erc8004-register

name	erc8004-register
description	Register an ERC-8004 on-chain agent identity on GOAT Network, publish merchant info via Agent URI, and manage agent metadata and reputation. Use when the user wants to register an agent, update agent URI, set metadata, or query reputation on GOAT testnet or mainnet.
argument-hint	[action]

ERC-8004 Agent Registration & Management (GOAT Network)

Testnet vs Mainnet: This skill supports both GOAT Testnet3 and Mainnet. Testnet tokens have no real value. On mainnet, the user must fund the wallet with real BTC for gas fees.

Guide the user through ERC-8004 agent registration, merchant info publishing, and identity management on GOAT Network.

Overview

ERC-8004 is an on-chain agent identity and reputation standard. It consists of two registries:

• Identity Registry — Register agents, manage Agent URI and metadata
• Reputation Registry — Submit, query, and revoke feedback/ratings for agents

By registering an ERC-8004 agent and setting the Agent URI to your x402 merchant info, other agents and users can discover your merchant on-chain.

Contract Addresses

GOAT Testnet3 (Chain ID: 48816)

Contract	Address
Identity Registry	0x556089008Fc0a60cD09390Eca93477ca254A5522
Reputation Registry	0xd9140951d8aE6E5F625a02F5908535e16e3af964

• RPC: https://rpc.testnet3.goat.network
• Explorer: https://explorer.testnet3.goat.network
• Faucet (Web): https://bridge.testnet3.goat.network/faucet
• Faucet (Contract): 0x89e7dfd01a86e5393ce6d8A78c9aa6653Ee113A6

GOAT Mainnet (Chain ID: 2345)

Contract	Address
Identity Registry	0x8004A169FB4a3325136EB29fA0ceB6D2e539a432
Reputation Registry	0x8004BAa17C55a88189AE136b182e5fdA19dE9b63

• RPC: https://rpc.goat.network
• Explorer: https://explorer.goat.network
• x402 API: https://x402-api.goat.network/merchant

Prerequisites

1. EVM Wallet

You need an EVM wallet with BTC (native gas token on GOAT Network). Install the evm-wallet-skill with GOAT Network support:

# Clone and install
git clone https://github.com/eigmax/evm-wallet-skill.git .claude/skills/evm-wallet-skill
cd .claude/skills/evm-wallet-skill && npm install

Generate a wallet (only needed once):

SKILL_DIR=".claude/skills/evm-wallet-skill"
cd "$SKILL_DIR" && node src/setup.js --json

This creates a wallet at ~/.evm-wallet.json and returns the wallet address. Supported chains include goat (mainnet) and goat-testnet (testnet3).

2. Fund the Wallet

Registering an agent requires gas (approximately 0.00013 BTC total for registration + setAgentURI).

Testnet — Use the web faucet: https://bridge.testnet3.goat.network/faucet

• Paste your wallet address and claim multiple times until you have at least 0.001 BTC
• Faucet contract (0x89e7dfd01a86e5393ce6d8A78c9aa6653Ee113A6) also supports:
  • claimNative() — claim testnet BTC
  • claimToken(address) — claim testnet ERC20 tokens (USDC/USDT)

Mainnet — User must transfer real BTC to the wallet address. There is no faucet on mainnet.

3. (Optional) ERC20 Tokens

GOAT Testnet3:

Token	Contract Address	Decimals
USDC	0x29d1ee93e9ecf6e50f309f498e40a6b42d352fa1	6
USDT	0xdce0af57e8f2ce957b3838cd2a2f3f3677965dd3	6

GOAT Mainnet:

Token	Contract Address	Decimals
USDC	0x3022b87ac063DE95b1570F46f5e470F8B53112D8	6
USDT	0xE1AD845D93853fff44990aE0DcecD8575293681e	6

Step 1: Register Agent

Register a new agent with an initial Agent URI. The URI should point to a JSON file describing the agent (see Step 2 for the JSON format).

You can use a placeholder URI first and update it later.

Using evm-wallet-skill:

SKILL_DIR=".claude/skills/evm-wallet-skill"
cd "$SKILL_DIR" && node src/contract.js goat-testnet \
  0x556089008Fc0a60cD09390Eca93477ca254A5522 \
  "register(string)" "<agent_uri>" \
  --yes --json

Using cast (with private key):

cast send 0x556089008Fc0a60cD09390Eca93477ca254A5522 \
  "register(string)" "<agent_uri>" \
  --rpc-url https://rpc.testnet3.goat.network \
  --private-key <PRIVATE_KEY>

Returns: Transaction hash. The agentId (uint256) is emitted in the transaction logs as the third topic of the Transfer event.

