This dataset presents the first integrated lexical and functional framework for deciphering the Indus script, covering 417 standardized glyphs (G001–G417). It proposes consistent semantic groupings across economic, administrative, and ritual domains, grounded in contextual frequency and functional morphology. The release includes three core components: Phase 1 High-Frequency Function Matrix (Top 25): a quantitative study of the most recurrent signs and their syntactic co-occurrence. Phase 2 Clause Typology and Grammar Rules: a structural outline of clause formation, relational markers, and compositional syntax. Indus Script Master Catalogue (G001–G417): a complete lexicon detailing each glyph’s proposed meaning, form, usage context, and confidence level. Together these files establish a reproducible foundation for future validation, peer commentary, and comparative epigraphic study.All material is original and released for scholarly use under the CC BY-NC 4.0 license.