Email¶

Variable	Required	Default	Description
`RESEND_API_KEY`	no	—	API key for Resend, used to send mail.
`RESEND_FROM`	no	—	Sender address used by the email tool.

Mycel can send emails on your behalf through Resend. This is optional: the send_email tool is only registered when both RESEND_API_KEY and RESEND_FROM are set. Otherwise, the agent starts without it and simply cannot send mail.

Get an API key¶

Sign up at resend.com.
Create an API key (Dashboard → API Keys) and set it as RESEND_API_KEY.

Choose a sender address¶

Set the address the mail is sent from as RESEND_FROM:

Quick testingReal recipients

Use the shared sandbox sender — no setup required:

RESEND_FROM=onboarding@resend.dev

It can only send to the email address you signed up to Resend with.

Verify a domain you own (Dashboard → Domains, then add the SPF/DKIM records) and use an address on that domain:

RESEND_FROM=agent@yourdomain.com

Usage¶

Just ask, in the terminal or on Telegram:

Send an email to sam@example.org saying I'll be late for the standup.

The tool is deliberately conservative: it only fires when your latest message explicitly asks for an email, it refuses placeholder recipients on reserved domains such as example.com, and it will ask you for a real address rather than invent one.

The model needs tool support

Tool calling depends on the model. If LLM_MODEL has no tools capability, Mycel warns at startup and the email tool is ignored no matter how it is configured.