/responses [Beta]

LiteLLM provides a BETA endpoint in the spec of OpenAI's /responses API

Feature	Supported	Notes
Cost Tracking	✅	Works with all supported models
Logging	✅	Works across all integrations
End-user Tracking	✅
Streaming	✅
Fallbacks	✅	Works between supported models
Loadbalancing	✅	Works between supported models
Supported LiteLLM Versions	1.63.8+
Supported LLM providers	All LiteLLM supported providers	openai, anthropic, bedrock, vertex_ai, gemini, azure, azure_ai etc.

Usage

LiteLLM Python SDK

OpenAI

Non-streaming

OpenAI Non-streaming Response

import litellm

# Non-streaming response
response = litellm.responses(
    model="openai/o1-pro",
    input="Tell me a three sentence bedtime story about a unicorn.",
    max_output_tokens=100
)

print(response)

Streaming

OpenAI Streaming Response

import litellm

# Streaming response
response = litellm.responses(
    model="openai/o1-pro",
    input="Tell me a three sentence bedtime story about a unicorn.",
    stream=True
)

for event in response:
    print(event)

Anthropic

Non-streaming

Anthropic Non-streaming Response

import litellm
import os

# Set API key
os.environ["ANTHROPIC_API_KEY"] = "your-anthropic-api-key"

# Non-streaming response
response = litellm.responses(
    model="anthropic/claude-3-5-sonnet-20240620",
    input="Tell me a three sentence bedtime story about a unicorn.",
    max_output_tokens=100
)

print(response)

Streaming

Anthropic Streaming Response

import litellm
import os

# Set API key
os.environ["ANTHROPIC_API_KEY"] = "your-anthropic-api-key"

# Streaming response
response = litellm.responses(
    model="anthropic/claude-3-5-sonnet-20240620",
    input="Tell me a three sentence bedtime story about a unicorn.",
    stream=True
)

for event in response:
    print(event)

Vertex AI

Non-streaming

Vertex AI Non-streaming Response

import litellm
import os

# Set credentials - Vertex AI uses application default credentials
# Run 'gcloud auth application-default login' to authenticate
os.environ["VERTEXAI_PROJECT"] = "your-gcp-project-id"
os.environ["VERTEXAI_LOCATION"] = "us-central1"

# Non-streaming response
response = litellm.responses(
    model="vertex_ai/gemini-1.5-pro",
    input="Tell me a three sentence bedtime story about a unicorn.",
    max_output_tokens=100
)

print(response)

Streaming

Vertex AI Streaming Response

import litellm
import os

# Set credentials - Vertex AI uses application default credentials
# Run 'gcloud auth application-default login' to authenticate
os.environ["VERTEXAI_PROJECT"] = "your-gcp-project-id"
os.environ["VERTEXAI_LOCATION"] = "us-central1"

# Streaming response
response = litellm.responses(
    model="vertex_ai/gemini-1.5-pro",
    input="Tell me a three sentence bedtime story about a unicorn.",
    stream=True
)

for event in response:
    print(event)

AWS Bedrock

Non-streaming

AWS Bedrock Non-streaming Response

import litellm
import os

# Set AWS credentials
os.environ["AWS_ACCESS_KEY_ID"] = "your-access-key-id"
os.environ["AWS_SECRET_ACCESS_KEY"] = "your-secret-access-key"
os.environ["AWS_REGION_NAME"] = "us-west-2"  # or your AWS region

# Non-streaming response
response = litellm.responses(
    model="bedrock/anthropic.claude-3-sonnet-20240229-v1:0",
    input="Tell me a three sentence bedtime story about a unicorn.",
    max_output_tokens=100
)

print(response)

Streaming

AWS Bedrock Streaming Response

import litellm
import os

# Set AWS credentials
os.environ["AWS_ACCESS_KEY_ID"] = "your-access-key-id"
os.environ["AWS_SECRET_ACCESS_KEY"] = "your-secret-access-key"
os.environ["AWS_REGION_NAME"] = "us-west-2"  # or your AWS region

# Streaming response
response = litellm.responses(
    model="bedrock/anthropic.claude-3-sonnet-20240229-v1:0",
    input="Tell me a three sentence bedtime story about a unicorn.",
    stream=True
)

for event in response:
    print(event)

Google AI Studio

Non-streaming

Google AI Studio Non-streaming Response

import litellm
import os

# Set API key for Google AI Studio
os.environ["GEMINI_API_KEY"] = "your-gemini-api-key"

# Non-streaming response
response = litellm.responses(
    model="gemini/gemini-1.5-flash",
    input="Tell me a three sentence bedtime story about a unicorn.",
    max_output_tokens=100
)

print(response)

Streaming

Google AI Studio Streaming Response

import litellm
import os

# Set API key for Google AI Studio
os.environ["GEMINI_API_KEY"] = "your-gemini-api-key"

# Streaming response
response = litellm.responses(
    model="gemini/gemini-1.5-flash",
    input="Tell me a three sentence bedtime story about a unicorn.",
    stream=True
)

for event in response:
    print(event)

LiteLLM Proxy with OpenAI SDK

First, set up and start your LiteLLM proxy server.

