firefrost-gaming/antigravity-skills-reference

Files

sickn33 1966f6a8a2 fix(skills): Restore vibeship imports

Rebuild the affected vibeship-derived skills from the pinned upstream
snapshot instead of leaving the truncated imported bodies on main.
Refresh the derived catalog and plugin mirrors so the canonical skills,
compatibility data, and generated artifacts stay in sync.

Refs #473

2026-04-07 18:25:18 +02:00

18 KiB

Raw Permalink Blame History

name, description, risk, source, date_added

name	description	risk	source	date_added
email-systems	Email has the highest ROI of any marketing channel. $36 for every $1 spent. Yet most startups treat it as an afterthought - bulk blasts, no personalization, landing in spam folders.	none	vibeship-spawner-skills (Apache 2.0)	2026-02-27

Email Systems

Email has the highest ROI of any marketing channel. $36 for every $1 spent. Yet most startups treat it as an afterthought - bulk blasts, no personalization, landing in spam folders.

This skill covers transactional email that works, marketing automation that converts, deliverability that reaches inboxes, and the infrastructure decisions that scale.

Principles

Transactional vs Marketing separation | Description: Transactional emails (password reset, receipts) need 100% delivery. Marketing emails (newsletters, promos) have lower priority. Use separate IP addresses and providers to protect transactional deliverability. | Examples: Good: Password resets via Postmark, marketing via ConvertKit | Bad: All emails through one SendGrid account
Permission is everything | Description: Only email people who asked to hear from you. Double opt-in for marketing. Easy unsubscribe. Clean your list ruthlessly. Bad lists destroy deliverability. | Examples: Good: Confirmed subscription + one-click unsubscribe | Bad: Scraped email list, hidden unsubscribe, bought contacts
Deliverability is infrastructure | Description: SPF, DKIM, DMARC are not optional. Warm up new IPs. Monitor bounce rates. Deliverability is earned through technical setup and good behavior. | Examples: Good: All DNS records configured, dedicated IP warmed for 4 weeks | Bad: Using free tier shared IP, no authentication records
One email, one goal | Description: Each email should have exactly one purpose and one CTA. Multiple asks means nothing gets clicked. Clear single action. | Examples: Good: "Click here to verify your email" (one button) | Bad: "Verify email, check out our blog, follow us on Twitter, refer a friend..."
Timing and frequency matter | Description: Wrong time = low open rates. Too frequent = unsubscribes. Let users set preferences. Test send times. Respect inbox fatigue. | Examples: Good: Weekly digest on Tuesday 10am user's timezone, preference center | Bad: Daily emails at random times, no way to reduce frequency

Patterns

Transactional Email Queue

Queue all transactional emails with retry logic and monitoring

When to use: Sending any critical email (password reset, receipts, confirmations)

// Don't block request on email send await queue.add('email', { template: 'password-reset', to: user.email, data: { resetToken, expiresAt } }, { attempts: 3, backoff: { type: 'exponential', delay: 2000 } });

Email Event Tracking

Track delivery, opens, clicks, bounces, and complaints

When to use: Any email campaign or transactional flow

Track lifecycle:

Queued: Email entered system
Sent: Handed to provider
Delivered: Reached inbox
Opened: Recipient viewed
Clicked: Recipient engaged
Bounced: Permanent failure
Complained: Marked as spam

Template Versioning

Version email templates for rollback and A/B testing

When to use: Changing production email templates

templates/ password-reset/ v1.tsx (current) v2.tsx (testing 10%) v1-deprecated.tsx (archived)

Deploy new version gradually

Monitor metrics before full rollout

Bounce Handling State Machine

Automatically handle bounces to protect sender reputation

When to use: Processing bounce and complaint webhooks

switch (bounceType) { case 'hard': await markEmailInvalid(email); break; case 'soft': await incrementBounceCount(email); if (count >= 3) await markEmailInvalid(email); break; case 'complaint': await unsubscribeImmediately(email); break; }

React Email Components

Build emails with reusable React components

When to use: Creating email templates

import { Button, Html } from '@react-email/components';

export default function WelcomeEmail({ userName }) { return ( <Html>

Welcome {userName}!

Get Started </Html> ); }

Preference Center

Let users control email frequency and topics

When to use: Building marketing or notification systems

Preferences: ☑ Product updates (weekly) ☑ New features (monthly) ☐ Marketing promotions ☑ Account notifications (always)

Respect preferences in all sends

Sharp Edges

Missing SPF, DKIM, or DMARC records

Severity: CRITICAL

Situation: Sending emails without authentication. Emails going to spam folder. Low open rates. No idea why. Turns out DNS records were never set up.

