Why Plan Mode Still Matters in AI Coding Assistants (Codex, Claude, Cursor)

Melvin Vivas · X video post · 2026-09-28 · 0:37 · 1,274 views · Open on X

Topics: AI Dev Tools & Productivity · Level: beginner

Summary

This is a short opinion clip. Melvin Vivas pushes back on the idea of removing "plan mode" from AI coding assistants like Codex, Claude Code and Cursor. He argues that even very capable models can change your code when you only meant to ask a question. A read-only planning mode protects against that, and taking away a feature that paying users rely on is frustrating.

Key points

• Plan mode lets you ask questions or plan work with an AI coding assistant without it changing your files.
• The creator's main argument: smarter models do not remove the risk of unwanted code changes, because a plain question can still lead the agent to update your code.
• He rejects the claim that "models are so intelligent you don't need plan mode anymore" as a reason to remove it.
• His user-side view: he pays for a subscription, depends on the feature, and removing it is frustrating.
• Practical takeaway: when you are only exploring or asking questions, use a planning or read-only mode so the agent does not make edits you didn't want.
• This is an opinion piece with no tutorial or step-by-step instructions.

Resources mentioned

• OpenAI Codex · tool · openai.com · paid
  OpenAI's coding agent. In the diagram it writes code, fixes review findings and drives the build loop. The creator also used it to make this video.
  Also in: An agent bot that installs and drives Codex on its own (Melvin Vivas on X · notes), Asking a Coder bot to install Codex (Melvin Vivas on X · notes), Sign in with ChatGPT: Setting Usage Limits for Each App (Melvin Vivas on X · notes), Codex Cloud Environments Must Be Saved & Published Before Use (Melvin Vivas on X · notes) and 240 more
• Claude Code · tool · code.claude.com · paid · recommended by both Bashiri Smith & Melvin Vivas
  Build agents and pipelines from the terminal; the guide's main agentic coding tool.
  Also in: Create Claude Code Plugins with /plugin-authoring (Melvin Vivas on X · notes), Claude Code mods: customize behavior and UI with plugins (Melvin Vivas on X · notes), AI Engineer Roadmap Overview: From ML Foundations to RAG, Agents & Ops (Bashiri Smith on Facebook · notes), SkillsBento: Free Plugin Marketplace for Codex and Claude Code (Melvin Vivas on X · notes) and 101 more
• Cursor · tool · x.com · free · recommended by both Bashiri Smith & Melvin Vivas
  AI-native code editor (VS Code with AI built in).
  Also in: GLM 5.3 and GLM 5.3 Flash now in Cursor (Melvin Vivas on X · notes), Grok Bot Can Now Hand Off Coding Tasks to Cursor (Melvin Vivas on X · notes), Why Plan Mode Still Matters in AI Coding Agents (Codex, Claude, Cursor) (Melvin Vivas on X · notes), AI DevBox v1.3.0: a GPU-ready Docker image with coding-agent CLIs (Melvin Vivas on X · notes) and 121 more

Try this

• Use plan mode or a read-only mode in your AI coding assistant when you only want answers or a plan, not code changes.