Solutions
Cheap OpenAI-compatible API
For a drop-in base URL for the OpenAI SDK with 50+ models, Somnus gives you 17 models on one OpenAI-compatible key. Usage is billed at list price but every top-up is credited 2× to 2.5×, so DeepSeek V4 Flash — the cheapest option here — effectively costs $0.11 / $0.33 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 | DeepSeek V4 Flash | DeepSeek | $0.22 / $0.66 | $0.11 / $0.33 |
| 2 | MiMo V2.5 Pro | Xiaomi | $0.44 / $0.87 | $0.22 / $0.44 |
| 3 | DeepSeek V4 Pro | DeepSeek | $0.66 / $1.98 | $0.33 / $0.99 |
| 4 | Gemini 3.8 Flash | $0.75 / $3.75 | $0.38 / $1.88 | |
| 5 | Claude Haiku 4.5 | Anthropic | $1 / $5 | $0.5 / $2.5 |
| 6 | GLM 5.3 | Zhipu | $1.4 / $4.4 | $0.7 / $2.2 |
| 7 | GPT-5.6 Luna | OpenAI | $1 / $6 | $0.5 / $3 |
| 8 | Qwen 3.8 Max | Alibaba | $1.65 / $4.95 | $0.83 / $2.48 |
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.
- $5 free credit on sign-up, no card needed.
- Switch models by changing one string — same key, same balance.
Point the OpenAI SDK at Somnus
import OpenAI from "openai";
const client = new OpenAI({
apiKey: process.env.SOMNUS_API_KEY,
baseURL: "https://gateway-production-c837.up.railway.app/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);Pick the model name from your dashboard.
| 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, DeepSeek V4 Flash has the lowest list price on Somnus ($0.22 / $0.66), about $0.11 / $0.33 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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