head to head · open source
dagster vs LangWatch
dagster has 16,183 GitHub stars, 2,296 forks, 2,589 open issues and last shipped 3 days ago. LangWatch has 4,833 stars, 395 forks, 939 open issues and last shipped 2 days ago. dagster leads on adoption by 235% (16,183 vs 4,833 stars). dagster is written in Python under Apache-2.0; LangWatch is written in TypeScript under Apache-2.0. dagster has attracted 14% as many forks as stars, LangWatch 8%. LangWatch was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 1 topic tag (analytics), 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
| dagster | LangWatch | |
|---|---|---|
| GitHub stars | ★ 16K | ★ 4.8K |
| License | Apache-2.0 | Apache-2.0 |
| Written in | Python | TypeScript |
| Last push | 2026-09-18 | 2026-09-19 |
| Forks | ⑂ 2.3K | ⑂ 395 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick dagster if
- You weight community size — 16K stars and counting
- You want the Apache-2.0 license terms
- Your stack matches Python
- You value the larger contributor base for long-term maintenance
pick LangWatch if
- You want the LangWatch feature set and don't need the biggest community
- You prefer the Apache-2.0 license terms
- Your stack matches TypeScript
- You evaluated both and LangWatch fits your workflow better
About dagster
Dagster is a cloud native data pipeline orchestrator written in Python and released under the Apache 2.0 licence, built for data engineers, data scientists, and machine learning teams who declare the tables, data sets, models, and reports their pipelines should produce and need those assets tested, observable, and kept up to date from local development through production.
read the full dagster overview →
About LangWatch
LangWatch is an open source TypeScript platform for LLM evaluations and AI agent testing, licensed under Apache 2.0. It lives in the machine learning infrastructure ecosystem for teams that build LLM powered agents and need to test, simulate, evaluate, and monitor agents before release and in production.
read the full LangWatch overview →
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Frequently asked questions
Is dagster or LangWatch more popular?
dagster has 16,183 GitHub stars and LangWatch has 4,833. dagster has the larger community by that measure.
Are dagster and LangWatch free?
Both are open source. dagster is licensed under Apache-2.0 and LangWatch under Apache-2.0. Neither carries a licence fee.
What is the difference between dagster and LangWatch?
dagster is written in Python and LangWatch 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, dagster or LangWatch?
Choose dagster if you want the larger community (16,183 stars) or its Apache-2.0 licence terms. Choose LangWatch if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.