Synapse

Work in progress. Synapse is under active development. APIs, CLI commands, and graph schema may change without notice.

Synapse is an LSP-powered, FalkorDB-backed tool that builds a queryable graph of a C# codebase. It indexes symbols, inheritance, interface implementations, method calls, and override relationships, then exposes them via an MCP server (for AI assistants) and a CLI (for humans).

Prerequisites

• Python 3.11+
• FalkorDB running on localhost:6379 (default)
• .NET SDK — required for the C# language server to index projects

Start FalkorDB with Docker:

docker run -p 6379:6379 --rm falkordb/falkordb:latest

Installation

pip install -e .

This installs two entry points:

• synapse — CLI
• synapse-mcp — MCP server

MCP Server Setup

Add Synapse to your MCP client config (e.g. Claude Desktop's claude_desktop_config.json):

{
  "mcpServers": {
    "synapse": {
      "command": "synapse-mcp"
    }
  }
}

By default the server connects to FalkorDB at localhost:6379. There are no required environment variables.

---

CLI

synapse <command> [args]

Project management

Command	Description
synapse index <path> [--language csharp]	Index a project into the graph
synapse watch <path>	Watch a project for file changes and keep the graph updated (runs until Ctrl+C)
synapse delete <path>	Remove a project and all its graph data
synapse status [path]	Show index status for one project, or list all indexed projects

Graph queries

Command	Description
synapse symbol <full_name>	Get a symbol's node and its relationships
synapse source <full_name> [--include-class]	Print the source code of a symbol
synapse callers <method_full_name>	Find all methods that call a given method
synapse callees <method_full_name>	Find all methods called by a given method
synapse implementations <interface_name>	Find all concrete implementations of an interface
synapse hierarchy <class_name>	Show the full inheritance chain for a class
synapse search <query> [--kind <kind>]	Search symbols by name, optionally filtered by kind (e.g. method, class)
synapse type-refs <full_name>	Find all symbols that reference a given type
synapse dependencies <full_name>	Find all types referenced by a given symbol
synapse context <full_name>	Get the full context needed to understand or modify a symbol
synapse query <cypher>	Execute a raw read-only Cypher query against the graph

Summaries

Summaries are free-text annotations attached to any symbol — useful for capturing architectural context that the graph alone doesn't convey.

Command	Description
synapse summary get <full_name>	Get the summary for a symbol
synapse summary set <full_name> <content>	Set the summary for a symbol
synapse summary list [--project <path>]	List all symbols that have summaries

Examples

# Index a C# project
synapse index /path/to/my/project

# Find everything that calls a specific method
synapse callers "MyNamespace.MyClass.DoWork"

# Find all classes that implement an interface
synapse implementations "IOrderService"

# See the inheritance hierarchy of a class
synapse hierarchy "MyNamespace.BaseController"

# Search for all methods containing "Payment"
synapse search "Payment" --kind method

# Get the source code for a method
synapse source "MyNamespace.MyClass.DoWork"

# Get all context needed to understand a symbol
synapse context "MyNamespace.MyClass"

# Watch for live updates while developing
synapse watch /path/to/my/project

---

MCP Tools

These tools are available to any MCP client connected to synapse-mcp.

Project management

Tool	Parameters	Description
index_project	path: str, language: str = "csharp"	Index a project into the graph
list_projects	—	List all indexed projects
delete_project	path: str	Remove a project from the graph
get_index_status	path: str	Get the current index status for a project
watch_project	path: str	Start watching a project for file changes
unwatch_project	path: str	Stop watching a project

Graph queries

Tool	Parameters	Description
get_symbol	full_name: str	Get a symbol's node and relationships by fully-qualified name
get_symbol_source	full_name: str, include_class_signature: bool = False	Get the source code of a symbol
find_implementations	interface_name: str	Find all concrete implementations of an interface
find_callers	method_full_name: str	Find all methods that call a given method
find_callees	method_full_name: str	Find all methods called by a given method
get_hierarchy	class_name: str	Get the full inheritance chain for a class
search_symbols	query: str, kind: str | None = None	Search symbols by name, optionally filtered by kind
find_type_references	full_name: str	Find all symbols that reference a given type
find_dependencies	full_name: str	Find all types referenced by a given symbol
get_context_for	full_name: str	Get the full context needed to understand or modify a symbol
execute_query	cypher: str	Execute a read-only Cypher query (mutating statements are blocked)

Summaries

Tool	Parameters	Description
set_summary	full_name: str, content: str	Attach a summary to a symbol
get_summary	full_name: str	Retrieve the summary for a symbol
list_summarized	project_path: str | None = None	List all symbols that have summaries, optionally scoped to a project

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Graph model

Node labels

Structural nodes (identified by path):

• :Repository — the indexed project root
• :Directory — a directory within the project
• :File — a source file

Symbol nodes (identified by full_name):

• :Package — a namespace or package
• :Class — classes, abstract classes, enums, and records (distinguished by the kind property)
• :Interface — interfaces
• :Method — methods (with signature, is_abstract, is_static, line properties)
• :Property — properties (with type_name)
• :Field — fields (with type_name)

A :Summarized label is added to any node that has a user-attached summary.

Relationships

• CONTAINS — structural containment: Repository→Directory, Directory→File, File→Symbol, and Class/Package→nested symbols
• IMPORTS — file imports a package/namespace
• CALLS — method calls another method
• OVERRIDES — method overrides a base method
• IMPLEMENTS — class implements an interface
• INHERITS — class inherits from another class, or interface extends another interface

Fully-qualified names (e.g. MyNamespace.MyClass.DoWork) are used as symbol identifiers throughout.

---

Development

python -m venv .venv
source .venv/bin/activate
pip install -e ".[dev]"

# Run unit tests (no FalkorDB or .NET required)
pytest tests/unit/

# Run integration tests (requires FalkorDB on localhost:6379 and .NET SDK)
pytest tests/integration/ -m integration