$ 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

2 of 74 harnesses · sorted by stars

Mastra · Mastra (Gatsby founders)

25,927 · high

The leading TypeScript agent framework (Apache 2.0 core since July 2025; some enterprise features commercial) offering agents, type-safe workflows with suspend/resume human-in-the-loop, memory, a unified router to 3,300+ models across ~94 providers, guardrails/scorers/tracing, Mastra Studio for interactive testing, and file-based agent definitions added July 2026.

Runtimes & SDKsopen-sourcefreemium✓ mcp✓ local models

Perplexity's Chromium-based agentic browser (free on all four platforms since April 2026) whose sidebar assistant reads pages and tabs and executes web tasks in the user's own browser, extended by 'Personal Computer' on Mac to local file editing, local computer use, and voice orchestration.

General / computer-useproprietaryfreemium
harnesses.sh — the agent harness directory