Uttam Satya means Supreme Truth. In Jain practice it is counted as one of the "ten supreme virtues" (Das Lakshan Parva) celebrated especially in the Digambar tradition. This virtue emphasizes truthfulness in thought, speech and conduct, as a essential path to true right belief and right conduct.

From Kundakunda’s works themselves, the primary focus is on the inner purity of the soul and the attainment of Samyak Darshan, Gyan, and Charitra (right faith, knowledge, and conduct). Truthfulness is a key aspect of pure conduct (caritra) in that framework, but the term “Uttam Satya” as a label for a separate sutra/section is more explicitly found in the Das Lakshan discussions of Digambar practice rather than as a standalone chapter in Kundakunda’s texts. If you would like, I can provide direct excerpts from Kundakunda (e.g., Samayasāra, Niyamasāra, or Pancastikāyāsaṙa) that illuminate how Satya is treated within the soul’s path to liberation, and then explain how those ideas map to the Uttam Satya concept in the Das Lakshan tradition.

You can read more about Uttam Satya in the context of the ten supreme virtues here