Symptoms:

Emails going to spam
Low deliverability rates
mail-tester.com score below 8
No DMARC reports received

Why this breaks: Email authentication (SPF, DKIM, DMARC) tells receiving servers you're legit. Without them, you look like a spammer. Modern email providers increasingly require all three.

Recommended fix:

Required DNS records:

SPF (Sender Policy Framework)

TXT record: v=spf1 include:_spf.google.com include:sendgrid.net ~all

DKIM (DomainKeys Identified Mail)

TXT record provided by your email provider Adds cryptographic signature to emails

DMARC (Domain-based Message Authentication)

TXT record: v=DMARC1; p=quarantine; rua=mailto:dmarc@yourdomain.com

Verify setup:

Send test email to mail-tester.com
Check MXToolbox for record validation
Monitor DMARC reports

Using shared IP for transactional email

Severity: HIGH

Situation: Password resets going to spam. Using free tier of email provider. Some other customer on your shared IP got flagged for spam. Your reputation is ruined by association.

Symptoms:

Transactional emails in spam
Inconsistent delivery
Using same provider for marketing and transactional

Why this breaks: Shared IPs share reputation. One bad actor affects everyone. For critical transactional email, you need your own IP or a provider with strict shared IP policies.

Recommended fix:

Transactional email strategy:

Option 1: Dedicated IP (high volume)

Get dedicated IP from your provider
Warm it up slowly (start with 100/day)
Maintain consistent volume

Option 2: Transactional-only provider

Postmark (very strict, great reputation)
Includes shared pool with high standards

Separate concerns:

Transactional: Postmark or Resend
Marketing: ConvertKit or Customer.io
Never mix marketing and transactional

Not processing bounce notifications

Severity: HIGH

Situation: Emailing same dead addresses over and over. Bounce rate climbing. Email provider threatening to suspend account. List is 40% dead.

Symptoms:

Bounce rate above 2%
No webhook handlers for bounces
Same emails failing repeatedly

Why this breaks: Bounces damage sender reputation. Email providers track bounce rates. Above 2% and you start looking like a spammer. Dead addresses must be removed immediately.

Recommended fix:

Bounce handling requirements:

Hard bounces:

Remove immediately on first occurrence Invalid address, domain doesn't exist

Soft bounces:

Retry 3 times over 72 hours After 3 failures, treat as hard bounce

Implementation:

// Webhook handler for bounces
app.post('/webhooks/email', (req, res) => {
  const event = req.body;
  if (event.type === 'bounce') {
    await markEmailInvalid(event.email);
    await removeFromAllLists(event.email);
  }
});

Monitor:

Track bounce rate by campaign Alert if bounce rate exceeds 1%

Missing or hidden unsubscribe link

Severity: CRITICAL

Situation: Users marking as spam because they cannot unsubscribe. Spam complaints rising. CAN-SPAM violation. Email provider suspends account.

Symptoms:

Hidden unsubscribe links
Multi-step unsubscribe process
No List-Unsubscribe header
High spam complaint rate

Why this breaks: Users who cannot unsubscribe will mark as spam. Spam complaints hurt reputation more than unsubscribes. Also it is literally illegal. CAN-SPAM, GDPR all require clear unsubscribe.

Recommended fix:

Unsubscribe requirements:

Visible:

Above the fold in email footer
Clear text, not hidden
Not styled to be invisible

One-click:

Link directly unsubscribes
No login required
No "are you sure" hoops

List-Unsubscribe header:

List-Unsubscribe: <mailto:unsubscribe@example.com>,
  <https://example.com/unsubscribe?token=xxx>
List-Unsubscribe-Post: List-Unsubscribe=One-Click

Preference center:

Option to reduce frequency instead of full unsubscribe

Sending HTML without plain text alternative

Severity: MEDIUM

Situation: Some users see blank emails. Spam filters flagging emails. Accessibility issues for screen readers. Email clients that strip HTML show nothing.

Symptoms:

No text/plain part in emails
Blank emails for some users
Lower engagement in some segments

Why this breaks: Not everyone can render HTML. Screen readers work better with plain text. Spam filters are suspicious of HTML-only. Multipart is the standard.

Recommended fix:

Always send multipart:

await resend.emails.send({
  from: 'you@example.com',
  to: 'user@example.com',
  subject: 'Welcome!',
  html: '<h1>Welcome!</h1><p>Thanks for signing up.</p>',
  text: 'Welcome!\n\nThanks for signing up.',
});

Auto-generate text from HTML:

Use html-to-text library as fallback But hand-crafted plain text is better

Plain text should be readable:

Not just HTML stripped of tags Actual formatted text content

Sending high volume from new IP immediately

Severity: HIGH

Situation: Just switched providers. Started sending 50,000 emails/day immediately. Massive deliverability issues. New IP has no reputation. Looks like spam.

