EDD Skill — Entity Document Diagram for MongoDB

A coding-agent skill that teaches your AI assistant EDD (Entity Document Diagram) — a concise, ERD-inspired notation purpose-built for MongoDB schema design.

Installation

npx skills add mongodb-developer/edd-skill

What It Does

Once installed, this skill activates whenever you:

• Design, review, or generate a MongoDB schema
• Model embedding vs. referencing decisions
• Ask for a schema diagram, data model, or entity diagram
• Write code that touches collection structure
• Ask casual questions like "how should I structure this in Mongo?"

The skill gives your coding agent a shared, unambiguous vocabulary for MongoDB data shapes — including embedded documents, extended references, bounded arrays, and polymorphic fields.

What's Included

File	Purpose
SKILL.md	Full EDD notation reference, design rules, Mermaid diagram generation, and worked examples
references/code-patterns.md	Ready-to-use code snippets for Mongoose, TypeScript, Zod, $jsonSchema, and aggregation

EDD Quick Reference

Construct	Syntax	Meaning
Scalar	field: type	Simple value
Embedded entity	field: EntityName	Subdocument
Extended reference	field: Entity{f1,f2,...}	Denormalized subset from another collection
Array	field: type[min,avg,max]	Array with cardinality 3-tuple
Polymorphic	field: oneOf(A,B,C)	Multiple possible shapes

Example

Entity: Order    [indexes: {buyerId:1,createdAt:-1}, {status:1}]

  _id: ObjectId
  buyer: User{_id,displayName,email}    # extended reference
  lineItems: LineItem[1,5,50]
  payment: oneOf(CreditCard,PayPal,BankTransfer)
  status: string
  total: decimal128
  createdAt: date

Every EDD output automatically includes a Mermaid erDiagram block for visual rendering.

License

Apache-2.0