JillionDB
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For people building with AI agents

See what your agent wants to do to your database before it does it.

Your coding agent proposes the change. You see it on your schema, in plain words, and nothing happens until you approve.

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Works with Claude Code, Cursor and any MCP client·Claude CodeCursor·PostgreSQL · MySQL · SQLite

Why it matters

Agents write database changes. Most get approved without a real look.

The SQL usually looks fine. The trouble is what it does to the data that’s already there.

nameAna · Ben · Chloé
full_name— · — · —

A rename that deletes

Asked to rename a column, the agent drops it and adds a new one. Every value that was in it is gone.

JillionDB flags it before it runs.

titleQuarterly report for the board
200 → 120

A limit that cuts

A text field gets shorter. Anything longer is cut off, or the change fails halfway through.

JillionDB flags it before it runs.

phone+44 20 7946 0958
phoneempty
NOT NULL

A rule old rows break

A field becomes required on a table that already has empty ones. It works on your laptop and fails in production.

JillionDB flags it before it runs.

How it works

Three steps. No SQL to read.

  1. 1

    Connect your agent

    One command adds JillionDB to Claude Code. Cursor and other tools take a few lines of settings.

    $ claude mcp add --scope user --transport http jilliondb https://jilliondb.com/mcp --header "Authorization: Bearer dbk_…"
  2. 2

    See the change on your schema

    Each proposal is drawn on your tables: green for safe, amber for careful, red for anything that can lose data, each with a reason in plain words.

    SafeCautionDestructive
  3. 3

    Approve, edit or reject

    Only you can approve. Your agent then gets the exact migration for your database, and a way to undo it.

    Approve

Fits your stack

It sits between your agent and your database.

Nothing to replace. Your agent proposes, you approve in JillionDB, and your own migration tool applies the SQL.

Risk, in plain words

Every change gets a level and a reason.

Safe
Add column “tasks.due_at”
Adds an empty column; existing rows are untouched.
Caution
Rename column “users.name” to “full_name”
Code that uses the old name stops working until it’s updated.
Destructive
Drop column “projects.legacy_code”
Deletes the column and its data.

Also a schema designer

Your whole database, drawn.

Use it with an agent, or on its own.

Draw tables and relationships

Drag between columns to connect tables. It stays smooth at hundreds of tables.

Import what you already have

Paste a dump from PostgreSQL, MySQL or SQLite, or from Rails, Django or Laravel. Anything that can’t be read is listed, never dropped quietly.

SQL or canvas, both ways

Edit the SQL and the drawing follows. Edit the drawing and the SQL follows.

Versions you can compare

Save a version, keep working, and see exactly what changed since.

Trust

Built to be safe to say yes to.

Schemas only

We never see your data or your database passwords.

Nothing runs on your database

JillionDB writes the SQL. Your own tools apply it, when you choose.

Tested on the real thing

Migrations are run on real PostgreSQL, MySQL and SQLite in our tests, data included.

Yours to take

Export your schema and SQL whenever you like.

Pricing

Start free. Upgrade when you outgrow it.

Free

$0for good

  • 1 project
  • 1 agent key
  • 30 days of version history
  • Every database and every feature
Create an account

Pro

$12a month

  • Unlimited projects
  • Unlimited agent keys
  • Unlimited version history
  • Every database and every feature
Coming soon

Early access: every account has everything until Pro launches.
Teams, with shared projects and reviews, are coming later.

Questions

Still curious?

The docs cover every step, from connecting your agent to reading a review.

Read the docs
What is JillionDB?

A place to review the database changes your AI coding agent wants to make. Each change is drawn on your schema with its risk and a reason, and nothing happens until you approve.

Do I need to know SQL?

No. Every change is explained in plain words, and the risk level tells you what to look at. The SQL is there when you want it.

Does JillionDB see my data?

No. It works with your schema only, the shape of your tables. It never connects to your database.

Which agents and databases?

Claude Code, Cursor and any tool that supports MCP. PostgreSQL, MySQL and SQLite.

Does it replace my migration tool?

No. Your agent writes the SQL JillionDB gives it wherever your project keeps migrations, and your usual tools apply it.

Can I use it without an agent?

Yes. It’s a full schema designer: draw tables, import an existing database, edit as SQL, compare versions and export migrations.

See it before it happens.

Open the demo and approve an agent’s change in under a minute.

Try the demo, no sign-up