Babushka for developers

93 practical calculators. One API.

Call the same calculation engine used by Babushka Market from Claude, ChatGPT, Zapier, n8n or your own app. JSON in, structured result, visible method and practical purchase quantity out.

Free tier

Create your API key

No billing details. We log endpoint and calculator usage to understand demand before introducing paid plans.

Endpoints

REST + MCP

API base: https://babushka-calculators.babushka-market.workers.dev
Catalogue: GET /v1/calculators
Calculate: POST /v1/calculate/:id
MCP: POST /mcp

Working example

Calculate fence paint

curl -X POST \
+  ()=>{throw Error(`Unexpectedly client reference export 'API_BASE' is called on server`)}/v1/calculate/bm.home.fence-paint-calculator \
+  -H "Authorization: Bearer $BABUSHKA_API_KEY" \
+  -H "Content-Type: application/json" \
+  -d '{"length":10,"height":1.5,"coats":2,"coverage":10,"waste":10,"packSize":5}'

Response

{
  "calculatorId": "bm.home.fence-paint-calculator",
  "result": { "requiredQuantity": 6.6, "purchaseUnits": 2, "purchaseQuantity": 10 },
  "method": { "formula": "Apply the entered values in consistent units, then round only the final purchase quantity to whole packs." },
  "commerce": { "purchaseCategory": "fence-paint" }
}

MCP configuration

Connect an MCP client

Use the streamable HTTP endpoint below and send your free key as a Bearer token. The server exposes one read-only tool per stable calculator ID.

URL: ()=>{throw Error(`Unexpectedly client reference export 'API_BASE' is called on server`)}/mcp
Authorization: Bearer $BABUSHKA_API_KEY

Supported methods include initialize, ping, tools/list and tools/call. Responses contain both MCP text content and structured calculator output.