> ## Documentation Index
> Fetch the complete documentation index at: https://docs.flashduty.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Data Collection
> Learn about the data types, event attributes, performance metrics, and data storage mechanisms collected by Web RUM SDK
Web RUM SDK automatically collects rich user behavior and performance data. Each RUM event includes default attributes (such as `view.url`, `device.type`, `geo.country`) as well as additional metrics and attributes specific to each event type.
## Default Attributes
Web RUM SDK automatically captures the following default attributes, applicable to all RUM event types.
| Attribute | Type | Description |
| ---------------- | ------- | ------------------------------------------------------------------- |
| `date` | Integer | Event timestamp (in milliseconds, epoch milliseconds) |
| `type` | String | Event type (e.g., `session`, `view`, `resource`, `error`, `action`) |
| `application.id` | String | Application unique identifier |
| `service` | String | Service name that generated this event |
| `env` | String | Application environment name (e.g., `prod`, `dev`, `staging`) |
| `version` | String | Application version |
| `sdk_version` | String | RUM SDK version |
| Attribute | Type | Description |
| -------------- | ------ | ---------------------------------------------------------------- |
| `device.type` | String | Device type (e.g., `Desktop`, `Mobile`, `Tablet`, `TV`, `Other`) |
| `device.brand` | String | Device brand (e.g., `Apple`, `Samsung`, `Huawei`) |
| `device.model` | String | Device model (e.g., `iPhone`, `iPad`) |
| `device.name` | String | Device commercial name |
| Attribute | Type | Description |
| ------------------ | ------ | -------------------------------------------------------- |
| `os.name` | String | Operating system name (e.g., `Mac OS`, `Windows`, `iOS`) |
| `os.version` | String | Operating system version (e.g., `10.15.7`, `11.0`) |
| `os.version_major` | String | Operating system major version (e.g., `10`, `11`) |
| Attribute | Type | Description |
| ------------------------- | ------ | ---------------------------------------------------------- |
| `browser.name` | String | Browser name (e.g., `Chrome`, `Firefox`, `Safari`, `Edge`) |
| `browser.version` | String | Browser version (e.g., `91.0.4472.124`) |
| `browser.version_major` | String | Browser major version (e.g., `91`) |
| `browser.user_agent` | String | User Agent string |
| `browser.viewport.width` | Number | Browser viewport width (pixels) |
| `browser.viewport.height` | Number | Browser viewport height (pixels) |
| Attribute | Type | Description |
| ------------------------- | ------ | ---------------------------------------------------------------------- |
| `geo.country` | String | Country name |
| `geo.country_iso_code` | String | Country ISO code (e.g., `US`, `CN`) |
| `geo.country_subdivision` | String | First-level administrative division (e.g., US states, China provinces) |
| `geo.continent_code` | String | Continent ISO code (e.g., `EU`, `AS`, `NA`) |
| `geo.continent` | String | Continent name |
| `geo.city` | String | City name |
Geo-location information is inferred by FlashCat backend based on client IP address. Precise GPS location is not collected on the client.
| Attribute | Type | Description |
| ----------- | ------ | --------------------------------------------------- |
| `usr.id` | String | User unique identifier |
| `usr.name` | String | User-friendly name, displayed by default in RUM UI |
| `usr.email` | String | User email address. Displayed if no username is set |
You can also add custom user attributes such as `usr.plan`, `usr.role`, etc. To set user information, see [SDK Integration Guide](/en/rum/sdk/web/sdk-integration#custom-user-identification).
## Event-Specific Attributes
Different event types have specific attributes and metrics.
| Attribute | Type | Description |
| --------------------------- | ------- | ---------------------------------------- |
| `session.id` | String | Session unique identifier |
| `session.type` | String | Session type (e.g., `user`, `synthetic`) |
| `session.is_active` | Boolean | Whether session is active |
| `session.initial_view.id` | String | Initial view ID in session |
| `session.initial_view.url` | String | Initial view URL in session |
| `session.initial_view.name` | String | Initial view name in session |
| `session.last_view.id` | String | Last view ID in session |
| `session.last_view.url` | String | Last view URL in session |
| `session.last_view.name` | String | Last view name in session |
| `session.has_replay` | Boolean | Whether session has replay enabled |
RUM collects all performance metrics from the [Navigation Timing API](https://www.w3.org/TR/navigation-timing/) as well as metrics related to [Core Web Vitals](https://web.dev/vitals/).
