[FEATURE] Subfolders / nested organization within a Claude.ai Project (web, desktop, mobile)

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

Surface: Claude.ai Projects (web, desktop, and mobile chat) — NOT the Claude Code CLI. Filing here as the public tracker; please route to the Claude.ai team. (Flagging explicitly because a prior Claude.ai request, #51040, was closed as "not related to Claude Code," and the Feature Category options below are Code-centric.)

A Claude.ai Project has no organization below the Project itself. As a Project accumulates conversations — especially when Claude.ai is used alongside Claude Code for planning and review — they pile into one flat list with no way to group them. Users end up tracking in external tools the very conversations that should be organizable in-product.

"Just use separate Projects" doesn't solve it: related sub-threads routinely share context, artifacts, and a knowledge base that surface in one chat and matter in another. Projects are isolated from one another, so splitting work across multiple Projects breaks that shared context. The natural unit is one Project with internal structure — not many disconnected Projects.

Proposed Solution

Allow nested subfolders inside a Project to group conversations (and ideally artifacts) hierarchically — the way any OS file manager has for decades — while the Project's shared knowledge base and instructions continue to apply across ALL subfolders (one shared context, organized).

How this differs from existing requests: this is the same underlying need already raised on the Code side (e.g. #64354's request to "add a level of hierarchy underneath" the session sidebar), applied to the Claude.ai Projects surface, which is currently uncovered. Please treat it as related but distinct — same idea, different surface — rather than folding it into the Code-sidebar threads (#59016, #68171, #66877).

Alternative Solutions

• Separate Projects per sub-topic — loses the shared knowledge base/context that is the whole point of a Project.
• External trackers (notes apps, docs, spreadsheets) — defeats in-product organization and adds maintenance overhead.
• Paid third-party browser extensions that bolt nested folders onto Claude conversations (e.g. Toolbox for Claude, up to 5 levels; AI Toolbox) — these run only on claude.ai in a desktop browser, NOT in the desktop or mobile apps, which is exactly why a native feature would matter.

Priority

Medium - Would be very helpful

Feature Category

Other

Use Case Example

1. I run one Project for a multi-workstream effort with several parallel threads (e.g. planning, research, drafting, review).
2. Today every chat lands in one flat list inside the Project, so finding the right one means scrolling and guessing.
3. With subfolders I would group them (e.g. "Planning", "Research", "Drafts"), each thread findable at a glance.
4. The Project's shared instructions and knowledge base would still apply across all of them — organized, not fragmented across separate Projects.

Additional Context

Illustrative mockup attached below (information architecture only — not a proposed visual design).

<img width="3138" height="3500" alt="Image" src="https://github.com/user-attachments/assets/08fc3762-2229-4714-8cb3-2fab8da96a47" />

Independent demand: in the r/ClaudeAI "What Claude features do you want?" thread, a user requested "Topics within Projects" (group a Project's chats into topics) and noted they came looking for how to file it — i.e. it was never formally submitted; others in the same thread asked for project-chat folders and per-project chat separation.

Prior art: nesting is a long-solved problem — graphical folders date to the Xerox Star (1981, ~45 years), and the underlying nested-directory concept is older still (Multics/Unix, late 1960s).