Klaviyo

Email, SMS, customer data, automation, analytics, and personalization

NOT REALLY · consider alternatives
price variesestimated build time not a true replacement; consolation build in one to two daysreplaced by 0 people

Do not mistake the interface for the product. Klaviyo's durable value is deliverability, reputation, network, which a solo one-shot build cannot reproduce responsibly. The prompt therefore builds only the closest honest personal consolation tool.

Build verification: not recorded. How we judge buildability

What you give up

  • bounce, complaint, and suppression handling
  • large-scale segmentation and automation
  • payments, recommendations, and audience network
  • sender reputation, deliverability, and suppression handling
  • sender reputation and deliverability operations

Why people still pay

Klaviyo: The editor is trivial compared with inbox placement, compliance, reputation, unsubscribe handling, analytics, and audience growth infrastructure.

Your build guide

The stack, security requirements, and agent rules for a focused replacement.

Before you start

  • Node.js 22
  • PostgreSQL
  • transactional or bulk email provider key in .env
  • Explicit README warning that this is a consolation build, not a production replacement
01
Use exactly this stack: Next.js 15 + TypeScript + PostgreSQL.
02
Model subscribers, consent records, campaigns, delivery attempts, and suppression state; keep stable source IDs and timestamps.
03
Interface for this commerce marketing workflow: a local web page with input, progress, review, and export views.
engineering roadmap

Implementation plan

1

Phase 1, architecture and data

Use exactly this stack: Next.js 15 + TypeScript + PostgreSQL. Model subscribers, consent records, campaigns, delivery attempts, and suppression state; keep stable source IDs and timestamps.

2

Phase 2, implement

For commerce marketing, import subscribers with consent source, status, and suppression flag.

3

Phase 3, implement

Compose a campaign, preview HTML/plain text, and queue an authorized send by stable message ID.

4

Phase 4, review and output

Process delivery, bounce, and unsubscribe events before publishing the archive or report.

5

Phase 5, recovery and acceptance

Verify this invariant with a saved fixture: Unsubscribed or bounced addresses must stay suppressed; retrying an ambiguous provider response cannot silently send twice. State the practical limit: bounce, complaint, and suppression handling.

the pro prompt
Build me a focused commerce marketing workflow for the personal core of Klaviyo. Requirements:

- Use exactly this stack: Next.js 15 + TypeScript + PostgreSQL. Model subscribers, consent records, campaigns, delivery attempts, and suppression state; keep stable source IDs and timestamps.
- Paid product context: Email, SMS, customer data, automation, analytics, and personalization. Build only this DIY scope: Build a small commerce marketing editor and subscriber database that exports clean HTML and sends only through a reputable user-supplied email provider.
- For commerce marketing, import subscribers with consent source, status, and suppression flag.
- Compose a campaign, preview HTML/plain text, and queue an authorized send by stable message ID.
- Process delivery, bounce, and unsubscribe events before publishing the archive or report.
- Use a local web page with input, progress, review, and export views. Required input or access: transactional or bulk email provider key in .env. Keep credentials in .env.
- Acceptance: with one labelled sample, show the input, saved intermediate state, and exported result; verify this invariant: Unsubscribed or bounced addresses must stay suppressed; retrying an ambiguous provider response cannot silently send twice.
- Out of scope: bounce, complaint, and suppression handling; large-scale segmentation and automation. Keep this a personal, inspectable workflow.
- Include a README with setup, a sample input, required keys or permissions, data location, and the supported scope.

$ open in your agent (prompt prefilled, you press enter), copy the prompt or copy AGENTS.md · generated from this app's build plan

prior art · use these instead of building, if you'd ratherlistmonkHigh-performance self-hosted newsletter and mailing-list manager.↗MauticOpen-source marketing automation platform.↗
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Klaviyo pricing

planmonthlyannual (per mo)what you get
free$0/workspace$0/workspaceUp to 250 active profiles, 500 email sends/month, $5 mobile messages/month, 10,000 Composer credits, email support first 60 days.
marketing paid plan——Paid by active profiles and message volume; account must fit billable active-profile tier.The live build-a-plan table did not expose selected paid quantities clearly enough to store one USD price.
enterprise——Custom enterprise terms; numeric caps not published.Contact sales.

free tier$0; 250 active profiles, 500 email sends/month, $5 mobile messages/month, 10,000 Composer credits, email support first 60 days.

billingmonthly usage/profile-based build-a-plan; no annual discount verified

hidden costsActive-profile enforcement can move accounts to a higher tier; mobile-message dollars do not roll over; short codes separate; add-ons include Customer Hub from $20/mo, Helpdesk from $10/mo, Customer Agent from $50/mo, Marketing Analytics from $100/mo; Composer credits expire.

pricing sources checked 2026-08-10 · pricing source ↗

Questions about Klaviyo

Can you build your own Klaviyo with AI?

A full replacement is not the recommended project. Do not mistake the interface for the product. Klaviyo's durable value is deliverability, reputation, network, which a solo one-shot build cannot reproduce responsibly. The prompt therefore builds only the closest honest personal consolation tool.

What does the Klaviyo build prompt cover?

The prompt starts with this scope: Build a small commerce marketing editor and subscriber database that exports clean HTML and sends only through a reputable user-supplied email provider. Full-product capabilities excluded from the comparison include: bounce, complaint, and suppression handling; large-scale segmentation and automation; payments, recommendations, and audience network. Follow the implementation plan and its prerequisites before expanding the build.

How do I use the prompt, AGENTS.md and agent skills?

Start with the Klaviyo prerequisites and stack, then copy the prompt into your coding agent. Save the project rules as AGENTS.md in the project root. Linked skills are optional packages or source instructions for specific tasks; review their current contents and install only those matching the chosen stack. A skill does not supply API credentials or verify the finished app.

How long will this Klaviyo project take?

The catalogue estimate is not a true replacement; consolation build in one to two days for the limited scope. Setup, integration approvals, debugging, deployment and ongoing maintenance can add time. This is an estimate, not a delivery guarantee.

What would I give up by replacing Klaviyo?

bounce, complaint, and suppression handling; large-scale segmentation and automation; payments, recommendations, and audience network; sender reputation, deliverability, and suppression handling; sender reputation and deliverability operations. Klaviyo: The editor is trivial compared with inbox placement, compliance, reputation, unsubscribe handling, analytics, and audience growth infrastructure.

What can I use instead of building Klaviyo?

The prior-art section lists listmonk, Mautic as starting points. Review their current scope, license and maintenance before adopting one.

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