You want a strong opensource and fully customisable harness?! None other than langchain’s deepagents. Try it yourself if in doubt.

You want a strong opensource and fully customisable harness?! None other than langchain’s deepagents. Try it yourself if in doubt. most of the agents we see being built do this the main cases where we see people using "agent in a sandbox" is when they are using claude agent sdk (which is poorly designed for "harness outside sandbox")

Related

• great q! deepagents has more 'batteries included', which langchain v1 is a very minimalistic agent harness if you are doing more complex wor…
• Deep Agents or @LangChain? Just use the right tool for the right job
• if you prefer blog format: https://blog.langchain.com/deep-agents-deploy-an-open-alternative-to-claude-managed-agents/
• Deep Agents Deploy: an open alternative to Claude Managed Agents
• anyways, try out deepagents https://github.com/langchain-ai/deepagents

Source: Harrison Chase (X) | 2026-04-09