Noirlab Datalab MCP server

@pipeworx/noirlab-datalab

NSF NOIRLab's Astro Data Lab — the DECam, Mayall and Blanco survey catalogues (Legacy Surveys/DECaLS, DES, DELVE, DECaPS, SMASH, NSC) alongside mirrored all-sky catalogues (Gaia DR3, AllWISE, CatWISE, 2MASS, SDSS, DESI), queryable as database tables. Around 130 schemas and tens of billions of rows.

Part of Pipeworx — an MCP gateway connecting AI agents to 1679+ live data sources.

Tools

or one table's columns. Call it first: table names are survey-specific and a guessed name is a query error, not an empty result.

• datalab_tables(schema?, table?, limit?) — list the survey data releases, one release's tables,

one, so a bare query cannot scan a billion-row table unbounded.

• datalab_query(sql, limit?) — run a read-only ADQL SELECT. A TOP n is injected when you omit

sky position, nearest first, with exact angular separation in degrees.

• datalabconesearch(table, ra, dec, radius?, columns?, limit?) — sources within a radius of a

Auth

Keyless — but only through the IVOA TAP endpoint. See the first trap below.

Data sources

Anonymous, and the only door this pack uses.

• — REQUEST=doQuery&LANG=ADQL&FORMAT=csv&QUERY=….

Traps

datalab Python client uses and what the docs lead with, but without a login it answers 401 The provided security token is invalid — and the widely-quoted X-DL-AuthToken: anonymous.0.0.anonaccess answers HTTP 200** with the body Error in query(). Try checking that you are logged in. A 200 carrying a failure is the worst shape a failure can take, and it is why this pack speaks TAP only. Measured 2026-09-17.

• /query/query?sql= is NOT anonymous, despite being the documented front door. It is what the

200 with a VOTable whose single INFO element carries QUERY_STATUS="ERROR". Read as data that is an empty result set. Every response is checked for that element before it is parsed.

• TAP reports every error as HTTP 200. Syntax errors, unknown tables, timeouts: all come back

CONTAINS(POINT('ICRS',ra,dec), CIRCLE('ICRS',…)) parses and is handed to PostgreSQL verbatim, which answers function circle(numeric, numeric, numeric) does not exist. The Q3C functions the backend actually has (q3cradialquery) are rejected by the ADQL parser one layer up. So both obvious cone-search spellings fail. datalabconesearch builds the search from trigonometry both layers accept: an indexable RA/Dec box (RA widened by 1/cos(dec), wrapping at 0h) to narrow the scan, then an exact great-circle distance to trim the box corners off and order by true separation.

• ADQL geometry is not implemented, and neither is Q3C.

Galactic plane selectively, so a northern target legitimately returns nothing from lsdr10 or desdr2. The zero-result note says to re-check against gaiadr3.gaiasource, which is all-sky.

• Row limits are SELECT TOP n, not LIMIT n. ADQL, not PostgreSQL.
• Zero rows is usually footprint, not absence. The DECam surveys cover the southern sky and the

Quick Start

Add to your MCP client (Claude Desktop, Cursor, Windsurf, etc.):

{
  "mcpServers": {
    "noirlab-datalab": {
      "url": "https://gateway.pipeworx.io/noirlab-datalab/mcp"
    }
  }
}

What this endpoint actually serves

tools/list at https://gateway.pipeworx.io/noirlab-datalab/mcp returns the tools in the table above plus the shared Pipeworx meta-tools — askpipeworx, discovertools, search_within, remember/recall and the rest of the gateway-wide set. So the tool count you see is larger than this table: a single-pack endpoint currently lists roughly 30 shared tools alongside the pack's own. The connection's initialize response states its exact scope, and is the authoritative answer for a given day.

Shortened. The full README is on GitHub.