Overview

Space weather from NOAA's Space Weather Prediction Center (SWPC) — geomagnetic storm scales, Kp index, aurora forecasts, solar wind, solar activity, and active alerts. Query current conditions, aurora visibility at a coordinate, or windowed plasma and magnetic-field time series from any MCP client. Runs as a stdio process, a local Streamable HTTP server, or the public hosted endpoint above.

Tools

Capability reference

noaa_spaceweather_get_conditions _tool

• include_discussion (bool, default false) is the only input — otherwise a single call composing storm scales and current Kp into one snapshot
• Returns today's observed R/S/G storm levels plus SWPC's 3-day forecast series, which starts with today
• yesterday carries the R/S/G levels SWPC assessed for the previous UTC day, with its date and no time — the feed states only when it was generated. Null when the feed carries no previous-day period
• Forecast days carry what SWPC issues: a G level, and for R and S a probability — R1–R2, R3 or greater, S1 or greater — with no level. A null level means SWPC forecasts none for that day, which is not the same as level 0
• Current Kp with G-scale equivalent and aurora-visibility latitude guidance
• With include_discussion, the forecaster-written Forecast Discussion split into its topic sections (Solar Activity, Energetic Particle, Solar Wind, Geospace), each with its 24-hour summary and 3-day forecast text
• Data sourced from the noaa-scales.json + noaa-planetary-k-index.json feeds, plus the discussion.txt product when the discussion is requested

noaa_spaceweather_get_kp_index _tool

• window_days (1–7, default 1) bounds the observed series; the forecast series is always SWPC's full 3-day forecast
• Each observed/forecast record carries Kp, G-scale equivalent, G-scale label, and aurora-latitude guidance
• G levels follow SWPC's minus-third band floors — G1 starts at Kp 4.67 (5−), G4 runs through 8.67 (9−), and only Kp 9 is G5
• Forecast excludes the feed's embedded historical "observed" entries — only forward-looking estimated/predicted rows
• observedCount reports how many observed readings matched the window

noaa_spaceweather_get_aurora_forecast _tool

• Without coordinates: global metadata only — grid point count, global peak probability, peak region
• With latitude/longitude (WGS84, required together): nearest 1°-grid lookup, the centered-dipole geomagnetic latitude those coordinates convert to, the minimum Kp and G level needed at that geomagnetic latitude, and a plain-language go/no-go verdict
• Darkness gating: the sun's elevation at the coordinates at the forecast time (sunElevationDeg) and the sky state it implies (darkness: day, civil_twilight, nautical_twilight, dark). In daylight the verdict reports aurora as not visible whatever the model probability; in twilight it adds that only bright aurora will show
• Horizon view: the strongest reading within 1000 km poleward and ±2° longitude (horizonMaxPercent, horizonMaxLatitude, horizonDistanceKm). When it reaches 10% and beats the overhead reading outside daylight, the verdict adds that aurora may be visible low on the poleward horizon
• invalid_coordinates error when only one of the pair is supplied
• OVATION model updates every ~5 minutes; forecast horizon is ~30–60 minutes ahead

noaa_spaceweather_get_solar_wind _tool

• window_hours (1–168, default 3) slices client-side from a feed that carries roughly the last 24 hours at ~1-minute cadence
• resolution (summary, reduced default, or full) sets the series detail. reduced bounds each returned series to 200 records: the window is bucketed by record count and one real measurement is emitted per bucket — the bucket's fastest speed for plasma, its most southward Bz for mag — with the newest record in the window always last. A series already inside the bound comes back untouched, so a default 3-hour call is unaffected; full returns every record (~1,400 per series over 24 hours); summary returns both series empty and keeps every headline field, about 2 KB whatever the window
• Plasma (speed, density, temperature) and magnetic field (Bx/By/Bz/Bt GSM) returned as separate oldest-first series
• bzStatus surfaces southward Bz (the storm driver) as a plain-language field, and bzMinInWindow with its time tag reports the window's most southward reading
• Window statistics: speedMaxInWindow with its time tag, densityMaxInWindow, btMaxInWindow, and bzSouthMinutesInWindow — the count of 1-minute records with Bz below 0, so a gap in the feed adds nothing. Every headline field is computed from the full window, before any reduction, at every resolution
• latestFeedPlasmaTime/latestFeedMagTime/feedStalenessHours distinguish an empty window from a stale feed
• Every record names its reporting spacecraft — no satellite is assumed as "the" active one

