OpenAI Codex App: death of the VSCode fork, multitasking worktrees, Skills Automations

**OpenAI** launched the **Codex app** on macOS as a dedicated agent-native command center for coding, featuring **multiple agents in parallel**, **built-in worktrees** for conflict isolation, **skills** for reusable bundles, and **scheduled automations**. The app emphasizes developer workflows like **Plan mode** for upfront task decomposition and is gaining positive adoption signals from insiders including **@sama**. There is movement towards ecosystem standardization of skills folders, signaling early conventions in agent tooling. Codex also exemplifies a "self-improving" product feedback loop combining humans and agents. In coding agents practice, best practices include a "test-first" approach to bug fixes, the "conductor" model where one developer manages 5-10 agents in parallel, and a neurosymbolic framing explaining why coding agents succeed due to software's verifiability and symbolic tooling. Benchmark skepticism remains about productivity studies that do not reflect agentic workflows.