New: 98,000+ skills indexed from GitHub repos with 100+ stars · every skill safety-checkedBrowse top skillsTop skills
Esc to closeBrowse all skills
Submit a skillBrowse skills
Submit a skillBrowse skills

Agent skill

Lifecycle Messaging

by avelikiy in avelikiy/great_cto

Email/SMS lifecycle and deliverability framework for SMB Product-Builder products that send transactional or lifecycle messages (booking reminders, CRM sequences, receipts, win-back).

MITAuto-check passedBackend & APIs

Install Lifecycle Messaging

skills CLI
$ npx skills add avelikiy/great_cto --skill lifecycle-messaging -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI
$ gh skill install avelikiy/great_cto lifecycle-messaging --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy
$ git clone --depth 1 https://github.com/avelikiy/great_cto.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/lifecycle-messaging .claude/skills/lifecycle-messaging && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Facts

Skill name
lifecycle-messaging
GitHub stars
103
Token cost
~1.3k tokens
SKILL.md length
432 words
Files
1
Skills in repo
28
Repo updated
First seen
Licence
MIT

At a glance

Email/SMS lifecycle and deliverability framework for SMB Product-Builder products that send transactional or lifecycle messages (booking reminders, CRM sequences, receipts, win-back).

  • Works in 6 steps: Transactional vs marketing — split them → Provider selection (pick one, justify it) → Domain authentication (non-negotiable… → …
  • Tasks that involve Transactional email
  • SKILL.md covers 1. Transactional vs marketing…, 2. Provider selection (pick…, 3. Domain authentication… and 4. Consent + compliance…, plus 3 more sections
  • Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md

What it does

Lifecycle Messaging is an agent skill from avelikiy/great_cto. Email/SMS lifecycle and deliverability framework for SMB Product-Builder products that send transactional or lifecycle messages (booking reminders, CRM sequences, receipts, win-back). Codifies provider selection (Resend/Postmark/Twilio/SendGrid), domain auth (SPF/DKIM/DMARC), consent and compliance (TCPA, CAN-SPAM, CASL, quiet hours, double opt-in), suppression-list discipline, and the transactional-vs-marketing split. Applied by integrations-engineer and senior-dev whenever a feature sends messages — so…

Its SKILL.md is about 1.3k tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.

It sits in Backend & APIs, covering Transactional email and Referral and retention marketing. It works with SendGrid. The repository describes itself as: You already have the agent. This is everything around it. greatcto runs Claude Code as a pipeline of 70 specialist agents — an independent model checks each stage before the next… The licence is MIT.

When your agent uses it

  • Tasks that involve Transactional email
  • Tasks that involve Referral and retention marketing

Example prompts

  • “/lifecycle-messaging”

Requirements

  • Pre-approved tools (allowed-tools): Read, Write, Grep, Glob, WebFetch

Workflow steps

6 steps, taken from the step headings in SKILL.md.

  1. Transactional vs marketing — split them
  2. Provider selection (pick one, justify it)
  3. Domain authentication (non-negotiable for email)
  4. Consent + compliance (US-first)
  5. Suppression discipline (the deliverability lifeline)
  6. Reliability patterns

What it can do on your machine

Read from SKILL.md and the folder at commit 5d6e760. It shows what the files ask for, not the result of running them.

  • Tool permissions

    Pre-approves these tools, so the agent can use them without asking each time:

    • Read
    • Write
    • Grep
    • Glob
    • WebFetch

    From allowed-tools in the SKILL.md frontmatter.

  • Runs code

    No scripts in the folder and no shell commands in SKILL.md.

    From the folder's file list and the shell code blocks in SKILL.md.

  • Network

    No URLs in SKILL.md.

    From URLs in SKILL.md, links to its own repository left out.

  • Credentials

    Names no API keys, tokens, secrets or passwords.

