head to head · open source
OpenViking vs oh-my-mermaid
OpenViking has 41,383 GitHub stars, 3,362 forks, 999 open issues and last shipped yesterday. oh-my-mermaid has 3,371 stars, 268 forks, 11 open issues and last shipped 7 months ago. OpenViking leads on adoption by 1,128% (41,383 vs 3,371 stars). OpenViking is written in Python under AGPL-3.0; oh-my-mermaid is written in TypeScript under MIT. OpenViking has attracted 8% as many forks as stars, oh-my-mermaid 8%. OpenViking 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
| OpenViking | oh-my-mermaid | |
|---|---|---|
| GitHub stars | ★ 41K | ★ 3.4K |
| License | AGPL-3.0 | MIT |
| Written in | Python | TypeScript |
| Last push | 2026-11-02 | 2026-04-07 |
| Forks | ⑂ 3.4K | ⑂ 268 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick OpenViking if
- You weight community size — 41K stars and counting
- You want the AGPL-3.0 license terms
- Your stack matches Python
- You value the larger contributor base for long-term maintenance
pick oh-my-mermaid if
- You want the oh-my-mermaid feature set and don't need the biggest community
- You prefer the MIT license terms
- Your stack matches TypeScript
- You evaluated both and oh-my-mermaid fits your workflow better
About OpenViking
The Context Database for AI Agents English / 中文 / 日本語 Website · Live Demo · GitHub · Issues · Docs · Blog Lark · WeChat · Discord · X What is OpenViking OpenViking is an open source context database for AI agents — one filesystem for everything an agent knows: knowledge, memory, and skills. Most agent memory is a black box: text goes in, embeddings come out, and nobody can see what was actually stored. OpenViking organizes context as a virtual filesystem under viking:// instead. Agents navigate it like files — ls , tree , read , write , grep — and you can open any directory to inspect and edit what your agent…
read the full OpenViking overview →
About oh-my-mermaid
English Türkçe 한국어 日本語 中文 Oh my mermaid AI writes code in seconds. Humans understand it in hours. But skip understanding, the codebase becomes a black box — even to you. omm closes the gap — architecture docs, generated by AI, for humans. Quick Start Paste this in your terminal: Then open your AI coding tool and use the /omm scan skill: That's it. View the result: Example omm scanned itself. This is what it found. How It Works Your AI analyzes the codebase and generates perspectives — different lenses on your architecture (structure, data flow, integrations...). Each perspective contains a Mermaid diagram and…
read the full oh-my-mermaid overview →
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Frequently asked questions
Is OpenViking or oh-my-mermaid more popular?
OpenViking has 41,383 GitHub stars and oh-my-mermaid has 3,371. OpenViking has the larger community by that measure.
Are OpenViking and oh-my-mermaid free?
Both are open source. OpenViking is licensed under AGPL-3.0 and oh-my-mermaid under MIT. Neither carries a licence fee.
What is the difference between OpenViking and oh-my-mermaid?
OpenViking is written in Python and oh-my-mermaid 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, OpenViking or oh-my-mermaid?
Choose OpenViking if you want the larger community (41,383 stars) or its AGPL-3.0 licence terms. Choose oh-my-mermaid if its feature set, stack or MIT licence fits better. Both are self-hostable.