Documentation

The Ensemble API

One versioned surface under /v1, authenticated with a bearer token. JSON by default; GeoJSON and NetCDF on the grid endpoints.

Quickstart

Every response carries the ensemble spread. There is no flag to enable it and no tier that withholds it.

01Request a key — the free tier needs no card.
02Send it as Authorization: Bearer.
03Read spread, not just p50.

Point forecast

curl https://api.ensemblegains.com/v1/forecast \
  -H "Authorization: Bearer $EG_API_KEY" \
  -G \
  -d lat=29.76 \
  -d lon=-95.37 \
  -d vars=temperature_2m,wind_gust_10m \
  -d horizon=72h

Endpoints

Method	Path	Description	From tier
GET	/v1/forecast	Point forecast. Returns p10/p50/p90 per step.	Developer
GET	/v1/forecast/grid	Bounding-box grid at 0.25° or finer. NetCDF or GeoJSON.	Builder
GET	/v1/nowcast	Minute-resolution precipitation, 0–120 min horizon.	Builder
GET	/v1/severe	Active severe risk: tornado, hail, wind, cyclone tracks.	Professional
GET	/v1/severe/cyclones	Active tropical cyclones with per-member track ensemble.	Professional
GET	/v1/air-quality	PM2.5, PM10, ozone, NO₂, AQI, pollen by species.	Builder
GET	/v1/climate/seasonal	1–12 month outlooks, ENSO state, drought probability.	Enterprise
GET	/v1/historical	ERA5-backed reanalysis, 1940–present.	Professional
GET	/v1/ensemble/members	Per-model member values and weights.	Professional
GET	/v1/skill	Live verification scores. Public, unauthenticated.	Developer
POST	/v1/alerts	Create a threshold alert with a webhook target.	Professional
GET	/v1/alerts	List, inspect and delete active subscriptions.	Professional

Response envelope

Present on every endpoint, so a response is always self-describing and a bad forecast is always auditable.

init_time: Model run timestamp, UTC ISO 8601
valid_time: The time being forecast
members: Count of contributing models
models: Names and weights of contributors
spread: p10 / p50 / p90 per variable
units: Explicit unit declaration
resolution_deg: Grid resolution used

Rate limits & reliability

X-RateLimit-*Limit, remaining and reset returned on every response.
429 + Retry-AfterNever a bare failure — you always know when to come back.
p95 < 200 msCached point forecasts. Under 800 ms uncached.
p95 < 150 msNowcasting. A late nowcast is not a nowcast.
OpenAPI 3.1Generated from source, never hand-maintained.
SDKsTypeScript and Python at launch.

Full reference is in progress

Per-endpoint parameters, error codes and the interactive playground land with the Phase 1 API release. Ask us for early access and we will wire you up against a staging key.

Request early access