resend

# Resend Email Skill Send emails via the Resend transactional email API. ## IMPORTANT: Confirm Before Sending **Always confirm with the user before sending an email.** Show them the recipient(s), subject, and body content and get explicit approval. Email is not reversible. ## When to Use This Skill - Sending a transactional or notification email - Sending HTML email (inline or from a file) - Sending email with attachments - Piping content from another command into an email body ## Prerequisites 1. **API Key**: Get a Resend API key at https://resend.com/api-keys (format: `re_xxxxxxxxx`) 2. **Add to secrets**: Add `export RESEND_API_KEY=re_xxxxxxxxx` to `~/.config/env/secrets.env` 3. **Verify domain** (optional): By default, send from `onboarding@resend.dev` (test only). For production, verify a domain at https://resend.com/domains 4. **Install requests**: `uv pip install --system requests` Credentials checked in order: `RESEND_API_KEY` env var > `~/.config/env/secrets.env` > `~/.claude.json` ## Quick Start ```bash # Simple text email python3 ~/.claude/skills/resend/scripts/send.py \ --to "recipient@example.com" \ --subject "Hello from Claude" \ --body "This is a test email." # HTML email from a file python3 ~/.claude/skills/resend/scripts/send.py \ --to "recipient@example.com" \ --subject "Weekly Report" \ --html report.html # Pipe content as body echo "Pipeline output here" | python3 ~/.claude/skills/resend/scripts/send.py \ --to "recipient@example.com" \ --subject "Build Results" # Multiple recipients with CC python3 ~/.claude/skills/resend/scripts/send.py \ --to "alice@example.com" "bob@example.com" \ --cc "manager@example.com" \ --subject "Meeting Notes" \ --body "Attached are the notes from today." # With attachments python3 ~/.claude/skills/resend/scripts/send.py \ --to "recipient@example.com" \ --subject "Invoice" \ --body "Please find the invoice attached." \ --attachments invoice.pdf # Custom from address (requires verified domain) python3 ~/.claude/skills/resend/scripts/send.py \ --from "tom@minoanmystery.org" \ --to "recipient@example.com" \ --subject "Test" \ --body "Sent from a verified domain." # Inline HTML string python3 ~/.claude/skills/resend/scripts/send.py \ --to "recipient@example.com" \ --subject "Styled Email" \ --html "<h1>Hello</h1><p>This is <strong>bold</strong>.</p>" # Dry run (print payload without sending) python3 ~/.claude/skills/resend/scripts/send.py \ --to "recipient@example.com" \ --subject "Test" \ --body "Hello" \ --dry-run ``` ## Parameters ```bash python3 ~/.claude/skills/resend/scripts/send.py [OPTIONS] ``` | Flag | Description | Required | |------|-------------|----------| | `--to EMAIL [EMAIL...]` | Recipient email address(es) | Yes | | `--subject TEXT` | Email subject line | Yes | | `--body TEXT` | Plain text body (or pipe via stdin) | One of --body, --html, or stdin | | `--html FILE_OR_STRING` | HTML body: path to .html file, or inline HTML string | One of --body, --html, or stdin | | `--from EMAIL` | Sender address (default: `Tom di Mino <tom@send.minoanmystery.org>`) | No | | `--cc EMAIL [EMAIL...]` | CC recipients | No | | `--bcc EMAIL [EMAIL...]` | BCC recipients | No | | `--reply-to EMAIL` | Reply-to address | No | | `--attachments FILE [FILE...]` | File paths to attach | No | | `--dry-run` | Print the payload without sending | No | **Body resolution**: `--body` and `--html` can be combined for multipart email (text + HTML). If neither is provided, stdin is used as plain text. `--body ""` sends an empty text part. ## Sender Aliases Use `--from ALIAS` as a shorthand for named senders: | Alias | Expands to | |-------|------------| | `tom` | `Tom di Mino <tom@send.minoanmystery.org>` | | `kothar` | `Kothar wa Khasis <kothar@send.minoanmystery.org>` | | `claudius` | `Claudius, Artifex Maximus <claudius@send.minoanmystery.org>` | | `minoan` | `Minoan Mystery <contact@send.minoanmystery.org>` | ```bash # Send as Kothar --from kothar # Send as Claudius --from claudius ``` If `--from` doesn't match an alias, it's used as-is (full email or `Name <email>` format). ## Test Addresses Resend provides test addresses that don't affect domain reputation: - `delivered@resend.dev` — simulates successful delivery - `bounced@resend.dev` — simulates a bounce ## Rate Limits Resend enforces **2 requests per second**. The script does not batch or retry — if sending multiple emails, add a 1-second delay between invocations. ## Troubleshooting | Problem | Fix | |---------|-----| | `RESEND_API_KEY not found` | Add `export RESEND_API_KEY=re_xxx` to `~/.config/env/secrets.env` | | `missing_required_field` | Ensure `--to` and `--subject` are provided, plus body content | | `validation_error` on from | Default `onboarding@resend.dev` only works for test sends. Verify a domain at resend.com/domains | | `rate_limit_exceeded` | Wait 1 second between sends (2 req/s limit) | | Attachment not found | Use absolute paths or paths relative to CWD |