openai-agents-js vs harness-sdk
Agent SDKs for JavaScript/TypeScript and Python compared
openai-agents-js provides a JavaScript and TypeScript framework for tool use, agent handoffs, sandboxed tasks, and realtime voice workflows. harness-sdk offers Python and TypeScript harnesses plus lower-level SDKs, with emphasis on configurable execution in your own process and broad model-provider support.
openai-agents-js: Build Multi-Agent and Voice Workflows
A TypeScript SDK for building LLM agents that use tools, delegate work, and manage conversations. It also supports sandboxed tasks and low-latency voice agents, making it useful for teams building more than a single prompt-and-response flow.
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.
| openai-agents-js | harness-sdk | |
|---|---|---|
| Language | TypeScript | Python |
| License | MIT | Apache-2.0 |
| Stars | 3.9k | 8.6k |
| Forks | 987 | 1.3k |
| Last analyzed | Oct 3, 2026 | Oct 3, 2026 |
Key differences
- openai-agents-js focuses on JavaScript and TypeScript, while harness-sdk provides Python and TypeScript tools.
- openai-agents-js highlights browser-based realtime voice agents and sandbox workspaces; harness-sdk highlights ready-made harnesses, configurable agent loops, and lifecycle controls.
- harness-sdk documents support for Amazon Bedrock, Anthropic, OpenAI, Gemini, and additional providers; openai-agents-js describes use with OpenAI APIs and other providers.
- harness-sdk includes a CLI for prototyping and chatting with a harness agent; openai-agents-js emphasizes sessions and tracing around agent workflows.
- openai-agents-js is licensed under MIT, while harness-sdk is licensed under Apache-2.0.
- Both support MCP, multi-agent workflows, guardrails, and tracing, but harness-sdk also lists structured output, evaluation, and execution limits.
Choose openai-agents-js if you…
- need a JavaScript or TypeScript framework for agent handoffs and tool use.
- want browser-based realtime voice interactions or sandboxed tasks.
- need conversation sessions and tracing within agent workflows.
Choose harness-sdk if you…
- want a ready-made Python or TypeScript harness with configurable defaults.
- need lower-level control over the agent loop or execution limits.
- want documented integrations with multiple model providers and a CLI for prototyping.
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This comparison is generated with AI from the OSRepos analyses of both projects. Always check each project's repository and documentation before choosing.