docs: Add multi-agent streaming docs (#284)

Author: mkmeral

docs/user-guide/concepts/multi-agent/graph.md

@@ -291,6 +291,51 @@ async def run_graph():
 result = asyncio.run(run_graph())
 ```
 
+## Streaming Events
+
+Graphs support real-time streaming of events during execution using [`stream_async`](../../../api-reference/multiagent.md#strands.multiagent.graph.Graph.stream_async). This provides visibility into node execution, parallel processing, and nested multi-agent systems.
+
+```python
+from strands import Agent
+from strands.multiagent import GraphBuilder
+
+# Create specialized agents
+researcher = Agent(name="researcher", system_prompt="You are a research specialist...")
+analyst = Agent(name="analyst", system_prompt="You are an analysis specialist...")
+
+# Build the graph
+builder = GraphBuilder()
+builder.add_node(researcher, "research")
+builder.add_node(analyst, "analysis")
+builder.add_edge("research", "analysis")
+builder.set_entry_point("research")
+graph = builder.build()
+
+# Stream events during execution
+async for event in graph.stream_async("Research and analyze market trends"):
+    # Track node execution
+    if event.get("type") == "multiagent_node_start":
+        print(f"🔄 Node {event['node_id']} starting")
+    
+    # Monitor agent events within nodes
+    elif event.get("type") == "multiagent_node_stream":
+        inner_event = event["event"]
+        if "data" in inner_event:
+            print(inner_event["data"], end="")
+    
+    # Track node completion
+    elif event.get("type") == "multiagent_node_stop":
+        node_result = event["node_result"]
+        print(f"\n✅ Node {event['node_id']} completed in {node_result.execution_time}ms")
+    
+    # Get final result
+    elif event.get("type") == "multiagent_result":
+        result = event["result"]
+        print(f"Graph completed: {result.status}")
+```
+
+See the [streaming overview](../streaming/overview.md#multi-agent-events) for details on all multi-agent event types.
+
 ## Graph Results
 
 When a Graph completes execution, it returns a [`GraphResult`](../../../api-reference/multiagent.md#strands.multiagent.graph.GraphResult) object with detailed information:

docs/user-guide/concepts/multi-agent/swarm.md

@@ -186,6 +186,47 @@ async def run_swarm():
 result = asyncio.run(run_swarm())
 ```
 
+## Streaming Events
+
+Swarms support real-time streaming of events during execution using [`stream_async`](../../../api-reference/multiagent.md#strands.multiagent.swarm.Swarm.stream_async). This provides visibility into agent collaboration, handoffs, and autonomous coordination.
+
+```python
+from strands import Agent
+from strands.multiagent import Swarm
+
+# Create specialized agents
+coordinator = Agent(name="coordinator", system_prompt="You coordinate tasks...")
+specialist = Agent(name="specialist", system_prompt="You handle specialized work...")
+
+# Create swarm
+swarm = Swarm([coordinator, specialist])
+
+# Stream events during execution
+async for event in swarm.stream_async("Design and implement a REST API"):
+    # Track node execution
+    if event.get("type") == "multiagent_node_start":
+        print(f"🔄 Agent {event['node_id']} taking control")
+    
+    # Monitor agent events
+    elif event.get("type") == "multiagent_node_stream":
+        inner_event = event["event"]
+        if "data" in inner_event:
+            print(inner_event["data"], end="")
+    
+    # Track handoffs
+    elif event.get("type") == "multiagent_handoff":
+        from_nodes = ", ".join(event['from_node_ids'])
+        to_nodes = ", ".join(event['to_node_ids'])
+        print(f"\n🔀 Handoff: {from_nodes} → {to_nodes}")
+    
+    # Get final result
+    elif event.get("type") == "multiagent_result":
+        result = event["result"]
+        print(f"\nSwarm completed: {result.status}")
+```
+
+See the [streaming overview](../streaming/overview.md#multi-agent-events) for details on all multi-agent event types.
+
 ## Swarm Results
 
 When a Swarm completes execution, it returns a [`SwarmResult`](../../../api-reference/multiagent.md#strands.multiagent.swarm.SwarmResult) object with detailed information:

docs/user-guide/concepts/streaming/overview.md

@@ -41,6 +41,33 @@ All streaming methods yield the same set of events:
 - `reasoning_signature`: Signature from reasoning process
 - `redactedContent`: Reasoning content redacted by the model
 
+### Multi-Agent Events
+
+Multi-agent systems ([Graph](../multi-agent/graph.md) and [Swarm](../multi-agent/swarm.md)) emit additional coordination events:
+
+- `multiagent_node_start`: When a node begins execution
+    - `type`: `"multiagent_node_start"`
+    - `node_id`: Unique identifier for the node
+    - `node_type`: Type of node (`"agent"`, `"swarm"`, `"graph"`)
+- `multiagent_node_stream`: Forwarded events from agents/multi-agents with node context
+    - `type`: `"multiagent_node_stream"`
+    - `node_id`: Identifier of the node generating the event
+    - `event`: The original agent event (nested)
+- `multiagent_node_stop`: When a node completes execution
+    - `type`: `"multiagent_node_stop"`
+    - `node_id`: Unique identifier for the node
+    - `node_result`: Complete NodeResult with execution details, metrics, and status
+- `multiagent_handoff`: When control is handed off between agents (Swarm) or batch transitions (Graph)
+    - `type`: `"multiagent_handoff"`
+    - `from_node_ids`: List of node IDs completing execution
+    - `to_node_ids`: List of node IDs beginning execution
+    - `message`: Optional handoff message (typically used in Swarm)
+- `multiagent_result`: Final multi-agent result
+    - `type`: `"multiagent_result"`
+    - `result`: The final GraphResult or SwarmResult
+
+See [Graph streaming](../multi-agent/graph.md#streaming-events) and [Swarm streaming](../multi-agent/swarm.md#streaming-events) for usage examples.
+
 ## Quick Examples
 
 ### Async Iterator Pattern