Codex

GitHub Agent HQ is GitHub’s unified Mission Control interface that lets you assign issues to Claude, Copilot, and Codex agents side-by-side, compare their pull requests, and manage all AI coding sessions from one dashboard — no external subscriptions beyond your existing Copilot plan required. What Is GitHub Agent HQ? The Unified Mission Control for AI Coding Agents GitHub Agent HQ is a centralized orchestration layer within GitHub that allows development teams to deploy, monitor, and compare multiple AI coding agents — including GitHub Copilot (workspace agent), Anthropic Claude, and OpenAI Codex — from a single unified interface. Launched in late 2025 and expanded significantly in early 2026, Agent HQ represents GitHub’s shift from a single-agent assistant model to a vendor-neutral, multi-agent development platform. As of April 2026, available Claude models include Claude Sonnet 4.6, Claude Opus 4.6, Claude Sonnet 4.5, and Claude Opus 4.5; Codex options span GPT-5.2-Codex through GPT-5.4. Agent HQ is included with all GitHub Copilot plans — no separate marketplace purchases required. The platform supports github.com, VS Code, and GitHub Mobile, giving every developer on your team access to the same agent orchestration tools regardless of their preferred environment. The key value proposition: instead of context-switching between different AI tools with incompatible workflows, Agent HQ standardizes the entire agentic development cycle under GitHub’s existing issue and PR model. ...

The composable AI coding stack pairs Cursor for interactive IDE flow, Claude Code for deep codebase reasoning, and OpenAI Codex for async fire-and-forget tasks. Used together, these three tools cover the full development loop — from architectural exploration to implementation to automated testing and PRs — without forcing you to choose a single winner. The AI Coding War That Never Happened (And What Emerged Instead) The narrative in early 2025 was simple: Cursor, Claude Code, and Codex were in a death match for developer mindshare. The tool that won would own the category. By mid-2026, that story was provably wrong. According to uvik.net’s 2026 benchmarks, 70% of engineers now use 2–4 AI coding tools simultaneously — and the market has rewarded every player. Cursor surpassed $2B ARR in Q1 2026 en route to a reported $50B valuation. Claude Code hit a $2.5B run-rate in just nine months. OpenAI Codex crossed 3 million weekly active users by April 2026, up from near-zero in mid-2025. Instead of consolidating, the tools diverged into distinct, complementary roles. Production teams stopped asking “which tool should I use?” and started asking “how do I wire them together?” The answer is a composable stack where each tool occupies a natural layer — and the three layers together cover the entire software development lifecycle more efficiently than any single product can. ...

GitHub now lets you pick your AI model when kicking off a coding agent task. Claude Sonnet 4.6, Claude Opus 4.6, GPT-5.2-Codex, and GPT-5.4 are all available — and which one you choose has a direct impact on code quality, task completion rate, and your monthly bill. This guide cuts through the noise with benchmarks, cost data, and a concrete decision framework so you can stop guessing and start shipping. ...

The best AI coding setup in 2026 isn’t a single tool — it’s a composable stack: Cursor as the IDE and orchestration layer, Claude Code as the deep-reasoning terminal agent, and OpenAI Codex as the cloud-native background automation engine. Using all three together costs as little as $40/month and delivers capabilities no single tool can match. What Is the Cursor + Claude Code + Codex Composable Stack? The Cursor + Claude Code + Codex composable stack is a three-tool AI coding architecture where each product owns a distinct phase of the development workflow: Cursor 3.0 handles the interactive editor and agent orchestration layer, Claude Code (powered by Anthropic’s Opus 4.6) executes deep reasoning and terminal-level autonomy, and OpenAI Codex runs cloud-native background automation across repositories. As of April 2026, 70% of professional engineers run 2–4 AI coding tools simultaneously — and the Cursor + Claude Code + Codex combination is the most cited trio. This isn’t tool hoarding. The three products solve fundamentally different problems, communicate via MCP (Model Context Protocol), and compound each other’s strengths. Claude Code now accounts for 4% of all GitHub commits globally, while Cursor has crossed $2B ARR with roughly 1 million paying users. The composable stack represents a shift from “which AI tool is best” to “which tool fits this specific task,” a mindset that the most productive 10% of developers have already internalized. ...

ChatGPT Workspace Agents are autonomous AI workers powered by Codex that your team builds once and runs continuously — reading files, calling APIs, posting to Slack, updating Salesforce, and completing multi-step workflows without hand-holding. Launched April 22, 2026, they replace custom GPTs for Business and Enterprise users. What Are ChatGPT Workspace Agents? (Powered by Codex) ChatGPT Workspace Agents are cloud-hosted autonomous AI workers that use OpenAI’s Codex model as their execution engine. Unlike chatbots that respond to a single prompt and stop, workspace agents can plan multi-step workflows, call connected tools (Slack, Google Workspace, Salesforce, Notion), write and run code, retain memory across sessions, and continue working in the background until a task is complete. Launched on April 22, 2026, they represent OpenAI’s clearest enterprise pivot to date: from conversational AI to operational AI. ...

AGENTS.md is a markdown file placed at your repository root that gives AI coding agents the project-specific instructions they need to work effectively — build commands, code style rules, testing conventions, and git workflow — without reading your entire codebase first. What Is AGENTS.md? The Open Standard Explained AGENTS.md is an open standard for AI agent instructions, stewarded by the Agentic AI Foundation (AAIF) under the Linux Foundation alongside MCP (Anthropic) and Goose (Block). It is a plain markdown file placed at the root of a code repository that tells AI coding agents how your project works — how to build it, test it, what style conventions to follow, and where the important parts live. Unlike README.md, which explains a project to humans, AGENTS.md speaks directly to AI tools. As of 2026, over 60,000 open-source repositories contain the file, and 20+ AI coding agents — including OpenAI Codex, Cursor, Claude Code, Windsurf, Devin, Gemini CLI, and Aider — read it natively. The Agentic AI market is projected to reach $10.86 billion in 2026, with 57% of developers already reporting AI agents in production. AGENTS.md has become the connective tissue between human intent and machine execution. The key takeaway: it is a living operational manual for AI, not documentation for humans. ...