head to head · open source
CopilotKit vs vellum-assistant
CopilotKit has 37,423 GitHub stars, 4,645 forks, 295 open issues and last shipped today. vellum-assistant has 1,292 stars, 187 forks, 179 open issues and last shipped yesterday. CopilotKit leads on adoption by 2,797% (37,423 vs 1,292 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 14%. CopilotKit 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 | ★ 37K | ★ 1.3K |
| License | MIT | MIT |
| Written in | TypeScript | TypeScript |
| Last push | 2026-09-20 | 2026-09-19 |
| Forks | ⑂ 4.6K | ⑂ 187 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick CopilotKit if
- You weight community size — 37K 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 is a frontend SDK for building agent native applications and generative UI experiences. It provides tooling and protocols to connect AI agents—regardless of backend framework—to user interfaces across web, mobile, and messaging platforms. It lives in the agentic AI ecosystem, specifically targeting developers who need to embed intelligent assistants into products without rebuilding agent logic for each surface.
read the full CopilotKit overview →
About vellum-assistant
Vellum Assistant is an MIT licensed, TypeScript personal AI assistant for individuals and small teams who want a persistent, self improving agent that runs across desktop, mobile, web, voice, email, Telegram, Slack and Twilio without building the memory and orchestration layer themselves.
read the full vellum-assistant overview →
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Frequently asked questions
Is CopilotKit or vellum-assistant more popular?
CopilotKit has 37,423 GitHub stars and vellum-assistant has 1,292. 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 (37,423 stars) or its MIT licence terms. Choose vellum-assistant if its feature set, stack or MIT licence fits better. Both are self-hostable.