API & MCP

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

HTTP API

• GET https://gisela.usefulweb.app/api/v1/tools – catalog
• GET https://gisela.usefulweb.app/api/v1/tools/{id} – inputs, output schema, examples
• POST https://gisela.usefulweb.app/api/v1/tools/{id}/calculate – run a tool
• GET https://gisela.usefulweb.app/api/v1/workflows · POST https://gisela.usefulweb.app/api/v1/workflows/{id}/run
• OpenAPI 3.1: /openapi.json · /openapi.yaml
• Errors: application/problem+json; 422 includes per-field errors.

Tools on GISela

• GISela Coordinate Reprojection – Convert GeoJSON, KML, GPX, CSV or shapefiles between WGS 84, UTM, LV95, British Grid and more. gisela_reproject
• GISela Buffer – Buffer zones around points, lines or polygons at a distance in metres, merged or one per feature. gisela_buffer
• GISela Shapefile to GeoJSON – Turn a zipped shapefile (.shp, .dbf, .prj) into GeoJSON in WGS 84 or another coordinate system. gisela_shapefile_to_geojson
• GISela Area & Length – True area, perimeter and length of polygons and lines on the WGS 84 ellipsoid, per feature. gisela_area_length

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://gisela.usefulweb.app/mcp – protocol revisions 2026-07-28 (stateless) and 2025-11-25 / 2025-06-18 / 2025-03-26 (initialize handshake).
• Tools: gisela_reproject, gisela_buffer, gisela_shapefile_to_geojson, gisela_area_length
• Local stdio connector: node src/mcp-stdio.ts

{
  "mcpServers": {
    "usefulweb": { "type": "http", "url": "https://gisela.usefulweb.app/mcp" }
  }
}