MCP server Synaptic

Synaptic

Give your coding assistant a map of the codebase, not a pile of files.

Synaptic maps a repository once so you and your coding assistant do not have to rediscover it every session. Ask how a system works, what depends on a symbol, or what a change may break. The answers come from a persistent, source-grounded knowledge graph, available from the CLI or through MCP. Synaptic can also remember past changes and plan small, reviewable API and dependency repairs.

Code extraction is local and deterministic. Synaptic ships as a single Rust binary with no runtime, database, account, or API key required.

Documentation | Quickstart | Benchmarks | Discord

Get started

Install the latest checksummed release:

# macOS / Linux
curl --proto '=https' --tlsv1.2 -LsSf https://raw.githubusercontent.com/ColinVaughn/Synaptic/main/install.sh | sh

# Windows PowerShell
irm https://raw.githubusercontent.com/ColinVaughn/Synaptic/main/install.ps1 | iex

Then run Synaptic from a repository:

synaptic extract .                         # build synaptic-out/graph.json
synaptic query "how does authentication work?"
synaptic affected parse_config             # what could this change break?

Extraction honors .gitignore and .synapticignore, skips common secret files, and stays offline unless you explicitly enable a network-backed feature.

Connect your coding assistant

synaptic install claude                    # Claude Code
synaptic install codex                     # Codex CLI
synaptic install codex --global            # Codex desktop app

Claude and Codex load only a small set of tools at startup, then find the rest on demand. This keeps prompts smaller without hiding capabilities. Gemini, Cursor, Copilot, OpenCode, Kilo, and generic AGENTS.md clients are supported too. See Assistant Integration.

What it does

Need	What Synaptic provides
Understand the code	Symbols, calls, imports, inheritance, resources, SQL, and cross-language boundaries in one graph
Find impact	Callers, references, reverse dependencies, dynamic-dispatch hazards, and affected tests
Change code safely	Change forecasts, refactor plans, architecture diffs, and optional verification in an isolated worktree
Remember the past	Source-linked history from commits, decisions, incidents, reviews, CI, and previous attempts
Maintain dependencies	API contract tracking and vulnerability evidence with small, reviewable repair workflows

Synaptic supports dozens of languages, incremental updates, multi-repository federation, structural search, SQL auditing, graph-aware PR review, and exports for GraphML, Cypher, Graphviz, Obsidian, and Markdown. Detailed capabilities live in the documentation, keeping this page focused on getting started.

See the architecture

synaptic chart

This creates a self-contained architecture map from the graph. Open a subsystem, select a symbol, and follow its real incoming and outgoing relationships without a server.

Built to save context

Synaptic returns the relevant slice of a graph instead of loading whole source files into an assistant's context. In the checked-in token benchmark, full graph answers used 27-38x fewer tokens than reading the source files referenced by those answers. That is a context-compression measurement, not a promise about total task cost. The methodology and raw results are in BENCHMARKS.md.

Common commands

Command	Purpose
synaptic extract .	Build the graph
synaptic update / synaptic watch	Keep it current
synaptic query "..."	Find the relevant subgraph for a question
synaptic affected <symbol>	Trace reverse impact
synaptic predict <files>	Forecast risk and select tests
synaptic speculate <files>	Verify a change in a throwaway worktree
synaptic memory search "..."	Find relevant repository history
synaptic serve	Run the MCP server

Run synaptic <command> --help for flags or use the complete command reference.

Pick a workflow

• CLI: the fastest path for local extraction, queries, automation, and MCP.
• Desktop: run synaptic-ui for visual repository setup, federation, assistant connection, updates, and the complete command catalog.
• Hosted: Synaptic Cloud provides a managed MCP service. See the GitHub automation guide for commit-triggered graph sync and verified repair workflows.

Update a release installation with synaptic self-update.

Documentation

• Installation and Quickstart
• Querying, languages, and output formats
• MCP server and assistant integration
• Repository memory, API maintenance, and vulnerability management
• Workspaces and federation, configuration, and development

Build from source

The repository pins Rust 1.97.1.

cargo install --path bin/synaptic
cargo install --path bin/synaptic-ui       # optional desktop app

For development and architecture notes, see the development guide.

Community and license

Questions, ideas, or something you built? Join the Discord community.

Synaptic is licensed under AGPL-3.0-or-later; see LICENSE and NOTICE. If you modify Synaptic and make it available over a network, you must offer those users the corresponding source. The separately maintained Synaptic Cloud service is proprietary and is not covered by this repository's license.