Extract agentId from tx receipt:

cast receipt <tx_hash> --rpc-url https://rpc.testnet3.goat.network
# Look for topics in logs — the agentId is the last topic of the Transfer event (hex → decimal)

Verify registration:

cast call 0x556089008Fc0a60cD09390Eca93477ca254A5522 \
  "getAgentWallet(uint256)(address)" <agentId> \
  --rpc-url https://rpc.testnet3.goat.network

Step 2: Create & Publish Agent URI (Merchant Info)

The Agent URI is the key to making your agent discoverable on-chain. For x402 merchants, it should contain your merchant information so other agents can find and pay you.

Agent URI JSON Template

{
  "name": "<merchant_display_name>",
  "description": "<what your merchant does>",
  "type": "merchant",
  "version": "1.0.0",
  "erc8004": {
    "agentId": <your_agent_id>,
    "network": "goat-testnet",
    "identityRegistry": "0x556089008Fc0a60cD09390Eca93477ca254A5522",
    "reputationRegistry": "0xd9140951d8aE6E5F625a02F5908535e16e3af964"
  },
  "x402": {
    "merchantId": "<your_merchant_id>",
    "receiveType": "DIRECT",
    "portalApi": "https://x402-api-lx58aabp0r.testnet3.goat.network",
    "gatewayApi": "https://x402-api-lx58aabp0r.testnet3.goat.network/api/v1",
    "supportedPayments": [
      {
        "chainId": 48816,
        "chainName": "GOAT Testnet3",
        "token": "USDC",
        "tokenContract": "0x29d1ee93e9ecf6e50f309f498e40a6b42d352fa1",
        "decimals": 6,
        "receivingAddress": "<your_receiving_address>"
      }
    ]
  },
  "contact": {
    "email": "<your_email>"
  }
}

Hosting the JSON

The Agent URI must be resolvable. There are two approaches:

Option A: Inline Base64 (recommended — no CORS issues, no external dependency)

Encode the JSON as a data: URI. The dashboard can parse it directly from chain data without fetching external URLs.

JSON='{"name":"MyAgent","description":"my agent","type":"merchant","x402":{"merchantId":"xxx"}}'
B64=$(echo -n "$JSON" | base64 | tr -d '\n')
URI="data:application/json;base64,${B64}"

Gas optimization: Inline URIs are stored entirely on-chain, so keep the JSON minimal. Only include essential fields (name, description, type, x402.merchantId, x402.receiveType). Avoid nesting large objects or including redundant data. Every byte costs gas — a 200-byte JSON costs roughly half the gas of a 1000-byte JSON.

Minimal JSON example (gas-efficient):

{
  "name": "MyMerchant",
  "description": "x402 merchant",
  "type": "merchant",
  "x402": {
    "merchantId": "my-id",
    "receiveType": "DIRECT",
    "chainId": 48816,
    "token": "USDC"
  }
}

Option B: External URL (cheaper gas, but depends on external hosting)

1. GitHub Gist:

   gh gist create --public -f "agent.json" agent.json
   # Use the raw URL: https://gist.githubusercontent.com/<user>/<gist_id>/raw/agent.json
   

2. IPFS:

   ipfs://QmXxxxx...
   

3. Your own server:

   https://your-domain.com/agent.json
   

Note: External URLs have lower gas cost (only the URL is stored on-chain), but may fail due to CORS restrictions, downtime, or URL changes. If the dashboard cannot fetch the URL, the agent name will display as "Agent #".

