GraceDB
LIGO/Virgo/KAGRA gravitational-wave alerts from GraceDB, plus public strain from GWOSC.
Install
Add this to your client's MCP configuration (Claude Desktop: claude_desktop_config.json; Cursor: .cursor/mcp.json; VS Code and others use the same "mcpServers" shape).
gracedb-mcpclaude mcp add gracedb -e 'GRACEDB_FORCE_NOAUTH=true' -e 'GRACEDB_SERVICE_URL=https://gracedb.ligo.org/api/' -e 'GRACEDB_MCP_DATA_DIR=~/.cache/gracedb-mcp' -- uvx gracedb-mcp==0.2.0
{
"mcpServers": {
"gracedb": {
"command": "uvx",
"args": [
"gracedb-mcp==0.2.0"
],
"env": {
"GRACEDB_FORCE_NOAUTH": "true",
"GRACEDB_SERVICE_URL": "https://gracedb.ligo.org/api/",
"GRACEDB_MCP_DATA_DIR": "~/.cache/gracedb-mcp"
}
}
}
}
Environment variables
GRACEDB_FORCE_NOAUTHSet to true for anonymous access to public superevents.GRACEDB_SERVICE_URLGraceDB API base URL (production or playground).GRACEDB_MCP_DATA_DIRDirectory for downloaded files.
ghcr.io/izabelamaria24/gracedb-mcp:0.2.0claude mcp add gracedb -e 'GRACEDB_FORCE_NOAUTH=true' -e 'GRACEDB_SERVICE_URL=https://gracedb.ligo.org/api/' -- docker run -i --rm ghcr.io/izabelamaria24/gracedb-mcp:0.2.0
{
"mcpServers": {
"gracedb": {
"command": "docker",
"args": [
"run",
"-i",
"--rm",
"ghcr.io/izabelamaria24/gracedb-mcp:0.2.0"
],
"env": {
"GRACEDB_FORCE_NOAUTH": "true",
"GRACEDB_SERVICE_URL": "https://gracedb.ligo.org/api/"
}
}
}
}
Environment variables
GRACEDB_FORCE_NOAUTHSet to true for anonymous access to public superevents.GRACEDB_SERVICE_URLGraceDB API base URL (production or playground).
Documentation
From the project's README on GitHub, refreshed weekly. Links open on GitHub.
Contents
GraceDB MCP Server
An open-source Model Context Protocol (MCP) server that
exposes LIGO/Virgo/KAGRA gravitational-wave alerts from
GraceDB to LLM agents. It bridges the official
ligo-gracedb client with the MCP standard so an
agent can query, classify, and fetch data for gravitational-wave candidate events.
Intended as the data-ingestion layer for a downstream signal-processing / anomaly-detection pipeline (e.g. isolating astrophysical "chirps" from instrumental glitches).
Tools
| Tool | What it does |
|---|---|
search_superevents | Search recent superevents by time window and significance (FAR / astrophysical probability). |
get_event_metadata | Full superevent record + source classification (BBH / BNS / NSBH / Terrestrial). |
download_event_files | Download GraceDB artifacts: skymaps, p_astro.json, PE results, logs. |
download_strain_data | Fetch public strain time series from GWOSC around the event GPS time. |
utc_to_gps | Convert an ISO-8601 UTC timestamp to GPS seconds. |
search_catalog_events | Search published GWOSC catalogue events (GWTC-1 to GWTC-5) by masses, distance, SNR, p_astro. |
get_catalog_event | Source parameters with 90% intervals for one event, by GW name or GraceDB id. |
get_event_labels | GraceDB labels (data quality, review, retraction, products ready) explained in plain English. |
check_data_availability | Which detectors have public GWOSC strain for an event or GPS span, before you download. |
⚠️ Important: where strain data actually comes from
GraceDB does not host raw strain data. It stores event artifacts (skymaps, classifications,
parameter-estimation results). The public strain time series lives at
GWOSC and is fetched by GPS time via gwpy. Public strain is only
available for released observing runs — fresh low-latency alerts will not have public strain
yet. download_strain_data reflects this: it reads t_0 from GraceDB, then pulls open data from
GWOSC (and cleanly reports when data isn't public).
Requirements
- Python 3.10+
mcp,ligo-gracedb,gwosc,python-dotenv- Optional:
gwpy(fordownload_strain_dataandutc_to_gps) — installed via thestrainextra.
