Problem

MCPB bundles built with scripts/build-mcpb.sh crash immediately on startup with module resolution errors.

Root Causes

1. Deleted yaml/dist/doc/ directory - The cleanup script removes all doc directories, but yaml package has actual code in dist/doc/directives.js (not documentation). This causes:

   Error: Cannot find module '../doc/directives.js'
   

2. Missing zod peer dependency - The --omit=peer flag skips installing zod, which is a required peer dependency of @modelcontextprotocol/sdk. This causes:

   Error: Cannot find module 'zod/v4'
   

Symptoms

• Server starts, receives MCP initialize request, then crashes
• Error appears as "Server transport closed unexpectedly"
• Works fine in local development, only affects MCPB bundles

Fix

Update build-mcpb.sh:

1. Exclude yaml/dist/doc from cleanup
2. Replace --omit=peer with --omit=dev to install required peer dependencies
3. Manually remove optional large packages (prisma CLI, typescript) after install

Testing

• Verified fix works with Node 20 and Node 24
• MCPB bundle now starts and responds to MCP requests correctly