API & MCP

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

HTTP API

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

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://ledgerly.usefulweb.app/mcp – protocol revisions 2026-07-28 (stateless) and 2025-11-25 / 2025-06-18 / 2025-03-26 (initialize handshake).
• Tools: subscription_stack, cancellation_navigator, bill_detective, hidden_fee_finder, loan_amortization_calculator, deadline_decoder, life_admin_generator, digital_estate_organizer, how_long_will_it_last, repair_or_replace, warranty_value_calculator, true_cost_calculator, is_it_worth_it, bulk_buy_brain, price_per_everything, break_even_explorer, decision_simulator, salary_reality_check, tip_bill_split_calculator, percentage_ratio_calculator, inflation_time_machine, currency_converter, historical_fx_chart, multi_currency_invoice_calculator, travel_exchange_fee_calculator
• Local stdio connector: node src/mcp-stdio.ts

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