mcp-tauri-automation: Instructions file for Codex

MCP Tauri Automation

Mission

This repository provides a stdio MCP server for launching and automating built Tauri desktop applications through tauri-driver and WebDriver. Keep the MCP protocol surface predictable, failures actionable, and platform behavior portable across supported desktop environments.

Layout

• src/index.ts — stdio entry point, configuration, and shutdown.
• src/server.ts — validated MCP tool schemas, bounded queue, and dispatch.
• src/tauri-driver.ts — WebDriver session and Tauri process lifecycle.
• src/ui-snapshot.ts — fixed, read-only, bounded DOM diagnostic.
• test/ — Node tests with local fake WebDriver servers and real MCP transports.
• src/types.ts — shared configuration, parameter, state, and response types.
• dist/ — generated TypeScript output; never edit or commit it.

Verification

npm ci
npm run verify

The full gate builds, tests, audits runtime dependencies, and dry-runs packaging. Use targeted tests while iterating and run the full gate on final source before publication. Native smoke requires a built Tauri test app and either embedded WebDriver or tauri-driver. Report unavailable native platforms as untested. Create sessions only on loopback, serialize calls, never automatically replay mutations, and delete only sessions owned by this server. Embedded app processes remain owned by their launcher. Keep snapshots bounded and omit form values.

Model Routing

• Use hosted subscription roles only: opus for architecture or MCP contract changes, sonnet for ordinary implementation, and haiku for bounded mechanical work.
• Do not use local LLMs for repository work. Do not delegate generic work to DGX Spark; Spark is not a cheap or default agent lane.
• Native subagents inherit the current model unless a delegation receipt proves a different hosted profile. Never claim a lower-tier route from prose alone.

Boundaries

• Preserve stdio for MCP protocol messages; diagnostics must not corrupt the protocol stream.
• Validate untrusted tool inputs and return structured errors. Do not expose credentials, environment values, arbitrary local files, or auth state.
• Keep process and WebDriver cleanup reliable on normal exit and signals.
• Do not edit generated dist/, dependency contents, or lockfile data by hand.
• Screenshots and other runtime output remain local and ignored.
• Changes to tool names, schemas, response shapes, environment variables, or process lifecycle are public-contract changes and require explicit review.