This file includes source code archive for Earth System Model (ESM) aerosol-cloud diagnostics package (ESMAC Diags) that facilitate routine evaluation of aerosols, clouds and aerosol-cloud interactions simulated by the Department of Energy’s (DOE) Energy Exascale Earth System Model (E3SM). This version (v2.1.2) is used in the manuscript "Earth System Model Aerosol-Cloud Diagnostics Package (ESMAC Diags) Version 2: Assessments of Aerosols, Clouds and Aerosol-Cloud Interactions Through Field Campaign and Long-Term Observations" to be submitted to Geoscientific Model Development.