Cloister

Modern in-browser analytical engines can query substantial local files without uploading them to a vendor service. The supplied research confirms two live open-source engines and no reviewed BI product combining browser-local OLAP with a signed no-egress artifact. That architecture is promising, but a signature cannot prove that no byte ever left the device.

Cloister should make the claim narrower and verifiable: a specific application build, loaded under a defined offline or network policy, processed listed local files in the browser, produced a report, and recorded observable network attempts and configuration. Browser extensions, operating systems, enterprise proxies, imported file links, telemetry, crash reporting, remote assets, malicious files, and user exports remain outside or must be controlled explicitly.

Regulated practices still own data rights, device security, access, retention, backup, reporting correctness, and professional obligations. Local processing reduces vendor exposure; it does not establish HIPAA, legal privilege, accounting confidentiality, privacy compliance, or report accuracy.

Privacy, operations, finance, and analytics owners at small healthcare, legal, accounting, and other regulated professional firms that need local file analysis.