Claude now has access to a server-side container environment

Who Should Read

Analysts who need to export data analysis results as Excel/PDF, or business developers wanting to automate repetitive document/slide work. Those who've used ChatGPT Code Interpreter and are curious about the Claude alternative.

Core Mechanics

• Claude.ai and desktop app can now directly create and edit Excel spreadsheets, Word documents, PowerPoint slides, and PDFs through conversation. Enable 'Upgraded file creation and analysis' in settings.
• Internally, it runs Python in a sandboxed server-side container — pip installs openpyxl and pandas, then executes scripts to generate files. Essentially the same pattern as ChatGPT's Code Interpreter.
• Can't be enabled simultaneously with the existing Analysis tool (browser-side JavaScript). Activating the new feature automatically disables the existing one — choose one or the other.
• Upload CSV data for one-stop statistical analysis, charts, and insight summaries. Upload PDFs for PowerPoint conversion, or format meeting notes as documents — cross-format workflows are possible.
• Available first on Max, Team, and Enterprise plans, with Pro users getting access later. GA across all paid plans since October 21, 2025, with network and data exfiltration controls added.
• Simon Willison reverse-engineered the container specs and published a detailed review testing complex tasks: SQLite DB PDF join diagrams, chart recreation from screenshots+XLSX.
• This feature grants internet access to Claude, posing data security risks. Anthropic officially warns to 'closely monitor chats when using sensitive data.'

Evidence

• Simon Willison confirmed via reverse engineering that it's a server-side Python environment with pip install and script execution. He also ran head-to-head comparisons with ChatGPT Code Interpreter.
• Multiple Pro/Max subscribers reported noticeably slower Claude response times over the past 2-3 weeks, with frequent 'freezing' bugs during artifact editing. Silent failures where the LLM thinks it edited but the artifact wasn't actually updated — requires requesting a new artifact as a workaround.
• Some pointed out this is actually a restoration of artifact file generation/download that existed earlier in summer. 'Isn't this just giving back what was taken away in June?' was a common complaint.
• A sharp comment about the missing Linux desktop app: 'It's a Tauri app so it should be trivial to build — proof that an AI development tool company can't leverage AI on its own product.'

How to Apply

• If you regularly clean up CSV/Excel data and create charts, enable 'Upgraded file creation and analysis' in Claude settings, upload your data files, and specify desired analysis and output format to receive Pandas-based analysis results as downloadable files.
• For cross-format tasks like converting PDF reports to PowerPoint or merging data from multiple sources into one Excel, this can significantly cut manual work. However, avoid uploading sensitive data.
• If already using ChatGPT Code Interpreter, run the same prompt and data through Claude for cross-validation as a second opinion. Especially useful for accuracy-critical tasks like statistical analysis or financial modeling.
• Given reported artifact editing freeze bugs, for complex iterative file modifications, requesting 'create a new artifact' each time is currently more stable than editing existing ones.

Terminology

Related Resources

• https://www.anthropic.com/news/create-files
• https://simonwillison.net/2025/Sep/9/claude-code-interpreter
• https://github.com/steveyegge/efrit