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Build a Blind App

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This is the 3rd step in the Blind App Quickstart. Before starting this guide,

  1. Install the Nillion SDK
  2. Create a Nada project and write your first Nada program

Also check that you have Node (>= v18.17) installed by running node -v

Install repo dependencies and run the starter​

Go back to the root directory you created and run the development command.

Open http://localhost:3000/ to see your starter app running locally at port 3000

npm run dev
Nillion Quickstart DemoNillion Quickstart Demo

For this Quickstart, we'll focus on the Nillion Operations page and the Nillion Blind Computation Demo page.

Connect the blind app to nillion-devnet​

In the screenshot of cra-nillion, you'll notice that cluster id and other configuration variables needed to connect to the Nillion Network are not set, so it's not possible to connect NillionClient.

Spin up a local Nillion devnet​

Open a separate terminal and run the devnet using any seed (the example uses "my-seed") so the cluster id, websockets, and other environment variables stay constant even when you restart nillion-devnet.

nillion-devnet

You will see an output like this:

nillion-devnet --seed my-seed
ℹ️ cluster id is 222257f5-f3ce-4b80-bdbc-0a51f6050996
ℹ️ using 256 bit prime
ℹ️ storing state in /var/folders/1_/2yw8krkx5q5dn2jbhx69s4_r0000gn/T/.tmpU00Jbm (62.14Gbs available)
🏃 starting nilchain node in: /var/folders/1_/2yw8krkx5q5dn2jbhx69s4_r0000gn/T/.tmpU00Jbm/nillion-chain
⛓  nilchain JSON RPC available at http://127.0.0.1:48102
⛓  nilchain gRPC available at localhost:26649
🏃 starting node 12D3KooWMGxv3uv4QrGFF7bbzxmTJThbtiZkHXAgo3nVrMutz6QN
⏳ waiting until bootnode is up...
🏃 starting node 12D3KooWKkbCcG2ujvJhHe5AiXznS9iFmzzy1jRgUTJEhk4vjF7q
🏃 starting node 12D3KooWMgLTrRAtP9HcUYTtsZNf27z5uKt3xJKXsSS2ohhPGnAm
👛 funding nilchain keys
📝 nillion CLI configuration written to /Users/steph/Library/Application Support/nillion.nillion/config.yaml
🌄 environment file written to /Users/XXX/Library/Application Support/nillion.nillion/nillion-devnet.env

Refresh your page and you should now be able to press the Login button and it should turn into Log Out. Ensure you are on the Devnet Tab.

Now you can interact with the local devnet and Store a Secrete Integer and Fetch the Value.

Interacting with our Nada Program

We want to now interact with the secret_addition Nada program we created in the previous step. So let's interact with the other module boxes.

  1. Upload your program from your nada/src/target/secret_addition.nada.bin
  2. Copy the programID and use it in the Compute section
  3. Copy the computeOutputID and use it in the Compute Output section
CNA OutputCNA Output

Next steps​

🚀 Woohoo! You've successfully built your first local blind app by writing a Nada program, storing the program on the network, storing secrets on the network, and running compute against secrets. Next, deploy your blind app to the Nillion Network Testnet so anyone in the world can try it.