noaa_spaceweather_get_solar_activity _tool

• include_regions (default true) toggles per-region active-solar-region detail to control response size
• flare_hours (1–168, default 24) bounds the discrete flare events returned, filtered on each flare's onset; the feed keeps a rolling 7 days, so 168 returns everything it carries
• Flare events come with the classes SWPC publishes — onset, peak, and decay, each with magnitude — the peak flux, and the NOAA R-scale level (0–5) that flux implies. Decay time and class are null while a flare is still in progress, and an empty window names the newest flare the feed holds
• GOES X-ray flux (0.1–0.8 nm) with flare-class letter (A/B/C/M/X), the class with magnitude (flareClassFull, derived by SWPC's truncation rule so it agrees with the published flare classes), and the unformatted flux alongside the display string; recent readings cover the past hour
• Daily F10.7 cm solar radio flux in sfu with its 90-day mean, from the Noon Penticton report — the value SWPC reports for the day. It can be up to ~24 h old, so its observation time rides with it
• 3-day C/M/X flare-class and proton-event probabilities under date-neutral names (cClassProbability, mClassProbability, xClassProbability, protonEventProbability); the deprecated *1Day names still carry the same values in structuredContent
• Each active region carries the C/M/X flare counts SWPC attributed to it on its observation day — the flare events carry no region, so these name the region driving current activity — its sunspot area in millionths of the hemisphere, and when SWPC first recorded it. Its flare probabilities cover the following day. A spotless region (plage) reads as such, with a null area
• Integral proton flux (≥10 MeV) drives the reported NOAA S-scale (0–5)
• Data sourced from the goes/primary/xrays-6-hour.json, goes/primary/xray-flares-7-day.json, f107_cm_flux.json, solar_probabilities.json, goes/primary/integral-protons-plot-3-day.json, and solar_regions.json feeds

noaa_spaceweather_get_alerts _tool

• active_only (default true) — in-force Warnings/Watches/Alerts only. A product stays in force until the feed says otherwise, so this also drops any product a later cancellation names by serial, and all but the newest Watch carrying THIS SUPERSEDES ANY/ALL PRIOR WATCHES IN EFFECT — alongside cancellations, Summaries, and products whose validity end has passed
• max_age_hours (1–720, default 48) bounds how far back to look for candidates; the SWPC feed itself has no expiry. Under active_only=true it does not cut off a product whose validity end is still ahead, so a multi-day Watch survives until the last day it forecasts a storm for ends; under active_only=false it is a literal age cutoff
• Each record carries product type, NOAA scale + level (0 means "no scale stated," not zero severity), serial number, parsed validity window, and full message text
• cancelled flags a record that cancels a prior product rather than being active; the product it cancels is a separate record, excluded by the serial link rather than by this flag
• Under active_only=true the response echoes the applied window and counts what it excluded, by reason — so an empty result reads as "quiet" or "everything was filtered" without a second call

Features

Built on @cyanheads/mcp-ts-core: stdio and Streamable HTTP transports, pluggable auth (none / jwt / oauth), swappable storage (in-memory, filesystem, Supabase, Cloudflare KV/R2/D1), structured logging with optional OpenTelemetry tracing.

SWPC-specific:

• All SWPC feeds are public and keyless — no API keys required
• Single SpaceWeatherService wraps every NOAA SWPC feed — the JSON products and the plain-text forecast discussion — behind one fetchWithTimeout + withRetry funnel, so both paths classify an upstream failure the same way — and every retry ladder runs inside one 45-second budget, so a hung upstream still returns the classified error before a 60-second client timeout
• Heterogeneous feed normalization: interleaved multi-spacecraft records (solar wind), keyed objects (storm scales), coordinate triples (OVATION), section-delimited text (forecast discussion)
• NOAA scale interpretation: raw Kp 6 → "G2 moderate storm — aurora possible to ~55° geomagnetic latitude"
• Feed freshness surfaced per-response: solar wind updates ~1 min, aurora ~5 min, Kp 3-hour intervals

