What if an agent didn’t just call your API, but owned what it built?

That’s what the Agentic Challenge’s Hello World demonstrates: a CLI script registers an ERC-8004 agent, settles its own registration fee through x402, then deploys an ERC-20 token the agent itself owns and controls, no manual top-ups mid-run, the CLI reads the live quote and pays it.

Shortly after, you have a real agent with a real, agent-owned asset on @base Sepolia.

Full walkthrough: https://docs.brickken.com/get-started/build-programme/agentic-hello-world?utm_source=twitter&utm_medium=social&utm_campaign=b2b_buildcampaign…

Join our campaign: https://landing.brickken.com/build-with-brickken?utm_source=twitter&utm_medium=social&utm_campaign=b2b_buildcampaign…

Agentic Challenge — Hello World - Brickken Documentation

Source: https://docs.brickken.com/get-started/build-programme/agentic-hello-world?utm_source=twitter&utm_medium=social&utm_campaign=b2b_buildcampaign This walkthrough is the first step for theAgentic Challenge. You will use the Brickken CLI and x402 on Base Sepolia to register an ERC-8004 agent and deploy an ERC-20 owned by your wallet.

Outcome

At the end, your terminal will show:

• a confirmed ERC-8004 agent registration andagentUuid;
• the stored agent profile read back through the Agentic API;
• a confirmed agent-owned ERC-20 deployment andtokenAddress;
• x402 settlement metadata for the executed operations.

The complete runnable sample is in the publicAgentic Hello World example.

Estimated time

Allow 15–20 minutes for setup, faucet funding, two x402 payments, and confirmation on Base Sepolia.

Prerequisites

The sample uses the public fixtures below so the registration request is runnable without inventing an image or service URL:

• Image:https://docs\.brickken\.com/images/build\-programme/hello\-world\-agent\.svg
• Service endpoint:https://docs\.brickken\.com/downloads/build\-programme/agent\-card\.json

Setup

Clone or download theexample directory, then run:

The environment contract is:

Optional variables let you replace the example agent name, image, service endpoint, and token symbol.

Run

Execute the pinned CLI workflow:

What the script does

1. brickken agent registerprepares and executes an ERC-8004 registration on Base Sepolia with\-\-execution\-mode client\-signed.
2. The script capturesagentUuidand the blockchain transaction hash, then polls the Base Sepolia RPC until the receipt succeeds.
3. brickken agent inforeads the stored profile. Without an API key, this getter uses x402 with the configured wallet.
4. brickken create\-tokendeploys an ERC-20 with the same wallet passed as\-\-signer\-addressand\-\-agent\-wallet.
5. The CLI waits for the deployment receipt and exposestokenAddress; the script checks the x402 settlement and address format.

For client-controlled modes, x402 pricing is split between prepare and send. The CLI performs both payment handshakes locally and reads the live quote, so the example does not assume a fixed amount or payment token. SeeAgentic pricingfor the execution-mode matrix.

Expected output

The script writes JSON files underout/and prints a summary similar to:

Verification

Inspect the sanitized fields inout/register\-output\.json,out/agent\-info\-output\.json, andout/create\-token\-output\.json:

• prepared\.info\.agentUuidexists;
• the registration receipt has status0x1;
• the registration send includes successful x402 settlement metadata;
• the profile read returns the same agent reference;
• sent\.successistruefor token deployment;
• tokenAddressis a 40-hex-character address;
• tokenReceipt\.statusis0x1andtokenTxHashidentifies the deployment receipt;
• sent\.\_x402\.settlement\.successistrue.

Troubleshooting

Security

• Use a disposable Base Sepolia wallet and keep the private key in an environment variable or secret manager.
• Review the live x402 quote before approving each payment; the CLI reads the amount, asset, recipient, and timeout from the challenge.
• Check chain, signer, agent wallet, token symbol, and recipient before executing a write.
• Do not commit\.envor the generatedout/JSON files.

Next challenge ideas

Next, addagent set\-uriandagent set\-metadata, then exercise the token lifecycle withmint,approve, andtransfer. For compliance-gated delegation, continue to theRAMS mandate workflow. MCP users can reach the same Agentic API through thehosted MCP server.