;
};
You can use custom sample data to set more dynamic values than is possible with [other types of data customization](/guides/custom-data).
🔐 Do not send Personal Identifiable Information (PII) to AppSignal. Filter PII (e.g., names, emails) and use an ID, hash, or pseudonymized identifier instead.
Use [Link Templates](https://docs.appsignal.com/application/link-templates) to link them back in your app.
See the table below for a list of accepted root values per language. Each nested object can contain values that result in valid JSON (strings, integers, floats, booleans, nulls, etc.).
| Language | Accepted root values |
| ---------- | -------------------- |
| Ruby | Arrays, Hashes |
| JavaScript | Arrays, Objects |
| Elixir | Lists, Maps |
| Python | Lists, Maps |
| PHP | Arrays, Objects |
It is not possible to filter or search on the data set as custom data. It only provides an additional area in the interface to list more metadata.
When using custom data for nested objects, you can view the object on the Incident Sample page for both Exception and Performance samples formatted as JSON, like in the example below:
```ruby Ruby theme={null}
# Call `add_custom_data` multiple times to add more custom data
# Hash example
Appsignal.add_custom_data(
:stroopwaffle => { :caramel => true },
:market => { :type => "outdoors" }
)
Appsignal.add_custom_data(:market => { :state => :closed })
Appsignal.add_custom_data(:market => { :state => :open })
# Custom data:
# {
# :stroopwaffle => { :caramel => true },
# :market => { :state => :open }
# }
# Array example
Appsignal.add_custom_data(["value 1"])
Appsignal.add_custom_data(["value 2"])
# Custom data: ["value 1", "value 2"]
# Mixed data type example
# The Hash and Array data type cannot be mixed at the root level
Appsignal.add_custom_data(:market => :open)
Appsignal.add_custom_data(["value 1"])
# Custom data: ["value 1"]
```
```elixir Elixir theme={null}
# Map
Appsignal.Span.set_sample_data(
Appsignal.Tracer.root_span,
"custom_data",
%{
stroopwaffle: %{
caramel: true,
origin: "market"
}
}
)
# List
Appsignal.Span.set_sample_data(
Appsignal.Tracer.root_span,
"custom_data",
[
"value 1",
"value 2"
]
)
```
```javascript Node.js theme={null}
import { setCustomData } from "@appsignal/nodejs";
// Object
setCustomData({
stroopwaffle: {
caramel: true,
origin: "market",
},
});
// Array
setCustomData(["value 1", "value 2"]);
```
```python Python theme={null}
from appsignal import set_custom_data
# Map
set_custom_data({
"stroopwaffle": {
"caramel": true,
"origin": "market"
}
})
# Array
set_custom_data(["value 1", "value 2"])
```
```php PHP theme={null}
[
'caramel' => true,
'origin' => 'market',
],
]);
```
If the application sets custom data multiple times, the Ruby gem will merge values at the root level. For other integrations, only the last set value is stored.
