native build fails, install Visual Studio Build Tools with the C++ build tools workload, then re-run setup.bat.

3. Index your project

ue-graph index "G:\YourProject\Source" my-project

Output:

Indexing G:\YourProject\Source as "my-project" (project)...

Done!
  Files:   1784  (new: 1784, changed: 0)
  Symbols: 45623
  Macros:  3210
  Calls:   28450
  Includes: 9120
  Time: 32.5s

4. Register with Claude Code

claude mcp add -s user ue-codegraph node "C:\path\to\ue-codegraph-mcp\build\index.js"

Verify with claude mcp list. Then start Claude Code in your project directory and run /mcp to confirm the server is connected.

Usage in Claude Code

Once registered, Claude automatically uses the MCP tools when you ask natural-language questions:

"Find everything that calls SetHP"
"Trace the call chain from DamageMyPlayer to ApplyDamage"
"Analyze the UAMirLuaManager class"
"Which files include AMirCharacter.h?"
"Show all BlueprintCallable functions in UAMirAbilityComponent"

CLI Commands

Use ue-graph directly from the terminal without Claude Code.

Index management

ue-graph index <path> [name]     # Index a codebase
ue-graph status                  # Show indexed codebases and stats
ue-graph reindex <file_path>     # Re-index a single file after changes
ue-graph delete <id|name|all>    # Remove a codebase from the index

Call graph

ue-graph callers SetHP                       # Who calls SetHP?
ue-graph callees BeginPlay                   # What does BeginPlay call?
ue-graph chain DamageMyPlayer SetHP          # Call path from A to B

Class analysis

ue-graph analyze UAMirLuaManager             # Methods, fields, UE macros
ue-graph hierarchy AAMirCharacter            # Inheritance tree (up + down)
ue-graph blueprint UAMirLuaManager           # Full Blueprint interface

Search

ue-graph search "SetHP"                      # FTS symbol search
ue-graph code "CL2LG_MY_CHARACTER_SPAWN_REQ" # Code text pattern search
ue-graph refs DamageMyPlayer                 # Where is this symbol used?

UE Macros

ue-graph macros UFUNCTION                    # All UFUNCTION macros
ue-graph macros UFUNCTION BlueprintCallable  # Filter by specifier
ue-graph deps "G:\...\MyActor.h"            # #include dependency graph

MCP Tools Reference

Known Limitations

Troubleshooting

All files fail with Invalid argument during indexing → Wrong Node.js version. Install Node.js 22 LTS, delete node_modules/, re-run setup.bat.

Native build errors (node-gyp, better-sqlite3) → Install Visual Studio Build Tools (C++ workload), then re-run setup.bat.

MCP server not visible in Claude Code → Confirm the path in claude mcp list is an absolute path. Restart Claude Code and run /mcp.

License

MIT