From Embulk v0.9.16 (Released on 2019/03/11) has started to support built-in json parser.

• The embulk built-in json parser has same behavior for the columns option.
• The embulk built-in json parser does not support automatic type conversion with the default_typecast option.

For more detail you can visit this article

JSONL (JSON Lines) parser plugin for Embulk

• Plugin type: parser
• Guess supported: yes

• type: Specify this parser as jsonl
• columns: Specify column name and type. See below (array, required)

• stop_on_invalid_record: Stop bulk load transaction if a file includes invalid record (such as invalid timestamp) (boolean, default: false)
• default_timezone: Default timezone of the timestamp (string, default: UTC)
• default_timestamp_format: Default timestamp format of the timestamp (string, default: %Y-%m-%d %H:%M:%S.%N %z)
• newline: Newline character (CRLF, LF or CR) (string, default: CRLF)
• charset: Character encoding (eg. ISO-8859-1, UTF-8) (string, default: UTF-8)
• default_typecast: Specify whether to cast values automatically to the specified types or not (boolean, default: true)
• min_rows_for_guess: Minimum rows for guess (integer, default: 4)

• name: Name of the column (string, required)
• type: Type of the column (string, required)
• timezone: Timezone of the timestamp if type is timestamp (string, default: default_timestamp)
• format: Format of the timestamp if type is timestamp (string, default: default_format)
• typecast: Whether cast values or not (boolean, default: default_typecast)

(If guess supported) you don't have to write parser: section in the configuration file. After writing in: section, you can let embulk guess parser: section using this command:

$ embulk gem install embulk-parser-jsonl
$ embulk guess -g jsonl config.yml -o guessed.yml

$ ./gradlew gem classpath