Install
Run straight from PyPI with uv:
uvx --from "gracedb-mcp[strain]" gracedb-mcp
Or from source:
git clone https://github.com/izabelamaria24/gracedb-mcp.git
cd gracedb-mcp
python -m venv .venv && source .venv/bin/activate
pip install -e ".[strain]" # omit [strain] if you don't need strain download
Configuration
Copy .env.example to .env and adjust. Anonymous access is enough for public superevents:
cp .env.example .env
| Variable | Purpose |
|---|---|
GRACEDB_SERVICE_URL | API base URL (production or playground). |
GRACEDB_FORCE_NOAUTH | true for anonymous public access. |
GRACEDB_PROXY / GRACEDB_CERT + GRACEDB_KEY | LVK member authentication (X.509). |
GRACEDB_MCP_DATA_DIR | Where downloaded files are written (default ~/.cache/gracedb-mcp; /data in Docker). |
Run locally
gracedb-mcp # speaks MCP JSON-RPC over stdio
Development
Requires Python 3.11+ (the mcp 2.x SDK needs 3.10+).
pip install -e ".[dev]"
pytest -q # tests mock the GraceDB client, no network needed
Run with Docker
A prebuilt image (linux/amd64 and arm64) is published to GHCR:
docker run --rm -i -v gracedb-data:/data ghcr.io/izabelamaria24/gracedb-mcp:latest
| Tag | Download | Contents |
|---|---|---|
latest, X.Y.Z | ~165 MB | Everything, including strain download (gwpy). |
latest-slim, X.Y.Z-slim | ~60 MB | All tools except download_strain_data and utc_to_gps. |
Or build it yourself (add --build-arg EXTRAS= for the slim variant):
docker build -t gracedb-mcp .
docker run --rm -i -v gracedb-data:/data gracedb-mcp
Connect to an MCP client
Claude Desktop / VS Code (mcp.json)
Add to your MCP client configuration:
{
"mcpServers": {
"gracedb": {
"command": "gracedb-mcp",
"env": {
"GRACEDB_FORCE_NOAUTH": "true",
"GRACEDB_MCP_DATA_DIR": "./data"
}
}
}
}
Or run the container directly:
{
"mcpServers": {
"gracedb": {
"command": "docker",
"args": ["run", "--rm", "-i", "-v", "gracedb-data:/data", "ghcr.io/izabelamaria24/gracedb-mcp:latest"]
}
}
}
Example agent prompts
- "Search for superevents from 2023-05-01 to 2023-06-01 with a FAR below 1e-8."
- "What's the source classification for S230518h? Is it more likely a BBH or an NSBH?"
- "Download the skymap and p_astro file for S230518h."
- "Fetch H1 and L1 strain around GW150914."
- "What are the masses of GW190814, and how certain are they?"
- "List GWTC-3 events with total mass under 10 solar masses."
- "Was S190814bv checked by a human? What do its labels mean?"
- "Is there public strain for GW190814 from every detector?"
RL environment (experimental)
gw_rl is a Gymnasium environment built on strain fetched by this server. Each episode shows the
agent a 1 s spectrogram and it answers noise, chirp or glitch (+1 correct, -1 wrong).
Real chirps are scarce, so training injects synthetic chirps into real detector noise; the real
catalogue events are kept for evaluation. Chirps are IMRPhenomD waveforms from LALSimulation
(--chirp imr, default) or a simple analytic sweep (--chirp toy). Glitches are real LIGO
glitches labelled by Gravity Spy (--glitch real, default)
or sine-Gaussian bursts (--glitch synthetic).
It is not part of the PyPI package; run it from a clone of this repository (needs pip 25.1+):
pip install -e . --group rl
python scripts/fetch_training_strain.py --catalog GWTC-3-confident # small files, a few MB
python scripts/fetch_glitches.py --files 30 # ~3 GB of GWOSC hour files, cached by gwpy
python scripts/train_agent.py --algo ppo mlp cnn --verbose
Roadmap
- Streamable-HTTP transport (in addition to stdio) for remote deployments.
- MCP resources for cached skymaps and p_astro files.
Disclaimer
Unofficial; not affiliated with or endorsed by LIGO, Virgo, KAGRA or GraceDB. Respect the GWOSC and GraceDB data-use policies.
If you publish results using data fetched by this server, cite the data sources: GWOSC (CC BY 4.0) and, for glitch labels, Gravity Spy.
License
GPL-3.0-or-later, matching its core dependencies ligo-gracedb and gwpy.
Frequently asked questions
What is GraceDB?
LIGO/Virgo/KAGRA gravitational-wave alerts from GraceDB, plus public strain from GWOSC.
How do I install GraceDB?
It runs on your machine. In Claude Code: claude mcp add gracedb -e 'GRACEDB_FORCE_NOAUTH=true' -e 'GRACEDB_SERVICE_URL=https://gracedb.ligo.org/api/' -e 'GRACEDB_MCP_DATA_DIR=~/.cache/gracedb-mcp' -- uvx gracedb-mcp==0.2.0. For other clients, paste the JSON configuration from this page into their MCP settings.
Does GraceDB need an API key?
Its registry entry lists no required key or secret. Some features may still need an account with the service it connects to.
Is GraceDB open source?
Yes. Its code is on GitHub under the GPL-3.0 license.
Who maintains GraceDB?
It is published by izabelamaria24. AI.tn lists it but does not maintain or endorse it.
From the official MCP Registry. Listing is not an endorsement: review a server's code and permissions before giving it access to your data.