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Cheap OpenAI-compatible API

For a drop-in base URL for the OpenAI SDK with 50+ models, Somnus gives you 23 models on one OpenAI-compatible key. Usage is billed at list price but every top-up is credited 2× to 2.5×, so Claude Haiku 5.5 — the cheapest option here — effectively costs $0.05 / $0.25 per 1M input/output tokens.

Choosing a cheap openai-compatible api

If your code already uses the OpenAI SDK, switching is two settings: the base URL and the API key. Chat completions, streaming and tool calls keep the same shape.

That compatibility means every model on Somnus — not only OpenAI's — is reachable from the SDK you already ship, so price comparisons become a config change.

Cheap OpenAI-compatible API: price ranking

#	Model	Maker	List (in / out)	Effective with Somnus
1	Claude Haiku 5.5	Anthropic	$0.1 / $0.5	$0.05 / $0.25
2	GPT-6 Luna	OpenAI	$0.1 / $0.5	$0.05 / $0.25
3	DeepSeek V4.1 Flash	DeepSeek	$0.15 / $0.6	$0.075 / $0.3
4	DeepSeek V4 Flash	DeepSeek	$0.22 / $0.66	$0.11 / $0.33
5	DeepSeek V4 Pro	DeepSeek	$0.66 / $1.98	$0.33 / $0.99
6	Gemini 3.8 Flash	Google	$0.75 / $3.75	$0.375 / $1.875
7	Claude Haiku 4.5	Anthropic	$1 / $5	$0.5 / $2.5
8	GLM 5.3	Zhipu	$1.4 / $4.4	$0.7 / $2.2

Ranked by blended price (3 input : 1 output tokens).

Why Somnus for cheap openai-compatible api

Somnus buys model access in bulk and passes the saving on as extra credit.
Pay-as-you-go. No monthly caps or throttling — spend your balance however you like.
$10 free credit after card verification.
Switch models by changing one string — same key, same balance.

Point the OpenAI SDK at Somnus

javascript

import OpenAI from "openai";

const client = new OpenAI({
  apiKey: process.env.SOMNUS_API_KEY,
  baseURL: "https://somnus.world/api/public/gateway/v1",
});

const resp = await client.chat.completions.create({
  model: "claude-sonnet-5",
  messages: [
    {"role": "user", "content": "Cheap OpenAI-compatible API"}
  ],
});
console.log(resp.choices[0].message.content);

Try model "claude-haiku-5-5" first.

Model AModel BInput tokensOutput tokens

	Claude Sonnet 5	GPT-5.6 Sol
Input / 1M	$2	$5
Output / 1M	$10	$30
This request	$0.0120	$0.0340
Blended / 1M (3:1)	$4.00	$11.25

Claude Sonnet 5 is 2.8× cheaper for this request.

Questions

What is the cheap openai-compatible api?

Among a drop-in base URL for the OpenAI SDK with 50+ models, Claude Haiku 5.5 has the lowest list price on Somnus ($0.1 / $0.5), about $0.05 / $0.25 effective.

Is it really that cheap?

Yes: usage is charged at list price, and each $1 you top up becomes $2–$2.50 of credit.

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$10 free credit after card verification.

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