The vectro CLI

The vectrojs package installs two commands. vectro serve makes every data file in a folder a table and serves it with serve, servePg and serveFlight, with no code. vectro-mcp is the MCP server for AI assistants. Both need Node 20 or later.

npx vectro serve --root ./data                 # or: npm install -g vectrojs, then vectro serve ...
npx vectro-mcp --root ./data

vectro serve

vectro serve --root <folder> [options]

Every CSV, TSV, JSON-lines, Arrow / Feather and .vectro file directly in the folder becomes a table named after its file (loaded as openTables loads it). HTTP is on by default; PostgreSQL and Flight SQL start when given a port. All of them share one set of tables.

Flag	Default	Meaning
--root <folder>	the current folder	The data folder.
--host <address>	127.0.0.1	The address every server listens on. 0.0.0.0 listens on every network, and then PostgreSQL and Flight SQL need --password.
--quiet	off	No log lines on stderr.

HTTP and OData (Excel, Power BI’s Web connector, Google Sheets, pandas):

Flag	Default	Meaning
--port <n>	$PORT, else 8787	The HTTP port.
--no-http	off	No HTTP server.
--token <secret>	$VECTRO_TOKEN	Requests need Authorization: Bearer <secret> (or Basic with the secret as the password, or &token=).
--cors	off	Allow pages from other sites.

PostgreSQL (Power BI, Tableau, Metabase, Grafana, psql):

Flag	Default	Meaning
--pg <port>	off	Also speak the PostgreSQL protocol on this port (5433 is usual).
--user <name>	any name	The only user name accepted.
--password <secret>	$VECTRO_PG_PASSWORD	The password. Without one, only this machine may connect.
--auth <method>	scram	scram, md5 or password.
--tls-cert <file>, --tls-key <file>	off	Encrypted connections; both are needed.
--database <name>	vectro	The database name reported.
--log-queries	off	Print every statement clients send.

Arrow Flight SQL (pandas, Polars, DuckDB through ADBC):

Flag	Default	Meaning
--flight <port>	off	Also serve Flight SQL on this port (grpc://host:port). Takes --user, --password, --tls-cert, --tls-key, --database and --log-queries as above.

On start it logs each server’s address and the tables with their row counts. POST /reload on the HTTP server reads the folder again. Ctrl-C (SIGINT) or SIGTERM closes the servers and exits. A flag without its value prints the usage and exits with status 2; a failure to start (a port in use, a missing folder, --host 0.0.0.0 with --pg and no password) prints vectro: <reason> and exits with status 1. vectro, vectro help and vectro --help print the usage; any other command prints it and exits with status 2. Unknown flags are ignored.

npx vectro serve --root ~/data --pg 5433 --user me --password secret
curl 'http://127.0.0.1:8787/sql?q=SELECT region, COUNT(*) AS n FROM orders GROUP BY 1&format=csv'
psql -h 127.0.0.1 -p 5433 -U me vectro
npx vectro serve --root ~/data --no-http --flight 31337 --host 0.0.0.0 --password secret

See Serving and BI tools for connecting each tool.

vectro-mcp

vectro-mcp [--root <folder>]

The Model Context Protocol server: it speaks JSON-RPC 2.0 over stdin and stdout (one message per line) with no dependencies, so an assistant such as Claude can load data files and query them with Vectro, locally, on every core. It also runs as node <package>/mcp/server.mjs.

Flag	Default	Meaning
--root <folder>	the current folder	The only folder the assistant may read files from. Paths outside it, through links included, are refused.

It logs to stderr ([vectro-mcp] ready; data folder ...), never to stdout, and exits when stdin closes. Calls are handled one at a time, in order.

# Claude Code
claude mcp add vectro -- npx vectro-mcp --root ~/data

{ "mcpServers": { "vectro": { "command": "npx", "args": ["vectro-mcp", "--root", "/Users/you/data"] } } }

The second is for Claude Desktop’s claude_desktop_config.json. The tools it offers are listed in MCP tools; setup for other clients is in MCP server.