Using the Participant Image

As a convenience, we provide a pre-configured participant image that can be used to start a Canton participant with sensible defaults.

Using this image requires setting several environment variables:

docker run \
    -e AUTH_TARGET_AUDIENCE="audience" \
    -e AUTH_JWKS_URL="fake.com/jwks" \
    -e CANTON_PARTICIPANT_POSTGRES_SERVER="canton-postgres" \
    -e CANTON_PARTICIPANT_POSTGRES_PORT="5432" \
    -v "$(pwd)/bootstrap.sc:/app/bootstrap.sc" \
    --rm -it \
    europe-docker.pkg.dev/da-images/public-unstable/docker/canton-participant:3.5.0-ad-hoc.20251021.17321.0.v2cdf16447

Note that you’ll need a valid postgres instance.

This image requires you to initialize the participant via a bootstrap script. See Manual identity initialization for more details.

To see all configuration defaults and possible env vars, run

cid=$(docker create europe-docker.pkg.dev/da-images/public-unstable/docker/canton-participant:3.5.0-ad-hoc.20251021.17321.0.v2cdf1644) && docker cp "$cid":/app/app.conf ./app.conf && docker rm "$cid"
cat app.conf

Logging

Logs are JSON encoded and sent to stdout. The log level is set via -e LOG_LEVEL_STDOUT=INFO. It defaults to DEBUG.

Bound Ports

canton-participant image binds:

• Ledger API port: 5001

• Admin API port: 5002

• HTTP Ledger API port: 7575

• GRPC Health Server port: 5061

canton-mediator image binds:

• Admin API port: 5007

• GRPC Health Server port: 5061

canton-sequencer image binds:

• Public API: 5008

• Admin API: 5009

• GRPC Health Server port: 5061

Supplying custom configuration and DARs

To supply custom configuration, either

1. add it via ADDITIONAL_CONFIG environment variable, or

2. mount /app/additional-config.conf into the container.

Dars must be added dynamically. This is done via remote console or the admin API.

To run a participant console with custom configuration:

docker run -e ADDITIONAL_CONFIG="canton.participants.participant1 {
      storage.type = memory
      admin-api.port = 5012
      ledger-api.port = 5011
      http-ledger-api.port = 5013
    }" \
    --rm -it \
    europe-docker.pkg.dev/da-images/public-unstable/docker/canton-participant:3.5.0-ad-hoc.20251021.17321.0.v2cdf1644 \
    --console

The –console flag starts canton in interactive console mode.