# What It Takes to Build a Production Agent Harness

DevFeed: [What It Takes to Build a Production Agent Harness](<https://devfeed.tech/articles/what-it-takes-to-build-a-production-agent-harness-18246.md>)

Original publisher: [Read original article](<https://blog.dailydoseofds.com/p/what-it-takes-to-build-a-production>)

Author: Avi Chawla

Published: 2026-09-14T19:50:37Z

Content type: article

Language: en

Sources: [Daily Dose of Data Science](<https://devfeed.tech/sources/daily-dose-of-data-science.md>)

Topics: [Agent Harness](<https://devfeed.tech/topics/agent-harness.md>), [LangChain](<https://devfeed.tech/topics/langchain.md>), [Artificial Intelligence](<https://devfeed.tech/topics/ai.md>), [Persistence](<https://devfeed.tech/topics/persistence.md>), [Graphs](<https://devfeed.tech/topics/graphs.md>)

Tags: [agent](<https://devfeed.tech/tags/agent.md>), [ai](<https://devfeed.tech/tags/ai.md>), [ai-engineer](<https://devfeed.tech/tags/ai-engineer.md>), [engineering](<https://devfeed.tech/tags/engineering.md>), [evaluation](<https://devfeed.tech/tags/evaluation.md>), [langchain](<https://devfeed.tech/tags/langchain.md>), [langgraph](<https://devfeed.tech/tags/langgraph.md>), [memory](<https://devfeed.tech/tags/memory.md>), [persistence](<https://devfeed.tech/tags/persistence.md>), [tools](<https://devfeed.tech/tags/tools.md>), [tracing](<https://devfeed.tech/tags/tracing.md>)

## AI overview

A hands-on series chapter explains how to build a production agent harness with LangChain and LangGraph. It covers model, message, prompt, and tool interactions; tool-call execution; state transitions; persistence; failure handling; tracing; evaluation; human approval; and resumable execution.

## Source excerpt

A hands-on nanodegree for production agent engineering.