Aion-2.0
About this model
Aion-2.0 is an AI model from Aion Labs, made available through the API on February 23, 2026. It can read up to 131,072 tokens in one request, roughly 246 pages of text, and write up to 32,768 tokens in a single answer.
Through the API it costs $0.80 per million input tokens and $1.60 per million output tokens. Its pricing sits in the middle of the market.
It supports extended reasoning: it can "think" step by step before answering, which helps on maths, code and complex questions. It can call tools and functions, so developers can connect it to search, databases or other software.
Quality scores
Rankings →Not rated yet. Independent test results usually appear a few weeks after a model is released.
Where to use it
Companies that serve this model through an API: 1. Prices per million tokens, cheapest first.
Availability and prices come from OpenRouter’s public API and are refreshed daily. Uptime is the share of successful requests over the last 24 hours. Some providers run a compressed version of open models (fp8, int4), which is cheaper but can be slightly less accurate.
Use it in your code
Call Aion-2.0 through OpenRouter’s OpenAI-compatible API: create a key on openrouter.ai, then run one of these examples.
curl https://openrouter.ai/api/v1/chat/completions \
-H "Authorization: Bearer $OPENROUTER_API_KEY" \
-H "Content-Type: application/json" \
-d '{"model": "aion-labs/aion-2.0", "messages": [{"role": "user", "content": "Hello! What can you do?"}]}'import os
from openai import OpenAI
client = OpenAI(base_url="https://openrouter.ai/api/v1", api_key=os.environ["OPENROUTER_API_KEY"])
reply = client.chat.completions.create(
model="aion-labs/aion-2.0",
messages=[{"role": "user", "content": "Hello! What can you do?"}],
)
print(reply.choices[0].message.content)import OpenAI from "openai";
const client = new OpenAI({ baseURL: "https://openrouter.ai/api/v1", apiKey: process.env.OPENROUTER_API_KEY });
const reply = await client.chat.completions.create({
model: "aion-labs/aion-2.0",
messages: [{ role: "user", content: "Hello! What can you do?" }],
});
console.log(reply.choices[0].message.content);The same code works with every model on this site: only the model ID changes. Many labs also offer their own API and SDK.
What it costs in practice
- 1,000 chat replies$0.88
- Summarise a 100-page document$0.042
- An app with 10,000 requests a day for a month$432
Similar-priced alternatives
| Model | Inputi | Outputi | Contexti | |
|---|---|---|---|---|
Hy4 previewTencent | $0.83 | $2.50 | 1M | Compare with ⇄ |
Gemini 3.8 FlashGoogle DeepMind | $0.75 | $3.75 | 1M | Compare with ⇄ |
GPT-5.4 MiniOpenAI | $0.75 | $4.50 | 400K | Compare with ⇄ |
KAT-Coder-Pro V2.5Kuaishou | $0.74 | $2.96 | 256K | Compare with ⇄ |
Sakana NamazuSakana AI | $0.95 | $4 | 256K | Compare with ⇄ |
DeepSeek V4 Pro 0423DeepSeek | $0.96 | $1.91 | 1M | Compare with ⇄ |
Frequently asked questions
- How much does Aion-2.0 cost?
- Aion-2.0 costs $0.80 per million input tokens and $1.60 per million output tokens through the API. For example, 1,000 chat replies of about 500 tokens in and 300 out cost around $0.88.
- What is the context window of Aion-2.0?
- Aion-2.0 can read up to 131,072 tokens in one request, about 246 pages of text. It can write up to 32,768 tokens in a single answer.
- Is Aion-2.0 open source?
- No. Aion-2.0 is a closed model: its weights are not published, so you use it through Aion Labs’s own apps and API, or through cloud providers.
- Who makes Aion-2.0?
- Aion-2.0 is made by Aion Labs. It became available through the API on February 23, 2026.
- Can Aion-2.0 read images?
- No. Aion-2.0 only accepts text as input.
- What are the alternatives to Aion-2.0?
- Models with a similar price from other companies include Hy4 preview, Gemini 3.8 Flash and GPT-5.4 Mini. You can compare them side by side on this page.