Email

Email is the default interface. No apps to install, works from any device.

Your agent’s address

Free tier: {name}-{hash}@tinyfat.com (e.g., [email protected])
Tiny tier: Custom alias like [email protected]

This is a real email address. Send from Gmail, Outlook, Apple Mail, your phone — anywhere.

How it works

You send email → Platform validates → Agent runs → Agent replies

You email [email protected]
Resend receives it, triggers webhook
Platform validates sender, enqueues job
Queue worker mounts agent’s storage, runs container
Agent processes your message (one turn)
Agent writes response to outbox
Platform sends the reply via Resend
You get the email

Response time is typically 10-30 seconds.

Email commands

Control your agent with commands in the subject or body:

Command	Effect
`/clear`	Start fresh session (keeps history)
`/resume`	List recent sessions
`/resume abc1`	Resume specific session
`/compact`	Compress context to save tokens
`/model`	Show current model
`/model haiku`	Switch to Haiku (~$0.001/msg)
`/model sonnet`	Switch to Sonnet (~$0.015/msg)
`/model opus`	Switch to Opus (~$0.075/msg)

Every response includes stats:

---
[buddy:a1b2 | ↑38 ↓5.0k R663k W37k $0.687 18.7%/200k | claude-haiku-4-5]

buddy:a1b2 — Agent name + session hash (for /resume)
↑38 ↓5.0k — Input/output tokens
R663k W37k — Cache read/write tokens
$0.687 — Cost this turn
18.7%/200k — Context usage
claude-haiku-4-5 — Model

Attachments

Send files to your agent:

Images: PNG, JPG, GIF, WebP — agent can analyze
Documents: PDF, TXT, MD — agent can read
Data: JSON, CSV — agent can process

Files are available during the turn at /inbox/attachments/.

Sending email from your agent

Your agent writes emails to /data/outbox/email/:

{
  "to": ["[email protected]"],
  "subject": "Report ready",
  "body": "Here's the analysis...",
  "status": "pending"
}

The platform picks these up and sends them.

Threading

Responses thread correctly in email clients:

In-Reply-To links to your message
References maintains the full chain
Gmail, Outlook, Apple Mail all group properly

Security

Allowed senders

Only whitelisted addresses can trigger your agent:

Exact: [email protected]
Domain: @company.com (anyone at domain)

Configure in Dashboard → Settings → Allowed Senders.

Webhook verification

Inbound emails are verified using Resend’s webhook signatures (Svix). Invalid payloads are rejected.

Troubleshooting

No response

Check allowed senders list
Verify API key is set
Check dashboard for errors

Went to spam

Add your agent’s address to contacts or mark “not spam”.

Threading broken

Some corporate email systems modify headers. Try a personal email client.

Next steps

Email JSON Reference — Full outbox format
Troubleshooting — Common issues