interface runtime {
    /// An error type that encapsulates the different errors that can occur fetching config
    variant config-error {
        /// This indicates an error from an "upstream" config source. 
        /// As this could be almost _anything_ (such as Vault, Kubernetes ConfigMaps, KeyValue buckets, etc), 
        /// the error message is a string.
        upstream(string),
        /// This indicates an error from an I/O operation. 
        /// As this could be almost _anything_ (such as a file read, network connection, etc), 
        /// the error message is a string. 
        /// Depending on how this ends up being consumed, 
        /// we may consider moving this to use the `wasi:io/error` type instead. 
        /// For simplicity right now in supporting multiple implementations, it is being left as a string.
        io(string),
    }

    /// Gets a single opaque config value set at the given key if it exists
    get: func(
        /// A string key to fetch
        key: string
    ) -> result<option<string>, config-error>;

    /// Gets a list of all set config data
    get-all: func() -> result<list<tuple<string, string>>, config-error>;
}