AgentsKit vs harness-sdk
JavaScript agent toolkit compared with Python and TypeScript SDK
agentskit and harness-sdk both help developers build AI agents with model integrations, tools, and execution components. agentskit focuses on a modular JavaScript and TypeScript ecosystem, while harness-sdk offers ready-made harnesses and lower-level SDKs for Python and TypeScript.
AgentsKit: Build Modular AI Agents in JavaScript
AgentsKit is a TypeScript toolkit for building AI agents in JavaScript, from chat interfaces to autonomous runtimes. Its small core and shared contracts connect provider adapters, tools, memory, retrieval, and UI packages.
harness-sdk: Build and Run AI Agents in Python and TypeScript
Strands Agents provides Python and TypeScript tools for building AI agents, from a ready-made harness to a customizable agent SDK. It suits teams that want model flexibility and control over agent execution without a hosted control plane.
| AgentsKit | harness-sdk | |
|---|---|---|
| Language | TypeScript | Python |
| License | MIT | Apache-2.0 |
| Stars | 36 | 8.6k |
| Forks | 3 | 1.3k |
| Last analyzed | Oct 20, 2026 | Oct 3, 2026 |
Key differences
- agentskit provides packages for agent components and interfaces, while harness-sdk offers both assembled harnesses and SDKs for configuring the agent loop.
- agentskit targets JavaScript and TypeScript; harness-sdk supports Python and TypeScript.
- agentskit lists an MIT license, while harness-sdk lists Apache-2.0.
- agentskit describes its core as stable and the rest of its ecosystem as beta; harness-sdk documents harness and SDK options, lifecycle controls, hooks, and tracing.
- agentskit targets Node.js 20+ and modern JavaScript runtimes, while harness-sdk documents requirements of Python 3.10+ and Node.js 22+.
- agentskit includes UI bindings for several frameworks and terminal apps; harness-sdk includes a CLI for prototyping and chatting with a harness agent.
Choose AgentsKit if you…
- need a modular JavaScript or TypeScript toolkit with substitutable components.
- want React, terminal, or other listed UI bindings for an agent.
- plan to combine agent runtime, tools, memory, and retrieval from a shared package ecosystem.
Choose harness-sdk if you…
- want a ready-made Python or TypeScript harness, or lower-level SDKs to control the agent loop.
- need lifecycle controls such as turn limits, token budgets, and cancellation.
- want hooks, tracing, guardrails, and evaluation support for agent execution.
Compare the numbers side by side, or add more projects
This comparison is generated with AI from the OSRepos analyses of both projects. Always check each project's repository and documentation before choosing.