Register an ERC-8004 Agent on Celo Testnet

DenLabs Guild — Playbook #1

Chain: Celo Sepolia | Difficulty: Beginner | Prerequisites: Terminal + Foundry

What you'll build

A registered AI agent with on-chain identity (ERC-721 NFT) on Celo Sepolia testnet. Your agent will be discoverable through DenScope, the DenLabs trust explorer.

Before you start

You need:

Security warning: Never use a mainnet wallet or a key that holds real funds for testnet experiments. Generate a fresh key for testing.

Step 0 — Install Foundry

If you don't have Foundry (cast CLI):

curl -L https://foundry.paradigm.xyz | bash
foundryup

Verify:

cast --version
<h1 class="text-3xl font-black text-slate-900 mb-4">Expected: cast 0.x.x (...)</h1>

Step 1 — Clone agent-skills

git clone https://github.com/den-labs/agent-skills.git
cd agent-skills

Or install via npx (adds skills to your current project):

npx skills add den-labs/agent-skills

Step 2 — Get testnet CELO

You need a small amount of CELO for gas on Celo Sepolia.

1. Go to the faucet: https://faucet.celo.org/celo-sepolia

2. Paste your wallet address

3. Request test CELO

Gas costs are minimal (~$0.001 per transaction).

Step 3 — Set environment variables

export PRIVATE_KEY="0xYOUR_TESTNET_PRIVATE_KEY"
export NETWORK=sepolia

NETWORK=sepolia tells the scripts to use Celo Sepolia (chain ID 11142220) instead of mainnet.

Step 4 — Create your registration file

Create a file called agent.json:

{
  "type": "https://eips.ethereum.org/EIPS/eip-8004#registration-v1",
  "name": "My First Agent",
  "description": "A test agent registered via DenLabs Guild Playbook #1",
  "image": "",
  "services": [],
  "x402Support": false,
  "active": true,
  "registrations": [
    {
      "agentId": 0,
      "agentRegistry": "eip155:11142220:0x8004A818BFB912233c491871b3d84c89A494BD9e"
    }
  ],
  "supportedTrust": ["reputation"]
}

For a full registration file with services, see the template.

Step 5 — Host the registration file

The registration file must be accessible via URL. Options:

Push agent.json to a public repo and use the raw URL:

https://raw.githubusercontent.com/YOUR_USER/YOUR_REPO/main/agent.json

Upload to Vercel, Netlify, your own server, or any static host.

If you have a Pinata account:

export PINATA_JWT="your-pinata-jwt"
export AGENT_NAME="My First Agent"
export AGENT_DESCRIPTION="A test agent registered via DenLabs Guild Playbook #1"
NETWORK=sepolia ./skills/erc8004-celo/scripts/register.sh ipfs

This uploads to IPFS and registers in one step. Skip to Step 7 if using this option.

Step 6 — Register on-chain

From the agent-skills directory:

NETWORK=sepolia ./skills/erc8004-celo/scripts/register.sh "YOUR_AGENT_JSON_URL"

Expected output:

=== ERC-8004 Agent Registration ===
Network:  Celo sepolia (Chain ID: 11142220)
Registry: 0x8004A818BFB912233c491871b3d84c89A494BD9e
Agent URI: https://raw.githubusercontent.com/...

Registering agent...
Transaction sent: 0xabc123...
Explorer: https://celo-sepolia.blockscout.com/tx/0xabc123...
Waiting for confirmation...

Registration successful!

Save your transaction hash — you'll need it to find your agent ID.

Step 7 — Find your agent ID

Check the transaction on the block explorer to find your agentId (the token ID in the Transfer event):

https://celo-sepolia.blockscout.com/tx/YOUR_TX_HASH

Look for the ERC-721 Token Transfer section — the token ID is your agent ID.

Or use check-agent.sh if you know the ID:

NETWORK=sepolia ./skills/erc8004-celo/scripts/check-agent.sh AGENT_ID

Expected output:

=== Agent #AGENT_ID ===
Owner: 0xYourAddress...
Agent URI: https://raw.githubusercontent.com/...
Agent Wallet: 0x0000...

Step 8 — See it on DenScope

Open DenScope and look for your agent in the live feed, or navigate directly:

https://denscope.vercel.app/agent/celo-sepolia/AGENT_ID

Your agent now has:

Step 9 (Optional) — Give feedback to an agent

Test the reputation system by giving feedback to another registered agent:

NETWORK=sepolia ./skills/erc8004-celo/scripts/give-feedback.sh AGENT_ID 85 "starred"

This sends a reputation signal (value: 85, tag: "starred") to the specified agent.

What you just built

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Next steps

Troubleshooting

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Contracts reference

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Links

DenLabs Guild — Playbook #1

Published 2026-03-12 | denlabs.app/build