Resend CLI

Project Setup (run on every activation)

On every activation, run through these checks in order before proceeding with the user's request. See references/setup.md for detailed procedures.

1. Project Configuration (.resend.md)

Read .resend.md from the project root. If it exists, parse the YAML frontmatter:

---
domain: nthplus.io
from: "Claude <claude@nthplus.io>"
instructions: |
  Keep emails professional and concise.
  Sign off with "Best regards"
---

Fields:

• domain — Sending domain
• from — Default sender in "Name <address>" format
• instructions — Behavioral guidelines for composing emails (tone, sign-off, formatting, CC rules, etc.)

If .resend.md is missing: Run first-time setup — see references/setup.md § First-Run Setup.

If the user asks to update/change config: Read the current file, ask what to change, update the frontmatter, confirm. See references/setup.md § Updating Configuration.

2. MCP Server (.mcp.json)

Check .mcp.json at the project root for a resend entry under mcpServers. If missing, set it up — see references/setup.md § MCP Server Setup.

When the MCP server is configured, mcp__resend__* tools are available for direct API access. Prefer MCP tools over the CLI for sending emails and managing resources.

Note: After adding the MCP server entry, the user may need to restart their Claude session for the tools to become available.

3. CLI Pre-flight (only when CLI is needed)

Only run these checks when an operation requires the CLI (webhook listening, diagnostics, auth management, or when MCP tools are unavailable):

~/.resend/bin/resend --version

If not found: curl -fsSL https://resend.com/install.sh | bash

Sending Emails

Always apply project configuration when sending:

1. Use the from value from .resend.md as the default sender
2. Follow instructions from the config (tone, format, sign-off, etc.)
3. The user can override any default per-email

Via MCP (preferred)

Use mcp__resend__* tools when the MCP server is configured. Pass the from address from config.

Via CLI (fallback)

~/.resend/bin/resend emails send \
  --from "<from-value-from-config>" \
  --to user@example.com \
  --subject "Subject" \
  --text "Body"

Common Patterns

Send HTML email:

~/.resend/bin/resend emails send --from "<FROM>" --to user@example.com --subject "Update" --html "<h1>Hello</h1>"

Send with attachments:

~/.resend/bin/resend emails send --from "<FROM>" --to user@example.com --subject "Files" --text "See attached" --attachment ./doc.pdf

Pipe HTML from file:

~/.resend/bin/resend emails send --from "<FROM>" --to user@example.com --subject "Newsletter" --html-file ./newsletter.html

Send using a template:

~/.resend/bin/resend emails send --from "<FROM>" --to user@example.com --template tmpl_abc123 --var name=Alice

Batch send from JSON:

~/.resend/bin/resend emails batch --file batch.json

Schedule for later:

~/.resend/bin/resend emails send --from "<FROM>" --to user@example.com --subject "Reminder" --text "..." --scheduled-at "2025-03-01T09:00:00Z"

Quick Reference

Task	Command
Send email	resend emails send --from ... --to ... --subject ... --text/--html ...
List sent emails	resend emails list
Batch send	resend emails batch --file emails.json
Cancel scheduled	resend emails cancel <id>
List domains	resend domains list
Verify domain	resend domains verify <id>
List contacts	resend contacts list
Create broadcast	resend broadcasts create --from ... --subject ... --segment-id ... --html ...
Send broadcast	resend broadcasts send <id>
List templates	resend templates list
Create webhook	resend webhooks create --endpoint https://... --events all
Listen webhooks	resend webhooks listen --url <tunnel-url>
Check auth	resend whoami
Diagnostics	resend doctor

Global Flags

• --api-key <key> — Override API key
• -p, --profile <name> — Use specific profile
• --json — Force JSON output
• -q, --quiet — Suppress spinners, implies --json

Output Behavior

• Interactive (TTY): Formatted text + spinners on stderr
• Machine (piped/CI/--json): JSON on stdout, nothing on stderr
• Errors: {"error":{"message":"...","code":"..."}} + exit code 1

Command Reference

For complete flags and options, see references/commands.md.

Command groups: emails, domains, api-keys, broadcasts, templates, contacts, contact-properties, segments, topics, webhooks, auth.