resend - SKILL.md Agent Skill

name: resend description: Send emails, manage domains, contacts and broadcasts via Resend API user-invocable: true argument-hint: [action or email address]

/resend

Connect to Resend to send transactional emails, manage domains, contacts, broadcasts and API keys. Pure Ruby, zero gems — stdlib only.

Structure

scripts/
├── auth.rb              # Bearer token auth + resend_request helper (required by all scripts)
├── check_setup.rb       # Check if token exists (outputs OK or SETUP_NEEDED)
├── save_token.rb        # Save and validate an API key
├── send_email.rb        # Send an email
├── email.rb             # Get email details
├── emails.rb            # List sent emails
├── cancel_email.rb      # Cancel a scheduled email
├── domains.rb           # List domains
├── domain.rb            # Get domain details with DNS records
├── create_domain.rb     # Create a domain
├── verify_domain.rb     # Verify a domain
├── delete_domain.rb     # Delete a domain
├── contacts.rb          # List contacts
├── create_contact.rb    # Create a contact
├── delete_contact.rb    # Delete a contact
├── broadcasts.rb        # List broadcasts
├── create_broadcast.rb  # Create a broadcast
├── send_broadcast.rb    # Send a broadcast
├── delete_broadcast.rb  # Delete a broadcast
├── api_keys.rb          # List API keys
├── create_api_key.rb    # Create an API key
└── delete_api_key.rb    # Delete an API key

Setup (check before using)

ruby ~/.claude/skills/resend/scripts/check_setup.rb

If the output is OK, proceed to the Flow section.

If the output is SETUP_NEEDED, guide the user step by step. Present ONE step at a time, wait for the user to confirm before moving to the next.

Step 1 — Ask the user to get their API key:

You need a Resend API key.

Go to https://resend.com/api-keys

Click Create API Key

Choose a name and permission level (full-access or sending-access)

Copy the key (starts with re_)

Paste the API key here.

Step 2 — When the user pastes the key, save it:

ruby ~/.claude/skills/resend/scripts/save_token.rb 'PASTED_KEY'

If the script outputs an error, the key is invalid. Ask the user to double-check and try again.

If setup is not complete, DO NOT proceed to the Flow. Complete all steps first.

Flow

The argument $ARGUMENTS may contain an action or email address.

Step 1: List domains

ruby ~/.claude/skills/resend/scripts/domains.rb

Present the domains and ask what the user wants to do.

Step 2: Actions

Send an email (requires user confirmation):

ruby ~/.claude/skills/resend/scripts/send_email.rb "Me <me@example.com>" "user@example.com" "Hello" --html "<h1>Hi!</h1>"
ruby ~/.claude/skills/resend/scripts/send_email.rb "me@example.com" "user@example.com" "Hello" --text "Plain text body"

Get email details:

ruby ~/.claude/skills/resend/scripts/email.rb EMAIL_ID

List sent emails:

ruby ~/.claude/skills/resend/scripts/emails.rb

Cancel a scheduled email (requires user confirmation):

ruby ~/.claude/skills/resend/scripts/cancel_email.rb EMAIL_ID

Create a domain (requires user confirmation):

ruby ~/.claude/skills/resend/scripts/create_domain.rb example.com
ruby ~/.claude/skills/resend/scripts/create_domain.rb example.com --region sa-east-1

Regions: us-east-1 (default), eu-west-1, sa-east-1, ap-northeast-1

Get domain details:

ruby ~/.claude/skills/resend/scripts/domain.rb DOMAIN_ID

Verify a domain:

ruby ~/.claude/skills/resend/scripts/verify_domain.rb DOMAIN_ID

Delete a domain (requires user confirmation):

ruby ~/.claude/skills/resend/scripts/delete_domain.rb DOMAIN_ID

List contacts:

ruby ~/.claude/skills/resend/scripts/contacts.rb

Create a contact (requires user confirmation):

ruby ~/.claude/skills/resend/scripts/create_contact.rb "user@example.com" --first-name "John" --last-name "Doe"

Delete a contact (requires user confirmation):

ruby ~/.claude/skills/resend/scripts/delete_contact.rb CONTACT_ID

List broadcasts:

ruby ~/.claude/skills/resend/scripts/broadcasts.rb

Create a broadcast (requires user confirmation):

ruby ~/.claude/skills/resend/scripts/create_broadcast.rb SEGMENT_ID "Me <me@example.com>" "Newsletter" --html "<h1>News</h1>" --name "March Newsletter"

Add --send to send immediately after creation.

Send a broadcast (requires user confirmation):

ruby ~/.claude/skills/resend/scripts/send_broadcast.rb BROADCAST_ID
ruby ~/.claude/skills/resend/scripts/send_broadcast.rb BROADCAST_ID --scheduled-at "2026-03-10T10:00:00Z"

Delete a broadcast (requires user confirmation):

ruby ~/.claude/skills/resend/scripts/delete_broadcast.rb BROADCAST_ID

List API keys:

ruby ~/.claude/skills/resend/scripts/api_keys.rb

Create an API key (requires user confirmation):

ruby ~/.claude/skills/resend/scripts/create_api_key.rb "my-key" --permission sending-access --domain-id DOMAIN_ID

Delete an API key (requires user confirmation):

ruby ~/.claude/skills/resend/scripts/delete_api_key.rb API_KEY_ID

Notes

Pure Ruby, zero gems — stdlib only (json, net/http, uri, fileutils)
Auth via Bearer token (API key starting with re_)
Token file: ~/.config/resend/token (outside the repo, never commit)
Requires User-Agent header (included automatically in auth helper)
Rate limit: 2 requests/second per team
Sending emails, managing domains/contacts/broadcasts, and API key operations require explicit user confirmation
Sender address format: "Name <email@domain.com>" or plain "email@domain.com"
Scheduled emails support ISO 8601 or natural language dates
Base URL: https://api.resend.com