    From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Lifecycle Messaging loads about 1.3k tokens when it runs. Until then it costs about 155 tokens; SKILL.md has 432 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it
~155
When it runs · the whole SKILL.md, loaded when a task matches
~1.3k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from avelikiy/great_cto at commit 5d6e760, republished under its MIT licence (© avelikiy). 432 words, ~1,278 tokens.

Download SKILL.mdSave it as .claude/skills/lifecycle-messaging/SKILL.md (or your agent's skills folder).
name
lifecycle-messaging
description
Email/SMS lifecycle and deliverability framework for SMB Product-Builder products that send transactional or lifecycle messages (booking reminders, CRM sequences, receipts, win-back). Codifies provider selection (Resend/Postmark/Twilio/SendGrid), domain auth (SPF/DKIM/DMARC), consent and compliance (TCPA, CAN-SPAM, CASL, quiet hours, double opt-in), suppression-list discipline, and the transactional-vs-marketing split. Applied by integrations-engineer and senior-dev whenever a feature sends messages — so deliverability and consent are designed in, not bolted on after the first spam complaint.
allowed-tools
Read, Write, Grep, Glob, WebFetch
when_to_use
Apply when a feature sends email or SMS: - integrations-engineer designing a Twilio / email-provider integration - senior-dev implementing booking reminders…
effort
medium
paths
docs/integrations/**, docs/architecture/**

Lifecycle messaging — deliverable, consented, compliant

Messages that don't arrive (poor deliverability) or that arrive without consent (TCPA/ CAN-SPAM violations) are both fatal for an SMB product. This skill makes both correct by construction. Design the consent + deliverability posture before the first send.

1. Transactional vs marketing — split them

Decide per message which bucket it is; they have different rules and should use different sending identities (often different subdomains / providers):

TransactionalMarketing / lifecycle
Examplesreceipt, booking confirm/reminder, password resetwin-back, promo, newsletter, nurture step
Consentimplied by the transactionexplicit opt-in required
Unsubscribenot required (but honor STOP)required, one-click, honored fast
Sending domaintxn. subdomainmail./news. subdomain

Never send marketing content on the transactional channel "because it delivers better" — that's how the transactional domain gets burned.

2. Provider selection (pick one, justify it)

  • Email — Postmark (best transactional deliverability, strict on marketing), Resend (DX-first, good default), SendGrid (scale). Default: Resend for transactional, add a marketing-grade ESP only when lifecycle volume justifies it.
  • SMS — Twilio (messaging service + sender pool), or Telnyx. Use a Messaging Service, not a single number, for scale + failover. A2P 10DLC registration is required for US application-to-person SMS — register the brand/campaign before sending.

3. Domain authentication (non-negotiable for email)

  • SPF — sender IP authorized in DNS.
  • DKIM — provider signing key published; messages signed.
  • DMARC — start p=none with rua reporting, ramp to p=quarantine→p=reject once aligned. Without DMARC alignment, lifecycle mail lands in spam.
  • Warm up a new sending domain gradually; never blast from a cold domain.
Show full SKILL.md (187 more words)Show less
  • CAN-SPAM (email) — valid physical postal address, accurate From/Subject, working one-click unsubscribe honored within 10 days.
  • TCPA (SMS/voice) — prior express written consent for marketing SMS; honor STOP/UNSTOP/ HELP keywords automatically; respect quiet hours (no marketing 9pm–8am recipient local time). Keep proof of consent (timestamp, source).
  • CASL (if CA recipients) — express opt-in + identification + unsubscribe.
  • Double opt-in for marketing lists where feasible — protects deliverability and proves consent.

5. Suppression discipline (the deliverability lifeline)

Maintain a single suppression list the sender checks before every send:

  • hard bounces → suppress permanently
  • spam complaints (FBL) → suppress + investigate
  • unsubscribes / STOP → suppress for that channel immediately
  • never re-import a suppressed address from a migration without re-consent

A send that ignores suppression is the fastest path to a blocklist.

