Self-hosting

Configuration reference

Every environment variable a self-hosted Brunel reads, grouped by purpose, with what is required and how to generate secrets.

Generate secrets with openssl rand -base64 32 unless stated otherwise. Never commit real values.

Storage

Variable	Purpose
`DATABASE_URL`	PostgreSQL connection string. Without it (and without Blob), the in-memory store is used and nothing persists
`BLOB_READ_WRITE_TOKEN`	Vercel Blob store, as an alternative to PostgreSQL
`BRUNEL_DEMO_MODE`	`1`: in-memory store and demo banner

Variable	Purpose
`AUTH_URL`	Public address, e.g. `https://brunel.example.com`
`AUTH_SECRET`	Encrypts the session cookie
`AUTH_GITHUB_ID`, `AUTH_GITHUB_SECRET`	GitHub OAuth app for sign-in
`AUTH_ENCRYPTION_KEY`	32 bytes, base64: seals GitHub tokens and other secrets (AES-256-GCM)
`AUTH_ENCRYPTION_KEY_PREVIOUS`	The previous key during a rotation; stored secrets are re-sealed by the daily job
`BRUNEL_ALLOWED_LOGINS`	Private mode: only these GitHub logins can use the instance (comma-separated)
`BRUNEL_OWNER_LOGINS`	Operators with the unlimited owner plan (comma-separated)

All optional: without them the deterministic architect answers.

Variable	Purpose
`REASONING_BASE_URL`, `REASONING_API_KEY`, `REASONING_MODEL`	An OpenAI-compatible reasoning endpoint
`REASONING_MAX_TOKENS`	Output token cap per call
`REASONING_MONTHLY_TOKEN_BUDGET`	Monthly token cap for the whole instance; beyond it, the deterministic architect answers
`ANTHROPIC_API_KEY`, `ANTHROPIC_MODEL`	Alternative provider configuration
`BRUNEL_LLM_OFF`	`1`: kill switch, never call an AI provider
`BRUNEL_LLM_MOCK`	`fixtures`: replay recorded answers (tests, offline demos)

Variable	Purpose
`GITHUB_TOKEN`	Optional server token for a higher public GitHub API rate limit
`BRUNEL_GITHUB_APP_ID`, `BRUNEL_GITHUB_APP_SLUG`, `BRUNEL_GITHUB_APP_PRIVATE_KEY`, `BRUNEL_GITHUB_APP_WEBHOOK_SECRET`	The optional GitHub App (all four together)

Variable	Purpose
`STRIPE_SECRET_KEY`, `STRIPE_WEBHOOK_SECRET`	Stripe checkout and webhooks
`STRIPE_PRICE_PRO`, `STRIPE_PRICE_BUSINESS`	Stripe price ids of the paid plans

Variable	Purpose
`BRUNEL_CERT_SIGNING_KEY`	Ed25519 private key (PKCS#8 PEM or base64 DER): `openssl genpkey -algorithm ed25519`
`BRUNEL_CERT_SIGNING_KEY_PREVIOUS`	The previous key during a rotation, published for verification only

Variable	Purpose
`CRON_SECRET`	Bearer secret of the daily and monthly jobs
`UPSTASH_REDIS_REST_URL`, `UPSTASH_REDIS_REST_TOKEN`	Shared rate limits across instances
`BRUNEL_GUEST_ANALYSES_PER_HOUR`	Guest analyses per address per hour (default 5)
`BRUNEL_OUTBOUND_ALLOWLIST`	Restrict user-configured destinations (webhooks, SSO issuer, own AI endpoint) to these hosts; `.example.com` covers subdomains
`BRUNEL_SECURITY_ALERT_WEBHOOK`	Slack-compatible webhook for critical security events

Variable	Purpose
`BRUNEL_SUBDOMAINS`	`1`: console on `console.`, `enterprise.` and `portal.`
`BRUNEL_API_SUBDOMAIN`	`1`: REST API and MCP on `api.`
`BRUNEL_CDN`	`1` at build time: static files from `cdn.`
`BRUNEL_DOCS_SUBDOMAIN`	`1`: this documentation on `docs.`