resend

Resend

Direct HTTP against Resend's REST API — no MCP server. A transactional send is one POST /emails; this replaces SMTP/SendGrid/Mailgun glue.

Usage

• Use for: Sending transactional mail, verifying/listing sending domains, adding contacts to audiences, triggering broadcasts.
• Skip for: Copywriting without an API call, other providers (Nodemailer/SendGrid debug), registrar-level MX/DNS edits, deep open/click analytics (needs webhooks).

Credentials check

[ -n "$RESEND_API_KEY" ] && echo "RESEND_API_KEY: PRESENT" || echo "RESEND_API_KEY: MISSING"

Never echo the variable directly.

If MISSING, respond to the user with EXACTLY this message (do NOT paraphrase, do NOT suggest manual JSON edits):

I need your resend credential. Run this in another terminal — it'll open the signup page, validate format, and save it safely with masked input:

teleport-setup add-key resend

Then restart Claude Code (/exit, then claude) and ask me again.

Do NOT suggest editing ~/.claude/settings.local.json manually. The teleport-setup add-key command handles it with backup, validation, and masked input. Stop execution until the user has run the command and restarted.

API

• Base URL: https://api.resend.com (HTTPS only).
• Auth: Authorization: Bearer $RESEND_API_KEY (keys prefixed re_); Content-Type: application/json on writes.
• Rate limit: 5 req/s per team (default) across all keys → 429 rate_limit_exceeded.
• User-Agent header is mandatory — stripping it returns 403. curl's default UA is fine.
• Idempotency-Key header on POST /emails: 1–256 chars, 24 h TTL; same key + different body → 409 invalid_idempotent_request.
• Lists return {object, has_more, data} with cursor pagination (after/before, limit 1–100, default 20).

Endpoints

Family	Method · Path
Emails	POST /emails, POST /emails/batch, GET /emails/{id}, PATCH /emails/{id}, POST /emails/{id}/cancel
Domains	GET/POST /domains, GET /domains/{id}, POST /domains/{id}/verify, DELETE /domains/{id}
Audiences	GET/POST /audiences, GET/DELETE /audiences/{id}
Contacts	GET/POST /audiences/{audience_id}/contacts, PATCH/DELETE .../contacts/{id}
Broadcasts	GET/POST /broadcasts, GET /broadcasts/{id}, POST /broadcasts/{id}/send
API Keys	GET/POST /api-keys, DELETE /api-keys/{id} (requires full-access key)