Django ORM Lens

Official

by FROWNINGdev · Python

Static-analysis MCP server for Django models. 5 read-only tools. No DB, no boot, no creds.

Topics

databasedeveloper-toolsdjangoer-diagrammermaidormpythonvscode-extensioncode-navigationdjango-toolsschema-visualizationai-agentsaidercursormcpmcp-servermodel-context-protocolpython-clischema-diagramstatic-analysis

README.md18 KBView on GitHub

Django ORM Lens — live sidebar and ER diagram for your Django models

Django ORM Lens

See your entire Django schema — in your editor, in your terminal, and from your AI agent.

Every app. Every model. Every field. Every relationship. Grouped, navigable, and one keystroke away from a live ER diagram.

Star on GitHub Sponsor

⚡ Install

VS Code / Cursor / Windsurf / any Code fork:

bash

code --install-extension frowningdev.django-orm-lens

Or search Django ORM Lens in the Extensions view.

Terminal & AI coding agents:

bash

pip install django-orm-lens              # CLI only
pip install "django-orm-lens[mcp]"       # + MCP server for AI agents

Requires Python 3.9+. Zero runtime dependencies for the CLI.

🎯 The problem

You open a Django project. It has 20 apps. You need to answer a simple question:

"Which app owns the Order model, and how is it connected to User?"

Today, that means: Ctrl+P, "models", scroll through 30 hits, open five files, Ctrl+F for class Order, read through 400 lines of ForeignKey('otherapp.Something') strings, try to remember what you learned two files ago.

Half a day gone. Every time. On every project.

✨ With Django ORM Lens

📚 A tree of everything

Every app → every model → every field → every Meta option. Grouped by application, sorted alphabetically, expandable.

Icons distinguish CharField from ForeignKey from ManyToManyField at a glance.

🕸️ A live ER diagram

One command opens a Mermaid entity-relationship diagram of your entire schema. Watch it redraw as you edit. Export to SVG.

ForeignKey, OneToOneField, and ManyToManyField become proper cardinality arrows.

🔎 Hover for relations

Hover over ForeignKey('app.Model') in any Python file → a card pops up with the target model's fields, relations, and a "Jump to" link. No Ctrl+F, no file dialog.

🧭 Jump-to-definition

Click any field in the tree → cursor lands on the exact line. Filter the tree by app or model name. Split models/ packages are fully supported.

⚡ Zero configuration

No DJANGO_SETTINGS_MODULE. No runserver. Parses models.py statically. Works with a broken venv, a missing dependency, or on someone else's laptop.

🎨 Native VS Code UI

Dark theme. Light theme. Your theme. Follows your icon theme, your font, your key bindings. Nothing garish, nothing branded.

📸 What it looks like

Django ORM Lens sidebar showing an app's models with fields, relations, and Meta options

Also included in the extension:

🕸️ Live ER diagram — Mermaid cardinality arrows, edge labels (CASCADE, through Model, as related_name), theme-aware, one-click SVG export
🔎 Hover cards — over any ForeignKey('app.Model') or ManyToManyField(...), with a one-click jump link
🧭 CodeLens — above every class Model line: field count, relation count, and an Open ER diagram action
🎨 Named themes — auto / default / dark / forest / neutral for the diagram webview

🤖 For terminals and AI coding agents

The same parser that powers the VS Code extension ships as a standalone Python package — with an optional MCP (Model Context Protocol) server so any MCP-compatible AI agent can navigate your Django schema without importing Django or booting your app.

CLI

bash

django-orm-lens scan -f json          # every app, every model, every field
django-orm-lens describe blog.Post    # one model in Markdown
django-orm-lens hover blog.Post       # compact hover card
django-orm-lens list | fzf            # flat app.Model — pipes anywhere
django-orm-lens er > schema.mmd       # Mermaid ER diagram

Every command accepts --path <dir> and --exclude <glob>.

MCP server

Tool	Purpose
`list_apps`	Every Django app in the workspace with model counts
`list_models`	Flat `app.Model` list, optional app filter
`describe_model`	Full field / relation / Meta detail for one model
`find_relations`	Inbound + outbound relations for one model
`er_diagram`	Mermaid `erDiagram` for the whole workspace

bash

# Start it directly
django-orm-lens-mcp

# Or via the CLI subcommand
django-orm-lens mcp

Set DJANGO_ORM_LENS_ROOT=/abs/path/to/project to point it anywhere.

