feat(react-core): add useCapabilities hook

Author: AlemTuzlak

packages/react-core/src/v2/hooks/index.ts

@@ -8,6 +8,7 @@ export { useRenderTool } from "./use-render-tool";
 export { useDefaultRenderTool } from "./use-default-render-tool";
 export { useHumanInTheLoop } from "./use-human-in-the-loop";
 export { useAgent, UseAgentUpdate } from "./use-agent";
+export { useCapabilities } from "./use-capabilities";
 export { useAgentContext } from "./use-agent-context";
 export type { AgentContextInput, JsonSerializable } from "./use-agent-context";
 export { useSuggestions } from "./use-suggestions";

packages/react-core/src/v2/hooks/use-capabilities.tsx

@@ -0,0 +1,22 @@
+import type { AgentCapabilities } from "@ag-ui/core";
+import { ProxiedCopilotRuntimeAgent } from "@copilotkit/core";
+import { useAgent } from "./use-agent";
+
+/**
+ * Returns the capabilities declared by the given agent (or the default agent).
+ * Capabilities are fetched from the runtime at connection time and are
+ * available synchronously — no loading state required.
+ *
+ * @param agentId - Optional agent ID. If omitted, uses the default agent.
+ * @returns The agent's capabilities, or `undefined` if the agent hasn't
+ *          connected yet or doesn't declare capabilities.
+ */
+export function useCapabilities(agentId?: string): AgentCapabilities | undefined {
+  const { agent } = useAgent({ agentId });
+
+  if (agent instanceof ProxiedCopilotRuntimeAgent) {
+    return agent.capabilities;
+  }
+
+  return undefined;
+}