Build your own Mailchimp and Klaviyo alternative with your AI agent
Campaign email to the people in your own records, sent only to contacts with a recorded consent for the topic, with a separate approval before anything goes out. It is built to replace Mailchimp, Klaviyo and similar tools for newsletters and one-off campaigns.
Paste one prompt. Your agent builds your version.
Paste it into Claude Code, Codex or Cursor. Your agent reads the blueprint, asks how your company works and shows you a one-page plan. Once you approve it, the agent builds your version on SegmentStream, turns every invariant into a test and deploys when you say so.
Read https://github.com/segmentstream/build-your-own/blob/main/AGENTS.md and follow it.
Build our Email marketing from the email-marketing blueprint.What your agent builds
Consent by topic, audiences on your own customer records, campaigns with a separate approval, and delivery events that keep your list clean.
What it is not
- Not transactional email (receipts, password resets, invoices). Those keep their own sender and never depend on marketing consent.
- Not a drag-and-drop email designer. Content is short HTML in one layout your project owns; the agent writes it, people review a preview.
- No automated journeys or drip sequences by default. They can be added with the same records; see the variations.
- Not legal advice. Consent and anti-spam rules (GDPR, CAN-SPAM and others) differ by country; your version follows the rules you choose, so check them with whoever advises you on privacy.
- One list of people, your own contacts, with a consent record per topic that says who decided it, when and where. No second copy of your list in a marketing tool.
- Audiences written as rules over your own companies, contacts and deals, such as “customers in Germany who have not received the spring launch”. They are resolved again every time a campaign is prepared.
- Before anything is sent you see exactly who will receive the campaign and why everyone else is left out: unsubscribed, bounced, suppressed, emailed recently.
- Drafting and approving are separate permissions. The approver confirms the exact number of recipients they reviewed, and an edit sends the campaign back to draft.
- One-click unsubscribe in every email, honoured even for a campaign that is already sending. Bounces and spam complaints stop future email to the address automatically.
- Results per campaign (delivered, bounced, complaints, unsubscribes, and opens and clicks if you turn them on) computed from the messages, never typed in.
- Your workspace agent drafts campaigns and audiences from plain words, and explains why a person did or did not get an email.
The hard parts are already running.
Your agent writes only the business logic. SegmentStream runs the infrastructure under it, so nobody on your team builds or operates it.
- The connection to your email provider: credentials stay in SegmentStream and your code never sees them.
- Durable workflows that prepare and send each campaign, survive restarts, and record every run.
- Webhook endpoints for unsubscribe links and the provider’s delivery events.
- A history of every consent change, with who made it, the record you will want when a regulator or an unhappy recipient asks.
- Mailchimp
- Klaviyo
- HubSpot Marketing Hub
- ActiveCampaign
- Brevo
- Kit (formerly ConvertKit)
- MailerLite
- Campaign Monitor
- Omnisend
Product names are trademarks of their owners, named only to describe what the blueprint can be compared with.
What’s in the blueprint
Five files your agent reads before it builds anything. Each opens on GitHub.
- BLUEPRINT.mdThe designRecords, actions, roles, workflows, data flow, screens and the build order.
- INTERVIEW.mdThe interviewWhat your agent asks about your company, and what each answer changes.
- INVARIANTS.mdThe invariantsRules that must hold in every version, each one a test in your project.
- VARIATIONS.mdThe variationsWhere companies legitimately differ, and the default for each.
- PITFALLS.mdThe pitfallsMistakes agents already made in production, so yours does not.
Blueprints are provided as is; see the disclaimer.
Related solutions
Build your company’s own software. Let agents run it.
$ segmentstream workspace create acme --region eu --subdomain acme
▸ Created workspace acme · database, warehouse and a private git repository
$ segmentstream workspace WORKSPACE-ID clone acme && cd acme
▸ your coding agent builds what your team asked for and runs the checks
$ git add -A && git commit -m "First version"
$ segmentstream deploy
▸ app, company agent, API and MCP tools live for your invited members
Our engineers build the first version on your data in two weeks, at a fixed price.
Or build it yourself with your coding agent:
curl -fsSL https://segmentstream.com/install.sh | sh