head to head · open source
Plunk vs Sessy
Plunk has 5,573 GitHub stars, 429 forks, 61 open issues and last shipped 2 days ago. Sessy has 944 stars, 44 forks, 7 open issues and last shipped 4 days ago. Plunk leads on adoption by 490% (5,573 vs 944 stars). Plunk is written in TypeScript under AGPL-3.0; Sessy is written in Ruby under a custom or non-standard licence. Plunk has attracted 8% as many forks as stars, Sessy 5%. Plunk was the more recently maintained of the two, and both are self-hostable with no licence fee.
Two open source projects, one decision. Both are free and self-hostable — the differences are community size, license terms, language stack and release pace.
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Side by side
| Plunk | Sessy | |
|---|---|---|
| GitHub stars | ★ 5.6K | ★ 944 |
| License | AGPL-3.0 | Custom / other |
| Written in | TypeScript | Ruby |
| Last push | 2026-11-01 | 2026-10-30 |
| Forks | ⑂ 429 | ⑂ 44 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Plunk if
- You weight community size — 5.6K stars and counting
- You want the AGPL-3.0 license terms
- Your stack matches TypeScript
- You value the larger contributor base for long-term maintenance
pick Sessy if
- You want the Sessy feature set and don't need the biggest community
- You prefer the Custom / other license terms
- Your stack matches Ruby
- You evaluated both and Sessy fits your workflow better
About Plunk
Plunk The Open Source Email Platform Introduction Transactional emails, marketing campaigns, and workflow automation — in one platform. Self hostable, $0.001 per email, no contact limits. An open source, self hosted alternative to tools SendGrid, Resend or Mailgun. Features Transactional Emails : Send emails straight from your API with template support and variable substitution SMTP : Use Plunk as an SMTP relay to send emails from any existing tool or framework Campaigns : Send newsletters and product updates to large audiences Workflows : Create advanced automations with triggers, delays, and conditional logic…
read the full Plunk overview →
About Sessy
Sessy Open source email observability for AWS SES by Marc Köhlbrugge. What is Sessy? Amazon SES is a fantastic email service: cost effective, reliable, and great deliverability. But it's frustratingly difficult to see what's actually happening with your emails. That's why many people turn to overpriced email services that are often just glorified SES wrappers with a nice UI. You end up paying a lot for something you could do yourself. Sessy is the open source alternative. Use raw SES and still get a beautiful interface to see what happens after you hit send: deliveries, bounces, complaints, opens, clicks, and…
read the full Sessy overview →
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Frequently asked questions
Is Plunk or Sessy more popular?
Plunk has 5,573 GitHub stars and Sessy has 944. Plunk has the larger community by that measure.
Are Plunk and Sessy free?
Both are open source. Plunk is licensed under AGPL-3.0, and Sessy has no licence declared in this registry. Both are free to self-host.
What is the difference between Plunk and Sessy?
Plunk is written in TypeScript and Sessy in Ruby. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, Plunk or Sessy?
Choose Plunk if you want the larger community (5,573 stars) or its AGPL-3.0 licence terms. Choose Sessy if its feature set, stack or Custom / other licence fits better. Both are self-hostable.