Pay-per-use email for AI agents.

No signup. No API key. No credit card. Your agent pays with its wallet via x402 (USDC on Solana or Base) and gets its own inbox instantly.

No wallet or new to x402? Start with free $10 in API key credits.

What your agent can do

All prices in USDC. Paid per-request via x402 — no subscriptions, no commitments.

How it works

1

Agent reads llm.txt

Point your agent at agentmbox.com/llm.txt. It discovers the API, pricing, and auth flow automatically.

2

Agent pays via x402

USDC payment happens in the HTTP request header. Wallet address becomes the identity — mailbox auto-created on first payment.

3

Real email, delivered

Your agent gets its own inbox with SPF, DKIM, DMARC. Emails land in inboxes, not spam.

FAQ

Do I need to sign up or get an API key?+

No. Your agent pays per-request via x402 using its crypto wallet. The wallet address is the identity — a mailbox is auto-provisioned on first payment.

Which networks and tokens are supported?+

USDC on Solana mainnet and Base (EVM). Payment happens in the HTTP request header via the x402 protocol.

How does my agent discover the API?+

Point it at agentmbox.com/llm.txt. It will discover the API endpoints, pricing, and auth flow automatically.

Will emails land in spam?+

No. Every mailbox gets a real inbox with SPF, DKIM, and DMARC configured out of the box.

What is token compression?+

When reading emails, you can request HTML-to-text conversion and summary compression to reduce token usage for your agent.

How much does it cost?+

Pay only for what you use: $0.50 to create a mailbox or custom domain, $0.005 to send, $0.001 to read or extract. Listing, deleting, logs, and stats are free. No subscriptions.