diff --git a/package-lock.json b/package-lock.json
index 2a241f1..2ca2d00 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -8,7 +8,7 @@
       "name": "adcp-registry",
       "version": "0.1.0",
       "dependencies": {
-        "@adcp/client": "^2.3.2",
+        "@adcp/client": "^2.5.5",
         "@modelcontextprotocol/sdk": "^1.0.4",
         "express": "^4.18.2"
       },
@@ -45,9 +45,9 @@
       }
     },
     "node_modules/@adcp/client": {
-      "version": "2.4.1",
-      "resolved": "https://registry.npmjs.org/@adcp/client/-/client-2.4.1.tgz",
-      "integrity": "sha512-xZHXLW0tMBlWlnCEcsisWKuvJGwbRhYRGRoYCHbklmBscSEG2FOz7vpTItxKhtgKi9hdmmbjIdh+00r/Pomv0A==",
+      "version": "2.5.5",
+      "resolved": "https://registry.npmjs.org/@adcp/client/-/client-2.5.5.tgz",
+      "integrity": "sha512-ADHD0c9j2EMmvjbrEsUMIlVXH8aF27/xrTCmmckqktULW4vIQpqHimrQjDaqBIYC+Cmn30AnCCuuNp+L01ZQ6g==",
       "license": "MIT",
       "dependencies": {
         "better-sqlite3": "^12.4.1",
diff --git a/package.json b/package.json
index b7de1a3..14b2547 100644
--- a/package.json
+++ b/package.json
@@ -16,7 +16,7 @@
     "test:coverage": "c8 vitest run"
   },
   "dependencies": {
-    "@adcp/client": "^2.3.2",
+    "@adcp/client": "^2.5.5",
     "@modelcontextprotocol/sdk": "^1.0.4",
     "express": "^4.18.2"
   },
diff --git a/server/src/properties.ts b/server/src/properties.ts
index 6a5973e..3a5d68c 100644
--- a/server/src/properties.ts
+++ b/server/src/properties.ts
@@ -1,4 +1,4 @@
-import { createMCPClient, createA2AClient } from "@adcp/client";
+import { AgentClient } from "@adcp/client";
 import type { Agent } from "./types.js";
 
 export interface PropertyInfo {
@@ -28,25 +28,24 @@ export class PropertiesService {
       return cached;
     }
 
-    const protocol = agent.protocol || "mcp";
     let properties: PropertyInfo[] = [];
     let error: string | undefined;
 
     try {
-      if (protocol === "a2a") {
-        const client = createA2AClient(agent.url);
-        const response = await client.callTool("list_authorized_properties", {});
+      // Create agent client with the new API
+      const agentConfig = {
+        id: agent.name,
+        name: agent.name,
+        agent_uri: agent.url,
+        protocol: (agent.protocol || "mcp") as "mcp" | "a2a",
+      };
+      const client = new AgentClient(agentConfig);
+      const result = await client.executeTask("list_authorized_properties", {});
 
-        // Extract properties from A2A response
-        const artifact = response?.result?.artifacts?.[0];
-        if (artifact?.parts?.[0]?.data?.properties) {
-          properties = artifact.parts[0].data.properties;
-        }
-      } else {
-        const client = createMCPClient(agent.url);
-        const response = await client.callTool("list_authorized_properties", {});
+      if ((result.status === "completed" || result.success) && result.data) {
+        const response = result.data;
 
-        // MCP response can have different formats:
+        // Handle different response formats:
         // 1. Array of properties directly
         if (Array.isArray(response)) {
           properties = response;
@@ -66,6 +65,8 @@ export class PropertiesService {
             description: response.portfolio_description,
           }));
         }
+      } else if (result.status === "error" || !result.success) {
+        error = `Agent returned error: ${result.error || "Unknown error"}`;
       }
     } catch (toolError: any) {
       error = `Agent does not support list_authorized_properties: ${toolError.message}`;
@@ -73,7 +74,7 @@ export class PropertiesService {
 
     const profile: AgentPropertiesProfile = {
       agent_url: agent.url,
-      protocol,
+      protocol: agent.protocol || "mcp",
       properties,
       last_fetched: new Date().toISOString(),
       error,