52 lines
2.8 KiB
Markdown
52 lines
2.8 KiB
Markdown
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# Workspace-Aware Browser Automation with MCP Roots
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Hi Playwright and Playwright-MCP teams,
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I wanted to share an architecture I've developed that might be interesting for both the core Playwright project and the MCP server implementation.
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## The Use Case
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I'm running multiple MCP clients, each working on different codebases. Each client needs isolated Playwright sessions where:
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- Browser windows display on the client's desktop context
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- Screenshots and videos save to the client's project directory
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- Sessions remain completely isolated from each other
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This is common when you have AI agents working on multiple projects simultaneously.
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## The MCP Roots Approach
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Instead of traditional configuration, I'm using MCP's "roots" capability to declare execution environments. Each client exposes system files that define their workspace:
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- `file:///path/to/their/project` - artifact save location
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- `file:///tmp/.X11-unix` - available X11 displays
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- `file:///dev/dri` - GPU capabilities
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The Playwright MCP server reads these exposed files to automatically configure browser contexts with the right display, output directories, and system capabilities.
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## Implementation Benefits
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**For Playwright:** This showcases the flexibility of programmatic browser context configuration - being able to dynamically set displays, recording paths, and isolation boundaries based on runtime environment detection.
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**For Playwright-MCP:** This demonstrates how MCP's roots system can extend beyond file access to environment declaration. Tool descriptions can educate clients about what system files to expose for optimal browser automation.
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## Technical Details
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The server uses MCP's `notifications/roots/list_changed` to detect when clients update their workspace context. When roots change, it re-scans the exposed system files and updates browser launch configurations accordingly.
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This creates truly dynamic workspace switching - clients can move between projects just by updating their exposed roots, and browser automation automatically follows their context.
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## Why This Matters
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This architecture eliminates the configuration burden while maintaining strong isolation. The workspace context is inherent to the MCP connection rather than requiring manual setup calls.
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It also follows UNIX principles nicely - reading actual system files (X11 sockets, DRI devices) gives real information about available capabilities rather than abstract configuration.
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## Current Status
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I have this working with session isolation, video recording, and multi-display support. Each client gets their own isolated browser environment that automatically adapts to their declared workspace.
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Would love to contribute this back or discuss how it might fit into the official Playwright-MCP implementation.
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---
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Thanks for the great tools that made this architecture possible!
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