6. Reliability patterns

  • Idempotent sends keyed on the domain event (a reminder for booking X sends once, even on retry) — coordinate the key with integrations-engineer.
  • Status-callback / webhook reconciliation: record delivered/bounced/failed; surface failures, don't swallow them.
  • Rate-limit + queue lifecycle sends; never loop-send.
  • Quiet-hours + timezone are computed from the recipient's locale, not the server's.

Output

When applied, contribute a Messaging section to the integration contract (docs/integrations/INTEGRATE-{slug}.md):

## Messaging
- channels: email <provider> / sms <provider>
- identities: txn = <subdomain>, marketing = <subdomain/ESP>
- domain auth: SPF/DKIM/DMARC plan = <state>
- consent: <implied/explicit per message type>; STOP/HELP = handled
- quiet hours: <recipient-local window>; 10DLC: <registered?>
- suppression: <store> checked pre-send
- idempotency key: <derivation>

© avelikiy, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

Just SKILL.md in skills/lifecycle-messaging of avelikiy/great_cto.

Open the folder on GitHubat commit 5d6e760

Compare with similar skills

Lifecycle Messaging next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Lifecycle Messaging compared with similar skills
SkillStarsUsed inTokensAuto-checkLicenceRepo updated
Lifecycle Messaging this skillavelikiy/great_cto103—~1.3kAutomated safety check: PassMIT
Deliverability Checkerguia-matthieu/clawfu-skills150—~1.1kAutomated safety check: PassMIT
Email Servicecohen-liel/hivemind110—~1.8kAutomated safety check: PassApache-2.0
Email Connectorericrisco/rsc-harness167—~3.1kAutomated safety check: PassMIT
Emailmagnus919/agent-skills113—~2.4kAutomated safety check: PassMIT
Converting Email Templatesaiskillstore/marketplace430—~1.8kAutomated safety check: PassNone

Similar skills

  • Deliverability Checker

    guia-matthieu/clawfu-skills

    Check email deliverability and DNS configuration. An agent skill from guia-matthieu/clawfu-skills.

    150 GitHub stars~1.1k tokensUpdated 7 days ago
    Backend & APIsAuto-check passed

  • Email Service

    cohen-liel/hivemind

    Email sending patterns for transactional and marketing emails.

    110 GitHub stars~1.8k tokensUpdated 5 mo ago
    Backend & APIsAuto-check passed

  • Email Connector

    ericrisco/rsc-harness

    A skill your agent uses when wiring server code to send transactional or bulk email via Resend, SendGrid, or Postmark: a provider-agnostic sendEmail() seam, idempotent retries, 100-cap batches with…

    167 GitHub stars~3.1k tokensUpdated yesterday
    Backend & APIsAuto-check passed

  • Email

    magnus919/agent-skills

    Send and diagnose transactional email through Twilio SendGrid from a terminal or agent: send messages, check deliverability (bounces and spam reports), and verify Signed Event Webhook signatures…

    113 GitHub stars~2.4k tokensUpdated 2 days ago
    Backend & APIsAuto-check passed

  • Converting Email Templates

    aiskillstore/marketplace

    A skill your agent uses when converting or migrating email templates from another provider (SendGrid, Mailgun, Mandrill, Postmark, Brevo, Amazon SES) to Mailtrap-compatible Handlebars syntax.

    430 GitHub stars~1.8k tokensUpdated yesterday
    Backend & APIsAuto-check passed

  • Mail Time

    veliovgroup/mail-time

    A skill your agent uses when building, wiring, reviewing, or debugging MailTime and ostrio:mailer email queues for horizontally scaled Node.js, Bun, or Meteor apps.

    143 GitHub stars~1k tokensUpdated yesterday
    DatabasesAuto-check passed

More from avelikiy/great_cto

All 28 skills in this repo

  • AnyDesign Design Analyzer

    avelikiy/great_cto

    Analyzes a screenshot, website or Figma file and writes a `design.md` with its token system, component inventory and reconstruction notes, or an `element.md` for one element.

