Configuration

Client Options

Options passed to RunApplication:

c.RunApplication(ctx, myApp,
    client.WithSecretKey("my-secret"),    // Auth token for hugr ↔ app communication
    client.WithStartupTimeout(500*time.Millisecond), // Delay before registering (default: 250ms)
)

Client Constructor Options

c := client.NewClient(url,
    client.WithTimeout(5*time.Minute),        // HTTP timeout (default: 5min)
    client.WithApiKey("key"),                  // API key for hugr auth
    client.WithUserRole("admin"),              // User role header
)

AppInfo Fields

Field	Required	Description
Name	Yes	Unique identifier. Becomes GraphQL module name
Description	No	Human-readable description
Version	Yes	Semantic version. Changes trigger migrations
URI	Yes	gRPC endpoint: grpc://host:port or grpc+tls://host:port
DefaultSchema	No	Schema name for top-level module (default: "default")

Environment Variables (App)

Variable	Description	Example
HUGR_URL	Hugr IPC endpoint	http://localhost:15100/ipc
APP_SECRET	Secret key for authentication	my-secret-key
APP_PORT	gRPC listen port	50051
APP_HOST	Hostname for URI registration	my-app
APP_VERSION	App version (if dynamic)	2.0.0
PG_DSN	PostgreSQL connection string	postgres://user:pass@host/db

Environment Variables (Hugr Server)

Variable	Description	Default
HUGR_APP_HEARTBEAT_INTERVAL	Time between health checks	30s
HUGR_APP_HEARTBEAT_TIMEOUT	Timeout per health check	10s
HUGR_APP_HEARTBEAT_RETRIES	Failures before suspend	3

DSN Path Format

The app's connection path stored in hugr:

grpc://host:port?secret_key=TOKEN&version=1.0.0

Parameter	Description
secret_key	Maps to Airport SECRET auth_token
version	App version for migration tracking

Reserved Names

Cannot be used as app names:

Name	Reason
function	GraphQL Function root type
mutation_function	GraphQL MutationFunction root type
core	System functions module
_system	Internal system use
Names starting with _	Reserved for internal types

DataSourceInfo.Path

Connection strings support environment variable substitution:

postgres://[$DB_USER]:[$DB_PASS]@[$DB_HOST]:5432/mydb

Variables in [$VAR] format are resolved from the hugr server's environment at provisioning time.