fix(registry): add team index for dapr-agents compatibility

The registerAgent method was only saving per-agent metadata keys but
not updating the team index at agents:{team}:_index. This index is
how dapr-agents discovers peers in multi-agent workflows.

Now follows the same two-step registration protocol as dapr-agents:
1. Save per-agent metadata key (agents:{team}:{name})
2. Update team index (agents:{team}:_index) with agent name list

Also adds partitionKey to state metadata for partitioned stores.

Signed-off-by: Javier Aliaga <javier@diagrid.io>

Author: javier-aliaga

quarkus/quarkus-agentic-dapr-agents-registry/src/main/java/io/quarkiverse/dapr/agents/registry/service/AgentRegistry.java

@@ -14,6 +14,9 @@
 package io.quarkiverse.dapr.agents.registry.service;
 
 import io.dapr.client.DaprClient;
+import io.dapr.client.domain.GetStateRequest;
+import io.dapr.client.domain.State;
+import io.dapr.utils.TypeRef;
 import io.quarkiverse.dapr.agents.registry.model.AgentMetadata;
 import io.quarkiverse.dapr.agents.registry.model.AgentMetadataSchema;
 import io.quarkus.runtime.StartupEvent;
@@ -31,6 +34,7 @@
 import java.lang.reflect.Type;
 import java.time.Instant;
 import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
@@ -254,14 +258,57 @@ private static <T> T invokeMethod(Annotation ann, String methodName, Class<T> re
   }
 
   /**
-   * Registers an agent schema in the Dapr state store.
+   * Registers an agent schema in the Dapr state store and updates the team index.
+   *
+   * <p>Two-step operation matching the Python dapr-agents registration protocol:
+   * <ol>
+   *   <li>Save per-agent metadata key ({@code agents:{team}:{name}})</li>
+   *   <li>Update the team index key ({@code agents:{team}:_index}) adding this agent name</li>
+   * </ol>
+   *
+   * <p>The team index is how dapr-agents discovers peers in multi-agent workflows.
    *
    * @param schema the agent metadata schema to register
    */
+  @SuppressWarnings("unchecked")
   public void registerAgent(AgentMetadataSchema schema) {
-    String key = "agents:" + team + ":" + schema.getName();
-    LOG.infof("Registering agent: %s", key);
-    client.saveState(statestore, key, null, schema,
-        Map.of("contentType", "application/json"), null).block();
+    String registryPrefix = "agents:" + team;
+    Map<String, String> meta = Map.of(
+        "contentType", "application/json",
+        "partitionKey", registryPrefix);
+
+    // Step 1: Save per-agent metadata key
+    String agentKey = registryPrefix + ":" + schema.getName();
+    LOG.infof("Registering agent: %s", agentKey);
+    client.saveState(statestore, agentKey, null, schema, meta, null).block();
+
+    // Step 2: Update team index (adds agent name to the list)
+    String indexKey = registryPrefix + ":_index";
+    GetStateRequest getRequest = new GetStateRequest(statestore, indexKey)
+        .setMetadata(meta);
+    State<Map> indexState = client.getState(getRequest, TypeRef.get(Map.class)).block();
+
+    Map<String, Object> indexData;
+    if (indexState != null && indexState.getValue() != null) {
+      indexData = new HashMap<>((Map<String, Object>) indexState.getValue());
+    } else {
+      indexData = new HashMap<>();
+    }
+
+    List<String> agentsList;
+    Object existing = indexData.get("agents");
+    if (existing instanceof List) {
+      agentsList = new ArrayList<>((List<String>) existing);
+    } else {
+      agentsList = new ArrayList<>();
+    }
+
+    if (!agentsList.contains(schema.getName())) {
+      agentsList.add(schema.getName());
+      indexData.put("agents", agentsList);
+      String etag = (indexState != null) ? indexState.getEtag() : null;
+      client.saveState(statestore, indexKey, etag, indexData, meta, null).block();
+      LOG.infof("Updated team index '%s' with agent '%s'", indexKey, schema.getName());
+    }
   }
 }

quarkus/quarkus-agentic-dapr-agents-registry/src/test/java/io/quarkiverse/dapr/agents/registry/service/AgentRegistryDevServicesTest.java

@@ -7,7 +7,11 @@
 import jakarta.inject.Inject;
 import org.junit.jupiter.api.Test;
 
+import io.dapr.utils.TypeRef;
+
 import java.time.Duration;
+import java.util.List;
+import java.util.Map;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.awaitility.Awaitility.await;
@@ -117,4 +121,23 @@ void allAutoDiscoveredAgentsShouldHaveConsistentMetadata() {
             }
         });
     }
+
+    @SuppressWarnings("unchecked")
+    @Test
+    void teamIndexShouldContainAllRegisteredAgents() {
+        String[] expectedAgents = {"test-agent-with-prompt", "test-agent-simple", "TestAgent.defaultNameAgent"};
+
+        await().atMost(Duration.ofSeconds(30)).untilAsserted(() -> {
+            State<Map> indexState = daprClient.getState(
+                    STATE_STORE, "agents:" + TEAM + ":_index", TypeRef.get(Map.class)).block();
+            assertThat(indexState).isNotNull();
+            assertThat(indexState.getValue()).isNotNull();
+
+            Map<String, Object> indexData = (Map<String, Object>) indexState.getValue();
+            assertThat(indexData).containsKey("agents");
+
+            List<String> agentsList = (List<String>) indexData.get("agents");
+            assertThat(agentsList).containsExactlyInAnyOrder(expectedAgents);
+        });
+    }
 }