Document updated on Jan 31, 2023

Supported Configuration Formats

The expected configuration file format by default is json, but KrakenD can parse any of these file formats:

• .json (recommended)
• .toml
• .yaml
• .yml
• .properties
• .props
• .prop
• .hcl

You can validate the syntax of any of these with krakend check

Why is JSON recommended?

You are free to choose json, yaml, toml or any of the other formats listed above at your best convenience. But have in mind the following limitations when choosing a file format that is not json:

• Using the UI: If you intend to generate or edit your configuration file using the KrakenDesigner, the input and output are always a .json file.
• Flexible Configuration: If you want to split the configuration file into different pieces or use variables inside the configuration, the flexible configuration works better with json, as formats that need a proper indentation present more problems to control it (e.g.: yaml).
• Documentation: All our examples in the documentation and repositories are today shown in json format, so it’s always more convenient to reuse snippets of code (copy and paste!).
• Linting: You cannot use the --lint flag on the check command because expects json content to validate its schema (you could convert the file using a 3rd party tool though). You can still use the rest of the check commands.

As you can see, if you are OK with the limitations above, you can freely choose any other format.

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