> ## Documentation Index
> Fetch the complete documentation index at: https://docs.reg121.com/llms.txt
> Use this file to discover all available pages before exploring further.

# REG121 Limitations: What the Platform Is Not Designed For

> A direct scoping guide for developers evaluating REG121. Understand the architectural boundaries before you build so you can make the right tool choice.

This page describes what REG121 is not designed to do. It is written as a factual scoping guide, not a disclaimer. If your use case sits outside these boundaries, REG121 is the wrong tool — and it is better to establish that before you build rather than after. Read this page alongside the architecture overview before committing to a project.

## Designed For

REG121 is designed for the following categories of work:

* **Business websites.** Marketing sites, landing pages, and informational sites for small to medium businesses.
* **Simple web applications.** Customer-facing web apps with structured data requirements, form submissions, and basic CRUD operations backed by a managed Postgres schema.
* **Customer-facing sites for small businesses.** Sites where the operator is the end customer, not a platform running other businesses on top of REG121.

## Not Designed For

The following use cases are outside REG121's scope. These are not gaps that workarounds can reliably bridge.

* **Web platforms and multi-sided marketplaces.** If your product is itself a platform — where your end users are businesses operating on top of your application, managing their own customers, products, or data — REG121 is not the right foundation. The platform does not support the multi-tenant data modeling, per-tenant isolation controls, or platform-layer administrative APIs that this architecture requires.
* **Native mobile applications.** REG121 does not generate or deploy iOS or Android applications. Generated sites are React web applications and are not packaged for native mobile distribution.
* **Desktop applications.** REG121 does not produce Electron apps, native desktop binaries, or any non-web runtime target.
* **Applications requiring direct, unrestricted database access or custom infrastructure configuration.** You do not get a database connection string, shell access, or the ability to modify infrastructure configuration. REG121 manages the underlying Postgres instance. Direct schema access tooling is not available in the current platform — its availability is pending engineering confirmation.
* **High-throughput data pipelines or analytics workloads.** The managed Postgres schema is scoped to application data for a single site. It is not sized or architected for bulk ingestion, stream processing, large-scale analytical queries, or ETL pipelines.
* **General-purpose cloud compute.** REG121 is not a cloud compute platform. You cannot deploy arbitrary server processes, run background workers, or provision compute resources outside the boundaries of a REG121 site.

## Architectural Boundaries

Each REG121-generated site is a self-contained unit: a React application paired with an isolated Postgres schema. That pairing defines the boundary of what the platform manages and what it exposes.

Architectures that require the following fall outside REG121's scope:

* **Shared state across sites.** There is no cross-site data layer. Each site's schema is isolated at the infrastructure level.
* **Cross-site queries.** The REST API and any other data access surface are scoped to a single site. You cannot query across multiple sites' schemas from within the platform.
* **Custom compute outside the React + Postgres model.** If your architecture requires custom server-side processes, stateful background workers, or infrastructure components not part of this model, REG121 does not provide a way to run or integrate them natively.

<Note>
  If you are unsure whether your use case fits, contact REG121 before building — it is better to know upfront.
</Note>