head to head · open source
openapi-generator vs optillm
openapi-generator has 26,752 GitHub stars, 7,678 forks, 5,752 open issues and last shipped 4 days ago. optillm has 4,296 stars, 388 forks, 23 open issues and last shipped 4 days ago. openapi-generator leads on adoption by 523% (26,752 vs 4,296 stars). openapi-generator is written in Java under Apache-2.0; optillm is written in Python under Apache-2.0. openapi-generator has attracted 29% as many forks as stars, optillm 9%. openapi-generator 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
| openapi-generator | optillm | |
|---|---|---|
| GitHub stars | ★ 27K | ★ 4.3K |
| License | Apache-2.0 | Apache-2.0 |
| Written in | Java | Python |
| Last push | 2026-09-17 | 2026-09-17 |
| Forks | ⑂ 7.7K | ⑂ 388 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick openapi-generator if
- You weight community size — 27K stars and counting
- You want the Apache-2.0 license terms
- Your stack matches Java
- You value the larger contributor base for long-term maintenance
pick optillm if
- You want the optillm feature set and don't need the biggest community
- You prefer the Apache-2.0 license terms
- Your stack matches Python
- You evaluated both and optillm fits your workflow better
About openapi-generator
OpenAPI Generator is an Apache 2.0 licensed Java tool that generates API client libraries, server stubs, documentation, and configuration automatically from an OpenAPI Specification, and it is built for development teams that keep a machine readable API description and want generated code to stay in step with it.
read the full openapi-generator overview →
About optillm
OptiLLM is a Python project that provides an optimizing inference proxy for large language models. It exposes an OpenAI API compatible endpoint and sits between an application and model providers, allowing callers to request reasoning oriented optimizations without changing model weights or adding training. The project lives in the developer tools and API development ecosystem, and its topics connect it to agents, agentic workflows, API gateways, chain of thought prompting, and generative AI inference.
read the full optillm overview →
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Frequently asked questions
Is openapi-generator or optillm more popular?
openapi-generator has 26,752 GitHub stars and optillm has 4,296. openapi-generator has the larger community by that measure.
Are openapi-generator and optillm free?
Both are open source. openapi-generator is licensed under Apache-2.0 and optillm under Apache-2.0. Neither carries a licence fee.
What is the difference between openapi-generator and optillm?
openapi-generator is written in Java and optillm 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, openapi-generator or optillm?
Choose openapi-generator if you want the larger community (26,752 stars) or its Apache-2.0 licence terms. Choose optillm if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.