Aion-3.5-Mini overview
Aion-3.5-Mini by AionLabs
Aion-3.5-Mini accepts text input and returns text completions through an OpenAI-compatible API, with reasoning enabled and support for tool use and web search.
Aion-3.5-Mini specs
- Model ID
aion-labs/aion-3.5-mini- Developer
- AionLabs
- Context window
- 262,144 tokens
- Max output
- 32,768 tokens
- Input
- Text
- Output
- Text
- API
- OpenAI-compatible, base URL
https://api.aimlapi.com/v1
What Is Aion-3.5-Mini API?
Aion 3.5 Mini is described as a multi-model roleplaying and storytelling system from AionLabs, built on the GLM family of models. It is presented as the smaller, lower-cost sibling of Aion 3.5 and uses the same collaborative generation process in which multiple specialized models contribute to a response.
The model is identified as aion-labs/aion-3.5-mini in the available sources.
Technical Reference
| Developer | AionLabs |
|---|---|
| Model ID | aion-labs/aion-3.5-mini |
| Release Date | September 23, 2026 |
| Context Window | 262,144 tokens (~262K) |
| Max Output Tokens | 32,768 tokens |
| Modalities | Text → Text |
| Capabilities | file input, parallel tool calls, reasoning, streaming, structured (JSON schema) output, tool/function calling, web search |
What Aion-3.5-Mini Brings to the Table
Model family
The model is described as being built on the GLM family of models.
System style
It uses a collaborative generation process where multiple specialized models contribute to one response.
Roleplay and storytelling
The model is positioned for roleplaying and storytelling use cases.
Smaller sibling
It is described as the smaller, lower-cost sibling of Aion 3.5.
Where Aion-3.5-Mini Makes the Most Sense
Narrative generation
Suitable for generating structured stories and narrative text.
Roleplaying applications
Positioned for roleplaying-style interactions and character-driven outputs.
Mature or darker themes
Sources say it handles mature or darker themes with notable nuance.
Aion-3.5-Mini vs the Alternatives
Aion 3.5
Described as the larger sibling model in the same AionLabs line.
Aion 3.0 Mini
Named in source material as the predecessor model that Aion 3.5 Mini replaces.
Sources: https://www.aionlabs.ai/docs/api-reference/ · https://www.orcarouter.ai/blog/aion-3-5-mini-release · https://pi.dev/models/openrouter/aion-labs-aion-3-5-mini
Use cases
Interactive fiction and roleplaying games with dynamic, evolving narratives are a stated fit for Aion 3.5 Mini.
Long-form content generation with consistent context is another documented use, with the model described as suitable for producing extended output while maintaining narrative coherence.
AI agents that need tool use, web search, and structured data output are also explicitly listed as a use case.
Private, low-cost automation for classification, routing, or lightweight coding tasks is documented as a further fit for the model.
Capabilities
- File input
- Reasoning
- Streaming
- Structured outputs
- Function calling
- Web search
Aion-3.5-Mini API pricing
| Usage | Price | Unit |
|---|---|---|
| Input | $0.7406 | 1M tokens |
| Output | $1.48 | 1M tokens |
| Cached input | $0.1904 | 1M tokens |
Prices from the AI/ML API price list, checked on Nov 4, 2026.
Aion-3.5-Mini vs other models: token prices
AI/ML API input and output rates for 5 models, per million tokens.
| Model | Input | Output |
|---|---|---|
| Aion-3.5-Mini | $0.7406 | $1.48 |
| Aion-3.0-Mini | $0.7406 | $1.48 |
| Aion-2.0 | $0.8464 | $1.69 |
| Aion-3.5 | $3.17 | $6.35 |
| Aion-3.0 | $3.17 | $6.35 |
How to use the Aion-3.5-Mini API
View docs
Build with your agent
Give your agent the model details, code and documentation.
1Get your API key
Create API keyexport AIMLAPI_KEY="8f2b4c7d9a1e6b3f…"2Make your first request
curl 'https://api.aimlapi.com/v1/chat/completions' \
-H "Authorization: Bearer $AIMLAPI_KEY" \
-H 'Content-Type: application/json' \
-d '{
"model": "aion-labs/aion-3.5-mini",
"messages": [
{
"role": "user",
"content": "Write a haiku about the ocean."
}
]
}'import os
import requests
headers = {
"Authorization": f"Bearer {os.environ['AIMLAPI_KEY']}",
"Content-Type": "application/json",
}
payload = {
"model": "aion-labs/aion-3.5-mini",
"messages": [
{
"role": "user",
"content": "Write a haiku about the ocean."
}
]
}
response = requests.post("https://api.aimlapi.com/v1/chat/completions", headers=headers, json=payload, timeout=120)
response.raise_for_status()
print(response.json())const response = await fetch("https://api.aimlapi.com/v1/chat/completions", {
method: "POST",
headers: {
Authorization: `Bearer ${process.env.AIMLAPI_KEY}`,
"Content-Type": "application/json",
},
body: JSON.stringify({
"model": "aion-labs/aion-3.5-mini",
"messages": [
{
"role": "user",
"content": "Write a haiku about the ocean."
}
]
}),
});
if (!response.ok) throw new Error(`HTTP ${response.status}`);
console.log(await response.json());Models similar to Aion-3.5-Mini
Aion-3.5-Mini FAQ
How much does Aion-3.5-Mini cost?
Aion-3.5-Mini costs $0.7406 input and $1.48 output per 1M tokens on AI/ML API, billed as you go with no subscription.
What is the Aion-3.5-Mini model ID?
Use aion-labs/aion-3.5-mini as the model parameter. Requests go to the OpenAI-compatible endpoint with your AI/ML API key.
What is the context window of Aion-3.5-Mini?
Aion-3.5-Mini accepts up to 262,144 tokens of context and returns up to 32,768 output tokens.