​
POST /v1/agents/{agent_id}/stream

Stream agent responses using Server-Sent Events (SSE) for real-time output.

​
Request

POST https://api.run-agent.ai/v1/agents/{agent_id}/stream
Content-Type: application/json
Authorization: Bearer YOUR_API_KEY
Accept: text/event-stream

​
Path Parameters

​
agent_id
string
required
The unique identifier of the agent

​
Request Body

Same as the invoke endpoint:
​
query
string
required
The input query for the agent
​
parameters
object
Additional parameters
​
session_id
string
Session ID for context

​
Response Format

Server-Sent Events stream with the following event types: 
event: start
data: {"message": "Stream started"}

event: chunk
data: {"content": "The weather in "}

event: chunk
data: {"content": "San Francisco is "}

event: done
data: {"message": "Stream complete", "usage": {...}}

​
Event Types

​
start

Sent when streaming begins 
event: start
data: {"message": "Stream started", "session_id": "abc123"}

​
chunk

Content chunks as they’re generated 
event: chunk
data: {"content": "Hello, ", "index": 0}

​
error

Error during streaming 
event: error
data: {"error": "Processing failed", "code": "STREAM_ERROR"}

​
done

Stream completion with metadata 
event: done
data: {
  "message": "Stream complete",
  "usage": {
    "total_tokens": 150
  },
  "execution_time": 2.5
}

​
Examples

​
JavaScript (Browser)

const eventSource = new EventSource(
  'https://api.run-agent.ai/v1/agents/agent-123/stream',
  {
    headers: {
      'Authorization': 'Bearer YOUR_API_KEY',
      'Content-Type': 'application/json'
    }
  }
);

eventSource.onmessage = (event) => {
  const data = JSON.parse(event.data);
  
  if (event.type === 'chunk') {
    // Append chunk to output
    document.getElementById('output').innerHTML += data.content;
  }
};

eventSource.onerror = (error) => {
  console.error('Stream error:', error);
  eventSource.close();
};

// Send request to start streaming
fetch('https://api.run-agent.ai/v1/agents/agent-123/stream', {
  method: 'POST',
  headers: {
    'Authorization': 'Bearer YOUR_API_KEY',
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    query: 'Tell me a story about space'
  })
});

​
Python

import requests
import json

def stream_agent_response(agent_id, query):
    url = f"https://api.run-agent.ai/v1/agents/{agent_id}/stream"
    headers = {
        "Authorization": "Bearer YOUR_API_KEY",
        "Content-Type": "application/json",
        "Accept": "text/event-stream"
    }
    
    response = requests.post(
        url,
        headers=headers,
        json={"query": query},
        stream=True
    )
    
    for line in response.iter_lines():
        if line:
            line = line.decode('utf-8')
            if line.startswith('data: '):
                data = json.loads(line[6:])
                if 'content' in data:
                    print(data['content'], end='', flush=True)

# Usage
stream_agent_response("agent-123", "Explain quantum computing")

​
Node.js

const EventSource = require('eventsource');

const eventSource = new EventSource(
  'https://api.run-agent.ai/v1/agents/agent-123/stream',
  {
    headers: {
      'Authorization': 'Bearer YOUR_API_KEY'
    }
  }
);

let fullResponse = '';

eventSource.addEventListener('chunk', (event) => {
  const data = JSON.parse(event.data);
  fullResponse += data.content;
  process.stdout.write(data.content);
});

eventSource.addEventListener('done', (event) => {
  const data = JSON.parse(event.data);
  console.log('\n\nStream complete:', data);
  eventSource.close();
});

eventSource.addEventListener('error', (event) => {
  console.error('Stream error:', event);
  eventSource.close();
});

​
Handling Stream Interruptions

​
Client-Side Reconnection

let reconnectAttempts = 0;
const maxReconnects = 3;

function connectStream() {
  const eventSource = new EventSource(url, options);
  
  eventSource.onerror = (error) => {
    eventSource.close();
    
    if (reconnectAttempts < maxReconnects) {
      reconnectAttempts++;
      setTimeout(() => {
        console.log(`Reconnecting... (${reconnectAttempts}/${maxReconnects})`);
        connectStream();
      }, Math.pow(2, reconnectAttempts) * 1000);
    }
  };
  
  eventSource.addEventListener('done', () => {
    reconnectAttempts = 0;  // Reset on success
  });
}

​
Resume from Position

{
  "query": "Continue the story",
  "parameters": {
    "resume_from_index": 150
  },
  "session_id": "abc123"
}

​
Stream Control

​
Abort Stream

Close the connection to stop streaming: 
// JavaScript
eventSource.close();

// Python
response.close()

// cURL
# Ctrl+C to interrupt

​
Rate Control

Control streaming speed with parameters: 
{
  "query": "Explain slowly",
  "parameters": {
    "stream_delay_ms": 100,
    "chunk_size": 10
  }
}

​
Error Handling

​
Network Errors

eventSource.onerror = (event) => {
  if (event.readyState === EventSource.CLOSED) {
    console.log('Connection closed');
  } else {
    console.error('Connection error:', event);
    // Implement retry logic
  }
};

​
Stream Errors

event: error
data: {"error": "Model overloaded", "code": "CAPACITY_ERROR", "retry_after": 30}

​
Best Practices

  1. Implement Reconnection Logic for network interruptions
  2. Handle Partial Responses gracefully
  3. Set Appropriate Timeouts for long-running streams
  4. Monitor Memory Usage when buffering responses
  5. Provide User Feedback during streaming

​
Performance Tips

  • Use compression when available
  • Process chunks as they arrive
  • Implement backpressure handling
  • Consider chunking large responses

​
See Also