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.

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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

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Prerequisites

Requirement	Version	Check
Node.js	22 LTS	node --version
npm	9+	npm --version
Claude Code	latest	claude --version

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.

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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.

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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"

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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

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MCP Tools Reference

Tool	Description
init_codebase	Index a UE source directory
get_index_status	Show registered codebases and stats
reindex_file	Re-index a single file
find_callers	Find all callers of a function
find_callees	Find all functions called by a function
find_call_chain	Shortest call path from function A to B
get_file_dependencies	#include graph (includes + included-by)
analyze_class	Class methods, fields, UE macros, base classes
get_class_hierarchy	Ancestor and descendant class tree
find_ue_macros	Search UE macros by type and specifier
get_macro_specifiers	Get specifiers for a specific symbol's macro
find_blueprint_exposed	All BlueprintCallable/BlueprintReadWrite symbols
get_blueprint_interface	Full Blueprint interface of a class
search_symbols	FTS5 symbol search
search_code	Code text pattern search
find_references	Cross-reference lookup

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Known Limitations

Issue	Workaround
analyze_class may fail on 3000+ line headers (forward declarations)	Use Grep + Read instead
Parent class lookup broken when GENERATED_BODY() is the only inheritance hint	Use grep 'class Foo.*public'
find_callees can mix results when multiple classes share the same method name	Use unique function names or find_callers

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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.

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License

MIT