Travsr for VS Code

Graph-native code intelligence. Live call graph, blast radius, and callers — without vector RAG.

Travsr builds a deterministic graph of your codebase on every git commit and exposes it to VS Code via MCP. Instead of guessing from text chunks, it traverses real structure: call edges, import edges, type references.

Features

Live status bar

A real-time indicator in the bottom status bar shows the health of your local Travsr graph.

State	Icon	When
Connecting	spinning sync	Extension just activated
Fresh	graph icon (green)	Graph is up-to-date
Indexing	spinning sync	File saved, re-indexing in progress
Stale	warning (amber)	Daemon returned an empty map
Disconnected	error (red)	Daemon process not running

The status bar polls every 30 seconds. Saving a file triggers an immediate re-query after 2 seconds. Click the item to see the current connection state.

Blast radius code lens

A code lens appears at the top of every .ts, .tsx, .rs, and .py file showing how many files would be affected if this file changed:

🩻 blast: 12 files

Click to open the full affected-file list in a panel. Counts above 99 display as 99+. The lens is omitted when the count is zero or the daemon is unavailable.

Callers and blast radius hover

Hovering over any symbol in a supported file shows an inline card with:

The top 5 callers of that symbol, with … and N more when there are more
The blast radius count for the containing file
Quick links to open the full callers list or blast radius panel

All three features degrade gracefully — if the Travsr daemon is not running, they silently do nothing rather than showing errors.

Requirements

The travsr binary installed and available on your PATH, or path set via the travsr.binaryPath setting.
VS Code 1.85.0 or later.

Install the CLI:

npm install -g travsr

Then initialise your repo:

cd your-repo
travsr init

Extension Settings

Setting	Default	Description
`travsr.binaryPath`	`"travsr"`	Path to the travsr binary. Set to an absolute path if travsr is not on your PATH.

How It Works

The extension spawns travsr mcp --stdio as a child process and communicates over JSON-RPC 2.0 (MCP stdio transport). It calls three MCP tools:

MCP Tool	Used By
`get_repo_map`	Status bar — polled every 30 s
`get_blast_radius(file)`	Code lens + hover card
`get_callers(symbol)`	Hover card callers list

The MCP client multiplexes requests by id over a single stdin/stdout pipe. All network errors surface as empty results so the extension never shows error popups in normal usage.

VS Code Extension Host
  StdioMcpClient  ──stdio──►  travsr mcp --stdio
    │
    ├── StatusBarProvider      (polls get_repo_map every 30 s)
    ├── BlastRadiusCodeLens    (get_blast_radius on file open / save)
    └── CallersHoverProvider   (get_callers + get_blast_radius on hover)

Supported Languages

Language	Status
TypeScript / TSX	Supported
Rust	Supported
Python	Supported
Go	Supported

License

MIT

Travsr