AionLabs' narrative-focused LLM with multi-model collaboration, tool use, and 256K context — optimized for roleplaying and storytelling.
curl https://api.venice.ai/api/v1/chat/completions \
-H "Authorization: Bearer $VENICE_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "aion-labs-aion-3-5",
"messages": [{ "role": "user", "content": "Explain quantum tunneling simply." }]
}'Overview
Aion 3.5 is a proprietary large language model from AionLabs, released in September 2026, designed for advanced roleplaying and storytelling. It features a 256K-token context window, supports tool use, reasoning, web search, and structured JSON output, and runs on Venice with anonymized privacy—no prompts stored or used for training.
On Venice, Aion 3.5 runs with zero retention—your prompts are never stored, profiled, or used for training, giving you full sovereignty over creative narratives. You get uncensored access to its full capabilities, including function calling and web search, without subscription lock-in. This is permissionless narrative AI: private, billed per token, and free from Big Tech surveillance.
Agent quickstart
The API is OpenAI-compatible: change the base URL and the model id and existing client code works unchanged.
curl https://api.venice.ai/api/v1/chat/completions \
-H "Authorization: Bearer $VENICE_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "aion-labs-aion-3-5",
"stream": true,
"messages": [{ "role": "user", "content": "Draft the release note." }]
}'curl https://api.venice.ai/api/v1/chat/completions \
-H "Authorization: Bearer $VENICE_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "aion-labs-aion-3-5",
"messages": [{ "role": "user", "content": "Find the rate limits." }],
"tools": [{
"type": "function",
"function": {
"name": "search_docs",
"description": "Search the API documentation.",
"parameters": {
"type": "object",
"properties": { "query": { "type": "string" } },
"required": ["query"]
}
}
}],
"tool_choice": "auto"
}'import os
from openai import OpenAI
client = OpenAI(
api_key=os.environ["VENICE_API_KEY"],
base_url="https://api.venice.ai/api/v1",
)
resp = client.chat.completions.create(
model="aion-labs-aion-3-5",
messages=[{"role": "user", "content": "Build without permission."}],
)
print(resp.choices[0].message.content)Specifications
Assessment
Use cases
Prompting
Use explicit role directives (e.g., 'Act as a noir detective') to anchor character voice.
Break complex tasks into steps with reasoning mode enabled for better logic flow.
Include JSON schema in your prompt when you need structured output for downstream parsing.
Use web search capability to pull in real-time lore or factual details during world-building.
Leverage the 256K context by summarizing key plot points early to maintain narrative continuity.
Cache repeated world-building prompts to reduce input costs on follow-up generations.
Alternatives
| Model | Best for | Context | Open weights | Price (Venice) |
|---|---|---|---|---|
| Aion 3.5 | Narrative & roleplaying | 262K tokens | No | $3.75 in · $7.50 out / 1M |
| Claude Opus 5 | High-intelligence tasks | 1M tokens | No | $6 in · $30 out / 1M |
| DeepSeek V4.1 Flash | Speed & cost efficiency | 1M tokens | Yes | $0.38 in · $1.50 out / 1M |
| Google Gemma 4 31B Instruct | Open-weight efficiency | 256K tokens | Yes | $0.12 in · $0.36 out / 1M |
Choose Aion 3.5 when you need a narrative-specialized model with strong roleplaying, multi-model collaboration, and tool use—ideal for immersive storytelling where context and character consistency matter more than raw cost efficiency.
Pricing
Billed per token on Venice: $3.75 per 1M input tokens and $7.50 per 1M output tokens.
New Venice accounts include a free daily allowance and 500 welcome credits — no credit card required.
Getting a key
Create a key in API settings. Nothing else is required to start.
Export it as VENICE_API_KEY so the snippets above run unedited.
Point an existing OpenAI client at https://api.venice.ai/api/v1. The scheme is part of the value: an OpenAI client given a bare host does not resolve it.
Pass aion-labs-aion-3-5 as the model and send the request.
FAQ
Aion 3.5 is a proprietary large language model from AionLabs, released in September 2026, designed for advanced roleplaying and storytelling. It features a 256K-token context window, supports tool use, reasoning, web search, and structured JSON output, and runs on Venice with anonymized privacy—no prompts stored or used for training.
On Venice, Aion 3.5 is billed per token: $3.75 per 1M input tokens and $7.50 per 1M output tokens. Cached input is cheaper at $0.94 per 1M tokens. There is no subscription—pay only for what you use.
No, Aion 3.5 is neither free nor open source. It is a proprietary model developed by AionLabs with closed weights, meaning it cannot be self-hosted or fine-tuned. Access is via API with per-token billing on platforms like Venice.
Yes, Aion 3.5 supports tool use and function calling on Venice, enabling it to interact with external systems, retrieve data, and automate workflows as part of narrative or research tasks.
Aion 3.5 has a 256K-token context window, allowing for long, detailed narratives and complex world-building with sustained memory across extended interactions.
Aion 3.5 is better for roleplaying and narrative depth with its multi-model collaboration, while Claude Opus 5 excels in general reasoning and has a larger 1M context. Opus is also more expensive. Choose Aion for storytelling, Opus for high-intelligence analysis.
Yes, Aion 3.5 supports web search on Venice, allowing it to pull in real-time information during storytelling or research tasks, enhancing factual grounding in narratives.
One key, free to start, no credit card.