Skip to content
LainstackDocs

Parse JSON

Parses JSON text into native Data.

@lainstack/data/parse-json · Data

How to use it

Section titled “How to use it”

Parse JSON turns one JSON text into native Data under value. The output has no declared field types. To get typed downstream references, follow it with @lainstack/data/apply-shape.

Choose it when a block gives you JSON as text. Do not use it for CSV files (use @lainstack/csv/parse). Do not use it to read values out of data that is already a record or list; reference those paths directly.

Traps:

  • The parser is strict. It accepts one JSON value only. No comments, trailing commas, or text after the value.
  • Text longer than 10,000 characters fails. Lists and records hold at most 100 items or fields. Nesting is at most 32 levels and the whole value at most 4,096 nodes.
  • Duplicate keys fail instead of keeping the last one.
  • A number that would lose precision fails, for example an integer above the safe integer range. Large identifiers must arrive as JSON strings.
  • A syntax error fails the step with json_syntax_invalid and the line and column. A limit or value problem fails with json_value_invalid. Neither retries.
  • text must be a text value. A record or list is invalid config.

Settings

Section titled “Settings”
Setting Key Type Details
Text (required) text Text Parse one strict JSON value into native Data.

Outputs

Section titled “Outputs”
Output Path Type
Value value Value