FeatherDB macOS 15+ · Apple Silicon & Intel

Give your AI a sandbox, not your production database.

FeatherDB is a native Postgres client for macOS with one MCP gateway your AI tools connect to. Live databases are read-only — enforced inside the transaction, not requested in a prompt. Sandboxes are real local clones with the personal data masked, so the agent can break something that costs nothing.

Version 1.0.3 · 68 MB · signed & notarized · 14-day trial, no account, no telemetry.

FeatherDB's data grid browsing a live customers table
The data grid on a live connection — real screenshot, seeded demo data.

What it actually enforces

Live is read-only. Postgres enforces it, not a prompt.

A write to a live database is refused before anything executes.

Every statement an AI sends to a live database runs inside BEGIN READ ONLY and is rolled back afterwards. A write is not talked out of it — Postgres refuses it, and the AI gets a message to relay to you. The capability is decided by what kind of database it is, never by how the request was worded.

Staged conversation — but the refusal is the gateway's actual message, byte for byte.

  • BEGIN READ ONLY
  • enforced in the transaction
  • refusal, not rollback cleanup

Sandboxes

The real schema, with the personal data already gone.

One click clones a live database into an embedded Postgres on your Mac.

Emails, names and phone numbers are replaced before they land — fail-closed, so a column the classifier cannot vouch for is not copied at all. The AI gets full read and write there, and the mask report shows exactly what happened to every column. Anything the agent breaks costs nothing.

A running FeatherDB sandbox with its PII mask report: email, name and phone masked; country emptied; notes nulled
Real screenshot: a sandbox cloned from a live database, with its PII mask report.
  • embedded Postgres 17
  • PII masked before copy
  • fail-closed
  • disposable

Migrations

Diff the sandbox against live. Review before anything applies.

Sandbox changes worth keeping become an ordered, safety-linted plan.

Each step is graded — DANGER for the ones that rewrite a table, WARN for the ones that lock it — and split into phases: transactional first, CONCURRENTLY indexes outside. Dangerous plans require an explicit confirmation, and a drift guard catches production changing underneath you.

A FeatherDB migration plan: an ALTER TABLE graded DANGER and a CONCURRENTLY index graded WARN, behind a confirmation checkbox
Real screenshot: a computed plan with graded steps and the confirmation gate.
  • graded steps
  • two-phase apply
  • drift guard
  • explicit confirm

Connects to

The first four install themselves — one click, no token to copy. Everything else gets the standard MCP config to paste. One gateway serves every database you expose; the AI names which one it wants, and what it may do there is decided by the kind of database it is, not by the request.

Pricing

$69
once, not per month
  • Perpetual licence — the version you bought keeps working forever, offline.
  • One year of updates included. Renew for $29/year to keep getting them; skip it and nothing stops working.
  • Two machines per licence.
  • 14-day trial, full features, no account and no card.
  • No usage metering. The AI calls are yours and go through your own subscription — FeatherDB never sits in that loop.

Checkout by Polar.sh, the merchant of record — your receipt and any VAT come from them. Activation is immediate: open the app, type your purchase email, enter the 6-digit code it sends you. No key to wait for.

Questions, answered

Does my data ever leave my Mac?

No. FeatherDB connects your Mac directly to your databases — rows, schemas, credentials, and query results never touch our servers. The app contacts a server in exactly three situations: buying, activating, and checking for updates, and the privacy policy lists precisely what each involves.

What can the AI actually do — and not do?

Your AI tools connect to one local MCP gateway. On a live database they can read, and only read — every statement runs inside BEGIN READ ONLY, so a write is refused by Postgres itself, not by a prompt. On a sandbox they get full read and write, because a sandbox is a disposable local clone with personal data already masked.

Which databases does it work with?

Postgres — connected directly over TLS (Supabase, Neon, RDS, and other managed hosts) or through an SSH tunnel to a box you own. Sandboxes run in an embedded Postgres 17 on your Mac; cloning from older servers works, and the diff planner flags version drift so you review those migrations by hand.

How does activation work? Do I need an account?

No account. Buy, open FeatherDB, type the email from your receipt, and enter the 6-digit code it sends you. One purchase covers two Macs — deactivate a machine in the app to free its seat. After activation the licence verifies offline; air-gapped Macs can paste a licence key instead.

What happens when my year of updates ends?

Nothing. The version you have keeps working forever, offline. Renewing ($29/year) is optional and only buys continued updates — skip it and come back whenever a new version is worth it to you.

Is there a Windows or Linux version?

No — FeatherDB is a native macOS app, built for macOS 15 or later on Apple Silicon and Intel. Going deep on one platform is what keeps it fast and native-feeling.