The full upstream README, mirrored here for reference. Install config, tool schemas, adoption signals, and an original overview live on the Jma listing page.
Japan Meteorological Agency (JMA) weather forecasts, warnings/advisories, and
earthquake reports — keyless, sourced straight from JMA's public bosai JSON
feeds.
Part of Pipeworx — an MCP gateway connecting AI agents to 1683+ live data sources.
jma_resolve_area(query) — resolve a place name (English romaji or
Japanese, e.g. "Tokyo", "Sapporo", "大阪") or a JMA area code to the
forecast OFFICE code used by jma_forecast / jma_warnings.jma_forecast(area) — 3-day short-term forecast (weather, precipitation
probability, temperature) plus 7-day weekly forecast (weather,
precipitation probability, forecast reliability, min/max temperature with
confidence range), per sub-area. Accepts a place name directly — it
resolves internally the same way as jma_resolve_area.jma_warnings(area) — current warnings and advisories (警報・注意報) for a
region: headline bulletin plus per-area status (issued / continuing /
lifted / none in effect) for every JMA warning category (heavy rain,
storm, flood, wave, storm surge, dense fog, thunderstorm, avalanche,
frost, and their "special warning" / emergency tiers), at both the
sub-prefecture and municipality level.jma_earthquakes(limit?, min_magnitude?, min_intensity?) — recent
earthquakes with magnitude, maximum seismic intensity (JMA's 10-step
震度 scale), epicenter, and report/occurrence time.Keyless. No registration, no API key.
https://www.jma.go.jp/bosai/common/const/area.json — the area master
list: 58 forecast offices plus every prefecture/region/city/ward/town JMA
itself names, in both Japanese and English. This is what
jma_resolve_area walks.https://www.jma.go.jp/bosai/forecast/data/forecast/<office>.json — the
3-day + weekly forecast for one office.https://www.jma.go.jp/bosai/warning/data/warning/<office>.json — current
warnings/advisories for one office.https://www.jma.go.jp/bosai/quake/data/list.json — a rolling feed of
recent earthquake bulletins (typically the last few weeks), newest first.130000). A caller will say "Tokyo" or
"Sapporo", not the office code — every tool that takes area resolves it
through area.json's full hierarchy (office → region → city/ward/town),
walking up to the owning office.alternatives. 伊達市 exists in both
Hokkaido and Fukushima, 川崎町 in both Miyagi and Fukuoka — nothing in the
query can separate them, so alternatives carries the others WITH the
office each resolves to. alternatives: [] therefore means the name really
was unique; it used to mean the opposite in exactly the cases that went
wrong.area.json's four levels overlap in code space. A handful of small
offices are their own single sub-region, so the same numeric code appears
in both offices and class10s (e.g. 011000 Soya). The parent-walk in
this pack always walks from the LEVEL you matched at (never by treating a
code as globally unique across the four dicts), which is what makes that
edge case resolve correctly instead of silently landing on the wrong
office.weatherCodes is a closed, JMA-published numeric set (three digits,
~110 in active use) — this pack ships a full static translation table
(weather_en) built from that fixed set, not a machine translation. The
free-text weathers[] narrative (with time modifiers like "後" / "時々" /
"一時") is intentionally left native-Japanese-only: it's compositional in
a way a static table can't safely cover, and a wrong on-the-fly
translation is worse than none.code field inside each area's warnings[]) are a
separate closed numeric set from weather codes (02-49, warnings /
advisories / special warnings / emergency warnings). Cross-checked against
a live Tokyo response: codes 14/15/16/20 in the areaTypes payload lined
up exactly with "強風", "高波", "落雷", "濃霧" in that response's own
headlineText, which is the validation this table was built against.maxi / int[].maxi) is JMA's own 10-step 震度
scale: 1,2,3,4,5-,5+,6-,6+,7 — 5-/5+ mean
"5 Lower"/"5 Upper", not "slightly less/more than 5". An empty string
means the bulletin carries no intensity (e.g. a "hypocenter update" record
with no shaking report).area.json is ~260KB and essentially static (JMA's forecast-area
boundaries are a standing administrative structure) — this pack caches it
in module scope for 24h rather than refetching per call.Add to your MCP client (Claude Desktop, Cursor, Windsurf, etc.):
tools/list at https://gateway.pipeworx.io/jma/mcp returns the tools in the table
above plus the shared Pipeworx meta-tools — ask_pipeworx,
discover_tools, 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.
This is deliberate, not multiplexing by accident. The meta-tools are what let a
scoped connection answer a question this pack does not cover — via
ask_pipeworx, which routes across the whole catalog — without you adding a
second MCP server. There is currently no way to mount a pack endpoint without
them; if the extra schemas cost you more context than the routing is worth,
connect to the full gateway once rather than to several pack endpoints.
Or connect to the full Pipeworx gateway to get every pack's tools listed directly, instead of just this one's:
Both URLs reach the same gateway and the same 1683+ data sources. The
only difference is which pack's tools are listed directly; ask_pipeworx
reaches all of them from either one.
No account needed for the first calls. Inspect any tool: GET https://gateway.pipeworx.io/v1/tools/jma_resolve_area. Find one: POST https://gateway.pipeworx.io/v1/tools/search_packs with {"query":"..."}.
This package also runs as a local stdio MCP server — no Pipeworx account, no gateway round-trip:
Or run it directly to confirm it starts:
It speaks MCP over stdin/stdout and answers initialize/tools/list/tools/call
for only this pack's tools — none of the shared meta-tools the gateway
connection above adds. Same source, same tools, no ask_pipeworx routing.
Instead of calling tools directly, you can ask questions in plain English — this works on the pack endpoint above as well as on the full gateway:
The gateway picks the right tool and fills the arguments automatically.
MIT