why do you even need plan mode?

“discuss your plan with me before implementing anything”

theres your plan mode

Plan mode isn’t that useful but planning is, I never used it much, but in the agent build mode, I lay down the specs, the architecture, and everything I can think of, and I ask the agent to make the blueprint with the specs that will be used throughout the project, I review them, make the needed edits and revisions, then code and review follow. This is good because you can use the blueprint in any other model or agent, even humans can read it and understand it, sure, sometimes it gets overly verbose but it’s better than nothing.

I can't speak for Claude, but in Codex, plan mode is very useful for finding serious issues with one's spec. I use it to improve my spec. I keep rerunning plan mode over my updated spec until it stops finding issues. It is only then that I execute the spec.

I don’t think it’s dead at all. I use it as a phase transition to let the agent decide when discovery is sufficient, as an intermediate phase between that and implementation. Even as a human dev you rarely go tinkering with files all over without first forming a plan.

yeah plan mode never was really alive to begin with

> This cut-and-paste workflow felt clunky and made it arduous to work through an idea while keeping track of the current plan.

I mean, it is, and if that were the workflow I’d be very fed up of it by now, but the plan mode in Claude’s VS Code extension has supported select and annotate directly since at the very least early 2026.

Waterfall is dead. Agile iteration is the future.

That’s the amazing realization?

We experienced another step function in model quality over the summer. Models are now one-shotting medium sized tasks that require significant engineering judgement. We're moving into an era where the production of software will be done entirely by machine, requiring only an abstract description of the need the system is to fulfill in business language. This has been the goal since the 1970s. "Plan mode" isn't necessary when the model can suss out what you need from a few sentences of prompt and make competent engineering decisions to fulfill that need.

Brooks was wrong. We have a silver bullet now.

Maybe, I always say "let's write a plan and refine it" which ends up being a nice rubber duck session to keep claude and friends from going off the rails implementing things like privacy or encryption or some other rabbit hole when I just need it to do a few features at a time so I can review while it starts the next few things. Maybe this is slower to deliver, but I don't spend a lot of time unwinding commits.

I don't necessarily use plan mode explicitly for this, but I might turn it on if I think something destructive is coming up, like a schema change or some other devops thing where claude may decide "oh we copied it all over so I can delete it from source" "oh I'm sorry I didn't catch that error code and assumed success, your data is now gone" lol. This happens a lot less but I've been bit right on the face by it before.

Are plans the wrong abstraction? You can use a big enough plan to spam tickets into linear and have claude burn them down. I find it increases subagent accuracy.

"AI-generated text is painful to read"