Unconditional throw breaks config reads when env vars are absent

getEnvVariable throws Missing environment variable: <name> if the named variable is not set and no default is provided. Before this PR, the isShared branch returned only { type: 'shared' } and never touched the env vars. After this PR every call to renderedOrganizationConfigToProjectCrud (which backs the /api/v1/internal/projects read endpoint) will throw for any project in shared-email mode that doesn't have all three of STACK_EMAIL_HOST, STACK_EMAIL_PORT, and STACK_EMAIL_SENDER defined. Self-hosted operators who haven't set these vars (or deliberately run without email) would find their entire project config endpoint broken after this change, even though no email-sending code was touched.

A safe approach is to fall back to undefined/null when the var is absent rather than throwing:

email_config: renderedConfig.emails.server.isShared ? {
  type: 'shared',
  ...(process.env.STACK_EMAIL_HOST ? { host: process.env.STACK_EMAIL_HOST } : {}),
  ...(process.env.STACK_EMAIL_PORT ? { port: parseInt(process.env.STACK_EMAIL_PORT) } : {}),
  ...(process.env.STACK_EMAIL_SENDER ? { sender_email: process.env.STACK_EMAIL_SENDER } : {}),
} : ...

Note: getEnvVariable cannot be used here with a fallback because an empty string is treated as "not set" by that utility; using process.env directly and checking truthiness is safer.

This is a comment left during a code review.
Path: apps/backend/src/lib/config.tsx
Line: 1166-1171

Comment:
**Unconditional throw breaks config reads when env vars are absent**

`getEnvVariable` throws `Missing environment variable: <name>` if the named variable is not set and no default is provided. Before this PR, the `isShared` branch returned only `{ type: 'shared' }` and never touched the env vars. After this PR every call to `renderedOrganizationConfigToProjectCrud` (which backs the `/api/v1/internal/projects` read endpoint) will throw for any project in shared-email mode that doesn't have all three of `STACK_EMAIL_HOST`, `STACK_EMAIL_PORT`, and `STACK_EMAIL_SENDER` defined. Self-hosted operators who haven't set these vars (or deliberately run without email) would find their entire project config endpoint broken after this change, even though no email-sending code was touched.

A safe approach is to fall back to `undefined`/`null` when the var is absent rather than throwing:

```typescript
email_config: renderedConfig.emails.server.isShared ? {
  type: 'shared',
  ...(process.env.STACK_EMAIL_HOST ? { host: process.env.STACK_EMAIL_HOST } : {}),
  ...(process.env.STACK_EMAIL_PORT ? { port: parseInt(process.env.STACK_EMAIL_PORT) } : {}),
  ...(process.env.STACK_EMAIL_SENDER ? { sender_email: process.env.STACK_EMAIL_SENDER } : {}),
} : ...
```

Note: `getEnvVariable` cannot be used here with a fallback because an empty string is treated as "not set" by that utility; using `process.env` directly and checking truthiness is safer.

How can I resolve this? If you propose a fix, please make it concise.

parseInt can silently produce NaN

If STACK_EMAIL_PORT is set but contains a non-integer value (e.g. "465abc" or whitespace), parseInt(...) returns NaN. This NaN value will be serialised and sent to the dashboard, where it may render as "NaN" in the port fields. Adding a validation guard or using Number() with a Number.isInteger check would make the failure explicit rather than silent.

This is a comment left during a code review.
Path: apps/backend/src/lib/config.tsx
Line: 1169

Comment:
**`parseInt` can silently produce `NaN`**

If `STACK_EMAIL_PORT` is set but contains a non-integer value (e.g. `"465abc"` or whitespace), `parseInt(...)` returns `NaN`. This `NaN` value will be serialised and sent to the dashboard, where it may render as `"NaN"` in the port fields. Adding a validation guard or using `Number()` with a `Number.isInteger` check would make the failure explicit rather than silent.

How can I resolve this? If you propose a fix, please make it concise.

⚠️ Potential issue | 🔴 Critical

#!/bin/bash
# Check whether STACK_EMAIL_HOST/PORT/SENDER are set unconditionally in deployment/env configs.
rg -nP 'STACK_EMAIL_(HOST|PORT|SENDER)\b' -C2
# Verify getEnvVariable semantics
rg -nP --type=ts -C3 'export function getEnvVariable\b'

cat -n packages/stack-shared/src/utils/env.tsx | head -50

sed -n '49,65p' packages/stack-shared/src/utils/env.tsx

# Check when isShared is set to true in email config
rg -n 'isShared' apps/backend/src/lib/config.tsx -B5 -A5 | head -60

# Look for where emails.server.isShared is actually set/determined
rg -n 'emails.server' apps/backend/src/lib/config.tsx -B3 -A3 | head -80

# Find where emails.server configuration is built/rendered
rg -n 'emails.*server' packages/stack-shared/src -A2 -B2 | grep -A5 -B5 'isShared'