    103 GitHub starsUsed in 1 repo~3.2k tokens
    Auto-check passed

  • Opportunity Solution Tree

    avelikiy/great_cto

    Builds an Opportunity Solution Tree that links one measurable outcome to customer opportunities, candidate solutions and experiments.

    103 GitHub stars~1.8k tokensUpdated yesterday
    Auto-check passed

  • Outcome-Focused Roadmap Rewriter

    avelikiy/great_cto

    Rewrites a feature-list roadmap into outcome statements that name the customer segment, the result they get and the business impact, grouped into themes.

    103 GitHub stars~1.3k tokensUpdated yesterday
    Auto-check passed

  • Exposed Secret Rotation

    avelikiy/great_cto

    Turns a leaked key, token or password into one tracked rotation task the moment it's spotted, instead of a reminder repeated every session.

    103 GitHub stars~884 tokensUpdated yesterday
    Auto-check: notes

  • Cost Model

    avelikiy/great_cto

    Standardized cost-estimation framework for greatcto plans. An agent skill from avelikiy/great_cto.

    103 GitHub starsUsed in 1 repo~1.3k tokens
    Auto-check passed

  • Skeptical Triage

    avelikiy/great_cto

    Runs a three-round self-challenge plus an arbiter over high-stakes findings, so false positives from reviews, audits and flaky-test verdicts do not become blockers.

    103 GitHub stars~2.1k tokensUpdated yesterday
    Auto-check: notes

Works with

Categories

Questions about Lifecycle Messaging

What does Lifecycle Messaging do?

Email/SMS lifecycle and deliverability framework for SMB Product-Builder products that send transactional or lifecycle messages (booking reminders, CRM sequences, receipts, win-back). Lifecycle Messaging is an agent skill from avelikiy/great_cto. Email/SMS lifecycle and deliverability framework for SMB Product-Builder products that send transactional or lifecycle messages (booking reminders, CRM sequences, receipts, win-back).

When should I use Lifecycle Messaging?

Lifecycle Messaging fits situations like: tasks that involve Transactional email; tasks that involve Referral and retention marketing.

How do I install Lifecycle Messaging in Claude Code?

Run `npx skills add avelikiy/great_cto --skill lifecycle-messaging -a claude-code`. Or copy the skill folder (skills/lifecycle-messaging in avelikiy/great_cto) into .claude/skills/lifecycle-messaging in your project. Claude Code loads it when a task matches its description.

How do I install Lifecycle Messaging in Codex?

Run `npx skills add avelikiy/great_cto --skill lifecycle-messaging -a codex`. Or copy the skill folder (skills/lifecycle-messaging in avelikiy/great_cto) into .agents/skills/lifecycle-messaging in your project. Codex loads it when a task matches its description.

Can I use Lifecycle Messaging in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add avelikiy/great_cto --skill lifecycle-messaging -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/lifecycle-messaging, .gemini/skills/lifecycle-messaging, .github/skills/lifecycle-messaging and .opencode/skills/lifecycle-messaging in your project.

What does Lifecycle Messaging need to run?

SKILL.md names no scripts, command-line tools or credentials: Lifecycle Messaging is instructions for the agent only. Its frontmatter pre-approves these tools: Read, Write, Grep, Glob, WebFetch.

Does Lifecycle Messaging access the network?

SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.

Is Lifecycle Messaging safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Lifecycle Messaging use?

Lifecycle Messaging is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Lifecycle Messaging use?

About 1.3k tokens (SKILL.md is roughly 5.1k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to Lifecycle Messaging?

Skills that share tags, products or a category with Lifecycle Messaging: Deliverability Checker (guia-matthieu/clawfu-skills, 150 stars), Email Service (cohen-liel/hivemind, 110 stars), Email Connector (ericrisco/rsc-harness, 167 stars) and Email (magnus919/agent-skills, 113 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Lifecycle Messaging?

avelikiy (a GitHub user) maintains it in avelikiy/great_cto, which has 103 GitHub stars. The repository holds 28 skills in this directory. The repository was last updated on October 7, 2026.

Source: avelikiy/great_cto on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.