Agent-friendly output:

• Observed timestamps on every response so agents can reason about data freshness
• Plain-language summaries and verdicts alongside raw values — agents can display or reason without re-interpreting indices
• Bz component surfaced as a first-class field in solar wind output (southward Bz = primary storm driver)
• Typed error contracts with recovery hints, split on whether retrying can help: a transient feed failure is feed_unavailable → "Retry in 30–60 s"; a feed path SWPC no longer serves is feed_moved → "Retrying will not help", raised on the first attempt

Getting started

Public Hosted Instance

A public instance is available at https://noaa-spaceweather.caseyjhand.com/mcp — no installation required. Point any MCP client at it via Streamable HTTP:

{
  "mcpServers": {
    "noaa-spaceweather-mcp-server": {
      "type": "streamable-http",
      "url": "https://noaa-spaceweather.caseyjhand.com/mcp"
    }
  }
}

Self-Hosted / Local

Add the following to your MCP client configuration file.

{
  "mcpServers": {
    "noaa-spaceweather": {
      "type": "stdio",
      "command": "bunx",
      "args": ["@cyanheads/noaa-spaceweather-mcp-server@latest"],
      "env": {
        "MCP_TRANSPORT_TYPE": "stdio",
        "MCP_LOG_LEVEL": "info"
      }
    }
  }
}

Or with npx (no Bun required):

{
  "mcpServers": {
    "noaa-spaceweather": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "@cyanheads/noaa-spaceweather-mcp-server@latest"],
      "env": {
        "MCP_TRANSPORT_TYPE": "stdio",
        "MCP_LOG_LEVEL": "info"
      }
    }
  }
}

Or with Docker:

{
  "mcpServers": {
    "noaa-spaceweather": {
      "type": "stdio",
      "command": "docker",
      "args": [
        "run", "-i", "--rm",
        "-e", "MCP_TRANSPORT_TYPE=stdio",
        "ghcr.io/cyanheads/noaa-spaceweather-mcp-server:latest"
      ]
    }
  }
}

For Streamable HTTP, set the transport and start the server:

MCP_TRANSPORT_TYPE=http MCP_HTTP_PORT=3010 bun run start:http
# Server listens at http://localhost:3010/mcp

Prerequisites

• Bun v1.3.0 or higher (or Node.js v24+).
• No API keys required — all SWPC feeds are public.

Installation

1. Clone the repository:

git clone https://github.com/cyanheads/noaa-spaceweather-mcp-server.git

2. Navigate into the directory:

cd noaa-spaceweather-mcp-server

3. Install dependencies:

bun install

4. Configure environment:

cp .env.example .env
# edit .env if needed — all defaults work out of the box

Configuration

No domain-specific API keys are required. See .env.example for the full list of optional overrides.

Running the server

Local development

• Build and run:

  sh

  # One-time build
  bun run rebuild
  
  # Run the built server
  bun run start:stdio
  # or
  bun run start:http
  

• Run checks and tests:

  sh

  bun run devcheck   # Lint, format, typecheck, security
  bun run test       # Vitest test suite
  bun run lint:mcp   # Validate MCP definitions against spec
  

Docker

docker build -t noaa-spaceweather-mcp-server .
docker run --rm -p 3010:3010 noaa-spaceweather-mcp-server

The Dockerfile defaults to HTTP transport, stateless session mode, and logs to /var/log/noaa-spaceweather-mcp-server. OpenTelemetry peer dependencies are installed by default — build with --build-arg OTEL_ENABLED=false to omit them.

Project structure

Development guide

See CLAUDE.md/AGENTS.md for development guidelines and architectural rules. The short version:

• Handlers throw, framework catches — no try/catch in tool logic
• Use ctx.log for request-scoped logging, ctx.state for tenant-scoped storage
• Register new tools via the barrel in src/mcp-server/tools/definitions/index.ts
• Wrap external API calls: validate raw → normalize to domain type → return output schema; never fabricate missing fields

Contributing

Issues are welcome. Run checks and tests before submitting:

bun run devcheck
bun run test

License

Apache-2.0 — see LICENSE for details.