Agent Harnesses are the autonomous agents themselves — software systems that can plan, reason, and take actions across the web and blockchain without step-by-step human guidance. This category spans the spectrum from developer-focused coding agents (Claude Code, Cursor, Devin) to general-purpose autonomous assistants (Manus, OpenAI Operator, Claude Cowork) to crypto-native agent frameworks (OpenClaw, ElizaOS, NemoClaw).

The defining feature of an agent harness is autonomy: these systems don't just answer questions — they browse websites, execute transactions, write and deploy code, and coordinate with other agents. The competitive landscape is heating up rapidly, with Google's Project Mariner, Perplexity Computer, and Simular AI all racing to build the most capable browser-based agents.