$ find your agent harness

Anthropic's Claude-only agent harness in native desktop form, redesigned April 14, 2026 around a multi-session sidebar for parallel agents across repos, with integrated terminal/editor/diff viewer, cloud-hosted 'Routines' that run on Anthropic infrastructure while your machine is off, and the ecosystem that originated Agent Skills, subagents, hooks, plugins, and the headless Agent SDK (repo is issue tracker/docs; stars 136,750).

Anthropic's terminal-native agentic coding tool and the category-defining harness, distinguished by its layered extensibility model (CLAUDE.md memory, Agent Skills, subagents, hooks, plugins, MCP) plus permission modes, checkpoints, and optional sandboxing, available from CLI/IDE/desktop/web with an Agent SDK for building on top.

AWS's Claude-powered agentic IDE (VS Code fork; launched internationally May 7, 2026 as the successor to Amazon Q Developer) whose signature is spec-driven development — generating requirements.md/design.md/tasks.md with EARS acceptance criteria before coding — plus event-driven agent hooks, steering files, AGENTS.md/Skills.md/MCP support, and 'Kiro Powers' pre-packaged AWS MCP servers; the GitHub repo (3,980 stars) is a public issue tracker, not the source.

Sourcegraph's opinionated no-model-picker coding agent (CLI + VS Code extension), distinguished by curated multi-model design with specialized subagents (Oracle for reasoning, Librarian for library research), Toolboxes (UNIX-script custom tools), skills with bundled MCP servers, and an ad-supported free mode alongside zero-markup pay-as-you-go credits.

Cursor's terminal/headless version of its IDE agent (shipped January 2026), distinguished by cloud handoff to isolated cloud VMs, sandboxed command execution with granular network/filesystem controls, hooks, async subagents, and shared MCP/rules/skills config with the Cursor editor.

VS Code-fork AI IDE whose Agent mode plus in-house Composer models, Background/Cloud Agents (isolated cloud VMs that report back as PRs), hooks, skills, and an agent SDK make it the most fully-built-out commercial agentic IDE; Composer 2 scored 61.7% on Terminal-Bench 2.0 and Composer 2.5 79.8% on SWE-bench Multilingual (SWE-bench Verified not reported).

Anthropic's cloud-hosted Claude Code at claude.ai/code: each session gets an isolated Anthropic-managed VM with the GitHub repo cloned and limited default network access, supports parallel steerable sessions across repos with automatic PR creation, sessions persist after browser close and are monitorable from the Claude mobile app; bundled with Pro/Max/Team/Enterprise plans (research preview).

AWS's fully managed, configuration-defined agent harness (GA June 17, 2026): two API calls (CreateHarness/InvokeHarness) stand up an agent with its own isolated session environment, filesystem and shell, cross-session memory, a curated skills catalog, and web browsing, running any Bedrock, OpenAI, Gemini, or LiteLLM-compatible model with mid-session provider switching and no separate harness charge.

Anthropic's non-technical desktop agent built on the Claude Code harness (no terminal required) that works over local folders, browsers (Claude in Chrome), and full computer use, with MCP connectors, Agent Skills, and plugins — expanded to web and mobile in July 2026 with cloud-run sessions for Max subscribers.