What Are Claude Projects? Building a Shared Team Knowledge Base — 2026 Guide

How a project differs from an ordinary chat

Most people start with Claude the same way: open a new chat, attach a file, ask a question, close it. Tomorrow the same files get attached again, and the same organisational context gets re-typed — "we are a contractor, this is our chart of accounts, budget is split across three funding sources" — every single time.

A project fixes that by moving context out of the conversation and into the room. Files and instructions belong to the room, not to the chat. Anyone who opens a new chat inside the project inherits the same context immediately.

Aspect	Ordinary chat	Project
Reference documents	Re-attached in every chat	Uploaded once; every chat in the room sees them
Standing instructions	Retyped each time, or forgotten	Set once in project instructions, applied everywhere
Chat history	Every topic mixed in one list	Scoped to the room, easy to find later
Sharing	One conversation at a time	The whole room including its knowledge (Team / Enterprise)
Answer consistency	Depends on how much context each person typed	Everyone gets the identical context

That last row is the one that matters most in an organisation. The recurring complaint is rarely "the AI was wrong" — it is "two colleagues asked the same question and got different answers", because one attached the current regulation and the other attached last year's copy.

The three parts of a project

Part	What it is	Real-world example
Project knowledge	The file library Claude draws on in every chat in the room	Procurement regulations, chart of accounts, SOP manuals, contract templates
Custom instructions	Standing rules that set the role, tone and output format	"Always cite the clause number. If the answer is not in the uploaded documents, say so."
Chats	Conversation history that lives in this room only	"Review the September TOR" / "Summarise the audit findings"

How much can project knowledge hold, and when does RAG kick in?

The first question every IT team asks is "how many files?". Per Anthropic's own documentation (checked 1 September 2026), the number of files is not the constraint — per-file size and total context capacity are.

Item	Limit	Notes
File size in project knowledge	30 MB per file	Text extraction only, except multimodal PDFs
Number of files in a project	No fixed cap	Bounded by total context capacity instead
Attachments in a single chat	500 MB per file · up to 20 files per chat	A separate allowance from project knowledge
PDFs	Up to 1,000 pages	Charts and images are read up to 100 pages; beyond that, text only
RAG mode	Expands capacity by up to 10x	Enabled automatically as knowledge approaches the context limit; paid plans only (Pro, Max, Team, Enterprise)

RAG (retrieval-augmented generation) means that instead of stuffing the entire library into context, the system retrieves only the passages relevant to the question. The library can therefore grow without answer quality collapsing. Nothing needs configuring — Claude switches modes on its own. The trade-off worth knowing: in RAG mode answers are grounded in the retrieved passages, not the whole corpus, so very broad prompts such as "summarise everything in here" perform worse than specific ones.

The companion number is model context size. The Team plan uses a 200K token context, while Claude Opus 5 and Sonnet 5 support a 1M token context on all paid plans when chatting directly with Claude. A full plan-by-plan breakdown is in every Claude plan limit compared.

Sharing: view-only versus edit

Projects can be created on any plan, including free accounts (capped at five projects). But sharing a project with colleagues is a Team and Enterprise feature — which is the main reason organisations move off individual subscriptions to Claude Team.

Permission	What it allows	Who should have it
Can view	Chat in the room and use its knowledge, but cannot change files or instructions	Everyday users in the department — the safest default
Can edit	Add or remove knowledge files and change the custom instructions	One or two content owners per room, accountable for keeping documents current

Projects can be shared with named individuals, with a bulk list of email addresses, or with the whole organisation; recipients find them under the "Shared with me" tab. Because permissions ride on user accounts, this ties directly into user management in Claude Team and Enterprise.

Five projects an organisation can stand up on day one

If you have just switched on Claude Team and cannot decide where to begin, these five rooms pay back fastest, because the documents already exist — nothing new has to be written.

Project	What goes in the knowledge	Instruction worth setting
Procurement rules	Procurement regulations, practice manuals, previously approved TOR examples	Always cite the clause; if not found, say not found
HR policy	Leave rules, benefits, employee handbook (with individual data removed)	Answer in plain language and point to the page number
Internal ERP manual	User guides, chart of accounts, period-close steps, recurring help-desk questions	Answer as numbered steps using the exact menu names in the system
Quotes and contracts	Quotation templates, standard terms, legal-approved clauses	Never invent new terms; select only from approved clause text
Management reporting	Monthly report formats, KPI definitions, approved sample reports	Use the KPI definitions in the knowledge; do not invent formulas

Three mistakes that make projects fail

1. One room for everything. A project called "Company documents" holding procurement rules, HR policy and marketing decks answers worse than three small rooms, because a single question pulls in unrelated material.

2. Nobody owns document currency. When a regulation changes, someone has to remove the old file. Keeping both the old and new versions in the same room is more dangerous than having neither, because Claude will answer from both without knowing which one is in force — the same failure mode organisations already know from passing Excel files around.

3. Treating a project like a database. Projects hold documents, not balances. Upload today's stock report and tomorrow the number in the library is already wrong. Anything that needs current figures has to come from the system of record.

Projects and ERP: where the line sits

The workable division is simple: the ERP holds the numbers that are true; the project holds the rules and the know-how. Stock balances, committed budget, approved purchase orders — those belong in an ERP system with an audit trail and named approvers. Questions like "which clause allows a direct-award purchase?" or "what is our period-close sequence?" are exactly what a project is for.

To be direct about our own product: Saeree ERP does not yet connect Claude to read live data inside the system, and the in-product AI assistant is still in development. What does work today, and works well, is using a project as the knowledge base for how to use the system — put the user manual, the chart of accounts and the questions the help desk answers repeatedly into a single room, and let users ask there before raising a ticket. That reduces help-desk queue time without changing a line of the system.

Organisations that want to go further — letting Claude read live data — should look at connectors and MCP, not at uploading reports into project knowledge.

Where projects fit, and where they do not

Good fit	Poor fit
Repeat questions about regulations, manuals and policies that sit still	Numbers that change daily, such as stock or remaining budget
Drafting documents from templates the organisation already approved	Documents that require digital signatures and an audit trail
Getting a team to answer customers with one consistent set of wording	Personal data or individual compensation in a widely shared room
Onboarding new staff so they can self-serve the manual first	Work where a wrong answer causes immediate harm with no human review

Conclusion

Claude Projects are the cheapest way to get a whole team answering from the same source, because context moves out of individual heads and into a room everyone shares. The numbers to remember are few: 30 MB per knowledge file, no cap on file count, RAG automatically extending capacity up to tenfold on paid plans, and sharing requiring Team or above.

What decides success is not how many files you upload. It is whether someone is accountable for the library being current. One room with a clear owner beats ten rooms with none.

A knowledge base nobody keeps current is more dangerous than no knowledge base at all — a wrong answer sounds more authoritative than no answer.

- The Saeree ERP team

References

• Anthropic — What are projects? (checked 1 Sep 2026)
• Anthropic — Retrieval augmented generation (RAG) for projects
• Anthropic — Upload files to Claude (file limits)
• Anthropic — Context window on paid Claude plans