What is Big Plan?
Big Plan turns your agent’s standard text plan into a rich, inert HTML document designed for human review. It runs on your machine, needs no account, and the plan file on your disk stays the source of truth.
Run it in your favourite agent harness as a skill:
Give me a /big-plan for implementing the following feature...Give me a $big-plan for implementing the following feature...Plans are a big deal
Section titled “Plans are a big deal”The big decisions happen in the plan, while they are still cheap to change. Once an agent starts executing, changing course means unwinding work; while the plan is on the table, changing everything costs one comment.
The more confident you are in the plan, the better your agent performs at execution and the faster your final review goes. That confidence comes from review, and review quality is set by how the plan presents itself.
The wall of text problem
Section titled “The wall of text problem”By default an agent’s plan arrives as thousands of words of Markdown, scrolled past in a terminal or skimmed in a raw diff. The most consequential document in the workflow is routinely the least readable one. When reading the plan is painful, review quietly collapses into rubber-stamping, and the decisions that matter most go unexamined.
We think of those plans of limited ambition as small plans. If plans matter this much to the human, they should present in a first-class way — and those are big plans.
What makes a good agent plan
Section titled “What makes a good agent plan”- Easy to scan. You don’t always want to read the whole plan. Sometimes it is better to scan the sections and read the details where they interest you.
- Easy to read. Sometimes a paragraph is best, but often a visual arrangement conveys the same information with far less cognitive load.
- Easy to update. It is painful to reference a specific paragraph of prose. You should be able to highlight a section and give the agent feedback on it.
- Token-efficient. Plans get written, revised, and re-read by agents, and every one of those interactions costs tokens.
- Versioned. Sometimes the plan updates and you are not sure what changed.
- Local and private. Your plan can contain sensitive information; it should not be shared with anyone else without a good reason.
Philosophy
Section titled “Philosophy”Big Plan makes two bets that shape everything else.
A plan should be structured, not freeform. Plans are MDX with a fixed library of typed components, so every plan renders into the same document shape. The agent spends its effort on the decisions rather than the presentation, and the tenth plan you review reads exactly like the first.
A plan on your own disk should not require an account. One standalone command renders it, the output is one HTML file, and nothing about reviewing it involves logging in or leaving your machine.
What Big Plan is not
Section titled “What Big Plan is not”- Not code review. Code review judges a change after the work is done, when pushing back is expensive. Big Plan reviews intent before any code exists.
- Not project management. No tickets, statuses, or boards. It exists only for the moment of agreement.
- Not a Markdown preview. A preview shows you the text. Big Plan is built for review: section navigation, readable code, typed components, anchored comments, and approval.
- Not a service. Everything runs on your machine and the rendered file makes no external requests.
Install Big Plan — Node.js 22, one command, nothing installed globally.