🔌 Integrations

Client	How to enable	Status
VS Code	`code --install-extension frowningdev.django-orm-lens`	✅
Cursor	same VSIX + optional MCP entry in `~/.cursor/mcp.json`	✅
Windsurf / VSCodium / any Code fork	install the VSIX from the Marketplace or GitHub Releases	✅
Aider	add `django-orm-lens-mcp` to your `mcp.json`	✅ (via MCP)
Continue.dev	register the MCP server in `~/.continue/config.json`	✅ (via MCP)
Zed	register the MCP server in Zed settings	✅ (via MCP)
Any MCP-compatible client	point `command` at `django-orm-lens-mcp`, set `DJANGO_ORM_LENS_ROOT`	✅
Discoverable via MCP Registry	official Model Context Protocol server directory	✅
Plain terminal / CI	`pip install django-orm-lens && django-orm-lens scan`	✅

Example: Cursor / any MCP client

jsonc

{
  "mcpServers": {
    "django-orm-lens": {
      "command": "django-orm-lens-mcp",
      "env": { "DJANGO_ORM_LENS_ROOT": "/abs/path/to/your/project" }
    }
  }
}

🚀 Get started (30 seconds)

In VS Code:

code --install-extension frowningdev.django-orm-lens
Open a folder with a manage.py or models.py
Click the Django ORM Lens icon in the activity bar
Expand apps → models → fields
Click the type-hierarchy icon at the top of the panel → ER diagram opens beside your code

In a terminal:

bash

pip install django-orm-lens
cd my-django-project
django-orm-lens scan -f table

As an AI agent tool:

bash

pip install "django-orm-lens[mcp]"

…then register django-orm-lens-mcp in your agent's MCP config (see the Integrations table above).

No settings screen. No sign-in. No telemetry.

🎯 Who this is for

Django developers joining a codebase with 10+ apps and getting lost in models.py sprawl.
Contract / freelance engineers who need to grasp an unfamiliar Django project in the first hour, not the first week.
Teams onboarding new hires who want a one-glance schema view without spinning up documentation infrastructure.
AI-agent power users (Cursor / Aider / Claude Desktop / Zed / Continue) who need the agent to answer schema questions accurately — without giving it database credentials or booting Django.
CI pipelines that verify schema shape (e.g. "did we accidentally break a related_name?") without importing the project.
Solo indie devs on a broken venv or someone else's laptop — no runserver, no manage.py migrate, still works.

🗺️ Market position

Django ORM Lens sits at the intersection of editor tooling and AI-agent tooling — a slot no existing package covers:

Segment	Existing option	What it costs you
Boot-and-graph	`django-extensions graph_models`	Requires Graphviz + Django settings + a working DB URL
Web-based viewer	`django-schema-graph`	Requires a running Django server; hosts one more thing to break
Admin panel	Django Admin	Requires runserver + auth + database — great for data, not for architecture
Editor plugin	PyCharm's Django Structure	Locked to PyCharm; no CLI, no AI-agent story
MCP server	(none until now)	AI agents guess your schema from source, imperfectly

Django ORM Lens is the only tool that ships three surfaces from one parser: a VS Code extension (any Code fork), a zero-dep CLI (terminals + CI), and an MCP server (AI agents). All static. All free. All MIT.

🤔 How is this different?

	Django ORM Lens	`django-extensions graph_models`	`django-schema-graph`	Django Admin	PyCharm Django Structure
Works without a bootable Django project	✅	❌	❌	❌	⚠️
Zero-install (no graphviz, no server)	✅	❌	❌	❌	❌ (needs PyCharm)
Works in VS Code / Cursor / any Code fork	✅	❌	❌	❌	❌
Sidebar tree inside the editor	✅	❌	❌	❌	✅
Live ER diagram	✅	✅	✅	❌	❌
Hover cards on `ForeignKey`	✅	❌	❌	❌	⚠️
CodeLens on model classes	✅	❌	❌	❌	❌
Split `models/` package support	✅	⚠️	⚠️	✅	✅
CLI for terminal / CI	✅	⚠️	❌	❌	❌
MCP server for AI agents	✅	❌	❌	❌	❌
Discoverable in the MCP Registry	✅	❌	❌	❌	❌
Free & open-source (MIT)	✅	✅	✅	✅	❌ (paid IDE)