Symptoms:

New IP/provider
Sending high volume immediately
Sudden deliverability drop

Why this breaks: New IPs have no reputation. Sending high volume immediately looks like a spammer who just spun up. You need to gradually build trust.

Recommended fix:

IP warm-up schedule:

Week 1: 50-100 emails/day Week 2: 200-500 emails/day Week 3: 500-1000 emails/day Week 4: 1000-5000 emails/day Continue doubling until at volume

Best practices:

Start with most engaged users
Send to Gmail/Microsoft first (they set reputation)
Maintain consistent volume
Don't spike and drop

During warm-up:

Monitor deliverability closely
Check feedback loops
Adjust pace if issues arise

Emailing people who did not opt in

Severity: CRITICAL

Situation: Bought an email list. Scraped emails from LinkedIn. Added conference contacts. Spam complaints through the roof. Provider suspends account. Maybe a lawsuit.

Symptoms:

Purchased email lists
Scraped contacts
High unsubscribe rate on first send
Spam complaints above 0.1%

Why this breaks: Permission-based email is not optional. It is the law (CAN-SPAM, GDPR). It is also effective - unwilling recipients hurt your metrics and reputation more than they help.

Recommended fix:

Permission requirements:

Explicit opt-in:

User actively chooses to receive email
Not pre-checked boxes
Clear what they are signing up for

Double opt-in:

Confirmation email with link
Only add to list after confirmation
Best practice for marketing lists

What you cannot do:

Buy email lists
Scrape emails from websites
Add conference contacts without consent
Use partner/customer lists without consent

Transactional exception:

Password resets, receipts, account alerts do not need marketing opt-in

Emails that are mostly or entirely images

Severity: MEDIUM

Situation: Beautiful designed email that is one big image. Users with images blocked see nothing. Spam filters flag it. Mobile loading is slow. No one can copy text.

Symptoms:

Single image emails
No text content visible
Missing or generic alt text
Low engagement when images blocked

Why this breaks: Images are blocked by default in many clients. Spam filters are suspicious of image-only emails. Accessibility suffers. Load times increase.

Recommended fix:

Balance images and text:

60/40 rule:

At least 60% text content
Images for enhancement, not content

Always include:

Alt text on every image
Key message in text, not just image
Fallback for images-off view

Test:

Preview with images disabled
Should still be usable

Example:

<img
  src="hero.jpg"
  alt="Save 50% this week - use code SAVE50"
  style="max-width: 100%"
/>
<p>Use code <strong>SAVE50</strong> to save 50% this week.</p>

Missing or default preview text

Severity: MEDIUM

Situation: Inbox shows "View this email in browser" or random HTML as preview. Lower open rates. First impression wasted on boilerplate.

Symptoms:

View in browser as preview
HTML code visible in preview
No preview component in template

Why this breaks: Preview text is prime real estate - appears right after subject line. Default or missing preview text wastes this space. Good preview text increases open rates 10-30%.

Recommended fix:

Add explicit preview text:

In HTML:

<div style="display:none;max-height:0;overflow:hidden;">
  Your preview text here. This appears in inbox preview.
  <!-- Add whitespace to push footer text out -->
  &nbsp;&zwnj;&nbsp;&zwnj;&nbsp;&zwnj;&nbsp;&zwnj;&nbsp;
</div>

With React Email:

<Preview>
  Your preview text here. This appears in inbox preview.
</Preview>

Best practices:

Complement the subject line
40-100 characters optimal
Create curiosity or value
Different from first line of email

Not handling partial send failures

Severity: HIGH

Situation: Sending to 10,000 users. API fails at 3,000. No tracking of what sent. Either double-send or lose 7,000. No way to know who got the email.

Symptoms:

No per-recipient send logging
Cannot tell who received email
Double-sending issues
No retry mechanism

Why this breaks: Bulk sends fail partially. APIs timeout. Rate limits hit. Without tracking individual send status, you cannot recover gracefully.

Recommended fix:

Track each send individually:

async function sendCampaign(emails: string[]) {
  const results = await Promise.allSettled(
    emails.map(async (email) => {
      try {
        const result = await resend.emails.send({ to: email, ... });
        await db.emailLog.create({
          email,
          status: 'sent',
          messageId: result.id,
        });
        return result;
      } catch (error) {
        await db.emailLog.create({
          email,
          status: 'failed',
          error: error.message,
        });
        throw error;
      }
    })
  );

  const failed = results.filter(r => r.status === 'rejected');
  // Retry failed sends or alert
}

Best practices:

Log every send attempt
Include message ID for tracking
Build retry queue for failures
Monitor success rate per campaign

Validation Checks

Missing plain text email part

Severity: WARNING

Emails should always include a plain text alternative

Message: Email being sent with HTML but no plain text part. Add 'text:' property for accessibility and deliverability.

