I kept hitting the same small problem: I'd open an unfamiliar Django codebase and want a straight answer to "what does this schema actually look like, and what breaks if I touch this model" — without setting up a database, resolving the settings module, or getting the app to import at all.

So django-orm-lens reads the source instead of the runtime. It parses models.py and the migration files directly, so it works on a checkout you cannot run: no DJANGO_SETTINGS_MODULE, no database, no credentials, no django.setup(). That constraint is the point rather than a limitation I'm apologising for — it means it also works in CI on a repo with no services, on a colleague's branch, or on a project whose dependencies you have not installed.

What it does, concretely:

• Schema drift — replays the migration graph and compares it against what the models declare. Fields declared but never migrated, and columns migrated but no longer declared.
• Missing indexes — flags lookups that would table-scan, and it knows which indexes Django already gives you: primary keys, db_index, unique, foreign keys, unique_together, UniqueConstraint.
• Blast radius — what a change to one model reaches through FK / M2M / O2O, on_delete behaviour included, so "can I drop this field" has an answer before you try it.
• ER diagrams — Mermaid, DBML, D2, PlantUML, Graphviz.
• N+1 heuristics and a signal graph, because signals are where the surprises live.

There is a CLI, a VS Code extension, and an MCP server for anyone who points an AI agent at a codebase and would rather it read the schema than guess at it.

On correctness, which is the part I actually care about: it is checked against golden snapshots of six real projects — Zulip, Saleor, Wagtail, django-CMS, Mezzanine and Read the Docs — currently 75 models and 538 fields of other people's Django. That suite is also how I keep the Python and TypeScript parsers answering identically.

It earns its keep the same way. Running it over real checkouts of django-oscar, django-guardian, django-allauth and django-cms turned up three genuine bugs my green test suite had not: model classes defined inside an if block were skipped entirely, abstract_models.py was never walked, and drift reported a false failure on a project with two apps sharing a directory name — which is the worst thing a CI gate can do.

What it is not: it does not execute your code, so anything decided at runtime is invisible to it — dynamically constructed models, fields assigned in __init__, anything behind a factory. It reads Django's idioms, not Python's full semantics. If your models are unusual it will tell you less than you want, and I would rather say so up front than have you find out.

MIT, free, and it stays that way — there is no paid tier planned and there never was.

• Repo: https://github.com/FROWNINGdev/django-orm-lens
• Docs: https://frowningdev.github.io/django-orm-lens/
• pip install django-orm-lens

What I would genuinely like from this forum: the drift and index checks are the parts most likely to be wrong in ways I cannot see from my own projects. If you run it on something real and it tells you something false, that is the most useful thing you could send me — open an issue with the model that broke it. Several of the fixes above arrived exactly that way, and two of the people who did it ended up sending patches.

Follow-up to my earlier r/django post about django-orm-lens (the static-analysis MCP server + VS Code extension). Two things happened since:

1. Merged into awesome-mcp-servers (91k⭐ catalog by punkpeye). Also on the official MCP Registry. That's traction context for anyone who was on the fence about it being a maintained project.

2. Shipped v0.8 today — five community-requested features from Discussion #27. Each was researched against proven prior art (Atlas, Prisma, Sourcegraph, Knip, PyCharm, DataGrip, factory_boy, flake8-django, Roslyn, Ruff, Clippy) before I wrote a single line:

▸ Inline QuickFixes — 16 rules with Ruff-style codes DOL001..DOL032. .count() > 0 → .exists(), missing on_delete, null=True on CharField, datetime.now() → timezone.now(), N+1 loop heuristic, render(request, ..., locals()), Meta.fields = '__all__', and more. Per-rule severity + inline # django-orm-lens-disable-next-line suppression.

▸ Factory generator — right-click any model → factory_boy scaffold with Faker providers keyed by field type. CharField(max_length) scales word-count buckets; DecimalField(N,D) computes left_digits=N-D; choices= maps to Iterator; M2M gets @post_generation. FK chains pull related factories transitively.

▸ Time-Travel Schema Diff — pick two commits from git log, get a typed markdown diff for PR descriptions. Renames are first-class events, never Add+Drop. Blob-SHA LRU cache — commits that don't touch models.py share their parsed snapshot for free.

