This article investigates the programmatic infrastructure of legislative transparency in Brazilian State Legislative Assemblies, with a focus on the availability of data in machine-readable formats and accessible via Application Programming Interfaces (APIs). Using a comparative and descriptive approach, the study analyzes all 26 state assemblies and the Federal District Legislative Chamber based on objective technical criteria, including the existence of APIs, thematic data scope, and documentation quality. A typology of digital maturity—high, medium, low, and absent—is proposed to classify the robustness of institutional digital transparency. Findings reveal a federative ecosystem marked by significant asymmetry and technical fragmentation. By exploring the idea of “democracy in JSON format”, this study argues that effective transparency depends on reusable, interoperable, and integrable digital infrastructures, with direct implications for social accountability and civic innovation.