head to head · open source
CopilotKit vs vellum-assistant
CopilotKit has 38,499 GitHub stars, 4,802 forks, 295 open issues and last shipped yesterday. vellum-assistant has 1,474 stars, 230 forks, 179 open issues and last shipped yesterday. CopilotKit leads on adoption by 2,512% (38,499 vs 1,474 stars). CopilotKit is written in TypeScript under MIT; vellum-assistant is written in TypeScript under MIT. CopilotKit has attracted 12% as many forks as stars, vellum-assistant 16%. vellum-assistant was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 3 topic tags (agent, agentic-ai, ai-assistant), 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
| CopilotKit | vellum-assistant | |
|---|---|---|
| GitHub stars | ★ 38K | ★ 1.5K |
| License | MIT | MIT |
| Written in | TypeScript | TypeScript |
| Last push | 2026-11-04 | 2026-11-04 |
| Forks | ⑂ 4.8K | ⑂ 230 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick CopilotKit if
- You weight community size — 38K stars and counting
- You want the MIT license terms
- Your stack matches TypeScript
- You value the larger contributor base for long-term maintenance
pick vellum-assistant if
- You want the vellum-assistant feature set and don't need the biggest community
- You prefer the MIT license terms
- Your stack matches TypeScript
- You evaluated both and vellum-assistant fits your workflow better
About CopilotKit
CopilotKit Docs · Examples · CopilotKit Intelligence · Discord Build agent native applications — on any framework, on any surface. Generative UI, shared state, and human in the loop workflows for React, Angular, Vue, React Native — and in Slack and Microsoft Teams. What is CopilotKit? CopilotKit is a best in class SDK for building full stack agentic applications, Generative UI, and chat applications. What started as a React library is now the horizontal layer between your agents and your users : the same agent can power your web app, your mobile app, and your team's Slack or Microsoft Teams workspace. We are the…
read the full CopilotKit overview →
About vellum-assistant
A personal AI assistant that evolves with you. 8 different types of memory (episodic, semantic, procedural, emotional, prospective, behavioral, narrative, shared) make it truly yours. It learns how you work, remembers what matters, and takes action across your apps. What It Does If you've set up a Personal AI on OpenClaw, Hermes Agent, or Claude Code, you know how long it takes, and how many times you have to hatch a new one to get it right. Vellum gets you the result you're looking for out of the box, one download away. Get Started 1. Sign up or download the app The desktop app is available for macOS and…
read the full vellum-assistant overview →
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Frequently asked questions
Is CopilotKit or vellum-assistant more popular?
CopilotKit has 38,499 GitHub stars and vellum-assistant has 1,474. CopilotKit has the larger community by that measure.
Are CopilotKit and vellum-assistant free?
Both are open source. CopilotKit is licensed under MIT and vellum-assistant under MIT. Neither carries a licence fee.
What is the difference between CopilotKit and vellum-assistant?
CopilotKit is written in TypeScript and vellum-assistant 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, CopilotKit or vellum-assistant?
Choose CopilotKit if you want the larger community (38,499 stars) or its MIT licence terms. Choose vellum-assistant if its feature set, stack or MIT licence fits better. Both are self-hostable.