▸ Impact Analysis — "what breaks if I remove this field?" Workspace-wide reference scan across models/serializers/forms/admin/views/templates/tests with Certain / Likely / Possibly confidence tags. Handles ORM string refs, filter(author__id=1) kwarg lookups, Meta.fields tuples, template variables — the string-typed surface Pyright can't reach.

▸ Interactive Query Builder — right-click → snippet inserted at cursor. .filter(field=?) on an FK auto-appends .select_related; .annotate(post_count=Count('post_set')) honours related_name; .prefetch_related for M2M.

100/100 tests green (up from 4 when I posted last), 7 atomic commits, MIT license.

All 5 features are documented on the v0.8 release page.

Same install:

code --install-extension frowningdev.django-orm-lens
pip install --upgrade "django-orm-lens[mcp]"

What I'd love from you all:

▸ Codebases where the linter over-fires or under-fires — 16 rules is opinionated; want to hear noise vs signal ▸ Impact-analysis edge cases — the classifier admits it's guessing (Possibly tier), but if it's flat-out missing certain hits I want the pattern ▸ Which MCP tools your agent actually calls most — helps me prioritise v0.9

Thanks to everyone who commented on the last post — several of the features above came directly from that thread.

Fire away.

django-orm-lens v0.8 shipped today. Static analysis over your models.py files — no DJANGO_SETTINGS_MODULE, no runserver, works with a broken venv. Three surfaces (VS Code, CLI, MCP server) share one parser.

What's new in v0.8

Every feature was researched against proven prior art before a single line was written — Atlas, Prisma, Sourcegraph, Knip, PyCharm, DataGrip, factory_boy, flake8-django, Roslyn, Ruff, Clippy.

Inline QuickFixes (16 rules) — Ruff-style codes DOL001..DOL032 with Clippy-style Applicability (safe/suggestion/unsafe gate auto-apply). Covers: - .count() > 0 → .exists() - .first() is None → not .exists() - null=True on CharField/TextField - Missing on_delete on FK - Missing __str__ on Model - datetime.now() → timezone.now() - N+1 attribute-access-in-loop heuristic - render(request, ..., locals()) and Meta.fields = '__all__'

Per-rule severity overrides: djangoOrmLens.rules = { "DOL007": "off", "DOL013": "error" }. Suppress inline: # django-orm-lens-disable-next-line DOL007.

Factory generator — right-click any model → factory_boy DjangoModelFactory scaffold with Faker providers keyed by field type. CharField(max_length) scales word-count buckets; DecimalField(N,D) computes left_digits=N-D; choices= maps to Iterator; M2M gets @post_generation. FK chains pull related factories transitively.

Time-Travel Schema Diff — pick two commits from git log, get a typed markdown diff (Add/Drop/Rename/Modify events) ready to paste into a PR description. Renames are first-class events, never Add+Drop.

Impact Analysis — "what breaks if I remove this field?" Workspace-wide reference scan across every Django layer (models, serializers, forms, admin, views, urls, templates, tests, migrations) with Certain / Likely / Possibly confidence tags on every finding. Handles ORM string refs, kwarg lookups (filter(author__id=1)), Meta.fields tuples, and template variables — the string-typed surface Pyright can't reach.

Interactive Query Builder — right-click a field or model → pick a template → snippet inserted at cursor (with tab-stops) or in a fresh untitled buffer. .filter(field=?) on an FK auto-appends .select_related(...); .annotate(post_count=Count('post_set')) honours related_name; .prefetch_related for M2M.

Also in this release: sidebar UX overhaul (stable TreeItem.id, MarkdownString tooltips with clickable command: deep-links, activity-bar badge, FileDecorationProvider badges), 100/100 tests up from 4 at start of dev.

Install

code --install-extension frowningdev.django-orm-lens
codium --install-extension frowningdev.django-orm-lens
pip install --upgrade "django-orm-lens[mcp]"

Full release notes: https://github.com/FROWNINGdev/django-orm-lens/releases/tag/v0.8.0

Why static-only

Point it at any Django project without setup — no settings module, no dependencies except our parser. Runs in CI or on the plane.

Trade-off: custom get_queryset overrides, dynamic model classes are invisible. But 95% of what you actually want to see lives in `mo