Backend Integration

This page uses your demo repos directly:

• backend reference: convengine-demo
• UI reference: zapper-ui

What each demo proves

• convengine-demo: Spring Boot consumer setup, transport mode config, step hooks, LLM wiring.
• zapper-ui: conversation client, SSE subscription, audit timeline UI.

1

Enable ConvEngine in backend

Add @EnableConvEngine and provide required beans.

2

Configure transport mode

Use profile yaml (sse, stomp, both) to switch runtime behavior.

3

Connect frontend

Frontend posts to message endpoint and listens to SSE/STOMP for audit updates.

convengine-demo: Core app bootstrap

ConvengineDemoApplication.java

package: com.github.salilvnairfile: convengine-demo/src/main/java/com/github/salilvnair/ConvengineDemoApplication.java

JAVA

@SpringBootApplication
@ComponentScan(basePackages = {"com.github.salilvnair.convengdemo"})
@EntityScan(basePackages = {"com.github.salilvnair.convengdemo.entity"})
@EnableJpaRepositories(basePackages = {"com.github.salilvnair.convengdemo.repo"})
public class ConvengineDemoApplication {
  public static void main(String[] args) {
    SpringApplication.run(ConvengineDemoApplication.class, args);
  }
}

ConvEngineConfig.java

package: com.github.salilvnair.convengdemo.configfile: convengine-demo/src/main/java/com/github/salilvnair/convengdemo/config/ConvEngineConfig.java

JAVA

@Configuration
@EnableConvEngine
@EnableConvEngineAsyncAuditDispatch // optional
@EnableConvEngineStompBrokerRelay   // optional
@EnableCcfCore
public class ConvEngineConfig {
  @Bean
  public RestWebServiceFacade restWebServiceFacade() {
    return new RestWebServiceFacade();
  }

  @Bean
  public ObjectMapper objectMapper() {
    return new ObjectMapper();
  }
}

convengine-demo: Runtime config

application.yml

file: convengine-demo/src/main/resources/application.yml

YAML

application-sse.yml

file: convengine-demo/src/main/resources/application-sse.yml

YAML

convengine:
  demo:
    stream-mode: SSE
  transport:
    sse:
      enabled: true
    stomp:
      enabled: false

application-stomp.yml

file: convengine-demo/src/main/resources/application-stomp.yml

YAML

convengine:
  demo:
    stream-mode: STOMP
  transport:
  sse:
    enabled: false
  stomp:
    enabled: true

application-both.yml

file: convengine-demo/src/main/resources/application-both.yml

YAML

convengine:
  demo:
    stream-mode: BOTH
  transport:
    sse:
      enabled: true
    stomp:
      enabled: true

Relay + async audit rollout

Keep broker.mode: SIMPLE and audit.dispatch.async-enabled: false for baseline. Enable relay and async in non-prod first, then tune queue-capacity, rejection-policy, and rate-limit using audit volume.

convengine-demo: Transport + Hook diagnostics

DemoTransportProperties.java

file: convengine-demo/src/main/java/com/github/salilvnair/convengdemo/config/DemoTransportProperties.java

JAVA

@Component
@ConfigurationProperties(prefix = "convengine.demo")
public class DemoTransportProperties {
  private StreamMode streamMode = StreamMode.SSE;
  private StepHook stepHook = new StepHook();

  public enum StreamMode { SSE, STOMP, BOTH }

  public static class StepHook {
    private boolean enabled = true;
  }
}

ConvEngineTransportStartupLogger.java

file: convengine-demo/src/main/java/com/github/salilvnair/convengdemo/config/ConvEngineTransportStartupLogger.java

JAVA

@Component
@RequiredArgsConstructor
public class ConvEngineTransportStartupLogger {
  private final DemoTransportProperties demoTransportProperties;
  private final ConvEngineTransportConfig transportConfig;
  private final Environment environment;

  @EventListener(ApplicationReadyEvent.class)
  public void logTransportConfiguration() {
    boolean sseEnabled = transportConfig.getSse().isEnabled();
    boolean stompEnabled = transportConfig.getStomp().isEnabled();
    // validates mode and prints endpoints
  }
}

DemoEngineStepHook.java

file: convengine-demo/src/main/java/com/github/salilvnair/convengdemo/config/DemoEngineStepHook.java

JAVA

@Component
@RequiredArgsConstructor
public class DemoEngineStepHook implements EngineStepHook {
  private static final Set<EngineStep.Name> TRACKED_STEPS = Set.of(
  EngineStep.Name.IntentResolutionStep,
  EngineStep.Name.SchemaExtractionStep,
  EngineStep.Name.RulesStep,
  EngineStep.Name.ResponseResolutionStep
  );

  @Override
  public boolean supports(EngineStep.Name stepName, EngineSession session) {
    return demoTransportProperties.getStepHook().isEnabled() && TRACKED_STEPS.contains(stepName);
  }

  @Override
  public void beforeStep(EngineStep.Name stepName, EngineSession session) { /* logs */ }
  @Override
  public void afterStep(EngineStep.Name stepName, EngineSession session, StepResult result) { /* logs */ }
  @Override
  public void onStepError(EngineStep.Name stepName, EngineSession session, Throwable error) { /* logs */ }
}

zapper-ui: How frontend consumes backend

convengine.api.js (zapper-ui)

file: zapper-ui/src/api/convengine.api.js

JS

const API_BASE = "http://localhost:8080/api/v1/conversation";

export async function sendMessage(conversationId, message, inputParams = {}, reset = false) { /* ... */ }
export async function fetchAudits(conversationId) { /* ... */ }
export function subscribeConversationSse(conversationId, handlers = {}) { /* ... */ }
// STOMP scaffold commented for optional enablement

App.jsx (zapper-ui)

file: zapper-ui/src/App.jsx

JSX

useEffect(() => {
  const stream = subscribeConversationSse(conversationId, {
    onConnected: () => setAuditVersion(v => v + 1),
    onEvent: () => setAuditVersion(v => v + 1),
  });
  return () => stream.close();
}, [conversationId]);

ChatPanel.jsx (zapper-ui)

file: zapper-ui/src/components/ChatPanel.jsx

JSX

const res = await sendMessage(conversationId, userText);
setMessages(m => [...m, { role: "assistant", text: assistantText }]);
// Typing indicator shown while request is in-flight

Backend + UI runbook

1. Start backend (convengine-demo) with profile sse, stomp, or both.
2. Start zapper-ui and point API base to backend URL.
3. Send message, verify live timeline from stream + detailed payloads from audit API.

Run commands

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