;
};
By default, the AppSignal integrations will track request session data for web applications in supported libraries.
You can set custom request session data on a transaction or span. Modifying the session data will overwrite the data set by the AppSignal instrumentations.
[All request session data is filtered](/guides/filter-data/filter-session-data) by our integrations before being sent to our servers.
🔐 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 |
| Go | JSON serialized string |
| Java | JSON serialized string |
| PHP | Arrays, Objects |
```ruby Ruby theme={null}
# Call `add_session_data` multiple times to set more session data
Appsignal.add_session_data(
:user_id => "123",
:menu => { :type => "hamburger" }
)
Appsignal.add_session_data(:menu => { :state => "closed" })
Appsignal.add_session_data(:menu => { :state => "open" })
# Session data:
# {
# :user_id => "123",
# :menu => { :state => "open" }
# }
```
```elixir Elixir theme={null}
Appsignal.Span.set_sample_data(
Appsignal.Tracer.root_span,
"session_data",
%{user_id: "123", menu: "open"}
)
```
```javascript Node.js theme={null}
import { setSessionData } from "@appsignal/nodejs";
setSessionData({ user_id: "123", menu: "open" });
```
```python Python theme={null}
from appsignal import set_session_data
set_session_data({"user_id": "123", "menu": "open"})
```
```go Go theme={null}
// Additional setup is required to first fetch or create a new span
import (
"encoding/json"
"go.opentelemetry.io/otel/attribute"
"go.opentelemetry.io/otel/trace"
)
session_data := map[string]interface{}{
"key1": "value1",
"key2": "value2",
"nested": map[string]interface{}{
"key3": "value3",
"key4": "value4",
},
}
json, _ := json.Marshal(session_data)
span.SetAttributes(attribute.String("appsignal.request.session_data", string(json)))
```
```java Java theme={null}
// Additional setup is required to first fetch or create a new span
import io.opentelemetry.api.trace.Span;
// We're using the Jackson JSON library
// You may need to add it to your project as a dependency
import com.fasterxml.jackson.databind.ObjectMapper;
import java.util.HashMap;
import java.util.Map;
Map sessionData = new HashMap<>();
sessionData.put("user_id", "123");
sessionData.put("menu", "open");
Map nested = new HashMap<>();
nested.put("key3", "value3");
nested.put("key4", "value4");
sessionData.put("nested", nested);
try {
ObjectMapper mapper = new ObjectMapper();
String jsonString = mapper.writeValueAsString(sessionData);
Span span = Span.current();
span.setAttribute("appsignal.request.session_data", jsonString);
} catch (Exception e) {
// Add error handling here
}
```
```php PHP theme={null}
'value1',
'param2' => 'value2',
'nested' => [
'param3' => 'value3',
'param4' => 'value4',
],
];
Appsignal::setSessionData($data);
```
For certain languages, additional setup is required.
Please follow the instructions for these languages:
* [Go](/go/custom-instrumentation)
* [Java](/java/custom-instrumentation)
Limitations
If the application sets session data multiple times, the Ruby gem will merge values at the root level.
For other integrations, only the last set value is stored.
This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.
