# What Is an Agent Harness? The Architecture Behind Claude Code, DeepSeek Harness, and Hermes Agent

DevFeed: [What Is an Agent Harness? The Architecture Behind Claude Code, DeepSeek Harness, and Hermes Agent](<https://devfeed.tech/articles/what-is-an-agent-harness-the-architecture-behind-claude-code-deepseek-harness-and-hermes-agent-4343.md>)

Original publisher: [Read original article](<https://www.freecodecamp.org/news/what-is-an-agent-harness/>)

Author: Rudrendu Paul

Published: 2026-09-11T15:07:18Z

Content type: tutorial

Language: en

Sources: [freeCodeCamp Programming Tutorials: Python, JavaScript, Git & More](<https://devfeed.tech/sources/freecodecamp-programming-tutorials-python-javascript-git-more.md>)

Topics: [AI Bots](<https://devfeed.tech/topics/ai-bots.md>), [AI-assisted coding](<https://devfeed.tech/topics/ai-assisted-coding.md>)

Tags: [agent](<https://devfeed.tech/tags/agent.md>), [ai-agents](<https://devfeed.tech/tags/ai-agents.md>), [architecture](<https://devfeed.tech/tags/architecture.md>), [artificial-intelligence](<https://devfeed.tech/tags/artificial-intelligence.md>), [claude-code](<https://devfeed.tech/tags/claude-code.md>), [deepseek](<https://devfeed.tech/tags/deepseek.md>), [developer-tools](<https://devfeed.tech/tags/developer-tools.md>), [llm](<https://devfeed.tech/tags/llm.md>), [machine-learning](<https://devfeed.tech/tags/machine-learning.md>), [mcp](<https://devfeed.tech/tags/mcp.md>), [memory](<https://devfeed.tech/tags/memory.md>), [python](<https://devfeed.tech/tags/python.md>), [sandbox](<https://devfeed.tech/tags/sandbox.md>), [software-engineering](<https://devfeed.tech/tags/software-engineering.md>), [tools](<https://devfeed.tech/tags/tools.md>)

## AI overview

An explainer and hands-on guide to agent harnesses: the runtime infrastructure around an LLM that manages model calls, tool execution, memory, and filesystem sandboxing. It compares popular harnesses and introduces a small Python implementation.

## Source excerpt

On August 13, 2026, DeepSeek published a GitHub repository called deepseek-harness. Within two days, it had passed 95,386 stars and 8,826 forks (a vanity metric on its own, but a spike this fast signa