Start LiteLLM Proxy Server

litellm --config /path/to/config.yaml

# RUNNING on http://0.0.0.0:4000

OpenAI

First, add this to your litellm proxy config.yaml:

OpenAI Proxy Configuration

model_list:
  - model_name: openai/o1-pro
    litellm_params:
      model: openai/o1-pro
      api_key: os.environ/OPENAI_API_KEY

Non-streaming

OpenAI Proxy Non-streaming Response

from openai import OpenAI

# Initialize client with your proxy URL
client = OpenAI(
    base_url="http://localhost:4000",  # Your proxy URL
    api_key="your-api-key"             # Your proxy API key
)

# Non-streaming response
response = client.responses.create(
    model="openai/o1-pro",
    input="Tell me a three sentence bedtime story about a unicorn."
)

print(response)

Streaming

OpenAI Proxy Streaming Response

from openai import OpenAI

# Initialize client with your proxy URL
client = OpenAI(
    base_url="http://localhost:4000",  # Your proxy URL
    api_key="your-api-key"             # Your proxy API key
)

# Streaming response
response = client.responses.create(
    model="openai/o1-pro",
    input="Tell me a three sentence bedtime story about a unicorn.",
    stream=True
)

for event in response:
    print(event)

Anthropic

First, add this to your litellm proxy config.yaml:

Anthropic Proxy Configuration

model_list:
  - model_name: anthropic/claude-3-5-sonnet-20240620
    litellm_params:
      model: anthropic/claude-3-5-sonnet-20240620
      api_key: os.environ/ANTHROPIC_API_KEY

Non-streaming

Anthropic Proxy Non-streaming Response

from openai import OpenAI

# Initialize client with your proxy URL
client = OpenAI(
    base_url="http://localhost:4000",  # Your proxy URL
    api_key="your-api-key"             # Your proxy API key
)

# Non-streaming response
response = client.responses.create(
    model="anthropic/claude-3-5-sonnet-20240620",
    input="Tell me a three sentence bedtime story about a unicorn."
)

print(response)

Streaming

Anthropic Proxy Streaming Response

from openai import OpenAI

# Initialize client with your proxy URL
client = OpenAI(
    base_url="http://localhost:4000",  # Your proxy URL
    api_key="your-api-key"             # Your proxy API key
)

# Streaming response
response = client.responses.create(
    model="anthropic/claude-3-5-sonnet-20240620",
    input="Tell me a three sentence bedtime story about a unicorn.",
    stream=True
)

for event in response:
    print(event)

Vertex AI

First, add this to your litellm proxy config.yaml:

Vertex AI Proxy Configuration

model_list:
  - model_name: vertex_ai/gemini-1.5-pro
    litellm_params:
      model: vertex_ai/gemini-1.5-pro
      vertex_project: your-gcp-project-id
      vertex_location: us-central1

Non-streaming

Vertex AI Proxy Non-streaming Response

from openai import OpenAI

# Initialize client with your proxy URL
client = OpenAI(
    base_url="http://localhost:4000",  # Your proxy URL
    api_key="your-api-key"             # Your proxy API key
)

# Non-streaming response
response = client.responses.create(
    model="vertex_ai/gemini-1.5-pro",
    input="Tell me a three sentence bedtime story about a unicorn."
)

print(response)

Streaming

Vertex AI Proxy Streaming Response

from openai import OpenAI

# Initialize client with your proxy URL
client = OpenAI(
    base_url="http://localhost:4000",  # Your proxy URL
    api_key="your-api-key"             # Your proxy API key
)

# Streaming response
response = client.responses.create(
    model="vertex_ai/gemini-1.5-pro",
    input="Tell me a three sentence bedtime story about a unicorn.",
    stream=True
)

for event in response:
    print(event)

AWS Bedrock

First, add this to your litellm proxy config.yaml:

AWS Bedrock Proxy Configuration

model_list:
  - model_name: bedrock/anthropic.claude-3-sonnet-20240229-v1:0
    litellm_params:
      model: bedrock/anthropic.claude-3-sonnet-20240229-v1:0
      aws_access_key_id: os.environ/AWS_ACCESS_KEY_ID
      aws_secret_access_key: os.environ/AWS_SECRET_ACCESS_KEY
      aws_region_name: us-west-2

Non-streaming

AWS Bedrock Proxy Non-streaming Response

from openai import OpenAI

# Initialize client with your proxy URL
client = OpenAI(
    base_url="http://localhost:4000",  # Your proxy URL
    api_key="your-api-key"             # Your proxy API key
)

# Non-streaming response
response = client.responses.create(
    model="bedrock/anthropic.claude-3-sonnet-20240229-v1:0",
    input="Tell me a three sentence bedtime story about a unicorn."
)

print(response)

