KAPEX by Sandstone Cloud

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Security

What this runs on, what has been checked, and what has not.

Last reviewed October 12, 2026

This page used to be long, and a reader had no way to tell which of the things on it existed. The short version is more useful, so this page says what is true today and names what is missing.

What is running

The KAPEX API is shut down and self-service signup is closed. A few older pages on other getkapex.ai addresses still load. Treat them as out of date.

When the hosted sandbox runs, it runs on Amazon Web Services in the US East region. Traffic reaches it over TLS. Nothing is served from a machine that is not AWS.

What has not been audited

There is no SOC 2 report. The only assessment that exists is an internal one, written in March 2026, which scored 9 of 36 controls as fully met, and 0 of 4 on availability. It was not performed by an auditor, and no auditor has been engaged. A Type II report also needs an observation period, and that period has not started. Anyone who was told otherwise was told wrong.

There is no Business Associate Agreement. Sandstone Cloud cannot sign one, and KAPEX should not be used with protected health information. Earlier versions of this page listed a BAA under an enterprise tier. That was not accurate and it has been removed.

There has been no external penetration test and no third-party code audit.

What the software does with data

Deletion is real and not a flag. A delete request removes the record rather than hiding it, and the removal is written to a ledger so that it can be shown to have happened. On one of KAPEX’s two sets of routes a single delete doesn’t write that record yet; the developer page says which.

When an app asks for a person’s memory as a file, it gets back only the people stored under the key it used. Ask for anyone else and nothing of theirs comes back.

Deployment is intended to be in the customer’s own environment, so that memory data stays there. That is the design and the licence model; it is not something a reader should take on trust while nothing is running.

Not all of it stays there, even then. While KAPEX reads a turn, it sends the text to a model of its own: by default one on Amazon Bedrock, or Anthropic directly if the Bedrock call fails and an Anthropic key is set. That provider belongs in your data review.

Who sees what you say You write to the app, and the app hands your words to its own model. The app also sends KAPEX your message before the reply and the turn after it, and KAPEX passes the text to a model of its own, from an outside provider. You The app The app’s model KAPEX KAPEX’s own model from an outside provider before the reply: your message after the reply: the turn
Who sees what you say You write to the app, and the app hands your words to its own model. The app also sends KAPEX your message before the reply and the turn after it, and KAPEX passes the text to a model of its own, from an outside provider. You The app The app’s model KAPEX KAPEX’s own model from an outside provider before the reply: your message after the reply: the turn

What a person can see and change

If you are evaluating KAPEX

Ask for the specific thing you need. If an answer to a diligence question is not on this page, the honest answer is usually that the artifact does not exist yet, and we would rather say so than send you a document that implies it does. Write to support@sandstonecloud.com.

Reporting a vulnerability

Email support@sandstonecloud.com with “Security” in the subject. A person reads it. Right now that person is Oliver. Please include enough detail to reproduce the issue. We will acknowledge within three business days.

There is no bug bounty programme and we are not offering payment. We will not pursue anyone who reports a genuine issue in good faith and gives us a reasonable chance to fix it before publishing.