Write JSON

Write JSON

Type: write-json  ·  Package: JSON Activities v1.0.4  ·  Output: string

Converts a value (a dictionary, a list, a table) to JSON and saves it to a file. Useful to produce settings files, export data or leave a summary another system can read.

How it works

Serializes value to JSON and writes it to path. By default it formats the result for readability (indented = true). Returns the written path.

• What gets converted: dictionaries → objects, lists → arrays, texts, numbers, booleans and dates (ISO 8601, 2026-10-15T08:30:00). A DataTable is saved as an array of objects, one per row (column → value; empty cells → null). A null value writes null.
• Special characters: accented letters and characters such as <, > or & are saved as \u00E1-style sequences. It is valid JSON and any reader (including Read JSON) gets them back unchanged.
• File: written as UTF-8 without BOM. If it exists, it is replaced; if the folder does not exist, it is created.
• Idempotent: repeating it with the same value leaves the same file.

Required parameters

Parameter	Type	Default	Description
path	string	—	Path of the output JSON file, including its folder.
value	object	—	The value to convert: dictionary, list, DataTable, text, number…

Optional parameters

Parameter	Type	Default	Description
indented	bool	true	Format with line breaks and indentation so it is easy to read. With false, everything goes on one line (smaller file).

Output

Returns a string with the path of the written file (as you gave it in path).

Common errors

Message	Cause and fix
The process cannot access the file '…' because it is being used by another process.	The file is open in another program.
Access to the path '…' is denied.	No write permission on the folder.
'path' is required.	The path expression evaluated to null.

If path has no folder (just a file name), the activity fails: use a full path. Values of special types (for example a single DataRow or an open session) cannot be converted to JSON: turn them into a dictionary first.

Example

Create Dictionary   → output: result
Set Dictionary Value   dict = result   key = "processed"   value = total
Set Dictionary Value   dict = result   key = "date"        value = today().ToString("yyyy-MM-dd")
Write JSON   path = "C:/output/summary.json"   value = result   → output: summaryPath
Log   message = "Summary saved to " + summaryPath

Result in C:/output/summary.json:

{
  "processed": 42,
  "date": "2026-10-15"
}

Related activities

• Read JSON — read a JSON file.
• Create Dictionary — build the value to save.