Overview
AgentsKit is a composable toolkit for building AI agents in JavaScript. Instead of another monolithic framework, it ships a small contracted core plus independently installable packages — every adapter, tool, skill, memory, retriever, and runtime is substitutable behind six formal, versioned contracts. Teams start with one package, grow into a full stack, and can change model vendors without rewriting application architecture.
Key Features
- Provider swap in one line:
openai(),anthropic(),gemini(),ollama(),deepseek(),grok()adapters behind the same adapter contract - Autonomous agent runtime with a ReAct loop, tool registry, skills, and multi-agent delegation through a tool the model already knows how to call
- UI surfaces for React, Ink (terminal), Vue, Svelte, Solid, Angular, and React Native sharing one chat contract
- Memory (chat, vector, graph, encrypted), plug-and-play RAG with reranking, sandboxed code execution, observability (LangSmith, OpenTelemetry, audit log), and agent evaluation with replay
- Expose AgentsKit tools as an MCP server for Claude Desktop, Cursor, and Windsurf; one-descriptor integrations for Slack, Teams, and email
- CLI (
npx @agentskit/cli init) scaffolds skills, tools, and adapters from templates
Use Cases
- Building a streaming chat UI in React (or Vue/Svelte/Solid/Angular/RN) with swappable providers
- Headless autonomous agents with tools, skills, and long-term memory
- Multi-agent delegation where a planner decomposes tasks and researcher/coder delegates execute with scoped tools and step budgets
- Terminal-first agents via Ink + CLI, and exposing internal tools to MCP clients like Claude Desktop
Technical Details
- Core has zero runtime dependencies under a CI-enforced 10 KB gzipped budget and is API-frozen at v1; six versioned ADRs (0001–0006) define the adapter, tool, memory, retriever, skill, and runtime contracts
- Every package carries an explicit stability tier (stable/beta), test floor, README, human guide, and agent handoff; numeric ecosystem claims are generated from repository sources by
scripts/compute-stats.mjsinto a committed claims ledger and fail CI on drift - First agent runs with no API key or network request through a local adapter factory; the README example is a byte-synchronized executable fixture that runs in CI
- The full public API fits under 2,000 tokens for agent consumption, with
llms.txtanddoc-bridge.config.jsonproviding machine-readable doc handoffs - Targets Node.js 20+ and modern runtimes with dual ESM/CJS output and strict TypeScript declarations; edge compatibility from the dependency-free core
- Ecosystem layering: the toolkit repo, a registry of ready-made agents/tools (registry.agentskit.io), and a patterns playbook (playbook.agentskit.io)