Cowork
Hand Claude a multi-step job, walk away, come back to real files. Cowork is Claude as an autonomous knowledge worker: it plans, executes on your desktop, and produces finished deliverables.
Everything else in the handbook is about chatting with Claude. Cowork is different. Instead of a back-and-forth conversation, you describe a job, Claude creates a plan, and then it executes that plan on its own. It reads and writes files on your machine, runs code in a local virtual machine, and produces actual outputs: formatted reports, spreadsheets with formulas, presentations, organised folder structures. You maintain visibility throughout and can redirect at any point, but the work happens without you holding its hand.
How it works
Describe the job. Claude plans and executes. Real files appear on your machine.
Cowork runs in the Claude Desktop app as a separate tab from Chat. You point it at a folder on your machine, describe what you want, and it works through the job. Code executes in an isolated virtual machine on your computer (not in the cloud), so your data stays local.
How it differs from chat
Doing research in chat vs handing it to Cowork
An hour of paste-and-chat. The synthesis is limited by context window. The output is plain text you then have to reformat. If you want it in a specific document structure, that is another round of prompting.
Claude reads all 11 files from the folder, creates a plan, synthesises across all of them (no context limit because it manages its own reading), and writes a formatted .docx back to your folder. You open the file, review it, and it is ready to send. Total interaction time: describing the job.
What Cowork produces
Cowork does not just produce chat text. It produces real files that open in their native applications.
Formatted reports
Word documents with proper headings, sections, and styling. Not a text dump, a document you can send to a client.
Spreadsheets with formulas
Excel files with real formulas, conditional formatting, and multiple sheets. Data analysis outputs that work when you open them.
Presentations
PowerPoint files with defined slide structures, consistent formatting, and content populated from your source material.
Organised folders
Claude reads file contents, understands what each file is, and sorts them into a logical folder structure with sensible names.
Best use cases
1. File organisation at scale
Point Claude at a folder of 200 unsorted files. It reads each one, determines whether it is an invoice (Accounting), a contract (Legal), a report (Operations), or an e-book (Documentation), and sorts them into named subfolders. Semantic sorting, not just by file type.
2. Research synthesis across many documents
A folder of academic papers, interview transcripts, and internal research notes. Claude reads all of them, finds the themes, compares findings across sources, and assembles a structured report with citations. The kind of job that takes a human two days takes Cowork an afternoon.
3. Data analysis and reporting
Raw CSVs with messy data. Claude cleans columns, normalises values, detects outliers, generates derived metrics, and produces analysis-ready spreadsheets. The output is a proper .xlsx, not a screenshot of a table.
4. Presentation generation from source material
Meeting notes, research summaries, or transcripts sitting in a folder. Claude reads them, plans a slide structure, and generates a real .pptx with defined sections. Not a perfect presentation, but a skeleton you can refine in twenty minutes rather than building from scratch.
5. Scheduled recurring tasks
Cowork supports scheduled tasks: set a cadence and it runs automatically. The machine needs to be on and the app running, but this means a Monday morning status report or a weekly data digest can be generated without you opening Claude at all.
Safety and limitations
Read this before using Cowork on anything important
- Not in audit logs. Cowork activity is NOT captured in audit logs, the Compliance API, or data exports. Do not use it for regulated workloads.
- You bear responsibility. You are responsible for all actions Claude takes through Cowork, including financial transactions, data modifications, and published content.
- Can delete files. Claude can read, write, and permanently delete local files in the folder you grant it access to. Be cautious with sensitive data. Consider pointing it at a copy rather than the original.
- No cross-session memory. Each task starts fresh. Claude does not remember what it did last time.
- App must be running. Tasks stop if the Claude Desktop app closes or the machine sleeps. Scheduled tasks require the app to be active at the scheduled time.
- High token usage. Complex multi-step tasks use significantly more of your usage allowance than chatting.
- Prompt injection risk. Documents Claude reads from your folders could contain malicious instructions. Only point Cowork at folders you trust.
Getting started
Open Claude Desktop. Cowork runs in the Claude Desktop app (macOS or Windows). Not available in the web browser or mobile app.
Click the Cowork tab. It is a separate tab alongside Chat in the main interface.
Point at a folder. Select the folder on your machine that contains the files you want Claude to work with. Only grant access to what is needed.
Describe the job clearly. What you want done, what the inputs are, what the output should look like, and where to save it. The clearer the description, the better the plan.
Review the plan before it executes. Claude will show you its plan before it starts running. Read it. Redirect if needed. Then let it run.
Cowork is Claude's most powerful tool and its most consequential one. It can save you hours on complex multi-step work, but it operates on your real files with real consequences. Use it thoughtfully, start with low-stakes tasks, and always review the plan before execution.
Next: Skills teach Claude your specific workflows. Or go back to the Tools hub.