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Connect your Resend API key and let your AI agents send transactional emails, manage audiences and contacts, create templates, and configure sending domains — all from Mantle.

What you unlock

Transactional email

Send single or batch emails through Resend — welcome messages, receipts, notifications, and more.

Audience management

Create audiences, manage contacts, and organize segments for targeted communication.

Email templates

Create, update, and publish email templates — manage your email design system from chat.

Domain management

Add sending domains, verify DNS records, and manage API keys for different services.

Connect Resend

1

Open Settings → Integrations

In any workspace go to Settings → Integrations and select Resend.
2

Get your API key

Log in at resend.com, go to API Keys, and create a new API key with the permissions your agent needs.
3

Paste and connect

Paste the key into the API Key field and click Connect.

Agent tools

Any agent in your workspace can use Resend tools once an API key is connected.

Emails

ToolDescription
Send emailSend a single transactional email
Send batch emailsSend multiple emails in a single request
Retrieve emailGet details and delivery status of a sent email
Cancel emailCancel a scheduled email before delivery
List emailsList sent emails with status filters

Audiences & Contacts

ToolDescription
Create audienceCreate a new audience for targeted emails
List audiencesList all audiences in your account
Create contactAdd a contact to an audience
Update contactUpdate contact details or subscription status
List contactsList contacts in an audience

Templates & Domains

ToolDescription
Create templateCreate a new email template
Publish templatePublish a template for use in sending
List templatesList all email templates
Create domainAdd a new sending domain
Verify domainVerify DNS records for a sending domain
List domainsList all configured sending domains

Triggers

Automated triggers for Resend are not yet available. Triggers will be added in a future update — check back soon.

Example use cases

Ask your agent to send an email to a specific address with a subject and body — it handles the API call and confirms delivery status. Great for one-off notifications or follow-ups.
Add or update contacts in your audience without opening the Resend dashboard. Ask your agent to add a new subscriber or update an existing contact’s metadata.
After sending a batch of emails, ask your agent to check the delivery status — it retrieves each email’s status (delivered, bounced, complained) and summarizes the results.

Troubleshooting

Verify the key was created at resend.com/api-keys and has the required permissions. Generate a fresh key if the current one doesn’t work.
Check that your sending domain is verified in Resend. Unverified domains will cause emails to fail. Use “List domains” and “Verify domain” to check and fix DNS configuration.
Some emails in a batch may fail due to invalid addresses or rate limits. Use “Retrieve email” to check the status of individual emails and identify the failures.
Templates must be published after changes. Use “Publish template” to make your latest edits available for sending.

Back to Integrations

View all available integrations