Since we released the last major version of Claude Code, Claude writes its plan to a file automatically for that reason! It also means you can continue to edit your plan as you go.

Opus 4.5 seems to be able to plan without asking, but I have used this pattern of "write a plan to an .md", review and maybe edit, and then execution, maybe in another thread,... I have used it with Codex and it works well.

Profilerating .md files need some attention though.

a very common pattern is planner / executor.

yes the executor only needs the next piece of the plan.

I tend to plan in an entirely different environment, which fits my workflow and has the added benefit of providing a clear boundary between the roles. I aim to spend far more time planning than executing. if I notice getting more caught up in execution than I expected, that's a signal to revise the plan.

I ask it to write a plan and when it starts the work, keep progress in another document and to never change the plan. If I didn't do this, somehow with each code change the plan document would grow and change. Keeping plan and progress separate prevented this from happening.

I ask claude to dump the plan into a file and ensure that the tasks have been split into subtasks such that the description of each subtask meets the threshold such that the probability of the LLM misinterpreting is very low.

I often use multiple documents to plan things that are too large to fit into a single planning mode session. It works great.

You can also use it in conjunction with planning mode—use the documents to pin everything down at a high-to-medium level, then break off chunks and pass those into planning mode for fine-grained code-level planning and a final checking over before implementation.