YAML

Description

yaml is a Stata command for reading, writing, and manipulating YAML configuration files. It provides a unified interface with nine subcommands that enable Stata users to integrate YAML-based workflows into their data pipelines.

The command implements the JSON Schema subset of YAML 1.2 (3rd Edition, 2021), the current authoritative YAML standard. It is implemented in pure Stata with no external dependencies.

Key features:

• Read YAML files into Stata’s data structure or frames
• Write YAML files from Stata datasets or scalars
• Query values using hierarchical key paths
• Validate configurations with required keys and type checking
• Multiple frame support (Stata 16+) for managing multiple configurations
• Fast-scan mode and Mata bulk parser for large metadata catalogs
• Indicators preset for wbopendata/unicefdata metadata

Examples

* Read a YAML configuration file
yaml read using config.yaml, replace

* View the structure
yaml describe

* Get a specific value
yaml get database:host
return list

* Validate required keys
yaml validate, required(name version database)

* Write modified configuration
yaml write using output.yaml, replace

* Parse wbopendata/unicefdata indicator metadata
yaml read using indicators.yaml, indicators replace
list key code name in 1/5

Citation

Azevedo, João Pedro. 2025. “yaml: Stata module for YAML file processing.” Statistical Software Components S459607, Boston College Department of Economics.

Documentation

• Stata: help yaml (after install)
• SSC page