Layered configuration system for Rust applications (with strong support for 12-factor applications).

• Set defaults
• Set explicit values (to programmatically override)
• Read from JSON, TOML, YAML, INI, RON, JSON5 files
• Read from environment
• Loosely typed — Configuration values may be read in any supported type, as long as there exists a reasonable conversion
• Access nested fields using a formatted path — Uses a subset of JSONPath; currently supports the child ( redis.port ) and subscript operators ( databases[0].name )

Please note this library

• can not be used to write changed configuration values back to the configuration file(s)!
• Is case insensitive and all the keys are converted to lowercase internally

[dependencies]
config = "0.14.0"

• ini - Adds support for reading INI files
• json - Adds support for reading JSON files
• yaml - Adds support for reading YAML files
• toml - Adds support for reading TOML files
• ron - Adds support for reading RON files
• json5 - Adds support for reading JSON5 files

Library provides out of the box support for most renowned data formats such as JSON or Yaml. Nonetheless, it contains an extensibility point - a Format trait that, once implemented, allows seamless integration with library's APIs using custom, less popular or proprietary data formats.

See custom_file_format example for more information.

See the documentation or examples for more usage information.

We currently support Rust 1.75.0 and newer.

config-rs is primarily distributed under the terms of both the MIT license and the Apache License (Version 2.0).

See LICENSE-APACHE and LICENSE-MIT for details.