API & MCP

Hydrometric for developers and agents

The full FEH2025 default-route assessment on the frozen NRFA Peak Flow Dataset, available over REST and the Model Context Protocol. The hydrologist stays in control: agents get the default route and every adopted choice is recorded.

Remote MCP server

Streamable HTTP at /api/mcp. Add it to Claude Code, Cursor, or any MCP-capable harness with one config block — no local install.

Per-user API keys

Bearer hm_live_ keys, created and revoked from your account. No cookies, no shared secrets.

Every default-route output

QMED, pooling, growth curve, design flows and the FEH report — the same audited result the browser shows, over JSON.

Authentication

Every request carries a Bearer hm_live_ key. Join the preview, then create a key under Account → API keys. Keys are per user and can be revoked at any time.

Legacy service integrations may instead send the shared HYDROMETRIC_API_KEY plus an x-hydrometric-user-email header. New integrations should use per-user keys.

Join the preview

MCP tools

The same list agents discover from /agents.txt. Run tools consume a credit; views over a cached run are free.

Tool	What it does
search_stations	Search the frozen NRFA Peak Flow Dataset by id, river or location. Free.
get_station	Descriptors, record length, suitability for one station. Free.
run_gauged_assessment	Full default-route FEH2025 assessment for a gauged station. 1 credit (free on cache hit).
run_ungauged_assessment	FEH statistical estimate from descriptors + BNG location. 1 credit.
get_qmed	Recommended QMED (m³/s) view over a cached run.
get_growth_curve	Adopted growth curve + pooling summary over a cached run.
get_design_flows	Design flows (m³/s) by return period over a cached run.
get_report	FEH report as Markdown; PDF/DOCX as signed-in URLs.
list_saved_analyses	The caller's saved analyses. Read-only.
get_saved_analysis	One saved analysis, adopted route resolved. Read-only.
get_catchment_map	Map figures for a station from the caller's saved analyses.
run_method_space	Method Space: every method-valid variant of an analysis (station, saved analysis or descriptors) — P10/P50/P90 + FSE per metric, named variants, compare your numbers, qmedRoute filter (all\|amax\|descriptors), PNG figure. £20 per run credit (free re-run of a paid analysis; admins/grantees exempt).
get_method_space_credits	Method Space credit balance + purchase URL. Free.

Credits and limits

run_* tools

1 credit each

Views over a cached run (get_qmed, get_growth_curve, …)

Free

Cache hits on run_gauged_assessment

Free

Preview allowance

5 assessments

Method Space comparison

£20 per run

Rate limit

60 requests/minute per key

Method Space via API compares any result — including a competitor's — against the Hydrometric default and the method space (the whole cloud, or one QMED route via qmedRoute). Exhausted quota returns a tool error with code quota_exhausted.

REST example

Ungauged FEH statistical estimate from catchment descriptors.

POST /api/v1/estimate

curl -X POST https://www.hydrometric.io/api/v1/estimate \
  -H "Authorization: Bearer hm_live_YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "descriptors": { "AREA": 174.2, "SAAR": 1084, "BFIHOST": 0.41, "FARL": 0.98, "URBEXT2000": 0.01 },
    "return_periods": [2, 20, 100],
    "easting": 412300,
    "northing": 296800
  }'