claude-mem/docs/context/claude-code/streaming.md

Streaming Input

Understanding the two input modes for Claude Agent SDK and when to use each

Overview

The Claude Agent SDK supports two distinct input modes for interacting with agents:

• Streaming Input Mode (Default & Recommended) - A persistent, interactive session
• Single Message Input - One-shot queries that use session state and resuming

This guide explains the differences, benefits, and use cases for each mode to help you choose the right approach for your application.

Streaming Input Mode (Recommended)

Streaming input mode is the preferred way to use the Claude Agent SDK. It provides full access to the agent's capabilities and enables rich, interactive experiences.

It allows the agent to operate as a long lived process that takes in user input, handles interruptions, surfaces permission requests, and handles session management.

How It Works

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sequenceDiagram
    participant App as Your Application
    participant Agent as Claude Agent
    participant Tools as Tools/Hooks
    participant FS as Environment/<br/>File System
    
    App->>Agent: Initialize with AsyncGenerator
    activate Agent
    
    App->>Agent: Yield Message 1
    Agent->>Tools: Execute tools
    Tools->>FS: Read files
    FS-->>Tools: File contents
    Tools->>FS: Write/Edit files
    FS-->>Tools: Success/Error
    Agent-->>App: Stream partial response
    Agent-->>App: Stream more content...
    Agent->>App: Complete Message 1
    
    App->>Agent: Yield Message 2 + Image
    Agent->>Tools: Process image & execute
    Tools->>FS: Access filesystem
    FS-->>Tools: Operation results
    Agent-->>App: Stream response 2
    
    App->>Agent: Queue Message 3
    App->>Agent: Interrupt/Cancel
    Agent->>App: Handle interruption
    
    Note over App,Agent: Session stays alive
    Note over Tools,FS: Persistent file system<br/>state maintained
    
    deactivate Agent

Benefits

Attach images directly to messages for visual analysis and understanding Send multiple messages that process sequentially, with ability to interrupt Full access to all tools and custom MCP servers during the session Use lifecycle hooks to customize behavior at various points See responses as they're generated, not just final results Maintain conversation context across multiple turns naturally

Implementation Example

```typescript TypeScript theme={null} import { query } from "@anthropic-ai/claude-agent-sdk"; import { readFileSync } from "fs";

async function* generateMessages() { // First message yield { type: "user" as const, message: { role: "user" as const, content: "Analyze this codebase for security issues" } };

// Wait for conditions or user input
await new Promise(resolve => setTimeout(resolve, 2000));

// Follow-up with image
yield {
  type: "user" as const,
  message: {
    role: "user" as const,
    content: [
      {
        type: "text",
        text: "Review this architecture diagram"
      },
      {
        type: "image",
        source: {
          type: "base64",
          media_type: "image/png",
          data: readFileSync("diagram.png", "base64")
        }
      }
    ]
  }
};

}

// Process streaming responses for await (const message of query({ prompt: generateMessages(), options: { maxTurns: 10, allowedTools: ["Read", "Grep"] } })) { if (message.type === "result") { console.log(message.result); } }

```python Python theme={null}
from claude_agent_sdk import ClaudeSDKClient, ClaudeAgentOptions, AssistantMessage, TextBlock
import asyncio
import base64

async def streaming_analysis():
    async def message_generator():
        # First message
        yield {
            "type": "user",
            "message": {
                "role": "user",
                "content": "Analyze this codebase for security issues"
            }
        }

        # Wait for conditions
        await asyncio.sleep(2)

        # Follow-up with image
        with open("diagram.png", "rb") as f:
            image_data = base64.b64encode(f.read()).decode()

        yield {
            "type": "user",
            "message": {
                "role": "user",
                "content": [
                    {
                        "type": "text",
                        "text": "Review this architecture diagram"
                    },
                    {
                        "type": "image",
                        "source": {
                            "type": "base64",
                            "media_type": "image/png",
                            "data": image_data
                        }
                    }
                ]
            }
        }

    # Use ClaudeSDKClient for streaming input
    options = ClaudeAgentOptions(
        max_turns=10,
        allowed_tools=["Read", "Grep"]
    )

    async with ClaudeSDKClient(options) as client:
        # Send streaming input
        await client.query(message_generator())

        # Process responses
        async for message in client.receive_response():
            if isinstance(message, AssistantMessage):
                for block in message.content:
                    if isinstance(block, TextBlock):
                        print(block.text)

asyncio.run(streaming_analysis())

Single Message Input

Single message input is simpler but more limited.

When to Use Single Message Input

Use single message input when:

• You need a one-shot response
• You do not need image attachments, hooks, etc.
• You need to operate in a stateless environment, such as a lambda function

Limitations

Single message input mode does **not** support:

• Direct image attachments in messages
• Dynamic message queueing
• Real-time interruption
• Hook integration
• Natural multi-turn conversations

Implementation Example

```typescript TypeScript theme={null} import { query } from "@anthropic-ai/claude-agent-sdk";

// Simple one-shot query for await (const message of query({ prompt: "Explain the authentication flow", options: { maxTurns: 1, allowedTools: ["Read", "Grep"] } })) { if (message.type === "result") { console.log(message.result); } }

// Continue conversation with session management for await (const message of query({ prompt: "Now explain the authorization process", options: { continue: true, maxTurns: 1 } })) { if (message.type === "result") { console.log(message.result); } }

```python Python theme={null}
from claude_agent_sdk import query, ClaudeAgentOptions, ResultMessage
import asyncio

async def single_message_example():
    # Simple one-shot query using query() function
    async for message in query(
        prompt="Explain the authentication flow",
        options=ClaudeAgentOptions(
            max_turns=1,
            allowed_tools=["Read", "Grep"]
        )
    ):
        if isinstance(message, ResultMessage):
            print(message.result)

    # Continue conversation with session management
    async for message in query(
        prompt="Now explain the authorization process",
        options=ClaudeAgentOptions(
            continue_conversation=True,
            max_turns=1
        )
    ):
        if isinstance(message, ResultMessage):
            print(message.result)

asyncio.run(single_message_example())