Codesteward Graph

Structural code graph server for AI agents. Parse any repository into a queryable graph via tree-sitter AST — and expose it as an MCP tool interface your AI agent can call directly. Supports Neo4j, JanusGraph, or GraphQLite (embedded SQLite — zero setup for local dev).

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What it does

Codesteward parses your codebase into a persistent structural graph and exposes four Model Context Protocol tools that AI agents (Claude Code, Cursor, Windsurf, Copilot, …) can call to answer questions like:

• "Which functions are protected by JWT auth?"
• "What does process_payment call, transitively?"
• "Which files depend on this external package?"
• "Is this route guarded by an auth middleware?"

Rather than scanning files repeatedly, the agent queries a pre-built graph — cross-file relationships, call chains, auth guards, and dependency edges all resolved in a single query.

Supported languages: TypeScript · JavaScript · Python · Java · Go · Rust · PHP · C# · Kotlin · Scala · C · C++ · SQL (context tagging) · COBOL (regex)

MCP Tools

| Tool | Description | | ---- | ----------- | | graph_rebuild | Parse a repository and write the structural graph to the configured backend (Neo4j, JanusGraph, or GraphQLite) or run in stub mode | | codebase_graph_query | Query via named templates (lexical, referential, semantic, dependency) or raw passthrough (cypher / gremlin) | | graph_augment | Add agent-inferred relationships (confidence Note: Claude Code requires "type": "stdio" in the server config. Other tools > (Cursor, Cline) don't need it.

| Tool | Config file | | ---- | ----------- | | Claude Code | ~/.claude.json (under mcpServers) | | Cursor | ~/.cursor/mcp.json | | Cline | cline_mcp_settings.json in VS Code globalStorage | | Codex CLI | ~/.codex/config.yaml (under mcp_servers) | | Gemini CLI | ~/.gemini/settings.json (under mcpServers) |

Requires uv. uvx downloads and caches the package on first run. The graph persists to ~/.codesteward/graph.db across sessions.

Docker + Neo4j — persistent graph

# 1. Point the server at your repository
export REPO_PATH=/path/to/your/repository

# 2. Start Neo4j + MCP server
docker compose -f docker-compose.neo4j.yml up -d

# 3. Copy config templates into the repo you want to analyse
cp templates/.mcp.json /path/to/your/repository/
cp templates/CLAUDE.md /path/to/your/repository/

The server runs at http://localhost:3000/sse. Call graph_rebuild() with no arguments — the server already knows the repo path from the volume mount.

Docker + JanusGraph — persistent graph (Apache 2.0)

# 1. Point the server at your repository
export REPO_PATH=/path/to/your/repository

# 2. Start JanusGraph + MCP server
docker compose -f docker-compose.janusgraph.yml up -d

# 3. Copy config templates into the repo you want to analyse
cp templates/.mcp.json /path/to/your/repository/
cp templates/CLAUDE.md /path/to/your/repository/

Same workflow as the Neo4j stack — all named query templates work identically. Raw query passthrough uses Gremlin instead of Cypher.

Manual Docker run

docker run -p 3000:3000 \
  -v /path/to/your/repo:/repos/project:ro \
  -e NEO4J_PASSWORD=secret \
  ghcr.io/codesteward/codesteward-graph:latest

For full setup instructions covering all AI tools, see the [setup guides](docs/setup/).

Installation

# All 14 languages + GraphQLite (recommended for local dev)
uv pip install "codesteward-mcp[graph-all,graphqlite]"

# Core languages only (TypeScript, JavaScript, Python, Java) + GraphQLite
uv pip install "codesteward-mcp[graph,graphqlite]"

# Individual language extras
uv pip install "codesteward-mcp[graph-go,graphqlite]"       # Go
uv pip install "codesteward-mcp[graph-rust,graphqlite]"     # Rust
uv pip install "codesteward-mcp[graph-csharp,graphqlite]"   # C#
uv pip install "codesteward-mcp[graph-kotlin,graphqlite]"   # Kotlin
uv pip install "codesteward-mcp[graph-scala,graphqlite]"    # Scala
uv pip install "codesteward-mcp[graph-c,graphqlite]"        # C
uv pip install "codesteward-mcp[graph-cpp,graphqlite]"      # C++
uv pip install "codesteward-mcp[graph-php,graphqlite]"      # PHP

# Neo4j backend (alternative — requires a running Neo4j 5+ server)
uv pip install "codesteward-mcp[graph-all]"

# JanusGraph backend (alternative — requires a running JanusGraph 1.0+ server)
uv pip install "codesteward-mcp[graph-all,janusgraph]"

Requires Python 3.12+. GraphQLite is the default backend for local development — an embedded SQLite graph database that requires no external services. The graph persists to ~/.codesteward/graph.db across sessions.

