Does my database schema leave my network?

No. Alex Architect runs on your infrastructure. It connects outward only to endpoints you configure yourself: your database, your identity provider, and an AI provider if you choose to enable one. There is no telemetry.

Clone the repository and run docker compose up --build -d. The editor is then at http://localhost:8080. It starts no database of its own.

What state is the project in?

Alpha. PostgreSQL and MySQL are first-class. Migration Apply is deliberately disabled, so diff and SQL export are read-only.

MIT · self-hosted · no seats to buy

Your schema diagram is a screenshot. It has been wrong since March.

Q: Can it generate a diagram from an existing database?

Yes. Point it at a PostgreSQL or MySQL database and it reads tables, columns, primary keys, foreign keys and indexes into a diagram. SQL Server, Oracle and SQLite are supported experimentally.

A self-hosted ER editor that reads your real database. One command to run, no seats to buy, nothing leaves your network.

Run it in one command Source on GitLab

PKEvery person in the data office can open the modelnot null
FKThe model points at a real database, not at a picture of onereferences production
NSchema metadata stays inside your networkno telemetry

PK`problem`A model only one person is allowed to fix

Three things go wrong, and they compound. The third is the one people notice; the first is the one that caused it.

Priced per seat

The licence goes to the architect

Serious ER tools are sold per person, so the seat goes to whoever draws. The analyst, the BA and the new engineer get a screenshot in Confluence instead — and a screenshot cannot be corrected by the person who spots the error.

Cloud-only

It never clears the security review

Browser-based editors want your DDL pasted in, or a route to your database. In a bank or a telecom that conversation ends in five minutes, and the team goes back to drawing rectangles by hand.

Draws, does not read

Nobody can tell if it is still true

Free tools draw pictures. They do not connect to production, so nothing tells you the diagram and the database drifted apart. The diagram stops being evidence and becomes decoration.

FK`origin`Three attempts in two years

There is one task that follows a data architect through an entire career: design a relational schema quickly, clearly, and without pain. It sounds modest. In practice it is a headache.

drawio is where almost everyone starts, and where almost everyone is first disappointed. You cannot generate a diagram from a schema that already exists, and working with relationships is awkward enough that pencil and paper would be faster. In Miro it is worse.

Over the years I worked with the serious tools — SAP PowerDesigner at Kaspi, IBM Data Architect on other projects, and a dozen ER editors in between. Every one of them beat drawio by an order of magnitude. Every one of them had a price, and not only in money.

Three times in two years I sat down to find an alternative. The market does move: some of the newer tools genuinely raise the bar for database design. The catch repeated itself every time. Not merely paid — priced out of reach. A week of trial here, a community edition there, a self-hosted build somewhere else, each limited enough that you cannot finish an ordinary day's work: stand up a new data mart, or make one small correction to an ER diagram.

Then Claude, Cursor and OpenRouter changed the arithmetic. If tools like this are only ever going to be built for large enterprise, I would build one on my own. The concept took a couple of days. Getting it to a working product, and fixing what that exposed, took two weeks.

Two weeks is not a claim about maturity — it is a claim about what building software costs now. The honest status of the project is further down this page, in full.

It works well enough that I am not waiting for beta testing to finish. The build is on GitLab, and so is every line of source. Fork it, run it, change it. MIT: no seats, no tiers, nothing held back for an edition you have to buy.

FK`how`It doesn't draw your database. It reads it.

Point it at PostgreSQL or MySQL and it imports tables, columns, keys and indexes. From there the model is yours to edit — and to check against the database it came from.

The Diff and migrate dialog against a live PostgreSQL connection: seven operations listed and a SQL preview showing CREATE TABLE and COMMENT ON COLUMN statements — Compared against a live PostgreSQL database: seven differences, each one listed, with the SQL written out for you to read. Alex Architect generates it and stops there — running it is your decision, in your own tooling.

The View menu showing conceptual, logical and physical detail levels for the same model — One model, three levels of detail. The architect reads the physical layer; everyone else reads business names on the same diagram, without a second document to keep in sync.

