# DaprEventBridge API

Event bridge that connects PURISTA services to the local Dapr sidecar.

---
Canonical: /handbook/api/classes/_purista_dapr-sdk.DaprEventBridge/
Source: dapr-sdk/src/DaprEventBridge/DaprEventBridge.impl.ts
Format: Markdown for agents
---

Event bridge that connects PURISTA services to the local Dapr sidecar.

Package: `@purista/dapr-sdk`

## Signature

```typescript
class DaprEventBridge
```

## Examples

```typescript
import { DaprConfigStore, DaprEventBridge, DaprSecretStore, DaprStateStore } from '@purista/dapr-sdk'

const eventBridge = new DaprEventBridge({
   serve,
 })

// start the services first ...

await eventBridge.start()
```

## Notes

### see

[Hono website](https://hono.dev)

## Members

### Constructors

- `new constructor(config: { apiPrefix: string; clientConfig: DaprClientConfig; commandPayloadAsCloudEvent: boolean; defaultCommandTimeout: number; enableHttpCompression: boolean; enableRestApiExpose: boolean; ... })` — Creates a Dapr-backed event bridge.

### Properties

- `app: Hono` — Hono application that hosts health, command, subscription and REST projection routes.
- `capabilities: EventBridgeCapabilities` — Runtime capability matrix used for strict startup validation.
- `client: HttpEventBridgeClient` — HTTP client adapter used for outgoing command invocations, event publication and health checks.
- `config: Complete<EventBridgeConfig<ConfigType>>`
- `defaultCommandTimeout: number` — The default time until when a command invocation automatically returns a time out error
- `inFlightExecutions: InFlightExecutionTracker`
- `instanceId: string` — Stable runtime instance id used to distinguish bridge processes.
- `isShuttingDown: boolean` — Indicates that shutdown has started and new HTTP requests should be rejected.
- `isStarted: boolean` — Indicates that the bridge has registered routes and started its HTTP server.
- `logger: Logger`
- `metricsRecorder: PuristaMetricsRecorder`
- `name: string` — Human-readable bridge name used in logs, traces, and metrics.
- `server: Server<typeof IncomingMessage, typeof ServerResponse> | Http2Server<typeof IncomingMessage, typeof ServerResponse, typeof Http2ServerRequest, typeof Http2ServerResponse> | Http2SecureServer<typeof IncomingMessage, typeof ServerResponse, typeof Http2ServerRequest, typeof Http2ServerResponse> | undefined` — Runtime server returned by the configured Hono `serve` adapter.
- `traceProvider: NodeTracerProvider`

### Methods

- `destroy(): Promise<void>` — Shut down event bridge as gracefully as possible
- `emitMessage<T>(message: Omit<EBMessage, "id" | "timestamp" | "correlationId">): Promise<Readonly<EBMessage>>` — Publishes an event message through the configured HTTP client.
- `getInFlightExecutionCount(): number` — Number of currently running handlers across all work kinds.
- `getInFlightExecutionCounts(): InFlightExecutionCounts` — Number of currently running handlers grouped by work kind.
- `getPausedSubscriptionConsumers(): PausedSubscriptionConsumersByRegistrationKey` — Returns paused subscription consumer states keyed by adapter registration key.
- `getTracer(): Tracer` — Returns open telemetry tracer of this service
- `invoke<T>(input: Omit<Command, "id" | "messageType" | "timestamp" | "correlationId">, ttl?: number): Promise<T>` — Invokes a PURISTA command over HTTP and returns the command payload.
- `isHealthy(): Promise<boolean>` — Reports whether the bridge is started and its sidecar/platform client is reachable.
- `isReady(): Promise<boolean>` — Reports whether the bridge can accept new HTTP requests.
- `openStream<Chunk, Final>(_input: Omit<StreamOpenRequest, "id" | "messageType" | "timestamp" | "correlationId">, _ttl?: number): Promise<StreamHandle<Chunk, Final>>` — Open a stream invocation.
- `registerCommand(address: EBMessageAddress, cb: (message: { contentEncoding: string; contentType: string; correlationId: string; eventName: string; id: string; messageType: Command; ... }) => Promise<Readonly<Omit<unknown, unknown>> | Readonly<Omit<unknown, unknown>>>, metadata: { expose: { contentEncodingRequest: string; contentEncodingResponse: string; contentTypeRequest: string; contentTypeResponse: string; deprecated: boolean; inputPayload: SchemaObject; ... } & { http: { method: unknown | unknown | unknown | unknown | unknown; mode: unknown | unknown; openApi: { additionalStatusCodes: unknown; description: unknown; isSecure: unknown; operationId: unknown; query: unknown; summary: unknown; ... }; path: string; stream: { documentationUrl: unknown; mode: unknown; protocol: unknown } } } }, eventBridgeConfig: DefinitionEventBridgeConfig): Promise<string>` — Registers the internal command endpoint, plus an optional REST projection.
- `registerStream(_address: EBMessageAddress, _cb: (message: StreamMessage) => Promise<void>, _metadata: StreamDefinitionMetadataBase, _eventBridgeConfig: DefinitionEventBridgeConfig): Promise<string>` — Register a service stream handler for a service target.
- `registerSubscription(subscription: Subscription, cb: (message: EBMessage) => Promise<Omit<{ contentEncoding: unknown; contentType: unknown; correlationId: unknown; eventName: unknown; id: unknown; messageType: unknown; ... }, unknown | unknown> | undefined>): Promise<string>` — Registers a PURISTA subscription and exposes it to Dapr Pub/Sub discovery.
- `resumeSubscriptionConsumer(_registrationKey: string): Promise<void>` — Resumes a paused subscription consumer by registration key.
- `runInFlight<T>(fn: () => Promise<T>, kind?: "command" | "subscription" | "stream" | "generic"): Promise<T>`
- `start(): Promise<void>` — Registers Dapr discovery routes and starts the HTTP event bridge.
- `startActiveSpan<F>(name: string, opts: SpanOptions, context: Context | undefined, fn: (span: Span) => Promise<F>): Promise<F>` — Start a child span for opentelemetry tracking
- `unregisterCommand(address: EBMessageAddress): Promise<void>` — Placeholder for transport-specific command unregistration.
- `unregisterStream(_address: EBMessageAddress): Promise<void>` — Unregister a service stream
- `unregisterSubscription(address: EBMessageAddress): Promise<void>` — Placeholder for transport-specific subscription unregistration.
- `waitForInFlightDrain(timeoutMs?: number): Promise<boolean>`
- `wrapInSpan<F>(name: string, opts: SpanOptions, fn: (span: Span) => Promise<F>, context?: Context): Promise<F>` — Start span for opentelemetry tracking on same level.
The created span will not become the "active" span within opentelemetry!