⚙️ Configuration

The defaults are opinionated and sensible. If you need to tweak:

jsonc

// .vscode/settings.json
{
  "djangoOrmLens.excludeGlobs": [
    "**/migrations/**",
    "**/node_modules/**",
    "**/venv/**",
    "**/.venv/**",
    "**/env/**"
  ],
  "djangoOrmLens.autoRefresh": true
}

Setting	Type	Default	What it does
`djangoOrmLens.excludeGlobs`	`string[]`	See above	Glob patterns to skip when scanning
`djangoOrmLens.autoRefresh`	`boolean`	`true`	Rescan on `models.py` changes

🧭 Commands

Open the command palette (Ctrl+Shift+P / Cmd+Shift+P) and type "Django ORM Lens":

Command	What it does
`Django ORM Lens: Refresh`	Force-rescan the workspace
`Django ORM Lens: Show ER Diagram`	Open the Mermaid ER diagram side-by-side
`Django ORM Lens: Filter Models`	Filter the tree by app / model / field name
`Django ORM Lens: Clear Filter`	Restore the full tree
`Django ORM Lens: Jump to Model`	Programmatic — triggered by tree clicks and hover cards

🗺️ Roadmap

Shipped

Next

Zoom + minimap + auto-layout inside the webview (#4)
ORM query autocomplete inside .filter() / .exclude() / .annotate() (#3)
App / model toggle checkboxes to declutter huge schemas

Later

Migration dependency graph
Third-party field support (django-mptt, django-taggit, django-model-utils)
JetBrains / PyCharm plugin (if there is demand)

Vote by 👍-ing the corresponding issue.

❓ FAQ

Do you send any of my code to a server?

No. Every byte stays on your machine. The parser is pure TypeScript (extension) or pure Python (CLI). No LLM calls, no telemetry, no analytics, no error reporting. The Mermaid renderer runs inside VS Code's webview sandbox.

Does it work with Poetry / uv / conda / no venv at all?

Yes. The extension reads Python source directly — it does not import Django and does not care what package manager you use. The CLI requires Python 3.9+, but that is it.

My models are split across multiple files inside a models/ package. Does that work?

Yes, since v0.2.0. Both the extension and the CLI walk models/*.py alongside classic models.py.

Can I use it with DRF serializers, Wagtail, Oscar, or third-party base models?

Any class that looks like a Django model is picked up: subclasses of models.Model, abstract bases starting with Abstract, common mixins ending in Mixin, and known base names like TimeStampedModel or PolymorphicModel. Non-model classes (ModelAdmin, ModelSerializer, Form, View, Manager, …) are filtered out.

Which AI agents can use the MCP server?

Any MCP-compatible client — Cursor, Aider, Continue.dev, Zed, and any other tool that speaks the protocol. Just point command at the installed django-orm-lens-mcp binary. See the Integrations section.

Is there a JetBrains / PyCharm version?

Not yet. PyCharm's Django Structure tool window is already good, so the value delta is smaller. If enough people ask, it becomes worth doing.

🆘 Support

🐛 Bug reports — GitHub Issues (please include a minimal models.py snippet)
💡 Feature requests / ideas — GitHub Discussions
📝 Marketplace reviews — rate the extension (the fastest signal that keeps this project moving)
🐍 PyPI page — pypi.org/project/django-orm-lens
💚 Sponsor — github.com/sponsors/FROWNINGdev

📜 License

Made for developers who care about their codebase.

Marketplace · PyPI · GitHub · Issues · Discussions · Sponsor

Install

Add to VS Code Add to Cursor

claude_desktop_config.json

json

{
  "mcpServers": {
    "django-orm-lens": {
      "command": "uvx",
      "args": [
        "django-orm-lens",
        "django-orm-lens-mcp"
      ]
    }
  }
}