Star History Monthly November 2025 | Agent SDK/Framework

AI agents are no longer just prototypes - they’re becoming the backbone of production systems. Developers are building structured, autonomous software that reasons, uses tools, and collaborates with users - powered by a fast-growing ecosystem of SDKs and frameworks.

This month, we highlight four standout projects shaping how intelligent applications are built and deployed:

Assistant UI	Chat-native UI toolkit for agent interfaces
Mastra	Full-stack TypeScript agent framework
Claude Agent SDKs	Official multi-language SDKs for building agents with Claude
VitePlus	Next-generation JavaScript toolchain for modern web apps

Assistant UI

→ Building Agent Interfaces

Assistant UI is an open-source toolkit for creating chat-style interfaces. It provides React components and APIs to embed conversational agents directly into your product - with modern design, beautiful defaults, and full TypeScript support.

• Strengths: Polished UI components, flexible integration, and built on shadcn/ui + Tailwind.
• Limitations: Primarily web-focused; native and mobile support are evolving.

👉 Assistant UI gives your agents a front-end identity - transforming LLM logic into elegant, human-centered experiences.

Mastra

→ Full-Stack TypeScript Agent Framework

Mastra is a rapidly maturing, full-stack framework for building AI agents with TypeScript. It unifies model orchestration, retrieval workflows, and observability - enabling developers to ship scalable, production-grade AI systems.

• Strengths: Type-safe, modular, integrates with 40+ model providers; strong tooling and documentation.
• Limitations: APIs evolve quickly as the framework expands.

👉 Mastra brings engineering rigor to AI development - making agents testable, composable, and ready for real-world use.

Claude Agent SDKs

→ Building Agents with Claude

Anthropic’s Claude Agent SDKs, available for multiple languages, including Python and TypeScript, provide structured abstractions for building Claude-powered agents. They include components for tool use, Model Context Protocol (MCP) integration, and persistent multi-step workflows - enabling developers to design reliable, autonomous systems.

• Strengths: First-party SDKs from Anthropic, unified across languages, aligned with Claude’s safety and reasoning architecture.
• Limitations: Memory persistence and orchestration layers are still maturing.

👉 The Claude Agent SDKs elevate agent development to a first-class discipline - offering developers a safe, composable foundation for building intelligent systems.

VitePlus

→ Next-Generation JavaScript Toolchain

(Note: VitePlus is in active development by VoidZero, the team behind Vite, with a public preview expected in early 2026.)

VitePlus isn’t an AI framework - it’s the evolution of Vite into a unified JavaScript toolchain. It adds commands for building, testing, linting, formatting, and managing monorepos, all powered by Rust-based tools like Rolldown and Oxlint for near-instant feedback.

• Strengths: Unified developer experience, high-speed incremental builds, strong TypeScript support.
• Limitations: Still in private development; not yet generally available.

👉 As AI-powered agents merge into everyday web apps, VitePlus provides the performance foundation and developer experience to ship them efficiently.

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✨ That’s November - four projects leading the Agent SDK & Framework Frontier. From SDKs and full-stack frameworks to next-generation developer toolchains, these projects are shaping how developers turn large language models into production-ready, intelligent applications.