io.github.n24q02m/better-code-review-graph MCP Server

Better Code Review Graph

mcp-name: io.github.n24q02m/better-code-review-graph

Knowledge graph for token-efficient code reviews -- semantic search and call-graph resolution across your codebase.

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Project	Tagline	Tag
agent-chat-plugin	Peer AI agents chat in a shared folder — no human relay, no orchestrator, wor...	Tooling
better-code-review-graph	Knowledge graph for token-efficient code reviews -- semantic search and call-...	MCP
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better-godot-mcp	Composite MCP server for Godot Engine -- 17 composite tools for AI-assisted g...	MCP
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better-semantic-release	Drop-in python-semantic-release fork with built-in release-safety guards (orp...	Tooling
better-telegram-mcp	Telegram for AI agents -- messages, chats, media, and contacts across both bo...	MCP
better-workspace-mcp	Google Workspace MCP server (Docs/Drive/Calendar/Gmail/Sheets/Slides/Tasks/Ch...	MCP
claude-plugins	Claude Code plugin marketplace for the n24q02m MCP servers -- install web sea...	Marketplace
imagine-mcp	Image and video understanding + generation for AI agents -- across Gemini, Op...	MCP
jules-task-archiver	Chrome Extension for bulk operations on Jules tasks via batchexecute API -- a...	Tooling
mcp-core	Shared foundation for building MCP servers -- Streamable HTTP transport, OAut...	MCP
mnemo-mcp	Persistent AI memory with hybrid search and embedded sync. Open, free, unlimi...	MCP
fastretrieval	Fast multi-model retrieval runtime for ONNX and GGUF embeddings, reranking, and model contracts	Library
skret	Secrets without the server.	CLI
tacet	A self-distilling neuro-symbolic cascade that amortises LLM cost across knowl...	Tooling
web-core	Shared web infrastructure package for search, scraping, HTTP security, and st...	Library
wet-mcp	Open-source MCP server for AI agents: web search, content extraction, and lib...	MCP

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An MCP server that parses your codebase with Tree-sitter, builds a structural graph of functions/classes/imports, and gives Claude (or any MCP client) precise context so it reads only what matters instead of the whole tree. Semantic search runs through the local ONNX model registry from fastretrieval by default (zero config, no API key), with an optional cloud embedding chain. Fork of code-review-graph with fixed multi-word search, qualified call resolution, dual-mode embeddings, output pagination, and production CI/CD.

v2.0 migration (BREAKING)

v2.0 adds temporal columns (valid_from_sha / valid_to_sha on every node + edge) and an opt-in security scanner. The schema migration is auto-applied on first GraphStore open, and a backup of the pre-2.0 DB is saved to <graph_db>.pre-2.0.bak so you can roll back. See BREAKING_CHANGES.md for the full schema-change list, behavior changes, environment requirements, and the downgrade procedure (CRG_DOWNGRADE_TO_1_X=1 uv run better-code-review-graph).

Table of contents

• v2.0 migration (BREAKING)
• Install
• Smithery
• Configuration
• Tools
• CLI
• Features
• Comparison
• Security
• Build from source
• Trust model
• Migration & changelog
• Documentation
• License

Install

The server runs over stdio by default and works with any MCP client. The recommended launcher is uvx (no install step -- it fetches and runs the published package in an isolated environment):

{
  "mcpServers": {
    "better-code-review-graph": {
      "command": "uvx",
      "args": ["--python", "3.13", "better-code-review-graph"],
      "env": { "MCP_TRANSPORT": "stdio" }
    }
  }
}

Or install it as a Python package:

uvx better-code-review-graph        # run without installing
pip install better-code-review-graph

The optional Semgrep engine for deeper security scans is a separate extra:

pip install 'better-code-review-graph[security]'

Install with an AI agent -- paste this to your AI coding agent:

Install MCP server better-code-review-graph following the steps at https://raw.githubusercontent.com/n24q02m/claude-plugins/main/plugins/better-code-review-graph/setup-with-agent.md

Full per-client setup (Claude Code, Codex, Gemini CLI, Cursor, Windsurf, raw mcp.json) is at mcp.n24q02m.com/servers/better-code-review-graph/setup/.

Smithery

The repo ships a smithery.yaml so the server can be built and run through Smithery. It deploys over stdio and needs no startup configuration -- the config schema is empty, and any optional cloud embedding/summary keys are supplied at runtime through the server's own config flow (see Configuration below). The launch command is the same uvx invocation as a local install:

startCommand:
  type: stdio
  commandFunction: |-
    (config) => ({ command: 'uvx', args: ['--python', '3.13', 'better-code-review-graph'] })

Configuration

Everything works out of the box with zero configuration -- semantic search uses the local ONNX registry from fastretrieval (Qwen3-Embedding-0.6B is the current built-in reference entry, ~570 MB downloaded on first graph embed). This reference entry is not a Qwen-only boundary: any built-in registry ID or valid non-Qwen artifact manifest follows the same resolver. All environment variables below are optional and only needed for cloud embeddings, LLM summaries, or an explicit BYO local artifact.

