Get Started

This guide covers the prerequisites and the basic project wiring for building on Canton with OpenZeppelin's Daml packages.

Prerequisites

• JDK 21: the Daml toolchain runs on Java. Install a recent OpenJDK 21 build and make sure JAVA_HOME points at it.
• DPM (Daml Package Manager): Digital Asset's package manager and SDK installer. Install it, then use it to provision the Daml SDK / Canton baseline:

curl https://get.digitalasset.com/install/install.sh | sh
dpm install 3.4.11   # or the baseline pinned in your project's daml.yaml

• A Daml project: a directory with a daml.yaml (single package) or a multi-package.yaml (workspace of packages). New to Daml? Start with the Daml documentation and the Canton Network overview.

Add OpenZeppelin Packages

OpenZeppelin's Canton library is distributed as Daml packages: each primitive is its own DAR, so you add only the ones you need.

1. Get the DARs. Clone OpenZeppelin/canton-contracts and build the library packages:

git clone https://github.com/OpenZeppelin/canton-contracts.git
cd canton-contracts
dpm build --all

Each package's DAR lands in its own .daml/dist/ directory (for example pausable/.daml/dist/oz-pausable-0.1.0.dar).

2. Declare them as data-dependencies. In your project's daml.yaml, reference the built DARs under data-dependencies (not dependencies, which is for the SDK's own libraries):

sdk-version: 3.4.11
name: my-app
source: daml
version: 0.1.0
dependencies:
  - daml-prim
  - daml-stdlib
data-dependencies:
  - ../canton-contracts/access-control/.daml/dist/oz-access-control-0.1.0.dar
  - ../canton-contracts/ownable/.daml/dist/oz-ownable-0.1.0.dar
  - ../canton-contracts/pausable/.daml/dist/oz-pausable-0.1.0.dar
build-options:
  - --target=2.1

Adjust the paths to wherever you cloned the repo, and pin the exact versions from its package manifests. If you only need one primitive, list only that DAR.

3. Import and build. Import the modules you declared and build your project:

import OpenZeppelin.Pausable

# from your project root, with DPM on PATH
dpm build

Refer to each component's page for the module path to import and the templates and interfaces it exposes:

• Access Control
• Ownable
• Pausable

Test Against a Local Canton Ledger

Daml Script tests run in-memory by default, but you can point the same scripts at a real local Canton ledger over gRPC, which is useful for validating time semantics, party visibility, and DAR uploads before targeting a shared network:

# start a local sandbox with your DAR uploaded
dpm sandbox --dar .daml/dist/<your-package>.dar

# run a script against it over the Ledger API
dpm script --dar .daml/dist/<your-package>.dar \
  --script-name My.Module:myScript \
  --ledger-host localhost --ledger-port 6865

If your scripts control ledger time with setTime, start the sandbox with --static-time and pass --static-time to dpm script as well: both default to wall-clock time, and ledger time only moves forward.

Explore Further

• The Settlement (CIP-112) primitive shows how to compose the library into an atomic, value-moving settlement flow.
• The Reference Implementations walk through complete application blueprints built on these pieces.
• The Canton Improvement Proposals (CIPs) repository holds the ecosystem standards these packages align with.