Working with files and projects

A chat with no material is limited to what Claude learned in training. A chat with your documents can work on your actual situation. This lesson covers how to bring material in and keep it organized.

Feature availability depends on your plan and the app you use. Check the current help pages at support.anthropic.com or docs.claude.com for what your account includes.

Attaching files

In the Claude apps you can usually attach documents and images to a message. Common uses:

• Summarize a long report and list open questions.
• Compare two contracts and highlight differences in obligations.
• Read a screenshot of an error message and explain it.
• Turn a spreadsheet export into a plain-English summary.

Tell Claude what the file is and what you want from it. "This is last quarter's customer feedback. Group the comments into themes and give me the three most frequent complaints with one quote each" works much better than "summarize."

Limits you will hit

Every conversation has a context limit: how much text the model can hold at once. Very long documents or very long chats can hit it. Signs include the model forgetting early details or the app telling you the chat is full. Two habits help:

• Start a new chat for a new topic.
• When a long chat has produced a decision or a draft, copy the result into a short summary and begin a fresh chat with that summary.

Ask it to quote

When you work from a document, ask Claude to quote the passage it is relying on. If it cannot find a quote, treat the claim with suspicion. This is one of the simplest ways to catch invented details.

Projects

Many Claude plans include a feature for grouping related chats and files into a project, with instructions that apply to every chat inside it. If your plan has it, a project is the right home for ongoing work such as a course you are teaching, a client engagement, or a book.

Good project instructions are short and stable:

Audience: small business owners in my area.
Tone: plain, friendly, no jargon.
Always give a one-line summary first.
Never invent statistics; say when you are unsure.

Put reference material in the project once, instead of pasting it into every chat.

Keep sensitive material in mind

Before attaching anything, ask whether it contains personal data, customer information, passwords, or anything you are not allowed to share. The next lessons cover privacy, but the habit starts here: attach what is needed, not everything you have.

Try it

Choose a document you are allowed to share, such as a public report, an article, or your own old essay. Attach it and run three requests in order:

1. "Summarize this in five bullet points."
2. "Which claims in your summary are you least sure about? Quote the lines you based them on."
3. "Write three questions a skeptical reader would ask."

If your plan has projects, create one called "Practice," add the document there, and write two lines of instructions. Repeat step one inside the project and compare.