Model chains

Embeddings and summaries are each driven by an ordered model chain -- a CSV of provider/model entries where the order is the litellm fallback order (first entry is the active model). The provider is inferred from the model prefix, so the matching <PROVIDER>_API_KEY is all you need to add.

Variable	Purpose	Empty (default)
EMBEDDING_MODELS	Cloud embedding chain, e.g. jina_ai/jina-embeddings-v5-text-small,gemini/gemini-embedding-001	Local fastretrieval registry
SUMMARY_MODELS	Summarizer chain for graph(action="summarize"), e.g. gemini/gemini-2.5-flash,openai/gpt-4o-mini	Summaries disabled

All vectors are stored at a fixed 768 dimensions (MRL truncation), so the embeddings table schema stays valid across providers. Switching embedding model changes the vector space; embeddings are tracked per provider and a provider switch triggers re-embedding rather than mixing incomparable vectors.

Provider API keys

Cloud models need the provider key for whatever prefixes appear in your chains. Without any cloud key the server stays on local ONNX. Summarizers must expose a chat-completion API (so Jina and Cohere are embedding-only).

Model prefix	API key env var	Get a key
jina_ai/	JINA_AI_API_KEY	https://jina.ai/api-key
gemini/	GEMINI_API_KEY (or GOOGLE_API_KEY)	https://aistudio.google.com/apikey
openai/ (or bare text-embedding-*)	OPENAI_API_KEY	https://platform.openai.com/api-keys
cohere/	COHERE_API_KEY	https://dashboard.cohere.com/api-keys
vertex_express/	GOOGLE_VERTEX_EXPRESS_API_KEY	https://cloud.google.com/vertex-ai/generative-ai/docs/start/express-mode/overview

Any other litellm provider works via its standard <PROVIDER>_API_KEY.

Advanced

Variable	Purpose
EMBEDDING_API_BASE	Custom OpenAI-compatible base URL for cloud embedding (SSRF-guarded)
LLM_API_BASE	Custom OpenAI-compatible base URL for the summarizer (SSRF-guarded)
DISABLE_LOCAL_EMBED	Skip the local ONNX download; embedding is unavailable unless a cloud chain is configured
LOCAL_EMBEDDING_MODEL	Built-in fastretrieval model ID, or a local directory containing fastretrieval-manifest.json
LOCAL_EMBEDDING_DIM	Required dimension for an external model ID without a manifest
LOCAL_EMBEDDING_MODEL_FILE	ONNX file path inside a manifest-backed artifact directory
LOCAL_EMBEDDING_POOLING	Explicit pooling for an external ID without a manifest: CLS, MEAN, LAST_TOKEN, or DISABLED
LOCAL_EMBEDDING_NORMALIZE	Explicit L2 normalization for an external ID without a manifest
CRG_DATA_DIR	Override the per-user data directory (default ~/.crg) used for per-user graphs and credentials in HTTP multi-user mode
EMBEDDING_BACKEND / EMBEDDING_MODEL / SUMMARY_MODEL	Deprecated singular vars, honored one release with a warning -- migrate to the *_MODELS chains

CRG intentionally exposes no local reranker settings because this server has no local reranker path. A custom external embedding ID without a manifest must provide LOCAL_EMBEDDING_DIM; a local artifact directory must provide a valid fastretrieval-manifest.json, otherwise startup fails closed.

Example -- cloud embeddings + summaries

{
  "mcpServers": {
    "better-code-review-graph": {
      "command": "uvx",
      "args": ["--python", "3.13", "better-code-review-graph"],
      "env": {
        "MCP_TRANSPORT": "stdio",
        "EMBEDDING_MODELS": "jina_ai/jina-embeddings-v5-text-small,gemini/gemini-embedding-001",
        "SUMMARY_MODELS": "gemini/gemini-2.5-flash",
        "JINA_AI_API_KEY": "jina_...",
        "GEMINI_API_KEY": "AIza..."
      }
    }
  }
}

You can also configure cloud keys interactively in HTTP mode via the relay setup form (config(action="setup_start") returns the browser URL). See the modes overview and multi-user setup.

Workspace username (HTTP setup form)

The relay setup form has an optional workspace username field. Entering the same username always lands you in the same per-sub bucket, so your keys and graph stay reachable across a re-authorization and across devices, instead of being tied to the one-off subject minted for each /authorize round-trip. Leaving it blank keeps the previous per-authorize behaviour.

Trust boundary: when the form is gated by a shared MCP_RELAY_PASSWORD, the username is a partition key, not a secret -- anyone who knows that password can type any username and reach that bucket. That is fine for a trusted group; an untrusted multi-tenant deployment needs a per-user secret or delegated OAuth instead.

