resend_implementation

A guide for adding Resend, an email-sending service, to an application. It covers setup questions for the application type, sending domain, email purpose, recipients, and troubleshooting.

In plain words
What is it for?
Use it when adding alert, welcome, password-reset, marketing, or status emails to Python, Node.js, or other applications.
Why use it?
It helps identify the configuration details needed before implementing email delivery, reducing setup mistakes.

Cursor rule

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add rules/jondoescoding/jondoescoding-coding-rules/resend_implementation
Clone the repo
git clone --depth 1 https://github.com/jondoescoding/jondoescoding-coding-rules
Per session 18 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 6,030 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00018 $0.06030
Opus 5 $0.00009 $0.03015
Sonnet 5 $0.00004 $0.01206
Haiku 4.5 $0.00002 $0.00603

Measured yesterday against content hash a85c8fa8f2fa, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

resend_implementation scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

templates/cursor-rules/python/email/resend_implementation.mdc · 849 lines

How it starts

The opening of the file, as written. The whole thing — 849 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Resend Email Implementation Guide

This rule provides a comprehensive guide for implementing Resend email functionality in any system, designed for developers at all levels.

🚀 SETUP: Integration Questions for AI Assistant

Before implementing Resend email functionality, the AI assistant should ask these key questions to ensure seamless integration:

📋 Required Information Checklist

Ask the user these questions in order:

  1. "What type of application are you integrating Resend into?"

    • FastAPI/Django/Flask web application
    • Node.js/Express application
    • Standalone Python script
    • Other framework (specify)
  2. "What domain will you be sending emails from?"

    • Do you own a custom domain? (e.g., yourcompany.com)
    • What email address should be the sender? (e.g., [email protected])
    • Have you verified this domain in Resend dashboard yet?
  3. "What types of emails will you be sending?"

    • Alert/notification emails
    • Welcome/onboarding emails
    • Password reset emails
    • Marketing emails
    • System status updates
  4. "Who should receive these emails?"

    • Admin email addresses for alerts
    • User email addresses from database
    • Fixed list of recipients
    • Dynamic recipient lists
  5. "Do you have a Resend account and API key?"

    • Have you signed up at resend.com?
    • Do you have your API key ready?
    • Where will you store the API key? (.env file, config service, etc.)
  6. "What's your current project structure?"

    • Where should email service files be created?
    • Do you have existing configuration/settings files?
    • Are you using environment variables already?
  7. "What level of email customization do you need?"

    • Simple text emails
    • HTML templates with styling
    • Dynamic content (user names, data, etc.)
    • Multiple email templates

🎯 AI Assistant Implementation Strategy

Based on user answers, the AI should:

  1. Customize code examples to match their framework (FastAPI, Django, etc.)
  2. Adapt file paths to their project structure
  3. Configure domain settings based on their verified domain
  4. Create appropriate templates for their email types
  5. Set up environment variables matching their configuration style
  6. Provide testing scripts tailored to their use case

Read the full file on GitHub · 849 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. yesterday First seen · 849 lines · 18 tokens per session scan A a85c8fa8f2fa

Subscribe to this mod's changes

resend_implementation is a cursor rule published in the GitHub repository jondoescoding/jondoescoding-coding-rules (2 stars, last pushed 1mo ago), licensed MIT. It adds 18 tokens to every session and 6,030 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.