---
title: 'Environment Variable Naming Convention'
---

Prowler is a monorepo composed of several runtime components — Prowler Local Server (the web user interface), Prowler API (the backend), Prowler SDK, and Prowler MCP Server (Model Context Protocol) — that frequently share a single `.env` file. To keep that shared configuration unambiguous, each component namespaces its environment variables with a component-specific prefix.

## Component Prefixes

Each component owns a dedicated prefix for the environment variables it reads:

| Component | Prefix | Status |
|-----------|--------|--------|
| Prowler Local Server (web UI) | `UI_` | Adopted |
| Prowler API (backend) | `API_` | Planned |
| Prowler SDK | `SDK_` | Planned |
| Prowler MCP Server | `MCP_` | Planned |

## Why Component Prefixes Matter

Component prefixes solve three concrete problems in a shared configuration file:

- **Collisions in a shared `.env`:** Several components historically read identically named variables. The API base URL, for example, is consumed by more than one component, so a single unprefixed name is ambiguous. A component prefix removes that ambiguity.
- **Explicit ownership:** A prefix states, at a glance, which component consumes a variable.
- **Reduced accidental exposure:** For Prowler Local Server, scoping browser-facing configuration under one intentional prefix prevents server-only values from leaking into the client bundle.

## Prowler Local Server

Prowler Local Server has adopted the `UI_` prefix. Its public configuration is resolved from the container environment at runtime rather than inlined at build time, so a single pre-built image serves any deployment. For the operational details on changing these values without rebuilding the image, see [Troubleshooting](/troubleshooting).

The former build-time variables map to the new runtime variables as follows:

| Former variable | New variable |
|-----------------|--------------|
| `NEXT_PUBLIC_API_BASE_URL` | `UI_API_BASE_URL` |
| `NEXT_PUBLIC_API_DOCS_URL` | `UI_API_DOCS_URL` |
| `NEXT_PUBLIC_GOOGLE_TAG_MANAGER_ID` | `UI_GOOGLE_TAG_MANAGER_ID` |
| `NEXT_PUBLIC_SENTRY_DSN`, `SENTRY_DSN` | `UI_SENTRY_DSN` |
| `NEXT_PUBLIC_SENTRY_ENVIRONMENT`, `SENTRY_ENVIRONMENT` | `UI_SENTRY_ENVIRONMENT` |

The build-time-only Sentry variables used for source-map upload — `SENTRY_ORG`, `SENTRY_PROJECT`, `SENTRY_AUTH_TOKEN`, and `SENTRY_RELEASE` — keep their names, as they are not part of Prowler Local Server's runtime configuration.

## Enabling Third-Party Integrations

Prowler Local Server gates each optional third-party integration behind an explicit enable flag. When an integration is configured through its new `UI_*` variables, it loads only when its flag is set to the exact string `"true"`; any other value, including unset, leaves it off. This default-off behavior keeps a deployment free of third-party egress unless it opts in. Deployments still using the deprecated legacy variable names keep loading without the flag, for backward compatibility (see [Deprecated Names](#deprecated-names)).

| Integration | Enable flag | Required configuration when enabled |
|-------------|-------------|-------------------------------------|
| Sentry (error monitoring) | `UI_SENTRY_ENABLED` | `UI_SENTRY_DSN` |
| Google Tag Manager | `UI_GOOGLE_TAG_MANAGER_ENABLED` | `UI_GOOGLE_TAG_MANAGER_ID` |
| PostHog (product analytics) | `UI_POSTHOG_ENABLED` | `UI_POSTHOG_KEY` and `UI_POSTHOG_HOST` |

When an integration is enabled but its required configuration is missing, Prowler Local Server fails fast at server startup with a clear error, so a misconfigured container never starts silently. A new `UI_*` value set while its enable flag is not `"true"` is ignored, and the server logs a one-time startup warning noting that the integration will not load. Legacy names follow the backward-compatible rule described in [Deprecated Names](#deprecated-names).

PostHog support is currently limited to configuration validation: Prowler Local Server reads and validates the PostHog variables but does not yet load a PostHog client.

<Warning>
Configuring an integration through the new `UI_*` variables now requires its enable flag. A deployment that adopted `UI_SENTRY_DSN` or `UI_GOOGLE_TAG_MANAGER_ID` must also set `UI_SENTRY_ENABLED=true` or `UI_GOOGLE_TAG_MANAGER_ENABLED=true` to keep the integration active. Deployments still using the legacy names (`NEXT_PUBLIC_*`, or `POSTHOG_KEY` and `POSTHOG_HOST`) keep working without the flag.
</Warning>

## Upcoming Breaking Change

<Warning>
Adopting the `API_`, `SDK_`, and `MCP_` prefixes for Prowler API, Prowler SDK, and Prowler MCP Server is a planned breaking change in a future release. Migrate environment configuration to the new names when upgrading.
</Warning>

Prowler API, Prowler SDK, and Prowler MCP Server have not yet adopted the convention. In a future release, the variables each of these components reads will be namespaced under `API_`, `SDK_`, and `MCP_` respectively. The per-component mapping from current to prefixed names will be documented when each change is released.

## Deprecated Names

- **Prowler Local Server:** The bare server-side `SENTRY_DSN` and `SENTRY_ENVIRONMENT` are no longer read; the server and edge runtimes now read `UI_SENTRY_DSN` and `UI_SENTRY_ENVIRONMENT`. The former `NEXT_PUBLIC_*` names — and, for PostHog, the unprefixed `POSTHOG_KEY` and `POSTHOG_HOST` — are deprecated but stay backward compatible: they are read at runtime regardless of the enable flag, so an existing deployment keeps its integration active without opting in. The new `UI_*` names, by contrast, load only when the matching enable flag is set to `"true"`. These legacy names will be removed in a future release, so migrate to the `UI_*` runtime variables — and set the enable flag — on the running container.
- **Prowler API, Prowler SDK, and Prowler MCP Server:** The current, unprefixed variable names are deprecated. They continue to work today and will be removed once the prefixed convention is adopted for each component, as described in [Upcoming Breaking Change](#upcoming-breaking-change).