One-time migration: existing users must re-enter their credentials once after this change. Nothing is deleted; credentials stored under the old random subject are simply no longer addressed.

Tools

Seven tools, each grouping related actions to keep the tool surface small.

graph -- Graph lifecycle

Actions: build | update | stats | embed | export | summarize

Action	Description
build	Full or incremental graph build. Set full_rebuild=true to re-parse all files; pass roots to federate extra repo directories into one graph.
update	Alias for build with full_rebuild=false (incremental).
stats	Graph size, languages, node/edge breakdown, embedding count.
embed	Compute vector embeddings for semantic search. Dual-mode: local ONNX or cloud chain.
export	Export the graph as graphml / json-ld / dot / cypher. Inline or to output_path.
summarize	LLM-generated one-paragraph docstrings for Function nodes (via the SUMMARY_MODELS chain; no-op when no provider key is set). Cost-capped via max_nodes.

query -- Graph queries

Actions: query | search | impact | large_functions | spot_check | renamed_in_diff | diff

Action	Description
query	Predefined patterns: callers_of, callees_of, imports_of, importers_of, children_of, tests_for, inheritors_of, file_summary.
search	Search code entities by name/keyword or semantic similarity.
impact	Blast radius of changed files. Auto-detects from git diff. Paginated with max_results.
large_functions	Find functions/classes exceeding a line-count threshold.
spot_check	Random callsite snippets from the last callers_of/callees_of/inheritors_of/importers_of result.
renamed_in_diff	Symbols whose callsite line shifted versus a base ref.
diff	Nodes added/removed/modified between two commit SHAs (from_sha, to_sha).

Most read actions accept as_of=<sha> for temporal (point-in-time) snapshots and repo=<repo_id> to scope a federated multi-repo graph.

review -- Code review context

Actions: context (default) | delta

Token-optimized review context with structural summary, impacted nodes, source snippets, and review guidance. context auto-detects changed files from the git diff; delta (with from_sha/to_sha, optional show_line_shifts) surfaces refactor moves between two commits.

config -- Server configuration and credential setup

Actions: status | set | cache_clear | setup_status | setup_start | setup_skip | setup_reset | setup_complete

Action	Description
status	Server info: version, graph path, node/edge counts, embedding backend, embeddings count.
set	Update a runtime setting (key=log_level).
cache_clear	Remove all computed embeddings.
setup_status	Show current credential state, providers configured, and setup URL.
setup_start	Start relay setup to configure API keys via browser (HTTP mode).
setup_skip	Set local mode (skip relay permanently, use ONNX only).
setup_reset	Clear credentials and reset state.
setup_complete	Re-resolve credentials from environment variables.

security -- Security scanning

Actions: scan | report | suppress | rule_list

Action	Description
scan	Run a security scan (engine='heuristic' default = 5 regex rules, or 'semgrep'). Findings persist on nodes.security_tags.
report	Re-emit cached findings as JSON (format='json') or SARIF v2.1.0 (format='sarif').
suppress	Suppress a finding by rule_id (or remove=true to un-suppress).
rule_list	List available rules for an engine.

The semgrep engine requires the [security] extra and runs Semgrep's p/auto registry pack plus a 3-rule curated overlay.

help -- Full documentation

Topics: graph | query | review | config | security | recipes

Returns complete documentation for each tool. Use when the compressed descriptions above are insufficient.

config__open_relay -- Re-trigger the relay setup form

Registered automatically from mcp-core. In HTTP mode it returns <PUBLIC_URL>/authorize so the agent can re-open the browser setup form (e.g. after credential expiry); in stdio mode it returns status: 'stdio_unsupported'.

CLI

Running better-code-review-graph with no arguments starts the MCP server over stdio (this is what an MCP client launches). A leading positional argument routes to a subcommand instead -- handy for building or embedding the graph directly from a shell or CI step, before any MCP client connects. Run these with uvx (or uv run from a source checkout):

# Start the MCP server over stdio (default -- no subcommand)
uvx better-code-review-graph

# Build (or incrementally update) the graph for the current repo
uvx better-code-review-graph graph build

# Full re-parse of every file instead of a git-diff incremental
uvx better-code-review-graph graph build --full-rebuild

# Compute embeddings for semantic search (local ONNX by default)
uvx better-code-review-graph graph embed

Command	Description
graph build	Full or incremental graph build. --full-rebuild re-parses every file; --base <ref> sets the git ref for the incremental diff (default HEAD~1); --repo-root <path> overrides the auto-detected repo root.
graph embed	Compute vector embeddings for the current graph (local ONNX or the configured cloud chain). Accepts --repo-root.
config status / config delete	Show or remove the stored credential config (--yes skips the delete confirmation).
doctor	Environment self-check: Python version, credential backend, store-dir writability, config and relay state.
relay status / relay open / relay reset	Inspect, open, or clear the browser relay setup session (HTTP mode).