N`features`What it does

Area	Detail
Modelling	Tables, columns, data types, PK and FK by drag-and-drop, crow's foot notation. Constraints, single and multi-column indexes. Areas with colour inheritance. Auto-layout by connected component.
Reverse engineering	PostgreSQL and MySQL first-class; SQL Server, Oracle and SQLite experimental. Browse a live catalog without importing anything.
Diff	Read-only comparison against a live database, with SQL preview, clipboard and file export.
Import and export	Import DDL and DBML. Export DDL, DBML, PNG, SVG, and HTML or Markdown documentation — whole project, one table, or one Area.
Access	Project roles: owner, editor, viewer. Instance administrators. Access requests with a stated reason. Invite by link.
Versions	Explicit save, last 50 commits, compare and restore. Undo and redo while you work.
AI assistant	Optional, on a key you supply. Asks questions about the schema or applies edits as one undoable step. Sends schema metadata only — never row data.
Sign-in	Sessions out of the box. Google and any standards-compliant OIDC provider, including Microsoft Entra ID.

The Team dialog listing four people on one project with owner, editor and viewer roles — Four people on one model, three different roles. This is the whole point: the analyst who spots the error can be the one who fixes it.

N`trust`What leaves your network

Nothing you did not configure yourself.

Outbound traffic

Only where you point it

Your database, your identity provider, and an AI provider if you turn one on. No telemetry, no analytics, no phone-home — the code is there to check.

Stored secrets

Encrypted, never returned

Database passwords are sealed with AES-256-GCM. The API returns whether a password exists, never the value — not in responses, not in logs, not in provider error messages.

N`status`Where the project actually is

Alpha. You would find all of this out in ten minutes anyway, so here it is first.

yesPostgreSQL and MySQL are first-class. Reverse engineering, diff and DDL export are tested against live databases on every release.
yesSeveral people, one instance. Roles, invitations and access requests work; you can see who else has the diagram open.
noMigration Apply is switched off on purpose. Diff and SQL export are read-only. Alex Architect will generate the SQL and let you read it; running it against your database is your call, made in your own tooling.
partSQL Server, Oracle, SQLite, ClickHouse, Redshift and StarRocks are experimental. They work in the cases we have tried and are not covered by the release gate.
noOne API process only. Presence and locks live in memory, so do not run two replicas. For a data office on one instance this is not a limit you will meet.

PK`start`Run it

It starts the editor only — no database of its own, nothing to sign up for.

# clone, then:
docker compose up --build -d

# http://localhost:8080 — sign in as admin / admin, then change the password

Deploying it for a company, with your own domain, TLS and single sign-on, is two commands and a Kustomize overlay — that path is written up separately.

Deployment guide Using the editor

N`faq`Questions people actually ask

Is it really free?

Yes. Alex Architect is MIT licensed and self-hosted. There is no paid tier, no seat count, and no feature held back for an edition you have to buy. You run it on your own machine or server and every feature is present.

Does my schema leave my network?

No. It runs on your infrastructure and connects outward only to endpoints you configure: your database, your identity provider, and an AI provider if you enable one. There is no telemetry.

Can it build a diagram from a database that already exists?

Yes. Point it at PostgreSQL or MySQL and it reads tables, columns, primary keys, foreign keys and indexes into a diagram. SQL Server, Oracle and SQLite are supported experimentally.

Will it change my database?

No. Migration Apply is disabled server-side. Diff generates SQL for you to read, copy or download; executing it is your decision, in your own tooling.

Can I use it commercially, or fork it?

Yes to both. The MIT licence permits commercial use, modification and redistribution. The full source is on GitLab.

PKproblemA model only one person is allowed to fix

The licence goes to the architect

It never clears the security review

Nobody can tell if it is still true

FKoriginThree attempts in two years

FKhowIt doesn't draw your database. It reads it.

NfeaturesWhat it does

NtrustWhat leaves your network