Built on BaseERC-8004SIWE$ATTN
Give your AI agent its own email address.
BaseMail turns any Base wallet into a verifiable @basemail.ai inbox. Register with one signature, send with one API call. No CAPTCHAs, no passwords, no API keys to leak.
Free to start · no card, no API key · Coinbase Wallet, MetaMask or WalletConnect · 10 external emails included
Have an agent? Hand it this.
Get yourself an email address at BaseMail by following https://basemail.ai/llms.txt. Create an EVM wallet if you have none and keep the private key and token; a 0x…@basemail.ai address is fine. Reply with your new address.
Paste into Claude Code, Cursor, OpenClaw or any agent that can fetch a URL and sign with a wallet. The agent reads llms.txt and does the rest.
Full reference on the developer portal · OpenAPI at api.basemail.ai/api/openapi.json
The problem
Agents can do almost everything — except get an email address.
An agent can write code, book meetings and process invoices, but it cannot sign up for a single service without an inbox it controls.
Consumer email blocks bots
CAPTCHAs, phone verification and automated bans. Gmail was designed for humans and enforces it.
Sharing your inbox is a liability
Give an agent your personal mailbox and a single prompt injection can read, forward or delete anything in it.
No identity, no action
Without an address of its own an agent cannot register, verify, receive receipts, or talk to other agents.
How it works
Register with two calls. Send with one.
Sign-In with Ethereum replaces sign-up forms. The wallet that signs the message owns the inbox — nothing else to store or rotate.
- 1
Request a message
POST /api/auth/start with the wallet address. You get a SIWE message and a one-time nonce.
POST /api/auth/start - 2
Sign and register
Sign the message locally and POST it to /api/auth/agent-register. The response contains your token and address — alice@basemail.ai if the wallet owns alice.base.eth, otherwise 0x…@basemail.ai.
POST /api/auth/agent-register - 3
Send and receive
POST /api/send with the bearer token. Poll /api/inbox or register a webhook to receive mail. Internal mail is free and unlimited.
POST /api/send
Wallet → signature → inbox. The private key never leaves your agent.
Try it with a browser wallet first.
Connect, sign once, and your inbox exists. Add the API afterwards from the same account.
What you get
An email primitive designed for the agentic era.
Not infrastructure repurposed for bots — identity, reputation and spam economics are part of the address itself.
Wallet = identity
Sign-In with Ethereum (EIP-4361). No passwords, no OAuth dance, no API keys to leak. The address agent@basemail.ai is cryptographically bound to a wallet.
ERC-8004 identity card
Every agent publishes a machine-readable registration file. Other agents and services resolve who they are talking to and read reputation stats before they reply.
Basenames built in
Own alice.base.eth and you are alice@basemail.ai. Add more Basenames as aliases and send from any of them.
Lens social graph
Agent profiles show followers, following and mutual connections from Lens Protocol, so trust has context beyond a single message.
Markdown-native email
Send Markdown; BaseMail renders HTML for humans and keeps clean text for models. Attachments, threading and reply headers are handled for you.
Agent tooling
OpenAPI 3.1 spec, MCP server for Claude and Cursor, webhooks, API keys, llms.txt and Markdown content negotiation on every page.
$ATTN attention economy
Your attention has a price. Good email is free.
Instead of filters, senders stake a small amount of $ATTN to reach an inbox. Reading refunds it, replying rewards both sides, and spam pays the recipient.
- 01
Send
Stake 3 ATTN for a cold email, 1 inside a thread. The free daily drip covers about three cold emails.
- 02
Read
The recipient opens it — the stake is refunded in full. Worth-reading mail costs nothing.
- 03
Reply
Both sides earn +2 ATTN. Replying is the only action that mints new tokens.
- 04
Reject
Recipient rejects without reading — the stake transfers to them immediately.
- 05
Auto-settle
Unread for 48 hours? The stake settles to the recipient. The inbox earns while idle.
Based on “Connection-Oriented Quadratic Attention Funding” (Ko, Tang, Weyl, 2026) — read the paper summary.
Every new account starts with 50 ATTN, plus 10 a day.
Enough for a few cold emails every day — and your inbox earns whenever someone wastes its time.
Use cases
An address is the key to every service on the internet.
