head to head · open source
langchain vs Foundry
langchain has 146,538 GitHub stars, 24,504 forks, 492 open issues and last shipped yesterday. Foundry has 872 stars, 129 forks, 5 open issues and last shipped 29 days ago. langchain leads on adoption by 16,705% (146,538 vs 872 stars). langchain is written in Python under MIT; Foundry is written in Python under Apache-2.0. langchain has attracted 17% as many forks as stars, Foundry 15%. langchain was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 3 topic tags (agents, ai, ai-agents), 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
| langchain | Foundry | |
|---|---|---|
| GitHub stars | ★ 147K | ★ 872 |
| License | MIT | Apache-2.0 |
| Written in | Python | Python |
| Last push | 2026-09-17 | 2026-08-20 |
| Forks | ⑂ 25K | ⑂ 129 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick langchain if
- You weight community size — 147K stars and counting
- You want the MIT license terms
- Your stack matches Python
- You value the larger contributor base for long-term maintenance
pick Foundry if
- You want the Foundry 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 Foundry fits your workflow better
About langchain
LangChain is an open source framework for building agents and LLM powered applications, written in Python and released under the MIT license. It lives in the AI and machine learning ecosystem, specifically among AI development platforms, and it works by chaining together interoperable components and third party integrations so that AI application development becomes simpler. The project describes itself as the agent engineering platform, and its abstractions are designed to keep applications working as the underlying technology evolves.
read the full langchain overview →
About Foundry
Foundry is a Python, Apache 2.0 licensed agentic engineering framework from Promptise that gives developers one install for building AI agents, the tools they call, the reasoning they follow, and the governed runtime that serves them to customers.
read the full Foundry overview →
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Frequently asked questions
Is langchain or Foundry more popular?
langchain has 146,538 GitHub stars and Foundry has 872. langchain has the larger community by that measure.
Are langchain and Foundry free?
Both are open source. langchain is licensed under MIT and Foundry under Apache-2.0. Neither carries a licence fee.
What is the difference between langchain and Foundry?
langchain is written in Python and Foundry 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, langchain or Foundry?
Choose langchain if you want the larger community (146,538 stars) or its MIT licence terms. Choose Foundry if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.