SDK API Reference

Core client and hook interfaces used by React and React Native SDK integrations.

Client API

`initialize()`
`isReady()`
`close()`
`variation(flagKey, defaultValue, context?)`
`evaluate(flagKey, defaultValue, context?)`
`on("ready" | "update" | "error", handler)`

Provider API

`FlagProvider` is key-first. `clientKey` is required, while all network/runtime tuning is optional.

`clientKey: string` (required)
`options?: BetsyClientOptions`
`client?: BetsyClient`
`singleton?: boolean` (default: `true`)
`singletonKey?: string` (default: `clientKey`)

Provider options

Option	Default	Description
baseUrl	Managed endpoint	Advanced override for self-hosted/proxy relay.
refreshIntervalMs	30000	Polling interval in milliseconds.
startWaitMs	1500	Initial wait before degraded-ready mode.
bootstrap	undefined	Initial snapshot for fast startup.
logger	noop	Custom logger hooks.
transport	HTTP transport	Custom transport implementation.

Hook API

`useFeatureFlag(flagKey, defaultValue, context?)`
`useFlagsReady()`
`useAllFlags(context?)`
`useFlagClient()`
`useFlagIdentity()` returns `identify`, `clearIdentity`, `getIdentity`

Evaluation context

Context keys should be stable and attributes should be normalized to avoid unintended targeting drift.

TSTypeScript

type EvaluationContext = {
  key?: string;
  anonymous?: boolean;
  attributes?: Record<string, string | number | boolean | null>;
};

type EvaluationReason =
  | "OFF"
  | "TARGET_MATCH"
  | "RULE_MATCH"
  | "FALLTHROUGH"
  | "DEFAULT"
  | "ERROR";

Evaluation result semantics

Result payloads include a reason code and variation ID where available, enabling debuggability and analytics.