head to head · open source
nebula vs SAG
nebula has 12,398 GitHub stars, 1,329 forks, 678 open issues and last shipped 12 days ago. SAG has 2,500 stars, 162 forks, 2 open issues and last shipped today. nebula leads on adoption by 396% (12,398 vs 2,500 stars). nebula is written in C++ under Apache-2.0; SAG is written in Python under MIT. nebula has attracted 11% as many forks as stars, SAG 6%. SAG was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 3 topic tags (graphrag, knowledge-base, knowledge-graph), 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
| nebula | SAG | |
|---|---|---|
| GitHub stars | ★ 12K | ★ 2.5K |
| License | Apache-2.0 | MIT |
| Written in | C++ | Python |
| Last push | 2026-09-08 | 2026-09-20 |
| Forks | ⑂ 1.3K | ⑂ 162 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick nebula if
- You weight community size — 12K stars and counting
- You want the Apache-2.0 license terms
- Your stack matches C++
- You value the larger contributor base for long-term maintenance
pick SAG if
- You want the SAG feature set and don't need the biggest community
- You prefer the MIT license terms
- Your stack matches Python
- You evaluated both and SAG fits your workflow better
About nebula
NebulaGraph is an open source, distributed graph database written in C++ and released under the Apache 2.0 license. It lives in the graph database ecosystem and appears in the CNCF Database Landscape. The project describes itself as symmetrically distributed, with storage and computing separated into distinct layers, horizontal scalability across nodes, strong data consistency enforced through the RAFT protocol, an OpenCypher compatible query language, role based access control, and a set of graph analytics algorithms. It has been developed for roughly eight years and carries 12,387 stars, 1,330 forks, and 678 op…
read the full nebula overview →
About SAG
SAG is an open source, local first knowledge base application and retrieval architecture, built for individuals and AI agents that need searchable, connected and traceable knowledge from their own documents.
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Frequently asked questions
Is nebula or SAG more popular?
nebula has 12,398 GitHub stars and SAG has 2,500. nebula has the larger community by that measure.
Are nebula and SAG free?
Both are open source. nebula is licensed under Apache-2.0 and SAG under MIT. Neither carries a licence fee.
What is the difference between nebula and SAG?
nebula is written in C++ and SAG in Python. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, nebula or SAG?
Choose nebula if you want the larger community (12,398 stars) or its Apache-2.0 licence terms. Choose SAG if its feature set, stack or MIT licence fits better. Both are self-hostable.