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HUD Gateway is an OpenAI-compatible inference service that provides a unified endpoint for accessing various LLM providers (Anthropic, OpenAI, Gemini, xAI, and more). It handles authentication, rate limiting, and credit management, allowing you to focus on building agents.

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Quick Start

The gateway is available at https://inference.hud.ai. You can use it with any OpenAI-compatible client.

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Using Python (OpenAI SDK)

from openai import AsyncOpenAI
import os

client = AsyncOpenAI(
    base_url="https://inference.hud.ai",
    api_key=os.environ["HUD_API_KEY"]
)

response = await client.chat.completions.create(
    model="claude-sonnet-4-5",
    messages=[{"role": "user", "content": "Hello!"}]
)
print(response.choices[0].message.content)

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Using curl

curl -X POST https://inference.hud.ai/chat/completions \
  -H "Authorization: Bearer <HUD_API_KEY>" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "claude-sonnet-4-5",
    "messages": [{"role": "user", "content": "Hello!"}]
  }'

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Supported Models

HUD Gateway supports models from major providers. For an up-to-date list, visit hud.ai/models.

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Anthropic

ModelRoutes
claude-sonnet-4-5chat, messages
claude-haiku-4-5chat, messages
claude-opus-4-5chat, messages
claude-opus-4-1chat, messages

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OpenAI

ModelRoutes
gpt-5.1chat, responses
gpt-5-minichat, responses
gpt-4ochat, responses
gpt-4o-minichat, responses
operatorresponses

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Google Gemini

ModelRoutes
gemini-3-pro-previewchat
gemini-2.5-prochat
gemini-2.5-computer-use-previewgemini

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xAI

ModelRoutes
grok-4-1-fastchat

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Z-AI (via OpenRouter)

ModelRoutes
z-ai/glm-4.5vchat

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Routes

Different models support different API routes:
  • chat - OpenAI Chat Completions API (/chat/completions)
  • messages - Anthropic Messages API (/messages)
  • responses - OpenAI Responses API (/responses)
  • gemini - Google Gemini native API

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Features

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Unified Billing

When using HUD Gateway with your HUD API key, usage is automatically deducted from your HUD credits. This simplifies billing by consolidating multiple provider invoices into one.

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Rate Limits

HUD Gateway automatically handles key rotation and rate limiting across our pool of enterprise keys.

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Using with HUD Agents

You can use HUD Gateway with OpenAIChatAgent for any model that supports the chat route: 
from hud.agents import OpenAIChatAgent
from hud.settings import settings

# Use any gateway model with OpenAIChatAgent
agent = OpenAIChatAgent.create(
    base_url=settings.hud_gateway_url,
    api_key=settings.api_key,
    checkpoint_name="grok-4-1-fast",  # or any chat-compatible model
)

result = await agent.run(task, max_steps=10)

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Building Custom Agents with Tracing

For a complete example of building a custom agent that uses HUD Gateway with full tracing support, see the custom agent example. This example demonstrates:
  • Using the @instrument decorator to capture inference traces
  • Building a custom MCPAgent with HUD Gateway
  • Automatic token usage and latency tracking
View your traces on the HUD Dashboard.