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Running with a Testnet Environment

Testnet environment in this guide refers to the Ethereum Sepolia Testnet as a Layer 1 and Espresso Decaf Testnet as a Layer 2 network. You can refer to the architecture section to read more on how the Cartesi Node interprets messages from both the layers. This environment provides a full blown Espresso integration with its live nodes.

There are two approaches to use the testnet environment:

  1. Run the Node in your local machine
  2. Deploy the Node to a cloud host

In this guide, we’ll focus on the 1st approach and in deployment section, we’ll take a look at how to deploy your Node to fly.io.

note

The guide assumes that you have already created a Cartesi dApp and have a snapshot image ready. You can follow the building guide to create a dApp and generate build artifacts.

Run the Rollups Node V2​

We're going to spin up a Cartesi Rollups Node V2 container using the node-recipes.

Step 1: Setup Docker Image​

Go to the application directory and copy the dockerfile, the docker compose file, and the node.mk.

wget -q https://github.com/prototyp3-dev/node-recipes/archive/refs/heads/feature/use-20250128-build.zip -O recipes.zip
unzip -q recipes.zip "node-recipes-feature-use-20250128-build/node/*" -d . && mv node-recipes-feature-use-20250128-build/node/* . && rmdir -p node-recipes-feature-use-20250128-build/node
rm recipes.zip

Pull the latest Cartesi Rollups Node V2 image.

docker pull ghcr.io/prototyp3-dev/test-node:test

Step 2: Create a .env file for Testnet​

Create a .env.sepolia file inside the application directory with the following variables:

# cartesi node configuration
CARTESI_LOG_LEVEL=info
CARTESI_AUTH_KIND=private_key
CARTESI_CONTRACTS_INPUT_BOX_ADDRESS=0x593E5BCf894D6829Dd26D0810DA7F064406aebB6
CARTESI_CONTRACTS_INPUT_BOX_DEPLOYMENT_BLOCK_NUMBER=6994348

# espresso configuration
MAIN_SEQUENCER=espresso
ESPRESSO_BASE_URL=https://query.decaf.testnet.espresso.network
ESPRESSO_NAMESPACE=51025
ESPRESSO_STARTING_BLOCK=<current-block-number>

# sepolia chain configuration
CARTESI_BLOCKCHAIN_HTTP_ENDPOINT=<sepolia-rpc-url>
CARTESI_BLOCKCHAIN_WS_ENDPOINT=<sepolia-ws-url>
CARTESI_BLOCKCHAIN_ID=11155111
CARTESI_AUTH_PRIVATE_KEY=<node-private-key>

Step 3: Run the Docker Containers​

make -f node.mk run-database-<testnet>
make -f node.mk run-node-<testnet>

To stop the containers later, run the following command:

make -f node.mk stop-<testnet>

Step 4: Deploy the App Contract on Sepolia​

make -f node.mk deploy-<testnet> OWNER=<app-and-auth-owner>

Your app is now ready to receive inputs from the Decaf testnet and Sepolia network. To start interacting, follow the steps in send inputs section.

note

You should set OWNER to the same owner of the CARTESI_AUTH_PRIVATE_KEY. Set CONSENSUS_ADDRESS to deploy a new application with same consensus already deployed. You can also set EPOCH_LENGTH, and SALT.

If want to register an already deployed application to the node use (optionally set IMAGE_PATH):

make -f node.mk register-<testnet> APPLICATION_ADDRESS=<app address> CONSENSUS_ADDRESS=<auth address>

Rapid prototyping with Testnet (using Nonodo)​

To run Nonodo with a full testnet setup, we must provide:

  • The URL of a gateway RPC on Sepolia
  • The application’s deployment address on Sepolia
  • The URL for accessing Espresso’s testnet
  • The Espresso block number from which to start looking for inputs; if absent, Nonodo will start looking at Espresso block 0; in practice, it is often a good idea to query Espresso’s current block height when deploying your application, and use that to appropriately specify this initial block number.
warning

Espresso’s testnet (called “Decaf”) only posts commitments to Sepolia, so you should not deploy your application to other testnets such as Optimism Sepolia or Arbitrum Sepolia.

  • Register your dApp Address

  • To run on the testnet environment you will need a dApp address on the network. For this we prepared a web page where you can resgister an address for your dApp https://address.mugen.builders In the above link you can connect with your wallet and using you public key generate a dApp address that will be used in the command that follows.

  • Start Nonodo using the command with the flag with the flag that enables integration with Espresso;

nonodo \
  --rpc-url https://eth-sepolia.g.alchemy.com/v2/_NNA-xQcIATiYWv_UsRuk7BGLmrbxcvM \
  --contracts-application-address <dapp> \
  --sequencer espresso \
  --espresso-url https://query.decaf.testnet.espresso.network \
  --from-block <blocknumber>

Running the Machine​

  • In another terminal, create and build a new Cartesi dApp using the following command:

1. Python​

cartesi create my-dapp --template python
cd my-dapp
cartesi build
  • Run the Cartesi Machine Locally on bare metal using the command;
cartesi-machine --network --flash-drive=label:root,filename:.cartesi/image.ext2 \
--volume=.:/mnt --env=ROLLUP_HTTP_SERVER_URL=http://10.0.2.2:5004 --workdir=/mnt -- python dapp.py

2. Rust​

cartesi create my-dapp --template rust
cd my-dapp
cartesi build
  • Run the Cartesi Machine Locally on bare metal using the command;
cartesi-machine --network --flash-drive=label:root,filename:.cartesi/image.ext2 --env=ROLLUP_HTTP_SERVER_URL=http://10.0.2.2:5004 -- /opt/cartesi/dapp/dapp

3. Golang​

cartesi create my-dapp --template go
cd my-dapp
cartesi build
  • Run the Cartesi Machine Locally on bare metal using the command;
cartesi-machine --network --flash-drive=label:root,filename:.cartesi/image.ext2 --env=ROLLUP_HTTP_SERVER_URL=http://10.0.2.2:5004 -- /opt/cartesi/dapp/dapp

4. Javascript​

cartesi create my-dapp --template javascript
cd my-dapp
cartesi build
  • Run the Cartesi Machine Locally on bare metal using the command;
cartesi-machine --network --flash-drive=label:root,filename:.cartesi/image.ext2 \
--volume=.:/mnt --env=ROLLUP_HTTP_SERVER_URL=http://10.0.2.2:5004 --workdir=/opt/cartesi/dapp -- node index