The graph build and graph embed subcommands print a JSON result and exit non-zero on error. The config, doctor, and relay subcommands come from the shared mcp-core CLI.

Features

What this fork fixes versus the upstream code-review-graph:

Feature	code-review-graph	better-code-review-graph
Multi-word search	Broken (literal substring)	AND-logic word splitting
callers_of/callees_of	Empty results (bare name targets)	Qualified name resolution + bare fallback
Embedding	sentence-transformers + torch (1.1 GB)	fastretrieval ONNX + cloud (200 MB), dual-mode
Output size	Unbounded (500K+ chars)	Paginated (max_results, truncated flag)
Tool design	9 individual tools	7 grouped tools: graph + query + review + config + security + help + config__open_relay
Plugin hooks	Invalid PostEdit/PostGit	Valid PostToolUse

Comparison

How better-code-review-graph stacks up against direct competitors in each pillar:

Capability	better-code-review-graph	Greptile	Sourcegraph (Cody / MCP)	CodeGraph (colbymchenry)
Codebase knowledge graph	Yes (Tree-sitter, 14 langs, SQLite)	Yes (functions/classes/deps)	Yes (precise code indexing)	Yes (Tree-sitter, 20+ langs, SQLite)
Persistent incremental updates	Yes (git-diff + file-hash re-parse)	?	Yes (continuous indexing)	Yes (OS file-watcher debounced)
Qualified call resolution (callers/callees)	Yes (same-file bare-call resolution + fallback)	?	Yes (go-to-def / find-references)	Yes (callers / callees / impact)
Semantic search / embeddings	Yes (fastretrieval local registry + cloud Jina/Gemini/OpenAI/Cohere)	?	Yes (semantic + keyword + regex)	No (FTS5 full-text only)
Token-optimized review context	Yes (review tool, git-diff scoped)	Yes (PR review comments)	No (code-context assistant)	No (context layer, not review)
Security scanning	Yes (Semgrep p/auto + 3-rule overlay, SARIF)	?	?	No
Self-hostable	Yes (stdio default, machine-bound)	Yes (Docker / K8s / air-gapped)	Yes (self-hosted instance)	Yes (100% local, no API keys)
Free / open source	Yes (Apache-2.0)	No (proprietary SaaS; free OSS tier)	No (Enterprise license, source private)	Yes (MIT)

Sources: Greptile · Greptile pricing · Sourcegraph MCP · CodeGraph. Cells marked ? are capabilities the competitor does not publicly document, not confirmed absences.

Security

• Graceful fallbacks -- Cloud embedding failure falls back to local ONNX.
• Error handling -- Tools return error strings with fix suggestions, never crash.
• Read-only mount -- Docker mode mounts the repo as :ro (read-only).
• SSRF-guarded endpoints -- Custom EMBEDDING_API_BASE / LLM_API_BASE URLs are validated before any outbound call.

To report a vulnerability, see SECURITY.md.

Build from source

git clone https://github.com/n24q02m/better-code-review-graph
cd better-code-review-graph
uv sync --group dev
uv run pytest
uv run better-code-review-graph

Requirements: Python 3.13, uv.

Trust model

This plugin implements TC-Local (machine-bound, single trust principal). See the mcp-core trust model for full classification.

Mode	Graph DB	Cloud credentials	Who can read your data?
stdio (default)	<repo>/.code-review-graph/graph.db (git-ignored)	~/.better-code-review-graph-mcp/config.json (AES-GCM, machine-bound key)	Only your OS user
HTTP self-host (multi-user)	Per-user ~/.crg/subs/<sub>/graph.db	Per-user ~/.crg/subs/<sub>/config.json	Only the authenticated user

Migration & changelog

The v2.0 release added temporal columns (valid_from_sha / valid_to_sha on every node and edge) plus an opt-in security scanner. The schema migration is auto-applied on first GraphStore open, and a backup of the pre-2.0 DB is written to <graph_db>.pre-2.0.bak. To downgrade and restore it:

CRG_DOWNGRADE_TO_1_X=1 uvx better-code-review-graph

Full schema-change list, behavior changes, and rollback procedure: BREAKING_CHANGES.md. Release-by-release history: CHANGELOG.md.

Documentation

Full docs at mcp.n24q02m.com/servers/better-code-review-graph/setup/:

• Setup -- install methods for Claude Code, Codex, Gemini CLI, Cursor, Windsurf, mcp.json
• Modes overview -- stdio / local-relay / remote-relay / remote-oauth
• Multi-user setup -- per-JWT-sub credential model

Use the help tool from any MCP client for inline per-tool reference.

License

Apache-2.0 -- See LICENSE.