Streaming

AWS Bedrock Proxy Streaming Response

from openai import OpenAI

# Initialize client with your proxy URL
client = OpenAI(
    base_url="http://localhost:4000",  # Your proxy URL
    api_key="your-api-key"             # Your proxy API key
)

# Streaming response
response = client.responses.create(
    model="bedrock/anthropic.claude-3-sonnet-20240229-v1:0",
    input="Tell me a three sentence bedtime story about a unicorn.",
    stream=True
)

for event in response:
    print(event)

Google AI Studio

First, add this to your litellm proxy config.yaml:

Google AI Studio Proxy Configuration

model_list:
  - model_name: gemini/gemini-1.5-flash
    litellm_params:
      model: gemini/gemini-1.5-flash
      api_key: os.environ/GEMINI_API_KEY

Non-streaming

Google AI Studio Proxy Non-streaming Response

from openai import OpenAI

# Initialize client with your proxy URL
client = OpenAI(
    base_url="http://localhost:4000",  # Your proxy URL
    api_key="your-api-key"             # Your proxy API key
)

# Non-streaming response
response = client.responses.create(
    model="gemini/gemini-1.5-flash",
    input="Tell me a three sentence bedtime story about a unicorn."
)

print(response)

Streaming

Google AI Studio Proxy Streaming Response

from openai import OpenAI

# Initialize client with your proxy URL
client = OpenAI(
    base_url="http://localhost:4000",  # Your proxy URL
    api_key="your-api-key"             # Your proxy API key
)

# Streaming response
response = client.responses.create(
    model="gemini/gemini-1.5-flash",
    input="Tell me a three sentence bedtime story about a unicorn.",
    stream=True
)

for event in response:
    print(event)

Supported Responses API Parameters

Provider	Supported Parameters
openai	All Responses API parameters are supported
azure	All Responses API parameters are supported
anthropic	See supported parameters here
bedrock	See supported parameters here
gemini	See supported parameters here
vertex_ai	See supported parameters here
azure_ai	See supported parameters here
All other llm api providers	See supported parameters here

Load Balancing with Routing Affinity

When using the Responses API with multiple deployments of the same model (e.g., multiple Azure OpenAI endpoints), LiteLLM provides routing affinity for conversations. This ensures that follow-up requests using a previous_response_id are routed to the same deployment that generated the original response.

Example Usage

Python SDK

Python SDK with Routing Affinity

import litellm

# Set up router with multiple deployments of the same model
router = litellm.Router(
    model_list=[
        {
            "model_name": "azure-gpt4-turbo",
            "litellm_params": {
                "model": "azure/gpt-4-turbo",
                "api_key": "your-api-key-1",
                "api_version": "2024-06-01",
                "api_base": "https://endpoint1.openai.azure.com",
            },
        },
        {
            "model_name": "azure-gpt4-turbo",
            "litellm_params": {
                "model": "azure/gpt-4-turbo",
                "api_key": "your-api-key-2",
                "api_version": "2024-06-01",
                "api_base": "https://endpoint2.openai.azure.com",
            },
        },
    ],
    optional_pre_call_checks=["responses_api_deployment_check"],
)

# Initial request
response = await router.aresponses(
    model="azure-gpt4-turbo",
    input="Hello, who are you?",
    truncation="auto",
)

# Store the response ID
response_id = response.id

# Follow-up request - will be automatically routed to the same deployment
follow_up = await router.aresponses(
    model="azure-gpt4-turbo",
    input="Tell me more about yourself",
    truncation="auto",
    previous_response_id=response_id  # This ensures routing to the same deployment
)

Proxy Server

1. Setup routing affinity on proxy config.yaml

To enable routing affinity for Responses API in your LiteLLM proxy, set optional_pre_call_checks: ["responses_api_deployment_check"] in your proxy config.yaml.

config.yaml with Responses API Routing Affinity

model_list:
  - model_name: azure-gpt4-turbo
    litellm_params:
      model: azure/gpt-4-turbo
      api_key: your-api-key-1
      api_version: 2024-06-01
      api_base: https://endpoint1.openai.azure.com
  - model_name: azure-gpt4-turbo
    litellm_params:
      model: azure/gpt-4-turbo
      api_key: your-api-key-2
      api_version: 2024-06-01
      api_base: https://endpoint2.openai.azure.com

router_settings:
  optional_pre_call_checks: ["responses_api_deployment_check"]

2. Use the OpenAI Python SDK to make requests to LiteLLM Proxy

OpenAI Client with Proxy Server

from openai import OpenAI

client = OpenAI(
    base_url="http://localhost:4000",
    api_key="your-api-key"
)

# Initial request
response = client.responses.create(
    model="azure-gpt4-turbo",
    input="Hello, who are you?"
)

response_id = response.id

# Follow-up request - will be automatically routed to the same deployment
follow_up = client.responses.create(
    model="azure-gpt4-turbo",
    input="Tell me more about yourself",
    previous_response_id=response_id  # This ensures routing to the same deployment
)