Add docs

Author: mme

docs/sdk/js/client/abstract-agent.mdx

@@ -111,13 +111,42 @@ Creates a deep copy of the agent instance.
 clone(): AbstractAgent
 ```
 
+### connectAgent()
+
+Establishes a persistent connection with an agent that implements the
+`connect()` method.
+
+```typescript
+connectAgent(parameters?: RunAgentParameters, subscriber?: AgentSubscriber): Promise<RunAgentResult>
+```
+
+Similar to `runAgent()` but uses the `connect()` method internally. The agent
+must implement `connect()` or this functionality must be provided by a framework
+like [CopilotKit](https://copilotkit.ai).
+
+## Observable Properties
+
+### events$
+
+An observable stream of all events emitted during agent execution.
+
+```typescript
+events$: Observable<BaseEvent>
+```
+
+This property provides direct access to the agent's event stream. Events are
+stored using a `ReplaySubject`, allowing late subscribers will receive all
+historical events.
+
 ## Properties
 
 - `agentId`: Unique identifier for the agent instance
 - `description`: Human-readable description
 - `threadId`: Conversation thread identifier
 - `messages`: Array of conversation messages
 - `state`: Current agent state object
+- `events$`: Observable stream of all `BaseEvent` objects emitted during agent
+  execution (replayed for late subscribers)
 
 ## Protected Methods
 
@@ -131,6 +160,17 @@ Executes the agent and returns an observable event stream.
 protected abstract run(input: RunAgentInput): RunAgent
 ```
 
+### connect()
+
+Establishes a persistent connection and returns an observable event stream.
+
+```typescript
+protected connect(input: RunAgentInput): RunAgent
+```
+
+Override this method to implement persistent connections. Default implementation
+throws `ConnectNotImplementedError`.
+
 ### apply()
 
 Processes events from the run and updates the agent state.