Runtime Env Whitelisting

BuildPad DaaS exposes runtime environment values to automation code through a strict allowlist model.

This feature is environment-variable only:

No database configuration
No settings UI
Controlled entirely by deployment env vars

Configuration Variables

Variable	Scope	Format
`RUNTIME_ENV_WHITELIST_GLOBAL`	Shared across all runtimes	Comma-separated keys
`RUNTIME_ENV_WHITELIST_EXTENSION`	Runtime extensions only	Comma-separated keys
`RUNTIME_ENV_WHITELIST_CRON`	Cron jobs only	Comma-separated keys
`RUNTIME_ENV_WHITELIST_CUSTOM_SERVICE`	Custom services only	Comma-separated keys

Example:


RUNTIME_ENV_WHITELIST_GLOBAL=API_BASE_URL,APP_REGION
RUNTIME_ENV_WHITELIST_EXTENSION=WEBHOOK_SIGNING_SALT
RUNTIME_ENV_WHITELIST_CRON=DIGEST_WINDOW_MINUTES
RUNTIME_ENV_WHITELIST_CUSTOM_SERVICE=SLACK_TOKEN

Prefix-Based Exposure

You can expose values by prefixing real runtime env vars:

Prefix	Scope
`RUNTIME_PUBLIC_`	Shared across all runtimes
`EXTENSION_PUBLIC_`	Runtime extensions only
`CRON_PUBLIC_`	Cron jobs only
`CUSTOM_SERVICE_PUBLIC_`	Custom services only

Example:


RUNTIME_PUBLIC_SITE_URL=https://daas.example.com
CRON_PUBLIC_BATCH_SIZE=500

In runtime code these become:

SITE_URL
BATCH_SIZE (cron only)

How To Use In Code

Runtime extension hook

Extension code receives services as a top-level variable (same object available as context.services):


export async function handler(payload, meta, context, services) {
  const apiBase = services.env.API_BASE_URL;
 
  // Equivalently:
  // const apiBase = context.services.env.API_BASE_URL;
 
  // context.env does NOT exist in extensions
  // ...
  return payload;
}

Cron job

Cron code receives context (job metadata: jobId, jobName, runId, etc.) and services. Use services.env:


async function run(context, services) {
  const batch = Number(services.env.BATCH_SIZE || '100');
  // context.env does NOT exist in cron jobs
  // ...
}

Custom service

Custom service code receives a single context argument. Use context.env:


export async function notify(channel, message) {
  const token = context.env.SLACK_TOKEN;
 
  // context.services.env also works
  // const token = context.services.env.SLACK_TOKEN;
 
  // There is no bare `services` variable in custom service code
  // ...
}

Key Format Rules

Key names must match [A-Z][A-Z0-9_]* (uppercase, digits, underscores).
Invalid names are silently ignored.
Duplicate entries are deduplicated.

Docker Example


environment:
  - RUNTIME_ENV_WHITELIST_GLOBAL=API_BASE_URL,APP_REGION
  - RUNTIME_ENV_WHITELIST_CUSTOM_SERVICE=SLACK_TOKEN
  - RUNTIME_PUBLIC_SITE_URL=https://daas.example.com
  - CUSTOM_SERVICE_PUBLIC_EMAIL_PROVIDER=ses

See Environment Variables for the full configuration reference.