Read JSON

Read JSON

Type: read-json  ·  Package: JSON Activities v1.0.4  ·  Output: object

Reads a JSON file and returns its content already structured: a dictionary (object) or a list (array), navigable by keys and indexes. You don’t need to parse any text: the result is ready to use.

How it works

Reads the file at path, parses its JSON and returns the structure. Then you access the data with expressions: data["key"], list[0], data["items"][0]["name"].

• Strict format: the file must be valid JSON. Comments (//), trailing commas and single quotes are not accepted.
• Encoding: UTF-8 (UTF-16/UTF-32 are also recognized when the file has a BOM).
• Value conversion: objects → dictionary, arrays → list, integers → long, decimals → double. See how values are converted.
• Read-only: the file is not changed. It is loaded fully into memory.

Required parameters

Parameter	Type	Default	Description
path	string	—	Path of the JSON file.

Optional parameters

None.

Output

Returns an object whose type depends on the JSON root:

• { … } → dictionary (Dictionary) with text keys.
• [ … ] → list (List).
• A single value ("text", 42, true) → that value.

Reading a key that does not exist returns an empty value, not an error: check it with isNull(config["key"]).

Common errors

Message	Cause and fix
File not found.	path does not exist. Check it with File Exists.
'…' is an invalid start of a value. LineNumber: … | BytePositionInLine: …. (or another system JSON error)	The content is not valid JSON: comments, trailing commas, single quotes or non-JSON text. The message gives the line and position. Fix the file.
The input does not contain any JSON tokens…	The file is empty.
The file does not contain valid JSON.	The file contains only null.
'path' is required.	The path expression evaluated to null.

Example

Read JSON   path = asset("config.json")   → output: config
Set Variable   name = outputFolder   value = config["outputFolder"]
Log   message = "First item: " + str(config["items"][0]["name"])

For Each   items = config["items"]   itemVariable = item
 └─ activities:
      Log   message = "Processing " + item["name"]

JSON from an API?

If the JSON comes in the response of an HTTP request, don’t write it to a file just to read it: it is already parsed in response.Body. Read JSON is for JSON stored in files. If you have the JSON in a text variable, use the parseJson(text) function in an expression.

Related activities

• Write JSON — save a value as JSON.
• HTTP GET — receive JSON from an API.