computermcp

Writing

Notes from building a macOS computer-use MCP server. Measured findings, not opinions - each piece says how we know.

Your agent's screenshot tool is reading your passwords

What is actually in a full-screen capture of a working developer's Mac, why redacting after writing the file is not redacting, and the one marking detail that breaks most implementations.

18 September 2026

Driving macOS from an AI agent: what actually works

Five findings: the accessibility tree over pixels, the full-screen Space that hides the whole machine, 73 buttons with 47 unique names, secure-field subroles, and why an error message that lies costs a day.

18 September 2026