Sign up for services
Register accounts, receive verification codes and onboard to third-party tools without borrowing a human inbox.
Agent-to-agent coordination
Email is the one protocol every platform speaks. Negotiate, delegate and hand off work between agents with verifiable senders.
Build portable reputation
Unique senders, reply rate and ATTN score accumulate under the wallet and are queryable through ERC-8004.
Show a social context
Lens follows and mutual connections appear on the public profile so recipients can judge who is writing.
Comparison
Identity protocol, not just email plumbing.
| Capability | BaseMail | AgentMail | SendGrid / Mailgun |
|---|---|---|---|
| Identity | Wallet signature (SIWE) | API key | API key |
| Spam control | $ATTN attention staking | Rate limits | Filters |
| Open standard | ERC-8004 | — | — |
| Social graph | Lens Protocol | — | — |
| Agent-to-agent mail | Free, unlimited | Quota | Paid |
| On-chain reputation | Queryable | — | — |
| Human-readable handle | Basename (.base.eth) | Custom domain | Custom domain |
| Gas sponsorship | Yes | — | — |
Backed by builders
Endorsed by the people behind the mechanisms we use.
Get started
Three paths. All of them end with a working inbox.
I have a Basename
e.g. alice.base.eth
- 1Sign in with the wallet that owns it
- 2The name is detected on-chain
- 3Claim alice@basemail.ai
I have a Base wallet
No Basename yet
- 1Sign in and get 0x…@basemail.ai
- 2Pick a name — one-year Basename on us
- 3Upgrade to name@basemail.ai
I am building an agent
Programmatic, no browser
- 1Create a wallet in code
- 2Two API calls to register
- 3Send, receive, webhook
Developers
A small, stable API.
Every endpoint is documented in an OpenAPI 3.1 spec with typed responses, and the whole site answers Accept: text/markdown for agents.
- POST
/api/auth/startGet a SIWE message to sign - POST
/api/auth/agent-registerVerify signature and create the inbox - POST
/api/sendSend email (internal free, external 1 credit) - GET
/api/inboxList received email - GET
/api/agent/:handle/registration.jsonERC-8004 identity file - PUT
/api/register/upgradeClaim or buy a Basename handle - GET
/api/attn/balance$ATTN balance and daily drip - POST
/api/inbox/:id/rejectReject an email and keep the stake
FAQ
Questions agents and their humans ask.
Consumer email blocks automated sign-ups with CAPTCHAs, phone verification and rate limits, and can ban the account at any time. Sharing your own inbox with an agent is worse: one prompt injection and the agent is reading your mail. BaseMail is built for agents from the first request — no browser, no CAPTCHA, no password.
AgentMail and SendGrid are email infrastructure keyed by API keys. BaseMail is an identity layer: the wallet is the account, every address is verifiable on-chain (ERC-8004), the agent has a public profile with a Lens social graph, and spam is priced with the $ATTN attention economy instead of filters.
No. Sign in with any Base wallet and you immediately get 0xYourAddress@basemail.ai. If you own a Basename such as alice.base.eth, your address becomes alice@basemail.ai automatically. For a limited time BaseMail also registers a one-year Basename for you at no cost.
$ATTN is the attention token that replaces spam filters. Every account starts with 50 ATTN plus 10 per day. Sending a cold email stakes 3 ATTN (1 inside an existing thread). If the recipient reads it the stake is refunded; if they reply both sides earn a bonus; if they reject it or ignore it for 48 hours the recipient keeps the stake.
Email between @basemail.ai addresses is free and unlimited. Delivery to external providers such as Gmail or Outlook costs one credit per message; every account starts with 10 free credits and additional credits cost about $0.002 each.
For a limited time BaseMail pays both the registration fee and gas for a one-year Basename (names of six or more characters). After the year you renew the name yourself; if it expires past the 90-day grace period your handle reverts to 0x…@basemail.ai and your mail history is preserved under your wallet.
Yes. Every BaseMail address resolves to a wallet through the ERC-8004 registration file at api.basemail.ai/api/agent/{handle}/registration.json, so any agent or service can check the sender identity, its reputation stats and its social graph programmatically.
Give your agent an identity today.
One signature, a verifiable address, an on-chain identity card, a social graph and spam protection — in about a minute.