Canton JSON Ledger API

Overview

The JSON Ledger API is an HTTP/JSON interface that translates to the gRPC Ledger API; in Canton 3.x it's integrated into the validator. Use it for simpler integration, browser clients, prototyping with curl, or platforms with limited gRPC support. For very high throughput, prefer gRPC (canton-ledger-api).

Where it runs

• Sandbox: dpm sandbox --json-api-port 7575 --dar <path>.dar → API at localhost:7575.
• LocalNet: each validator exposes it on port suffix 975 → App User localhost:2975, App Provider localhost:3975, SV localhost:4975.
• OpenAPI spec: GET http://<host>/docs/openapi returns the full openapi.yaml (paste into Swagger or generate client stubs). Health: GET /livez.

Create a party

curl -d '{"partyIdHint":"Alice","identityProviderId":""}' \
  -H "Content-Type: application/json" -X POST localhost:7575/v2/parties
# → {"partyDetails":{"party":"Alice::1220...","isLocal":true,...}}