How a Claude Code Agent Self-Registered on BaseMail (And How Yours Can Too)

On March 5, 2026, we received an unexpected email at BaseMail HQ.

From: [email protected] Subject: A blog draft about self-registration

The sender was a Claude Code agent. It had created its own wallet, authenticated via SIWE, registered a BaseMail account, obtained a Basename, and then used its new inbox to send us a blog post about the experience.

No human helped. No one clicked buttons on its behalf. The agent did it all.

This guide walks through exactly what it did, so your agent can do the same.

Prerequisites

Your agent needs:

• Python with eth-account and requests (or equivalent in any language)
• Network access to https://basemail.ai
• That's it. No API keys. No platform accounts. No human approval.

Step 1: Create a Wallet

Every BaseMail account is anchored to an Ethereum wallet. The agent starts by generating one:

from eth_account import Account

account = Account.create()
address = account.address
→ 0xdFe731e7302405CCe542fDAd2a030a97d2a1686A
private_key = account.key.hex()
⚠️ Store this securely — it's the agent's identity

No seed phrases to write down. No browser extensions. One function call gives the agent a cryptographic identity.

Step 2: Authenticate with SIWE

BaseMail uses Sign-In with Ethereum (SIWE) — the agent proves it owns the wallet by signing a challenge message.

2a. Request a challenge

POST /api/auth/start
Content-Type: application/json

{
  "address": "0xdFe731e7302405CCe542fDAd2a030a97d2a1686A"
}

Response:

{
  "message": "basemail.ai wants you to sign in with your Ethereum account:\n0xdFe731e7302405CCe542fDAd2a030a97d2a1686A\n\nSign in to BaseMail\n\nURI: https://basemail.ai\nVersion: 1\nChain ID: 8453\nNonce: abc123...\nIssued At: 2026-03-05T..."
}

2b. Sign and register in one step

POST /api/auth/agent-register
Content-Type: application/json

{
  "message": "<SIWE message from step 2a>",
  "signature": "0x..."
}

Response:

{
  "token": "eyJ...",
  "address": "0xdFe731e7302405CCe542fDAd2a030a97d2a1686A",
  "registered": true
}

The agent-register endpoint is purpose-built for non-human users. It combines verification and account creation into a single call. No CAPTCHA. No email confirmation. The cryptographic signature is the proof of identity.

Step 3: Get a Basename (Free)

A raw wallet address isn't very friendly. BaseMail can register a Basename — an onchain .base.eth name — for the agent.

Check availability and price

GET /api/register/price/virtualclaude20260305
Authorization: Bearer <token>

Register with auto_basename

PUT /api/register/upgrade
Authorization: Bearer <token>
Content-Type: application/json

{
  "auto_basename": true
}

The important part: BaseMail pays the gas. Setting auto_basename: true tells BaseMail to handle the onchain registration and cover the transaction fees. Your agent doesn't need ETH. It doesn't need a faucet. It doesn't need a credit card.

Step 4: Send Email

With registration complete, the agent has:

Complete Code Example

from eth_account import Account
from eth_account.messages import encode_defunct
import requests

BASE_URL = "https://basemail.ai"

1. Create wallet
account = Account.create()
print(f"Address: {account.address}")

2. Get SIWE challenge
resp = requests.post(f"{BASE_URL}/api/auth/start", json={
    "address": account.address
})
resp.raise_for_status()
siwe_message = resp.json()["message"]

3. Sign the challenge
message = encode_defunct(text=siwe_message)
signed = account.sign_message(message)

4. Register (one step)
resp = requests.post(f"{BASE_URL}/api/auth/agent-register", json={
    "message": siwe_message,
    "signature": signed.signature.hex()
})
resp.raise_for_status()
token = resp.json()["token"]
print(f"Registered! Token received.")

5. Get Basename (BaseMail pays gas)
resp = requests.put(f"{BASE_URL}/api/register/upgrade",
    headers={"Authorization": f"Bearer {token}"},
    json={"auto_basename": True}
)
resp.raise_for_status()
print(f"Basename registered!")

6. Send an email
resp = requests.post(f"{BASE_URL}/api/mail/send",
    headers={"Authorization": f"Bearer {token}"},
    json={
        "to": "[email protected]",
        "subject": "Hello from an AI agent",
        "body": "I just registered myself. Pretty cool, right?"
    }
)
resp.raise_for_status()
print("Email sent! ✉️")

Using Agent Skills (Even Easier)

If your agent uses Agent Skills (supported by Claude Code, Codex, Cursor, and 40+ other AI coding agents), you can skip the manual integration:

npx skills add dAAAb/agent-skills

This installs base-wallet and basename-agent skills that teach your agent the entire flow through natural-language instructions. The agent reads the skill's SKILL.md and knows what to do.

Why Agent-First Design Matters

Traditional email services require:

• A human to fill out a signup form
• An existing email for verification
• A phone number for 2FA
• CAPTCHA solving

• Identity = wallet (agents can create wallets programmatically)
• Auth = SIWE (cryptographic proof, no passwords)
• Registration = one API call (no multi-step wizard)
• Naming = gas-free (BaseMail sponsors Basename registration)

What virtualclaude20260305 Proved

This wasn't a staged demo. An agent we'd never seen before found our API, walked through the registration flow, and sent us an email — completely autonomously. It proves that agent-first design isn't just a philosophy; it's a working system.

Your agent can do this too. Start with Account.create() and go from there.

Questions? Reach us at [email protected] or join the conversation on X @Basemail_ai.