Configuration

Pia Server uses standard ASP.NET Core configuration: layered sources with environment variables overriding appsettings.json. Sensitive values (secrets, master key) must come from environment variables in production.

Source order (lowest precedence first)

1. appsettings.json
2. appsettings.{Environment}.json (e.g. appsettings.Production.json)
3. Environment variables
4. Command-line arguments

Sections

Database

Key	Env	Purpose
Database:Provider	Database__Provider	sqlite (default in dev) or postgresql
Database:ConnectionString	Database__ConnectionString	EF Core connection string for the chosen provider

PostgreSQL example:

Host=postgres;Database=pia;Username=pia;Password=<db-password>

Migrations are applied automatically on startup.

Jwt

Key	Env	Purpose
Jwt:SecretKey	JWT_SECRET_KEY	HMAC signing key, ≥ 32 chars
Jwt:Issuer	—	Default pia-server
Jwt:Audience	—	Default pia-client
Jwt:AccessTokenLifetime	—	Default 15 minutes
Jwt:RefreshTokenLifetime	—	Default 30 days

OAuth

{
  "OAuth": {
    "Google":    { "ClientId": "...", "ClientSecret": "..." },
    "Microsoft": { "ClientId": "...", "ClientSecret": "..." }
  }
}

In production, prefer environment variables: OAUTH_GOOGLE_CLIENT_ID / _SECRET, OAUTH_MICROSOFT_CLIENT_ID / _SECRET. See Microsoft Entra ID OAuth for the full Entra setup.

Encryption

Key	Env	Purpose
Encryption:MasterKey	ENCRYPTION_MASTER_KEY	64 hex chars (32 bytes) — used to derive per-user keys via HKDF

Generate once, back up forever

Generate with openssl rand -hex 32. Store offline (password manager, sealed envelope). If lost, encrypted columns are permanently unrecoverable — see Encryption at rest.

Ai

The default upstream AI provider, plus optional per-mode overrides selected by the X-Pia-Mode header.

Key	Env	Purpose
Ai:Provider	AI_PROVIDER	openai, azure, anthropic, mistral, …
Ai:ApiKey	AI_API_KEY	Upstream API key
Ai:Model	AI_MODEL	e.g. gpt-4o-mini
Ai:Endpoint	AI_ENDPOINT	Upstream base URL

Per-mode overrides:

Variable	Mode
AI_ASSISTANT_PROVIDER / _API_KEY / _MODEL / _ENDPOINT	Assistant
AI_RESEARCH_PROVIDER / _API_KEY / _MODEL / _ENDPOINT	Research
(default Ai:*)	Optimize

If a mode override isn’t set, the default provider is used.

License

Key	Purpose
License:Path	Path to the licence XML (default licence.xml next to the binary)

See Licensing for how licences are issued.

Environment variable summary

The keys most commonly set in production:

Required	Variable
✓	ASPNETCORE_ENVIRONMENT (Production)
✓	Database__Provider and Database__ConnectionString
✓	JWT_SECRET_KEY
✓	ENCRYPTION_MASTER_KEY
✓ (Postgres)	POSTGRES_PASSWORD (must match the password embedded in the connection string)
optional	AI_*
optional	OAUTH_*_CLIENT_ID / _SECRET

appsettings.json is committed; .env.prod is not (and should be chmod 600).

Restart vs hot-reload

Most operator-tunable settings are read via IOptionsMonitor<T> and re-bind on file change — for example, rate limit and quota policies on the /admin/limits page apply immediately.

These settings only take effect after a restart:

• Database:Provider and ConnectionString
• Jwt:SecretKey (changing it invalidates all outstanding tokens)
• Encryption:MasterKey (changing it strands all existing ciphertext — see Encryption at rest)

The admin UI surfaces a banner when a change requires a restart, with a Restart button that delegates to RestartCapability. In environments where a process restart isn’t safe (e.g. a single-replica deployment without a supervising orchestrator), the capability is no-op and the operator must restart the container manually.