Antigravity CLI is a terminal agent Google announced at I/O on May 19, 2026. Written in Go (versus Gemini CLI's Node.js), its binary is called agy, and it shares the same agent harness as the desktop Antigravity 2.0. It is also Gemini CLI's successor — the personal-tier Gemini CLI service ends on June 18, 2026.
GitHub Copilot Coding Agent lets you assign an Issue to Copilot, which then automatically creates a branch, writes code, runs CI, and opens a PR — all inside a cloud sandbox. The key to success is setting up AGENTS.md; without it, the agent tends to go off track. Best suited for well-defined medium-sized tasks; requires Pro+ (1,500 premium requests/month) or Enterprise plan.
Not everyone should use a coding agent to modify code directly. AI Native teams need interface specs, test-first development, monorepo, security guardrails, human-in-the-loop, and token budget controls. Building an agent platform layer on top of coding agents and clearly redefining developer roles is the right path forward.
An open-source coding agent reference implementation from Vercel Labs. A three-layer architecture separates the web UI, agent workflow, and sandbox VM — designed as a starting point for teams that want to self-host their own Claude Code or Cursor Background Agent.
Claude Code is Anthropic's agentic coding tool that runs in the terminal, IDEs, Slack, GitHub, and on the web. Its core extension system has six layers: CLAUDE.md (persistent context), Skills (on-demand workflows), Hooks (deterministic automation), Subagents (isolated delegation), MCP (external tool connections), and Agent Teams (multi-agent collaboration).
Codex CLI is OpenAI's open-source terminal coding agent built in Rust. It supports MCP, subagents, image input, and code review. Paired with the codex-1 (o3-optimized) or GPT-5-Codex model, it can read, write, and execute code directly on your local machine.
Gemini CLI is Google's open-source terminal AI agent (Apache 2.0). ⚠️ Announced end-of-service on 2026/06/18 — official migration path is Antigravity CLI. Free accounts get 60 requests/minute and 1,000 requests/day; Skills, Hooks, and Subagents all carry over.
OpenCode is an open-source AI coding agent built in Go (95K+ GitHub stars) with a built-in TUI, support for 75+ LLMs, LSP integration, Vim-style editing, and SQLite session management. Free, no subscription required — works with local or cloud models.
Pi is a minimalist coding agent built in TypeScript by Mario Zechner, featuring just 4 core tools (read, write, edit, bash) and a 300-word system prompt. It's extensible via Extensions, Skills, and Prompt Templates, runs on the Bun runtime, and ships with built-in Ollama support via `ollama launch pi`.