Is day3 good for indie hackers?

Yes. It's deliberately minimal, priced by sends so the list grows free, and ships embeddable forms plus AI drafting on every paid plan. Built for solo founders, not marketing teams.

Can I add a signup form to my own site?

Yes. Use a hosted page, an auto-resizing iframe, a JS popup, or a plain HTML form that POSTs to day3, whichever fits your stack.

Can I write and send a campaign from my code editor?

You can write, preview and test one. day3 runs an MCP server, so Claude Code, Cursor or VS Code can read your audiences, draft a campaign into real editable blocks, and send you a test. Sending to a real audience needs a key deliberately created with the campaigns:send permission.

What does day3 cost if I only send a few times a year?

Whatever tier covers the sends you actually make, and you can move down between sends. Since the list costs nothing in between, an occasional sender pays far less than on a per-subscriber plan. Allowances don't roll over, so pick the tier that fits the send rather than the year.

Is there an API on the free tier?

Yes, the full REST API including transactional sending. The free tier's 500-subscriber cap applies to API writes too, and sending is sandboxed to your own org members, so you can integrate end to end before paying anything.

Who it's for

For indie developers

Ship the update, send the email, get back to building.

Email your users about what's new, without paying per subscriber or learning a marketing platform. Built for a team of one.

Sound familiar?

You're a team of one, with no hours to spend wiring up audiences and automations.
The list is an asset you built by hand. Paying more just to keep it is backwards.
You want a form to drop into your site and a changelog email you can send in five minutes.
Writing the email is the part that stops you shipping the announcement at all.

How day3 fits

Forms you can embed anywhere

Hosted page, iframe, popup, or raw HTML. Paste it into your site, bio, or docs, with double opt-in on by default.

Billed on sends, not your list

The audience you built stays free to keep. You pay only when you actually send.

Draft it where you already work

Point Claude Code, Cursor, or VS Code at day3's MCP server and describe the email next to the commits it's about. It arrives as editable composer blocks.

No upsell path

No funnels, no automation, no sales call. Just the email and who gets it.

What that costs, concretely

3,000 subscribers picked up over two years, emailed roughly every six weeks when a release lands.

$3/mo

3,000 emails a month fits the 5,000 plan. The 3,000 subscribers are free, on this plan and every other.

Per-subscriber pricing meters all 3,000 every month, including the five weeks in six when you send nothing.

The changelog email you keep not sending

The common failure for a solo developer isn't picking the wrong email tool, it's never sending the email. The release ships, the changelog gets written for the docs, and the announcement stays in a draft because writing it properly is a separate hour you don't have and the tool wants you to pick a template first.

Two things in day3 target exactly that hour. The composer has no template step: a campaign is a subject, a body, and an audience, on one screen. And the MCP server means you can write the thing from your editor, where the commit messages and the changelog file already are, rather than from a blank text box in a browser tab.

In practice that looks like telling Claude Code to draft a release email from the changelog entries since the last tag. What lands in day3 is editable blocks, not a wall of HTML, so you fix the two sentences that are wrong and send. The AI assistant in the app does the same job from a brief if you'd rather not leave the browser.

Sending to a real audience from an editor needs an API key explicitly minted with the campaigns:send permission, and that permission can't be added to a key later. So an assistant holding your ordinary key can draft and preview all day and reach nobody. That's the guard that makes this safe to leave switched on.

When day3 is the wrong call

If your newsletter is the product rather than an announcement channel for one, day3 is the wrong shape. There are no paid subscriptions, no archive pages, no referral or recommendation network, and no public web home for the letter. A creator platform will serve you better, and so will a markdown-first tool if writing in Markdown inside the app is the thing you actually want.

Questions

Is day3 good for indie hackers?: Yes. It's deliberately minimal, priced by sends so the list grows free, and ships embeddable forms plus AI drafting on every paid plan. Built for solo founders, not marketing teams.
Can I add a signup form to my own site?: Yes. Use a hosted page, an auto-resizing iframe, a JS popup, or a plain HTML form that POSTs to day3, whichever fits your stack.
Can I write and send a campaign from my code editor?: You can write, preview and test one. day3 runs an MCP server, so Claude Code, Cursor or VS Code can read your audiences, draft a campaign into real editable blocks, and send you a test. Sending to a real audience needs a key deliberately created with the campaigns:send permission.
What does day3 cost if I only send a few times a year?: Whatever tier covers the sends you actually make, and you can move down between sends. Since the list costs nothing in between, an occasional sender pays far less than on a per-subscriber plan. Allowances don't roll over, so pick the tier that fits the send rather than the year.
Is there an API on the free tier?: Yes, the full REST API including transactional sending. The free tier's 500-subscriber cap applies to API writes too, and sending is sandboxed to your own org members, so you can integrate end to end before paying anything.

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