JillionDB + Cursor

Safe database changes for Cursor

Cursor’s agent can change your schema as fast as your code. JillionDB shows you each change on your schema, in plain words, before it runs.

Try the demo, no sign-up Set up in a minute

Agent mode moves fast

Cursor’s agent can write a migration and apply it in one go. The risky part is easy to miss in a long diff.

SQL isn’t the whole story

A migration can look fine and still cut off text, fail on rows you already have, or drop a column you meant to rename.

You stay the one who decides

Cursor proposes, you see the change on a drawing of your schema, and nothing happens until you approve.

Set up in a minute

1
Create a key in Settings, then add this to .cursor/mcp.json in your project, or to ~/.cursor/mcp.json for every project. Put your key in place of dbk_…
```
{
  "mcpServers": {
    "jilliondb": {
      "url": "https://jilliondb.com/mcp",
      "headers": { "Authorization": "Bearer dbk_…" }
    }
  }
}
```
2
Open Cursor’s settings, find MCP, and check that jilliondb shows as connected.

Make it the rule

Add a project rule so Cursor always proposes database changes through JillionDB:

.cursor/rules/database.mdc

---
description: Database schema changes
alwaysApply: true
---

Never write or run database migrations on your own. Propose every database schema change through the jilliondb MCP server with propose_change, give me the review link, and wait. When get_proposal says it is approved, write the migration it returns exactly as given.

Get your key in Settings Full setup guide

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.

What happens next

1
Ask for a change
In plain words, like “add a timezone to users”.
2
Review it
Open the link the agent gives you. Each change is on your schema with its risk and a reason.
3
Approve, edit or reject
Your agent gets the exact migration, or your note, and carries on.

Questions

Still curious?

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

Read the docs

Does JillionDB see my data?

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

Does it replace my migration tool?

No. JillionDB writes plain SQL and your agent puts it where your project keeps migrations. Prisma, Drizzle, Rails, Django, Laravel or plain SQL files all work.

What does it cost?

It’s free during early access. Pro will be $12 a month for unlimited projects, keys and history.

Which databases?

PostgreSQL, MySQL and SQLite.

See it before it happens.

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

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