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# dynamic_to_json
> This page explains how to use the dynamic_to_json function in APL.
Use the `dynamic_to_json` function to convert a dynamic-typed value—such as a property bag, array, or nested JSON structure—into a canonical JSON string representation. This is helpful when you want to serialize dynamic data for storage, transmission, or further string manipulation.
You typically use `dynamic_to_json` when working with semi-structured data that you need to convert to a string format, especially when exporting data or passing dynamic values to functions that expect string input.
## For users of other query languages
If you come from other query languages, this section explains how to adjust your existing queries to achieve the same results in APL.
In Splunk, you typically use `tojson` or `mvjoin` with JSON formatting to convert structured data to JSON strings. In APL, `dynamic_to_json` provides a similar conversion from dynamic values to canonical JSON strings.
```sql Splunk example theme={null}
... | eval json_output = tojson({"key": "value"})
```
```kusto APL equivalent theme={null}
print dynamic_value = bag_pack("key", "value")
| extend json_output = dynamic_to_json(dynamic_value)
```
In standard SQL, you use `JSON_OBJECT` or `JSON_ARRAY` functions to create JSON strings, or `CAST(... AS JSON)` to convert values. In APL, `dynamic_to_json` converts dynamic values (which can be created from JSON strings using `todynamic`) back into canonical JSON string representations.
```sql SQL example theme={null}
SELECT JSON_OBJECT('key' VALUE 'value') AS json_output FROM dual;
```
```kusto APL equivalent theme={null}
print dynamic_value = bag_pack("key", "value")
| extend json_output = dynamic_to_json(dynamic_value)
```
## Usage
### Syntax
```kusto theme={null}
dynamic_to_json(dynamic)
```
### Parameters
| Name | Type | Description |
| ------- | ------- | ---------------------------------------------- |
| dynamic | dynamic | The dynamic value to convert to a JSON string. |
### Returns
Returns a canonical JSON string representation of the input according to the following rules:
* If the input is a scalar value of type other than `dynamic`, the output is the result of applying `tostring()` to that value.
* If the input is an array of values, the output is composed of the characters `[`, `,`, and `]` interspersed with the canonical representation of each array element.
* If the input is a property bag, the output is composed of the characters `{`, `,`, and `}` interspersed with colon (`:`)-delimited name/value pairs of the properties. The pairs are sorted by the names, and the values are in the canonical representation described here.
## Use case examples
Convert a dynamic object containing request metadata to a JSON string for logging or export purposes.
**Query**
```kusto theme={null}
['sample-http-logs']
| extend metadata = bag_pack('method', method, 'status', status, 'duration', req_duration_ms)
| extend json_metadata = dynamic_to_json(metadata)
| project _time, ['uri'], json_metadata
```
[Run in Playground](https://play.axiom.co/axiom-play-qf1k/query?initForm=%7B%22apl%22%3A%22%5B'sample-http-logs'%5D%20%7C%20extend%20metadata%20%3D%20bag_pack\('method'%2C%20method%2C%20'status'%2C%20status%2C%20'duration'%2C%20req_duration_ms\)%20%7C%20extend%20json_metadata%20%3D%20dynamic_to_json\(metadata\)%20%7C%20project%20_time%2C%20%5B'uri'%5D%2C%20json_metadata%22%7D)
**Output**
| \_time | uri | json\_metadata |
| ---------------- | ---------- | ----------------------------------------------- |
| Jun 24, 09:28:10 | /api/users | \{"duration":150,"method":"GET","status":"200"} |
This example creates a dynamic object from log fields and converts it to a JSON string, which you can use for exporting structured data or passing to string manipulation functions.
Serialize trace attributes stored as dynamic values into JSON strings for analysis or export.
**Query**
```kusto theme={null}
['otel-demo-traces']
| extend trace_attributes = bag_pack('service', ['service.name'], 'kind', ['kind'], 'status', ['status_code'])
| extend json_attributes = dynamic_to_json(trace_attributes)
| project _time, ['trace_id'], json_attributes
```
[Run in Playground](https://play.axiom.co/axiom-play-qf1k/query?initForm=%7B%22apl%22%3A%22%5B'otel-demo-traces'%5D%20%7C%20extend%20trace_attributes%20%3D%20bag_pack\('service'%2C%20%5B'service.name'%5D%2C%20'kind'%2C%20%5B'kind'%5D%2C%20'status'%2C%20%5B'status_code'%5D\)%20%7C%20extend%20json_attributes%20%3D%20dynamic_to_json\(trace_attributes\)%20%7C%20project%20_time%2C%20%5B'trace_id'%5D%2C%20json_attributes%22%7D)
**Output**
| \_time | trace\_id | json\_attributes |
| ---------------- | --------- | ------------------------------------------------------ |
| Jun 24, 09:28:10 | abc123 | \{"kind":"server","service":"frontend","status":"200"} |
This example converts trace attributes from dynamic format to JSON strings, making it easier to export or analyze trace metadata as structured text.
Convert dynamic security event data to JSON strings for reporting or integration with external systems.
**Query**
```kusto theme={null}
['sample-http-logs']
| extend security_event = bag_pack('timestamp', _time, 'status', ['status'], 'uri', ['uri'], 'location', strcat(['geo.city'], ', ', ['geo.country']))
| extend event_json = dynamic_to_json(security_event)
| project _time, event_json
```
[Run in Playground](https://play.axiom.co/axiom-play-qf1k/query?initForm=%7B%22apl%22%3A%22%5B'sample-http-logs'%5D%20%7C%20extend%20security_event%20%3D%20bag_pack\('timestamp'%2C%20_time%2C%20'status'%2C%20%5B'status'%5D%2C%20'uri'%2C%20%5B'uri'%5D%2C%20'location'%2C%20strcat\(%5B'geo.city'%5D%2C%20'%2C%20'%2C%20%5B'geo.country'%5D\)\)%20%7C%20extend%20event_json%20%3D%20dynamic_to_json\(security_event\)%20%7C%20project%20_time%2C%20event_json%22%7D)
**Output**
| \_time | event\_json |
| ---------------- | --------------------------------------------------------------------------------------------- |
| Jun 24, 09:28:10 | \{"location":"New York, US","status":"403","timestamp":"2024-06-24T09:28:10Z","uri":"/admin"} |
This example creates a structured security event as a dynamic object and converts it to JSON, which you can use for alerting systems or security information and event management (SIEM) integrations.
## List of related functions
* [todynamic](/apl/scalar-functions/conversion-functions/todynamic): Converts a JSON string to a dynamic value. Use `todynamic` to parse JSON strings, and `dynamic_to_json` to serialize dynamic values back to strings.
* [tostring](/apl/scalar-functions/conversion-functions/tostring): Converts any scalar value to a string. Use `tostring` for simple scalar conversions, and `dynamic_to_json` when you need canonical JSON formatting for dynamic values.
* [parse\_json](/apl/scalar-functions/string-functions/parse-json): Parses a JSON string into a dynamic value. Use `parse_json` to create dynamic values from JSON strings, and `dynamic_to_json` to convert them back.
* [toarray](/apl/scalar-functions/conversion-functions/toarray): Converts a dynamic value to an array. Use `toarray` when you need array operations, and `dynamic_to_json` when you need string output.