API & MCP

Everything a person can do on Garden Watering Need, a program or AI agent can do with the same inputs and get the identical result.

HTTP API

• POST https://hearthwateringneed.usefulweb.site/api/v1/calculate – run Garden Watering Need
• GET https://hearthwateringneed.usefulweb.site/api/v1/tool – inputs, output schema, examples
• OpenAPI 3.1: /openapi.json · /openapi.yaml
• Errors: application/problem+json; 422 includes per-field errors.

Garden Watering Need

Estimates how much to water each garden bed over the next days: FAO-56 Penman–Monteith reference evapotranspiration from the MET Norway forecast, times the crop coefficient of each planting and its growth stage, minus the rain that reaches the roots — in millimetres and litres, with a suggested number of waterings.

Example request

Berlin: tomatoes, beans and lettuce

curl -X POST https://hearthwateringneed.usefulweb.site/api/v1/calculate -H 'content-type: application/json' -d '{"place":"52.52, 13.40","timeZone":"Europe/Berlin","days":7,"plantings":[{"bed":"Bed 1","crop":"tomato","areaM2":0.36},{"bed":"Bed 1","crop":"bush-bean","areaM2":0.54},{"bed":"Bed 2","crop":"lettuce","areaM2":1.2}]}'

Every result contains

inputs (normalised, defaults applied), summary, result (validated against the published schema), units, assumptions, sources, warnings, computedAt and links.

MCP (Model Context Protocol)

• Streamable HTTP endpoint: https://hearthwateringneed.usefulweb.site/mcp – protocol revisions 2026-07-28 (stateless) and 2025-11-25 / 2025-06-18 / 2025-03-26 (initialize handshake).
• Tools: hearth_watering_need
• Local stdio connector: node src/mcp-stdio.ts --tool=hearth-watering-need

{
  "mcpServers": {
    "hearth-watering-need": { "type": "http", "url": "https://hearthwateringneed.usefulweb.site/mcp" }
  }
}