Pricing per million tokens, context window, capabilities — pulled from each provider's public docs. All 2 are available via the same AIgateway OpenAI-compatible endpoint; flip the model string to switch.
GPT-5.5 pro uses OpenAI's Responses API with built-in tools, improved reasoning, and stateful context management.
xAI's Grok 4.5, a frontier model built for coding, agentic tasks, and knowledge work. Accepts text and image inputs, and supports function calling, structured outputs, and configurable reasoning effort (low, medium, high).
from openai import OpenAI
client = OpenAI(
base_url="https://api.aigateway.sh/v1",
api_key="sk-aig-...",
)
# GPT-5.5 Pro
client.chat.completions.create(
model="openai/gpt-5.5-pro",
messages=[{"role":"user","content":"hello"}],
)
# Grok 4.5
client.chat.completions.create(
model="xai/grok-4.5",
messages=[{"role":"user","content":"hello"}],
)