Configuration

All settings can be provided via environment variables, a YAML config file, or CLI flags. Priority: CLI flags > env vars > YAML file > defaults.

| Setting | Env var | Default | Description | | ------- | ------- | ------- | ----------- | | Transport | TRANSPORT | sse | sse, http, or stdio | | Host | HOST | 0.0.0.0 | HTTP bind host | | Port | PORT | 3000 | HTTP bind port | | Graph backend | GRAPH_BACKEND | auto | auto, neo4j, janusgraph, or graphqlite. Auto-detects: Neo4j if password set, JanusGraph if URL changed, otherwise GraphQLite | | Neo4j URI | NEO4J_URI | bolt://localhost:7687 | Neo4j connection URI | | Neo4j user | NEO4J_USER | neo4j | Neo4j username | | Neo4j password | NEO4J_PASSWORD | (empty) | Set to enable Neo4j backend | | JanusGraph URL | JANUSGRAPH_URL | ws://localhost:8182/gremlin | Gremlin Server WebSocket URL | | GraphQLite DB path | GRAPHQLITE_DB_PATH | ~/.codesteward/graph.db | SQLite database file path | | Default tenant | DEFAULT_TENANT_ID | local | Tenant namespace | | Default repo | DEFAULT_REPO_ID | (empty) | Repo ID | | Default repo path | DEFAULT_REPO_PATH | /repos/project | Server-side path for graph_rebuild | | Workspace | WORKSPACE_BASE | workspace | Directory for build metadata | | Log level | LOG_LEVEL | INFO | DEBUG / INFO / WARNING / ERROR |

Taint Analysis (optional)

The taint_analysis tool is registered automatically when the codesteward-taint binary is on PATH. Without it the server starts normally and the other four tools are unaffected.

Docker

Pass --build-arg TAINT_VERSION= to download and bundle the binary:

docker build --build-arg TAINT_VERSION=0.1.0 -t codesteward-mcp:taint .

Standalone

Download a pre-built binary from the codesteward-taint releases and place it on PATH:

# macOS (Apple Silicon)
curl -L https://github.com/Codesteward/codesteward-taint/releases/latest/download/codesteward-taint-darwin-arm64 \
     -o /usr/local/bin/codesteward-taint
chmod +x /usr/local/bin/codesteward-taint

Workflow

graph_rebuild          # build the structural graph first
taint_analysis         # trace taint paths; writes TAINT_FLOW edges to Neo4j
codebase_graph_query   # query_type="semantic" to read findings

Graph Model

Nodes — LexicalNode

Every parsed symbol becomes a LexicalNode:

| Property | Description | | -------- | ----------- | | node_id | Stable unique ID: {node_type}:{tenant_id}:{repo_id}:{file}:{name} | | node_type | function, class, method, file, module, external | | name | Symbol name | | file | Repo-relative file path | | line_start / line_end | Source location | | language | Detected language | | tenant_id / repo_id | Multi-tenancy namespace | | confidence | 1.0 for parser-emitted; < 1.0 for agent-inferred |

Edges

| Edge type | Meaning | | --------- | ------- | | CALLS | Function A calls function B (cross-file resolved) | | IMPORTS | File/module imports another | | EXTENDS | Class inherits from another | | GUARDED_BY | Function protected by a decorator/annotation (@login_required, @UseGuards, FastAPI Depends, @PreAuthorize, …) | | PROTECTED_BY | Function protected by router-scope middleware (APIRouter, Express router.use(), Gin group, Actix scope, Laravel route group, ASP.NET MapGroup().RequireAuthorization()) | | DEPENDS_ON | File depends on an external package | | TAINT_FLOW | Untrusted input reaches a dangerous sink (written by codesteward-taint; queryable via semantic) | | calls / guarded_by / taint_flow / … | Agent-inferred edges with confidence < 1.0 via graph_augment |

Development

# Setup
uv venv && source .venv/bin/activate
uv sync --all-packages --extra graph-all

# Run tests
pytest tests/ -v

# Run the server locally
codesteward-mcp --transport sse --port 3000

# Lint + type-check
ruff check src/ tests/
mypy src/

Releases

See [CHANGELOG.md](CHANGELOG.md) for the full history or browse GitHub Releases.

License

Apache License 2.0 — Copyright (c) 2026, bitkaio LLC

Source & license

This open-source MCP server is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: Codesteward
• Source: Codesteward/codesteward-graph
• License: Apache-2.0
• Homepage: https://codesteward.ai/product/graph-server

Install and usage instructions live in the source repository linked above.