What it costs to start an open source project (my real numbers)

Description and use

The developer calculated monthly costs for hosting, email, and domain for UseHourly, plus the AI assistant Claude. Total cost is about $26/month, staying around $25–$30 even with 10,000 active users. If costs exceed $100, sponsorship will be sought.

Problem

A developer wants to understand the ongoing costs of hosting and maintaining an open‑source web app (UseHourly) and how those costs scale with user growth.

Outcome

The project costs about $26/month to run, with an additional $20–$100 for the AI assistant. Even with 10,000 active users, the total remains roughly $25–$30/month, largely due to generous free tiers in hosting and email services.

Workflow

• 1. Host the app and database on Cloudflare’s minimum paid plan – $5/month.
• 2. Use Resend Pro for email delivery – $20/month.
• 3. Register and renew the domain usehourly.app – ~$1/month.
• 4. Run CI/CD with CircleCI free plan – $0/month.
• 5. Pay for Claude AI assistant – $20/month for Pro or $100/month for Max.
• 6. Estimate scaling costs by assuming each user is active 20 days/month with few requests – results in ~$25–$30/month for 10,000 users.

Evidence

Cloudflare (hosting and database) $5

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Resend (email) $20

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Domain (usehourly.app) $1 for the first year, about $12 a year after that (about $1 a month)

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AI coding assistant (Claude) $20 on the Pro plan, which should be enough for most people. I pay $100 for Max because I work on about five projects at the same time, so UseHourly is only part of that.

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Running it (hosting, email, domain) about $26 a month

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Running it plus the assistant about $46 a month on the $20 plan (about $126 with the $100 plan I use for all my projects)

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Rough total a month about $25 to $30 for 10,000 users

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