$ find your agent harness

A curated, verified, cross-vendor directory of AI agent harnesses — the runtime scaffolding that turns a model into an agent.

74 harnesses profiled · 9-axis capability schema · last verified 2026-07-08

3 of 74 harnesses · sorted by stars

browser-use · Browser Use Inc. (YC-backed, SF)

103,000 · high

MIT-licensed Python library (103k stars) that lets any LLM drive a real Chrome browser via DOM+vision instead of brittle selectors, now flanked by a desktop app and a usage-based cloud with stealth browsers, proxies, and a 24/7 'Browser Use Box' agent.

General / computer-useopen-sourcebyok✓ mcp✓ local modelsoptional

OpenAI's built-in agent mode that absorbed Operator and Deep Research: a cloud virtual computer with browser, terminal, and connectors that researches, fills forms, and edits files, pausing for user approval on consequential actions and handing back control for logins/payments.

General / computer-useproprietarysubscription✓ mcpcloud-remote

Google's successor lineage to Project Mariner (shut down as a standalone May 2026): Gemini Agent plus the I/O 2026 'Gemini Spark', a 24/7 always-on personal agent on dedicated cloud machines with deep Gmail/Workspace integration, MCP tool support, and check-before-acting guardrails, gated to AI Ultra ($100/mo) beta.

General / computer-useproprietarysubscription✓ mcpcloud-remote
harnesses.sh — the agent harness directory