OpenAI Codex vs Google Antigravity: Architecture, Workflow, and Key Differences

AI coding tools are no longer just autocomplete engines. For the last few years, developers used AI mainly to write faster: generate a function, explain an error, complete boilerplate, or suggest a code snippet. That was useful, but the human developer still controlled almost every step. Now the shift is toward agentic software development. Tools like OpenAI Codex and Google Antigravity are not only helping developers write code. They are starting to inspect repositories, understand tasks, edit files, run commands, verify outputs, and return work for human review. But Codex and Antigravity are not the same kind of product. They represent two different architectures for the future of software development. Codex: Delegated Engineering Agent OpenAI Codex is best understood as a delegated software engineering agent. The developer gives it a scoped task: fix a bug, review a pull request, write tests, refactor a module, or implement a defined feature. Codex then works through the codebase, makes changes, runs checks where possible, and returns a result that the developer can review. Its natural workflow is close to how software teams already work: Task → Repository Context → Code Changes → Tests/Checks → Pull Request or Reviewable Output This makes Codex useful for structured engineering work. It fits naturally into GitHub-style workflows, pull requests, code reviews, tests, and CI/CD practices. In simple terms, Codex feels like assigning work to an AI engineer. Antigravity: Agent-Orchestration Environment Google Antigravity takes a different approach. It is better understood as an agent-first development environment. Instead of focusing only on one delegated task, Antigravity is designed around supervising agents inside the development workspace. Agents can operate across the editor, terminal, browser, and artifacts. They can help plan, build, verify, and explain the work. Its workflow looks more like this: Goal → Agent Orchestration → Workspace Execution → Browser Verif