Go Configuration

Client Options

The Go SDK uses functional options for configuration:

client := flags.NewClient(
    flags.WithAuth(flags.Auth{
        ProjectID:     "your-project-id",
        AgentID:       "your-agent-id",
        EnvironmentID: "your-environment-id",
    }),
    flags.WithBaseURL("https://custom-api.flags.gg"),
    flags.WithMaxRetries(5),
    flags.WithMemory(),
)

Options Reference

Option	Default	Description
WithAuth(Auth)	—	Required. Set project, agent, and environment IDs
WithBaseURL(string)	https://api.flags.gg	Custom API endpoint
WithMaxRetries(int)	3	Max retry attempts on failure
WithMemory()	SQLite	Use in-memory cache instead of SQLite
SetFileName(*string)	/tmp/flags.db	Custom SQLite database path
WithBackgroundRefresh()	off	Refresh flags asynchronously in a goroutine instead of inline on each lookup
WithErrorHandler(func(error))	—	Callback invoked whenever a refresh or fetch error occurs

Client Methods

Method	Description
Is(name string) *Flag	Get a flag wrapper, then call .Enabled()
List() ([]FeatureFlag, error)	Return all cached flags
GetMultiple(names ...string) map[string]bool	Look up several flags in one call
AllEnabled(names ...string) bool	True if every named flag is enabled
AnyEnabled(names ...string) bool	True if any named flag is enabled
Close()	Stop the background refresh goroutine and wait for it to exit

Thread Safety

The client is safe for concurrent use. All operations use sync.RWMutex internally.

Error Handling

The client handles errors gracefully:

• API failures fall back to cached values
• Unknown flags return false (disabled)
• The circuit breaker prevents cascading failures after 3 consecutive errors
• Errors during background refresh are reported via WithErrorHandler if configured