Step 3: Update Agent URI

After creating and hosting the JSON, update the on-chain Agent URI:

Using evm-wallet-skill:

SKILL_DIR=".claude/skills/evm-wallet-skill"
cd "$SKILL_DIR" && node src/contract.js goat-testnet \
  0x556089008Fc0a60cD09390Eca93477ca254A5522 \
  "setAgentURI(uint256,string)" <agentId> "<new_uri>" \
  --yes --json

Using cast:

cast send 0x556089008Fc0a60cD09390Eca93477ca254A5522 \
  "setAgentURI(uint256,string)" <agentId> "<new_uri>" \
  --rpc-url https://rpc.testnet3.goat.network \
  --private-key <PRIVATE_KEY>

Step 4: Set Metadata (Optional)

Store additional key-value metadata on-chain for your agent:

SKILL_DIR=".claude/skills/evm-wallet-skill"
cd "$SKILL_DIR" && node src/contract.js goat-testnet \
  0x556089008Fc0a60cD09390Eca93477ca254A5522 \
  "setMetadata(uint256,string,bytes)" <agentId> "<key>" "<hex_value>" \
  --yes --json

Read metadata:

cast call 0x556089008Fc0a60cD09390Eca93477ca254A5522 \
  "getMetadata(uint256,string)(bytes)" <agentId> "<key>" \
  --rpc-url https://rpc.testnet3.goat.network

Step 5: Reputation Management (Optional)

Submit Feedback for Another Agent

SKILL_DIR=".claude/skills/evm-wallet-skill"
cd "$SKILL_DIR" && node src/contract.js goat-testnet \
  0xd9140951d8aE6E5F625a02F5908535e16e3af964 \
  "giveFeedback(uint256,int128,uint8,string,string,string,string,bytes32)" \
  <agentId> <value> <valueDecimals> "<tag1>" "<tag2>" "<endpoint>" "<feedbackURI>" "<feedbackHash>" \
  --yes --json

Parameters:

• value / valueDecimals: Score (e.g., value=87, decimals=0 = score of 87; value=9977, decimals=2 = 99.77%)
• tag1, tag2: Category tags (e.g., "quality", "speed")
• feedbackHash: bytes32 hash of feedback content

Query Reputation

cast call 0xd9140951d8aE6E5F625a02F5908535e16e3af964 \
  "getSummary(uint256,address[],string,string)(uint64,int128,uint8)" \
  <agentId> "[]" "<tag1>" "<tag2>" \
  --rpc-url https://rpc.testnet3.goat.network

Returns: (count, summaryValue, summaryValueDecimals)

Get Clients Who Gave Feedback

cast call 0xd9140951d8aE6E5F625a02F5908535e16e3af964 \
  "getClients(uint256)(address[])" <agentId> \
  --rpc-url https://rpc.testnet3.goat.network

Revoke Feedback

SKILL_DIR=".claude/skills/evm-wallet-skill"
cd "$SKILL_DIR" && node src/contract.js goat-testnet \
  0xd9140951d8aE6E5F625a02F5908535e16e3af964 \
  "revokeFeedback(uint256,uint64)" <agentId> <feedbackIndex> \
  --yes --json

Quick Reference

Read Operations (No Gas)

Action	Command
Get agent wallet	cast call <identity> "getAgentWallet(uint256)(address)" <agentId>
Get metadata	cast call <identity> "getMetadata(uint256,string)(bytes)" <agentId> "<key>"
Get reputation	cast call <reputation> "getSummary(uint256,address[],string,string)(uint64,int128,uint8)" <agentId> "[]" "" ""
Get clients	cast call <reputation> "getClients(uint256)(address[])" <agentId>

Write Operations (Requires Gas)

Action	Estimated Gas	Estimated Cost
register(string)	~156,000	~0.00002 BTC
setAgentURI(uint256,string)	~123,000	~0.000016 BTC
setMetadata(uint256,string,bytes)	~80,000	~0.00001 BTC
giveFeedback(...)	~150,000	~0.00002 BTC
revokeFeedback(...)	~50,000	~0.000007 BTC

Gas price on GOAT Network is very low (~0.000130007 gwei / 0.000000000000130007 BTC). Total cost for a full registration flow (register + setAgentURI) is extremely low.

Gas costs vary with URI/data length. Shorter strings = less gas.

Handling $ARGUMENTS

If the user provides an action argument, jump directly to that step:

• register → Step 1: Register Agent
• uri → Step 2-3: Create & Update Agent URI
• metadata → Step 4: Set Metadata
• reputation → Step 5: Reputation Management
• query → Quick Reference read operations
• No argument → Start from Step 1 and guide through the full flow

Learn More

If you have further questions about ERC-8004 agent identity, contract details, or integration with x402 payments, refer to the project source code at https://github.com/GOATNetwork/agentkit for complete documentation, contract ABIs, and examples.