How do I use Solar Mini 4 through YepAPI?

Sign up for a free API key, then send requests to the /v1/ai/chat endpoint.

UpstageText Generation/v1/ai/chat

Solar Mini 4

Access Solar Mini 4 through one API key. Upstage Compact 35B MoE.

Solar Mini 4 is Upstage's compact, cost-efficient language model, a 35B-parameter mixture-of-experts with 3B active parameters and a 524,288-token context window. Solar Mini 4 is for the cheapest tier of agent work: routing, extraction and summarisation over long documents at near-zero cost.

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2,400+

Developers

1.2M+

API calls served

100+

Endpoints

$0.01

Per call

Yep, that's it.

Try it live

Send a message and see Solar Mini 4 respond in real time.

POST/v1/ai/chatupstage/solar-mini4

Message *

Max Tokens

Maximum tokens in the response.

Stream

Real-time tokens

Hit "Send Request" to see the response

Context Window

524K tokens

Max Output

131K tokens

Input Price

$0.07 / 1M tokens

Output Price

$0.30 / 1M tokens

Strengths

✓

Near-zero cost

$0.07 per 1M input and $0.30 per 1M output tokens.

✓

3B active parameters

A 35B MoE with only 3B active per token, so it is fast.

✓

524K context

Handles up to 524,288 input tokens and returns up to 131,072 output tokens per call.

✓

Tools and structured output

Function calling and JSON schema outputs.

Quick start

Copy this snippet and start making calls with Solar Mini 4.

const res = await fetch('https://api.yepapi.com/v1/ai/chat', {
  method: 'POST',
  headers: {
    'x-api-key': 'YOUR_API_KEY',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    "model": "upstage/solar-mini4",
    "messages": [
      {
        "role": "user",
        "content": "Explain API gateways in 2 sentences."
      }
    ],
    "maxTokens": 256
  }),
});
const { data } = await res.json();
console.log(data.message.content);

Why use Solar Mini 4 through YepAPI?

✓One API key for all models — no separate accounts

✓OpenAI SDK compatible — just change the base URL

✓No monthly minimums — pay per token

✓Switch models with one line of code

✓Full provider passthrough — citations, search results, and all extras included

✓Streaming and non-streaming support on every model

✓Works with Cursor, Claude, LangChain, and any LLM tool

✓Unified billing across all providers

Solar Mini 4 API — pricing, context window & access

Solar Mini 4 is Upstage's compact, cost-efficient language model, a 35B-parameter mixture-of-experts with 3B active parameters and a 524,288-token context window. It pairs a 524,288-token context window with up to 131,072 output tokens per response, at $0.07 per 1M input and $0.30 per 1M output tokens through YepAPI.

Through YepAPI you call Solar Mini 4 on an OpenAI-compatible endpoint with a single key — the same key that reaches GPT-6, Claude, Gemini, Grok and the SEO, SERP and scraping APIs. Input: text.

What is Solar Mini 4?

Solar Mini 4 is Upstage's compact, cost-efficient language model, a 35B-parameter mixture-of-experts with 3B active parameters and a 524,288-token context window. It is built for agentic use cases where response speed and cost matter, returning up to 131,072 output tokens at $0.07 / $0.30 per 1M tokens. It accepts text as input, handles up to 524,288 tokens of context and returns up to 131,072 output tokens per call.

Build with Solar Mini 4 via YepAPI

YepAPI serves Solar Mini 4 on the OpenAI-compatible /v1/ai/chat endpoint. Point your base URL at YepAPI, add your key, and set the model string to solar-mini4 (or the full upstage/solar-mini4). Function calling, structured outputs and reasoning settings pass straight through, and switching to any other model on the platform is a one-string change per request.

Solar Mini 4 API pricing — $0.07 / 1M input, $0.30 / 1M output

Solar Mini 4 costs $0.07 per 1M input tokens and $0.30 per 1M output tokens through YepAPI, pay per token with no minimums. Failed calls are never charged, and every request is itemised in your dashboard API Logs so you can see exactly what a 131,072-token response cost.

Solar Mini 4 use cases

Solar Mini 4 is for the cheapest tier of agent work: routing, extraction and summarisation over long documents at near-zero cost.

Try Solar Mini 4 free

Every new YepAPI account includes $5 in free credit with no card required — enough to test Solar Mini 4 on your own prompts before committing to paid usage. Create an account, copy your key, and call solar-mini4 right away.