• Added support for command files: a sequence of mapshaper commands stored in a .txt file, with # comments and no need for shell quoting or backslash line continuations. Run a command file with -run <file> (or just mapshaper commands.txt).
• Added {{VAR}} variable interpolation for mapshaper command options, resolved at run time against environment variables ({{env.HOME}}), variables set by -vars and -defaults, and variables defined dynamically by commands like -calc, -define and -each.
• Added the -vars command to assign variables (from key=value pairs or a JSON file) and the -defaults command to set variables only if they are not already defined.
• The -dissolve command now repairs polygon topology by default, producing correct output on inputs that contain overlaps, gaps or other topology errors. The legacy fast algorithm is still available via -dissolve no-repair, which prints a warning if it detects segment intersections in the input.
• The -dissolve2 command is now a deprecated alias for -dissolve.
• Added a batch-mode flag to the -i command, which makes batch processing of multiple input files explicit (mapshaper *.shp batch-mode -o dest/). Implicit batch mode (triggered by passing multiple files without a flag) is now deprecated and will print a notice; the default will change in a future release so multiple files are imported together unless batch-mode is given.