head to head · open source
Zammad vs Cossistant
Zammad has 5,924 GitHub stars, 1,056 forks, 451 open issues and last shipped yesterday. Cossistant has 722 stars, 49 forks, 4 open issues and last shipped 2 months ago. Zammad leads on adoption by 720% (5,924 vs 722 stars). Zammad is written in Ruby under AGPL-3.0; Cossistant is written in TypeScript under AGPL-3.0. Zammad has attracted 18% as many forks as stars, Cossistant 7%. Zammad was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 1 topic tag (support), so they are genuine substitutes rather than adjacent tools.
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
| Zammad | Cossistant | |
|---|---|---|
| GitHub stars | ★ 5.9K | ★ 722 |
| License | AGPL-3.0 | AGPL-3.0 |
| Written in | Ruby | TypeScript |
| Last push | 2026-09-17 | 2026-08-04 |
| Forks | ⑂ 1.1K | ⑂ 49 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Zammad if
- You weight community size — 5.9K stars and counting
- You want the AGPL-3.0 license terms
- Your stack matches Ruby
- You value the larger contributor base for long-term maintenance
pick Cossistant if
- You want the Cossistant feature set and don't need the biggest community
- You prefer the AGPL-3.0 license terms
- Your stack matches TypeScript
- You evaluated both and Cossistant fits your workflow better
About Zammad
Zammad is a web based, open source helpdesk and customer support platform, released under the GNU AGPLv3 and written primarily in Ruby on the Rails framework. The source code lives on GitHub and is owned by the Zammad Foundation, an entity that the README describes as independent of commercial providers such as Zammad GmbH. Development is carried out by the team at Zammad GmbH together with the community, and the project states that the software is and will stay open source.
read the full Zammad overview →
About Cossistant
Cossistant is an open source, AI native customer support platform for React and Next.js developers and SaaS startups that need a customizable chat support widget with AI support agents, real time messaging, and complete backend infrastructure they can host themselves.
read the full Cossistant overview →
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Frequently asked questions
Is Zammad or Cossistant more popular?
Zammad has 5,924 GitHub stars and Cossistant has 722. Zammad has the larger community by that measure.
Are Zammad and Cossistant free?
Both are open source. Zammad is licensed under AGPL-3.0 and Cossistant under AGPL-3.0. Neither carries a licence fee.
What is the difference between Zammad and Cossistant?
Zammad is written in Ruby and Cossistant in TypeScript. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, Zammad or Cossistant?
Choose Zammad if you want the larger community (5,924 stars) or its AGPL-3.0 licence terms. Choose Cossistant if its feature set, stack or AGPL-3.0 licence fits better. Both are self-hostable.