# Find where isShared is assigned/set for emails
rg -n 'isShared.*=' packages/stack-shared/src/config/schema.ts -B5 -A2

# Search for where isShared is computed in the config schema
rg -n 'isShared:' packages/stack-shared/src/config/schema.ts -B5 -A5

# Check if STACK_EMAIL_HOST/PORT/SENDER are set in any standard deployment configs
find . -name ".env*" -o -name "*.env" | head -20 | xargs grep -l "STACK_EMAIL" 2>/dev/null || echo "No .env files found with STACK_EMAIL"

# Check contents of these env files for STACK_EMAIL variables
echo "=== apps/backend/.env ===" && cat apps/backend/.env | grep -i "STACK_EMAIL" || echo "Not found"
echo -e "\n=== apps/backend/.env.development ===" && cat apps/backend/.env.development | grep -i "STACK_EMAIL" || echo "Not found"
echo -e "\n=== docker/server/.env ===" && cat docker/server/.env | grep -i "STACK_EMAIL" || echo "Not found"

Critical: getEnvVariable throws when STACK_EMAIL_* are unset, breaking all config rendering in shared mode.

getEnvVariable(name) throws Missing environment variable: ... when the variable is absent or an empty string without a provided default (see packages/stack-shared/src/utils/env.tsx). The default email configuration sets isShared: true, so any self-hosted deployment without explicit STACK_EMAIL_HOST / STACK_EMAIL_PORT / STACK_EMAIL_SENDER values — including the provided docker/server/.env template which defines these variables as empty strings — will crash when rendering organization configs on the dashboard hot path.

The downstream UI already handles undefined values for these fields (shown in apps/dashboard/.../email-settings/domain-settings.tsx with fallback text "Configured via STACK_EMAIL_SENDER"). Pass explicit defaults or undefined instead of throwing. Additionally, parseInt lacks an explicit radix; a non-numeric STACK_EMAIL_PORT produces NaN, which then fails the admin read schema validation.

    email_config: renderedConfig.emails.server.isShared ? {
      type: 'shared',
-     host: getEnvVariable("STACK_EMAIL_HOST"),
-     port: parseInt(getEnvVariable("STACK_EMAIL_PORT")),
-     sender_email: getEnvVariable("STACK_EMAIL_SENDER"),
+     host: getEnvVariable("STACK_EMAIL_HOST", "") || undefined,
+     port: (() => {
+       const raw = getEnvVariable("STACK_EMAIL_PORT", "");
+       if (!raw) return undefined;
+       const parsed = parseInt(raw, 10);
+       return Number.isFinite(parsed) ? parsed : undefined;
+     })(),
+     sender_email: getEnvVariable("STACK_EMAIL_SENDER", "") || undefined,
    } : renderedConfig.emails.server.provider === "managed" ? {

Verify each finding against the current code and only fix it if needed.

In `@apps/backend/src/lib/config.tsx` around lines 1166 - 1170, The config code
currently calls
getEnvVariable("STACK_EMAIL_HOST"/"STACK_EMAIL_PORT"/"STACK_EMAIL_SENDER")
without defaults which throws when those envs are empty; update the email_config
shared branch so it passes explicit defaults (use undefined) to getEnvVariable
for host and sender and for port parse the returned string with parseInt(...,
10) and guard NaN to produce undefined (i.e., call
getEnvVariable("STACK_EMAIL_PORT", undefined), then const port = parsed === NaN
? undefined : parsed), ensuring email_config construction (the email_config
object and its shared branch) yields undefined for missing values instead of
throwing.

renderedOrganizationConfigToProjectCrud now calls getEnvVariable("STACK_EMAIL_*") whenever renderedConfig.emails.server.isShared is true. Since the default config sets emails.server.isShared: true (see packages/stack-shared/src/config/schema.ts:643-655), this can make every project config serialization throw (and potentially break the dashboard) in environments where STACK_EMAIL_* isn’t configured yet. Consider reading these env vars optionally (e.g. via process.env and omitting undefined/empty values) so the config endpoint remains usable, and let the UI fall back as intended.

port: parseInt(getEnvVariable("STACK_EMAIL_PORT")) can yield NaN for invalid input, which would serialize to null in JSON and violate the expected number | undefined shape. It’d be safer to parse with Number.parseInt(..., 10) and explicitly validate Number.isFinite(port) (throwing a clear error if invalid) or omit the field when the env var is unset.

This new shared-email serialization behavior isn’t covered by the in-source vitest tests in this file. Adding a small test for renderedOrganizationConfigToProjectCrud that (1) includes STACK_EMAIL_HOST/PORT/SENDER when set, and (2) does not throw / omits fields when unset, would help prevent regressions.

Missing default values for getEnvVariable calls cause all project read endpoints to crash when shared email env vars are not configured