@c7-digital/ledger

OpenAPI v2 compatible Daml ledger client (that could replace @daml/ledger) for the new Canton JSON API v2.

Overview

This package provides a TypeScript client for interacting with Canton's JSON Ledger API v2, which replaces the deprecated v1 API that @daml/ledger targets.

Features

• Type-safe API: Generated TypeScript types from OpenAPI specification
• OpenAPI v2 Support: Targets the new Canton JSON API v2 endpoints
• Auto-generated Types: Uses openapi-typescript to generate accurate type definitions

Versioning

This package follows the Canton SDK versioning scheme. The package version matches the Canton OpenAPI specification version used to generate the types.

Current version: 3.4.9

• Corresponds to Canton SDK version 3.4.9
• Types are generated from the OpenAPI spec for this specific Canton version
• When Canton releases a new version, this package will be updated to match

Version compatibility: Use the package version that matches your Canton participant node version for best compatibility.

Installation

pnpm install @c7-digital/ledger

Or build from source:

pnpm install
pnpm build

Usage

import { Ledger } from "@c7-digital/ledger";

const ledger = new Ledger({
  token: "your-jwt-token",
  httpBaseUrl: "http://localhost:7575",
});

// Query contracts
const contracts = await ledger.query(MyTemplate);

// Create contracts
const result = await ledger.create(MyTemplate, payload, [actAsParty]);

// Exercise choices
const choiceResult = await ledger.exercise(MyChoice, contractId, argument, [actAsParty]);

Migration from @daml/ledger

Key differences:

• create() and exercise() methods now require an actAs parameter
• Some method signatures have been updated to match OpenAPI v2 spec
• New type definitions generated from OpenAPI specification

Development

# Build the package
pnpm build

# Clean build artifacts
pnpm clean

# Watch for changes
pnpm watch

# Run tests
pnpm test

# Lint code
pnpm lint

OpenAPI Specification

The package uses the OpenAPI specification from Canton 3.4.9. The spec is saved as a version specific file (e.x. openapi_3.4.9.yaml) and types are automatically generated into src/generated/api.ts.

To update the specification:

1. Download from docs.digitalasset.com or from your participant node.
2. Update the build script to use the new SDK version
3. Run pnpm build to regenerate types