Alternatives
An Anthropic API alternative with one key for 50+ models
Anthropic provides its Claude models through the Claude API (the Anthropic API), with its own SDKs and Messages API format.
What developers use it for
- Long-document analysis and writing with Claude
- Coding assistants and agents
- Teams that want Claude specifically
Things to consider
- The native Messages API differs from the OpenAI chat format, so switching providers usually means code changes.
- Only Claude models are available on the Anthropic API.
Where Somnus fits
Through Somnus you call Claude models with the OpenAI-style chat format, alongside other makers' models, from the same key.
Every Somnus top-up is credited at 2× or more, and usage is billed at each model's list price, so a dollar of credit buys at least two dollars of usage.
Calling Somnus with the OpenAI SDK
from openai import OpenAI
import os
client = OpenAI(
api_key=os.environ["SOMNUS_API_KEY"],
base_url="https://somnus.world/api/public/gateway/v1",
)
resp = client.chat.completions.create(
model="claude-sonnet-5",
messages=[
{"role": "user", "content": "Hello"}
],
)
print(resp.choices[0].message.content)Somnus uses the OpenAI chat-completions format, so you use the openai package instead of a provider-specific SDK.
Questions
Is Somnus affiliated with Anthropic?
No. Somnus is independent. This page summarises Anthropic's public information, linked below.
Can I keep using Anthropic too?
Yes. Many teams use Somnus for multi-model access alongside a direct provider account.
Is there a free trial?
New Somnus accounts start with $10 of free credit after card verification.
Sources
Last checked 2026-09-29. Prices and features of other providers change — confirm on their sites.
Explore Somnus as another API option
Try it side by side with Anthropic — new accounts get $10 of free credit after card verification.
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