Hardcoded from email address

Severity: WARNING

From addresses should come from environment variables

Message: From email appears hardcoded. Use environment variable for flexibility.

Missing bounce webhook handler

Severity: WARNING

Email bounces should be handled to maintain list hygiene

Message: Email provider used but no bounce handling detected. Implement webhook handler for bounces.

Missing List-Unsubscribe header

Severity: INFO

Marketing emails should include List-Unsubscribe header

Message: Marketing email detected without List-Unsubscribe header. Add header for better deliverability.

Synchronous email send in request handler

Severity: WARNING

Email sends should be queued, not blocking

Message: Email sent synchronously in request handler. Consider queuing for better reliability.

Email send without retry logic

Severity: INFO

Email sends should have retry mechanism for failures

Message: Email send without apparent retry logic. Add retry for transient failures.

Email API key in code

Severity: ERROR

API keys should come from environment variables

Message: Email API key appears hardcoded in source code. Use environment variable.

Bulk email without rate limiting

Severity: WARNING

Bulk sends should respect provider rate limits

Message: Bulk email sending without apparent rate limiting. Add throttling to avoid hitting limits.

Email without preview text

Severity: INFO

Emails should include preview/preheader text

Message: Email template without preview text. Add hidden preheader for inbox preview.

Email send without logging

Severity: WARNING

Email sends should be logged for debugging and auditing

Message: Email being sent without apparent logging. Log sends for debugging and compliance.

Collaboration

Delegation Triggers

copy|subject|messaging|content -> copywriting (Email needs copy)
design|template|visual|layout -> ui-design (Email needs design)
track|analytics|measure|metrics -> analytics-architecture (Email needs tracking)
infrastructure|deploy|server|queue -> devops (Email needs infrastructure)

Email Marketing Stack

Skills: email-systems, copywriting, marketing, analytics-architecture

Workflow:

1. Infrastructure setup (email-systems)
2. Template creation (email-systems)
3. Copy writing (copywriting)
4. Campaign launch (marketing)
5. Performance tracking (analytics-architecture)

Transactional Email

Skills: email-systems, backend, devops

Workflow:

1. Provider setup (email-systems)
2. Template coding (email-systems)
3. Queue integration (backend)
4. Monitoring (devops)

When to Use

Use this skill when the request clearly matches the capabilities and patterns described above.

18 KiB Raw Permalink Blame History

Email Systems

Principles

Patterns

Transactional Email Queue

Email Event Tracking

Track lifecycle:

Template Versioning

Deploy new version gradually

Monitor metrics before full rollout

Bounce Handling State Machine

React Email Components

Welcome {userName}!

Preference Center

Respect preferences in all sends

Required for GDPR compliance

Sharp Edges

Missing SPF, DKIM, or DMARC records

Required DNS records:

SPF (Sender Policy Framework)

DKIM (DomainKeys Identified Mail)

DMARC (Domain-based Message Authentication)

Verify setup:

Using shared IP for transactional email

Transactional email strategy:

Option 1: Dedicated IP (high volume)

Option 2: Transactional-only provider

Separate concerns:

Not processing bounce notifications

Bounce handling requirements:

Hard bounces:

Soft bounces:

Implementation:

Monitor:

Missing or hidden unsubscribe link

Unsubscribe requirements:

Visible:

One-click:

List-Unsubscribe header:

Preference center:

Sending HTML without plain text alternative

Always send multipart:

Auto-generate text from HTML:

Plain text should be readable:

Sending high volume from new IP immediately

IP warm-up schedule:

Best practices:

During warm-up:

Emailing people who did not opt in

Permission requirements:

Explicit opt-in:

Double opt-in:

What you cannot do:

Transactional exception:

Emails that are mostly or entirely images

Balance images and text:

60/40 rule:

Always include:

Test:

Example:

Missing or default preview text

Add explicit preview text:

In HTML:

With React Email:

Best practices:

Not handling partial send failures

Track each send individually:

Best practices:

Validation Checks

Missing plain text email part

Hardcoded from email address

Missing bounce webhook handler

Missing List-Unsubscribe header

Synchronous email send in request handler

Email send without retry logic

Email API key in code

Bulk email without rate limiting

Email without preview text

Email send without logging

Collaboration

18 KiB

Raw Permalink Blame History