How do I install the Erd skill?

Run npx skillmds@latest add khaitrang1995/erd in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

This skill has not completed SkillMD's automated safety review yet. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Erd?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

KhaiTrang1995 (@khaitrang1995) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Erd by khaitrang1995 — Agent Skill

Name: Erd
Author: KhaiTrang1995

File contents

/erd — Entity-Relationship Diagram (draw.io)

When to use

Data model for design docs / BA–dev alignment
A few–dozens of entities described in words (no SQL importer needed)
Need a hand-editable .drawio file

Switch to /diagram when: large SQL DDL file (sqlerd.py), auto-layout for dozens of tables, or batch PNG export.

Input examples

/erd Order 1-N OrderLine, Order N-1 Customer, Order 1-1 Payment --feature booking
/erd auth module: User, Role, UserRole (N-N), Permission
/erd @schema.sql   → suggest /diagram --from-sql if >8 tables

Workflow

Phase 1 — Inventory

List:

Entity	PK	Attributes (short)	Notes

Relationships: A 1—N B, A N—N B (// associative entity if needed).

Missing relationship names / cardinality → ask 1–2 questions; do not invent FKs.

Phase 2 — L3 layout preview

Node + edge table (ASCII/table). User reviews before XML.

Phase 3 — Generate XML

Use @_templates/erd.drawio as the frame:

Entity = rounded rect (or swimlane-style header): bold entity name + attr list
Mark PK as PK; FK as FK (text only)
Edge: endArrow=ERoneToMany / ERmandOne / ERzeroToMany when appropriate; fallback endArrow=block + labels 1 / N on the edge
Palette: entity fill #dae8fc, associative #fff2cc, external ref #f5f5f5 (per conventions)
Grid 20; entity box ~200×(40 + 20×attr count)

Phase 4 — L1 → Write

docs/diagrams/{feature}/erd-{slug}.drawio

Mandatory rules

@.claude/rules/drawio-conventions.md (core shapes, escape XML)
@.claude/rules/naming-conventions.md
@.claude/rules/approval-gate.md
Do not invent columns/relationships; TBD + ask
≤ 15 entities per page — more: split by domain or use /diagram + sqlerd/autolayout

Output

docs/diagrams/{feature}/erd-{slug}.drawio

References

@_templates/erd.drawio
@.claude/rules/drawio-conventions.md
Advanced: skill /diagram + scripts/sqlerd.py

---name: erddescription: Generate ERD .drawio — entities, attributes, 1-1/1-N/N-N relationships, PK/FK. Hand-authored XML with TechSphereX AI palette; complex SQL DDL → /diagram --from-sql.---# /erd — Entity-Relationship Diagram (draw.io)## When to use- Data model for design docs / BA–dev alignment- A few–dozens of entities described in words (no SQL importer needed)- Need a hand-editable `.drawio` file**Switch to `/diagram` when:** large SQL DDL file (`sqlerd.py`), auto-layout for dozens of tables, or batch PNG export.## Input examples```/erd Order 1-N OrderLine, Order N-1 Customer, Order 1-1 Payment --feature booking/erd auth module: User, Role, UserRole (N-N), Permission/erd @schema.sql → suggest /diagram --from-sql if >8 tables```## Workflow### Phase 1 — InventoryList:| Entity | PK | Attributes (short) | Notes ||--------|----|--------------------|-------|| | | | |Relationships: `A 1—N B`, `A N—N B` (// associative entity if needed).Missing relationship names / cardinality → ask 1–2 questions; **do not invent** FKs.### Phase 2 — L3 layout previewNode + edge table (ASCII/table). User reviews before XML.### Phase 3 — Generate XMLUse `@_templates/erd.drawio` as the frame:- Entity = rounded rect (or swimlane-style header): **bold entity name** + attr list- Mark PK as `PK`; FK as `FK` (text only)- Edge: `endArrow=ERoneToMany` / `ERmandOne` / `ERzeroToMany` when appropriate; fallback `endArrow=block` + labels `1` / `N` on the edge- Palette: entity fill `#dae8fc`, associative `#fff2cc`, external ref `#f5f5f5` (per conventions)- Grid 20; entity box ~200×(40 + 20×attr count)### Phase 4 — L1 → Write`docs/diagrams/{feature}/erd-{slug}.drawio`## Mandatory rules- @.claude/rules/drawio-conventions.md (core shapes, escape XML)- @.claude/rules/naming-conventions.md- @.claude/rules/approval-gate.md- Do not invent columns/relationships; TBD + ask- ≤ 15 entities per page — more: split by domain or use `/diagram` + sqlerd/autolayout## Output`docs/diagrams/{feature}/erd-{slug}.drawio`## References- @_templates/erd.drawio- @.claude/rules/drawio-conventions.md- Advanced: skill `/diagram` + `scripts/sqlerd.py`

Frequently asked questions

Erd