Resend Email Sender

Send emails using Resend API. Use when the user needs to send emails without configuring SMTP servers. Supports text and HTML emails, multiple recipients, CC...

Security Scan

The skill is mostly what it says (sends email via Resend) but has inconsistencies and a surprising behavior (it looks for and loads a .openclaw workspace .env), and the registry metadata does not declare the required RESEND_API_KEY — review before use.

Purpose & Capability

The code and SKILL.md implement sending mail via Resend and need a RESEND_API_KEY and optional RESEND_FROM; this matches the declared purpose. However the registry metadata claims no required env vars/credentials while the runtime requires RESEND_API_KEY — an inconsistency that should be corrected or explained.

Instruction Scope

The included script load_env() will look for and parse a .env file in two places: home/.openclaw/workspace/.env and ./ .env, and will inject any key=value pairs into the process env if not already set. Loading home/.openclaw/workspace/.env is surprising: that path may contain unrelated secrets or environment variables. The script only sends data to the Resend API, but implicitly importing arbitrary .env variables increases scope and risk.

Install Mechanism

No install spec or external downloads; this is an instruction-only skill with a bundled Python script. Nothing is fetched from external URLs and no archives are extracted.

Credentials

Runtime requires a single API credential (RESEND_API_KEY) which is proportionate to sending email via Resend. However the skill also reads .openclaw workspace .env and will load any variables there into the environment — this could expose unrelated secrets if that .env contains them. Also the registry metadata failing to declare RESEND_API_KEY reduces transparency.

Persistence & Privilege

Skill does not request always:true, does not modify other skills or system configuration, and does not persist new credentials itself. Autonomous invocation is allowed by default (normal for skills) and is not combined with other high-risk flags.

What to consider before installing

This skill appears to do what it says (send mail through Resend) but take these precautions before installing or running it: 1) The runtime requires RESEND_API_KEY even though the registry metadata doesn't declare it — set a dedicated API key with minimal scope and rotate it if needed. 2) The script will load and export variables from home/.openclaw/workspace/.env (if present) before falling back to local .env; if you keep other secrets there, they could be picked up unintentionally. Consider placing the API key in a dedicated env or passing it directly rather than storing many secrets in a shared .env. 3) Review the included scripts/send_email.py yourself (or run in an isolated environment) — it uses curl via subprocess to post to https://api.resend.com/emails and does not appear to exfiltrate data elsewhere, but reading arbitrary .env files increases risk. 4) If you will let agents invoke this skill autonomously, ensure the agent's permissions and the API key scope are limited. If you want, provide the developer with a request to update the registry metadata to declare RESEND_API_KEY as a required credential and to document why the home .openclaw workspace .env is consulted.

Send emails via Resend API - no SMTP configuration needed.

Quick Start

1. Configure

Set environment variables in .env:

RESEND_API_KEY=your_resend_api_key
RESEND_FROM=[e-mail]  # Optional, defaults to Resend test domain

Get API key at https://resend.com

2. Send Email

openclaw run resend-email \
  --to="[e-mail]" \
  --subject="Hello" \
  --text="Plain text message"

Usage

Basic Text Email

openclaw run resend-email \
  --to="[e-mail]" \
  --subject="Notification" \
  --text="Your task is complete."

HTML Email

openclaw run resend-email \
  --to="[e-mail]" \
  --subject="Welcome" \
  --html="<h1>Welcome!</h1><p>Thanks for joining.</p>"

Multiple Recipients

openclaw run resend-email \
  --to="[e-mail],[e-mail],[e-mail]" \
  --subject="Team Update" \
  --text="Meeting at 3 PM."

CC and BCC

openclaw run resend-email \
  --to="[e-mail]" \
  --cc="[e-mail]" \
  --bcc="[e-mail]" \
  --subject="Report" \
  --text="Please find the attached report."

From Agent

When agent needs to send email:

# Use exec to call the skill
exec openclaw run resend-email \
  --to="[e-mail]" \
  --subject="Automated Notification" \
  --text="This email was sent automatically by the agent."

Configuration Options

Variable	Required	Default	Description
RESEND_API_KEY	Yes	-	Your Resend API key
RESEND_FROM	No	[e-mail]	Default sender address

Sender Addresses

• Test domain: [e-mail] (default, no setup required)
• Custom domain: [e-mail] (requires domain verification in Resend dashboard)

Limitations

• Attachments not supported (Resend API requires base64 encoding)
• Rate limits apply based on Resend plan
• Email size limits per Resend documentation

Troubleshooting

"RESEND_API_KEY not configured"

• Set RESEND_API_KEY in .env file or environment

"Failed to send email: Unauthorized"

• Check API key is correct and active
• Verify API key has email sending permission

"Failed to send email: Bad Request"

• Check recipient email format is valid
• Verify from address is verified (for custom domains)

Resources

• scripts/send_email.py - Main email sending script