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.
Claude Opus 4.5 brings further reasoning, coding, and agentic improvements over Opus 4.1, with stronger tool use and tighter instruction following.
Claude Sonnet 5.5 offers the best combination of speed and intelligence, with adaptive thinking for coding, tool use, reasoning, and long-horizon work.
from openai import OpenAI
client = OpenAI(
base_url="https://api.aigateway.sh/v1",
api_key="sk-aig-...",
)
# Claude Opus 4.5
client.chat.completions.create(
model="anthropic/claude-opus-4.5",
messages=[{"role":"user","content":"hello"}],
)
# Claude Sonnet 5.5
client.chat.completions.create(
model="anthropic/claude-sonnet-5.5",
messages=[{"role":"user","content":"hello"}],
)