# Env Configuration

> Adding or reading env vars, updating .env.example, or validating config at startup with parseEnv / parseEnvOptional.

- Skill: `latitude-dev/env-configuration` (Agent Skill)
- Install (CLI): `npx skillmds@latest add latitude-dev/env-configuration`
- Raw SKILL.md: https://api.skillmd.com/api/skills/latitude-dev/env-configuration/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: latitude-dev (https://skillmd.com/u/latitude-dev)
- Updated: 2026-09-10
- Page: https://skillmd.com/skills/latitude-dev/env-configuration

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# Environment configuration

**When to use:** Adding or reading env vars, updating `.env.example`, or validating config at startup with `parseEnv` / `parseEnvOptional`.

## `LAT_` prefix convention

All application environment variables **must** be prefixed with `LAT_` so they do not collide with third-party services, Docker, or common names.

**Use `LAT_` for:**

- Database URLs and pool settings (`LAT_DATABASE_URL`, `LAT_PG_POOL_MAX`, …)
- Service endpoints the app reads (`LAT_CLICKHOUSE_URL`, `LAT_REDIS_HOST`, …)
- App ports (`LAT_API_PORT`, `LAT_WEB_PORT`, `LAT_INGEST_PORT`)
- Auth, email, OAuth, billing, CORS (`LAT_BETTER_AUTH_SECRET`, `LAT_MAILPIT_HOST`, …)
- Any new variable consumed by Latitude application code

**Do not use `LAT_` for:**

- `NODE_ENV`
- Docker-only init variables (`POSTGRES_USER`, `CLICKHOUSE_USER`, …)
- Config read only by container images (Weaviate, Redis in compose, etc.)
- Browser-exposed Vite vars: use **`VITE_LAT_*`** (Vite requires the `VITE_` prefix)

**Reference:** `.env.example` lists Docker “Services” vs “Latitude Application” (`LAT_*`) variables.

## `.env.example` maintenance

Every new variable **must** appear in `.env.example`:

- **Required:** uncommented with a sensible local default (e.g. `LAT_API_PORT=3001`)
- **Optional:** commented with a placeholder (e.g. `# LAT_STRIPE_SECRET_KEY=sk_test_xxx`)

## Keep the self-host surfaces in sync

Self-hosters configure Latitude through these env vars, so adding, renaming, or removing one means updating more than `.env.example`. Whenever you touch a `LAT_*` var, also reflect it in:

1. **The configuration reference** `docs/deployment/configuration.mdx` — so operators know what the var does — **unless** it is specific to *Latitude's own cloud* deployment, which stays out of the self-host docs: payments/Stripe, marketing/lifecycle email (Loops), support chat (Intercom), and internal analytics/observability vendors (PostHog, Datadog/OTEL export, GTM, Framer, ipinfo). General app/infra/auth/AI/email-transport vars all belong in the reference.
2. **The Helm chart** `charts/latitude/` — decide where the var belongs:
   - non-secret → `templates/configmap.yaml` (and a `values.yaml` knob if it's a first-class setting);
   - secret → `templates/secret.yaml` **and** the chart README's `existingSecret` key list;
   - optional/rare → no template change needed; the documented `config.extraEnv` / `secrets.extra` pass-through already covers it.

`docker-stack.yml` needs no per-var change (it consumes the whole `.env.production`), but a new **required** var must land in `.env.example`'s production guidance. The Railway template is dashboard-authored — no repo change. See [`dev-docs/self-hosting.md`](../../../dev-docs/self-hosting.md) for the tier/contract overview.

## Parsing in code

**Always** use `parseEnv` or `parseEnvOptional` from `@platform/env` — never `process.env.FOO` ad hoc or unprefixed names for app config.

```typescript
// ❌ Bad - unprefixed or direct access
const port = Number(process.env.PORT)

// ✅ Good - pass the variable name string (parseEnv reads process.env internally)
import { parseEnv, parseEnvOptional } from "@platform/env"
import { Effect } from "effect"

const port = Effect.runSync(parseEnv("LAT_API_PORT", "number", 3001))
const dbUrl = Effect.runSync(parseEnv("LAT_DATABASE_URL", "string"))
```

For where configuration is wired in apps (clients, routes), see [architecture-boundaries](../architecture-boundaries/SKILL.md).