AionLabs: Aion 3.5

AionLabs: Aion 3.5 is a proprietary text-generation system released on September 23, 2026. It is described as a multi-model stack built on the GLM family, where several specialized models collaborate on each completion to improve narrative structure, tension, conflict, and nuanced handling of mature or darker themes. The product is positioned primarily for immersive roleplay and long-form storytelling rather than as an open-weight general-purpose checkpoint.

Through the Aion Labs and OpenRouter APIs, Aion 3.5 exposes a 262,144-token context window, up to 32,768 completion tokens per request, mandatory chain-of-thought-style reasoning with configurable effort (low, high, or max; default high), tool and function calling, and JSON-oriented structured outputs via response_format. Pricing is typically quoted at roughly $3.00 per million input tokens and $6.00 per million output tokens, with discounted cached-input reads where supported.

Independent trackers such as Epoch AI and DataLearner have not published standard academic or coding leaderboard scores for this exact model ID as of early October 2026. Third-party suites (for example NC Bench creative-writing evaluations) report strong roleplay-oriented results, but those are not part of the canonical benchmark set used here. Developers access the model only via hosted APIs; weights and parameter counts are not publicly released.