Claude Cowork in Practice – Real Files, Real Workflows By the end of this lesson, students should be able to: How file work happens in Cowork. Cowork allows you to work with documents directly – uploading files to a Project or session and giving Claude assignments that reference them. Claude can read, analyze, summarize, extract from, compare, and produce output based on the content of those files. What works well. Uploading files – in session vs. in Project. In-session uploads: Files uploaded during a conversation are available for that conversation only. Good for one-off tasks involving a specific document. Project uploads: Files uploaded to a Project are available across all conversations in that Project. Good for reference materials you will use repeatedly: style guides, client briefs, product documentation, standards documents. Referencing files in assignments. When a file is available in the session or Project, tell Claude explicitly which file(s) to use and what to do with them. "Using only the uploaded [document name]…" or "Based on all three uploaded contracts…" are natural references. Ambiguity about which file to use can cause Claude to work from the wrong source or blend sources inappropriately. Multi-document task patterns. Common patterns that work well in Cowork: For each pattern, specify which documents, what to produce, and in what format. Reviewing file-based outputs. When Claude produces output based on documents you uploaded, review it against those documents: Claude can misread dense or complex documents, summarize at the wrong level of detail, or skip sections it deemed less relevant. Cross-reference significant outputs against source material before use. A proposal manager uploads five past winning proposals to a Cowork Project. She gives Claude a task: "Review the five uploaded proposals and extract: (1) the opening paragraph structure each uses, (2) the three most common themes in the problem statements, and (3) the types of evidence each uses to support claims." Claude works through all five and returns a structured summary. She reviews it against the proposals manually for two of them to spot-check accuracy. One theme in the problem statements section is described slightly incorrectly – she corrects it. The synthesis saves her three hours of manual document review; spot-checking the output against source material takes fifteen minutes and catches the one error. For very long documents, give Claude a "roadmap" before assigning the main task: "This document is a 45-page technical specification. The sections most relevant to our task are sections 3, 5, and 8. Focus on those." Claude processes entire documents but works better when you identify the high-relevance sections for complex tasks – it reduces the chance of the final output over-representing less relevant sections. Files uploaded to Cowork Projects are stored in your Anthropic account. Do not upload documents containing passwords or credentials, regulated personal health information, confidential client data you are not authorized to share with third-party cloud services, or legally privileged materials not approved for cloud storage. Review your organization's data governance policy before uploading internal business documents. Select a multi-document task from your actual work – any task that involves reading and synthesizing two or more existing documents. Upload the relevant documents to a Cowork Project, write a clear task assignment for Claude, and run it. After reviewing the output, spot-check it against at least one of the source documents manually. Note any discrepancies and how you would steer the next iteration. You should be able to upload files to both in-session and Project contexts, write assignments that clearly reference which files to use, name three multi-document task patterns, and describe a document output review workflow. Log in and enroll to access lesson quizzes.
Lesson 2: Working with Files and Documents in Cowork
Lesson Objectives
Lesson Content
Practical Example
Lesser-Known Tip
Safety Notes
Practice Task
Completion Check