Aion 3.5

Aion 3.5 is a text-to-text AI model released by Aion Labs, listed in OpenRouter's catalog under the model key aion-labs/aion-3.5. The model was made available on the listed release date and is positioned as a general-purpose language model with reasoning, tool calling, and temperature control capabilities. It accepts and produces text only, making it suitable for conversational, analytical, and structured-output workflows where developers need programmatic integration through API tool use.

Aion 3.5 enters a crowded late-2026 model landscape that includes competing releases such as OpenAI's GPT-6 family, Anthropic's Claude Opus 5.5, Grok 4.7, and DeepSeek V4.1 Flash. Its 262144-token context window and 32768-token output ceiling give it room for long-document reasoning, multi-step analysis, and extended tool-calling chains. Priced at $the listed price per million input tokens and $the listed price per million output tokens, with discounted cache reads at $the listed price per million tokens, it offers a balanced cost profile for production workloads that combine retrieval, reasoning, and function execution.