API & MCP

Everything a person can do on Succession Sowing Planner, a program or AI agent can do with the same inputs and get the identical result.

HTTP API

POST https://greenplotsuccessionplanner.usefulweb.site/api/v1/calculate – run Succession Sowing Planner
GET https://greenplotsuccessionplanner.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.

Succession Sowing Planner

Plans repeat sowings of one vegetable, herb or flower from your frost dates: a sowing every few weeks, each with its harvest window and number of plants, until the last sowing that still ripens before the autumn frost — with gaps in the harvest pointed out and a timeline chart.

Inputs of Succession Sowing Planner
Field	Type	Default	Description
`plant`	select (tomato, pepper, eggplant, potato, cucumber, zucchini, squash, melon, sweetcorn, bush-bean, pole-bean, pea, broad-bean, lettuce, spinach, chard, beet, carrot, parsnip, radish, turnip, onion, sp	"lettuce"	Plant
`lastFrost` (required)	text	"04-20"	Last spring frost (MM-DD). Month and day, for example 04-20. Hearth’s Frost Dates Finder gives it for Germany and the United States.
`firstFrost` (required)	text	"10-20"	First autumn frost (MM-DD)
`year`	integer	2027	Season (year of the spring frost)
`intervalWeeks`	integer	0	Weeks between sowings (0 = the plant’s usual interval)
`squares`	integer	2	30 cm squares per sowing
`start`	date	—	First sowing (optional). Empty = start of the sowing window.

Example request

Lettuce every three weeks, two squares each

curl -X POST https://greenplotsuccessionplanner.usefulweb.site/api/v1/calculate -H 'content-type: application/json' -d '{"plant":"lettuce","lastFrost":"04-08","firstFrost":"11-02","year":2027,"intervalWeeks":0,"squares":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://greenplotsuccessionplanner.usefulweb.site/mcp – protocol revisions 2026-07-28 (stateless) and 2025-11-25 / 2025-06-18 / 2025-03-26 (initialize handshake).
Tools: greenplot_succession_planner
Local stdio connector: node src/mcp-stdio.ts --tool=greenplot-succession-planner

{
  "mcpServers": {
    "greenplot-succession-planner": { "type": "http", "url": "https://greenplotsuccessionplanner.usefulweb.site/mcp" }
  }
}