# Walden

> Walden is an idea book for building with coding agents. Think an idea all the way through, then hand it to your engineers or your agents to build.

Building software has gotten fast: engineering teams ship faster with AI tools, and solo founders use AI as their whole product team. The bottleneck now is knowing what to build. Walden helps you ask the right questions early and throughout planning: who the user is, what problem the product solves, and the best way to solve it.

## What it does

- You work an idea out in parts: the problem, the approach, what is still unknown, and what you will not do. What it is worth is there too, if you need to weigh it against other work.
- Second readers (a builder, whoever decides, a fair skeptic, or one you write) ask questions beside the part they are about and never rewrite the idea. The chat can draft an idea from a sentence; drafts are not counted until you keep them.
- Walden reads your idea and asks whether someone could pick it up without coming back to you. Each part gets two checks: does it do its job, and could a builder work from it. It never blocks you; you decide when to hand it off.
- Flows, UI sketches and canvases sit beside the idea. Connect a repository and the readers, the chat and the sketches read your codebase.
- Hand it off to a coding agent (Claude Code, Cursor or any agent that supports MCP), which reads the idea from Walden, keeps its task list there, and cannot change a word; a person marks it built. Or hand it off as a package for your engineering team.
- Teams: invite designers and engineers while the idea is taking shape. Editors write with you; viewers read along and ask questions, for free.
- It borrows from Shape Up and product-minded engineering.

## Who it is for

Founders, product managers, designers, and solo builders who use AI coding agents (Claude Code, Cursor and the like) or work with an engineering team, and want to decide what to build before building it.

## Plans

- Free: $0. Ideas, flows, sketches and canvases; present and hand off; 20 AI credits to start, then 5 a day. No credit card.
- Personal: $20 a month or $200 a year. 400 credits a month, top-ups, your own model key.
- Team: $30 per seat a month or $300 per seat a year. A shared workspace, invited readers, 400 credits per person shared across the team.

## Links

- [Walden](https://walden.so/): the site, and where to start an idea book
- [Privacy](https://walden.so/privacy): what Walden collects and why
- [Terms](https://walden.so/terms): the agreement, plans and credits