**Core Web Vitals**
| Attribute | Type | Description |
| -------------------------------- | ----------- | ---------------------------------------------------------------------------------------------- |
| `view.largest_contentful_paint` | Number (ns) | Largest Contentful Paint (LCP), render time of the largest visible content element in viewport |
| `view.first_input_delay` | Number (ns) | First Input Delay (FID), time from user's first interaction to browser's actual response |
| `view.cumulative_layout_shift` | Number | Cumulative Layout Shift (CLS), quantifies unexpected movement of visible elements in viewport |
| `view.interaction_to_next_paint` | Number (ns) | Interaction to Next Paint (INP), measures latency of all user interactions with the page |
**Navigation Performance Metrics**
| Attribute | Type | Description |
| ----------------------------- | ----------- | --------------------------------------------------------------------------------------------------------------- |
| `view.time_spent` | Number (ns) | Time user spent on this view |
| `view.loading_time` | Number (ns) | Time for page to fully load (triggered at `loadEventEnd`) |
| `view.first_contentful_paint` | Number (ns) | First Contentful Paint (FCP), time when browser first renders any text, image, non-blank canvas or SVG |
| `view.first_byte` | Number (ns) | Time to First Byte (TTFB), time from user initiating page load to browser receiving first byte of HTML document |
| `view.dom_interactive` | Number (ns) | Time when parser finished working on main document (`domInteractive`) |
| `view.dom_content_loaded` | Number (ns) | Time when initial HTML document is fully loaded and parsed |
| `view.dom_complete` | Number (ns) | Time when page and all sub-resources are ready (`domComplete`) |
| `view.load_event` | Number (ns) | Time when load event fired (`loadEventEnd`), indicating page fully loaded |
**Network Timing Metrics**
| Attribute | Type | Description |
| ------------------------------------- | ----------- | ----------------------------------------- |
| `view.redirect.duration` | Number (ns) | Time spent on redirects |
| `view.dns.duration` | Number (ns) | Time spent on DNS lookup |
| `view.connect.duration` | Number (ns) | Time spent establishing server connection |
| `view.ssl.duration` | Number (ns) | Time spent on TLS handshake |
| `view.request.duration` | Number (ns) | Time spent requesting HTML document |
| `view.response.duration` | Number (ns) | Time spent downloading HTML document |
| `view.in_foreground_periods.count` | Number | Number of times view was in foreground |
| `view.in_foreground_periods.duration` | Number (ns) | Total time view was in foreground |
| Attribute | Type | Description |
| ---------------------- | ------- | --------------------------------------------- |
| `view.id` | String | View unique identifier |
| `view.url` | String | View URL |
| `view.name` | String | Customizable view name |
| `view.referrer` | String | Previous page URL (referrer) |
| `view.action.count` | Number | Number of user actions collected in this view |
| `view.error.count` | Number | Number of errors collected in this view |
| `view.resource.count` | Number | Number of resources collected in this view |
| `view.long_task.count` | Number | Number of long tasks collected in this view |
| `view.is_active` | Boolean | Whether view is active |
RUM collects detailed network timing information from the [Resource Timing API](https://www.w3.org/TR/resource-timing-2/) for individual resource loading.
| Attribute | Type | Description |
| --------------------------------- | -------------- | ------------------------------------------------------------ |
| `resource.duration` | Number (ns) | Total time to load resource |
| `resource.size` | Number (bytes) | Resource size |
| `resource.connect.duration` | Number (ns) | Time to establish server connection |
| `resource.ssl.duration` | Number (ns) | Time for TLS handshake (HTTPS only) |
| `resource.dns.duration` | Number (ns) | Time for DNS resolution |
| `resource.redirect.duration` | Number (ns) | Time for redirects |
| `resource.first_byte.duration` | Number (ns) | Time waiting to receive first byte of response |
| `resource.download.duration` | Number (ns) | Time to download response |
| `resource.render_blocking_status` | String | Resource render blocking status (`blocking`, `non-blocking`) |
| `resource.first_party` | Boolean | Whether resource is first-party (same domain as application) |
| Attribute | Type | Description |
| -------------------------- | ------ | -------------------------------------------------------------------------------- |
| `resource.id` | String | Resource unique identifier |
| `resource.type` | String | Resource type (e.g., `xhr`, `fetch`, `css`, `js`, `image`, `font`, `media`) |
| `resource.method` | String | HTTP method (e.g., `GET`, `POST`, `PUT`, `DELETE`) |
| `resource.status_code` | Number | HTTP response status code |
| `resource.url` | String | Resource URL |
| `resource.url_host` | String | URL host part |
| `resource.url_path` | String | URL path part |
| `resource.url_query` | Object | URL query parameters, parsed as key-value pairs |
| `resource.url_scheme` | String | URL scheme (e.g., `https`, `http`) |
| `resource.provider.name` | String | Resource provider name, defaults to `unknown` |
| `resource.provider.domain` | String | Resource provider domain |
| `resource.provider.type` | String | Resource provider type (e.g., `first-party`, `cdn`, `ad`, `analytics`, `social`) |
If GraphQL request tracking is enabled, the following attributes are attached to `resource` events:
| Attribute | Type | Description |
| --------------------------------- | ------ | ---------------------------------------------------------------------------------------------------- |
| `resource.graphql.operation_type` | String | GraphQL operation type (`query`, `mutation`, `subscription`) |
| `resource.graphql.operation_name` | String | GraphQL operation name (if provided in request) |
| `resource.graphql.variables` | String | GraphQL variables sent with request |
| `resource.graphql.payload` | String | GraphQL query (limited to 32 KB, only available when `trackPayload` is enabled) |
| `resource.graphql.errors_count` | Number | Number of errors returned in GraphQL response (only available when `trackResponseErrors` is enabled) |
| `resource.graphql.errors` | Array | GraphQL errors array, containing message, code, locations and path |
Long tasks are tasks that block the main thread for 50 milliseconds or longer. These tasks cause high input delay, slow interactions, or janky animations/scrolling.
| Attribute | Type | Description |
| --------------------------- | ----------- | ---------------------------------------------------- |
| `long_task.duration` | Number (ns) | Long task duration |
| `long_task.is_frozen_frame` | Boolean | Whether it's a frozen frame (duration exceeds 700ms) |
Long task detection is only available in browsers that support the Long Tasks API (Chrome, Edge). Safari and Firefox don't support this feature.
Frontend errors are collected via RUM. Error messages and stack traces (if available) are included.
**General Error Attributes**
| Attribute | Type | Description |
| ---------------------- | ------ | ----------------------------------------------------------------------------------------------------- |
| `error.id` | String | Error unique identifier |
| `error.source` | String | Error source (e.g., `console`, `network`, `source`, `logger`, `agent`, `webview`, `custom`, `report`) |
| `error.type` | String | Error type (in some cases, error code) |
| `error.message` | String | Concise, human-readable one-line error message |
| `error.stack` | String | Error stack trace or supplementary information |
| `error.issue_id` | String | Error issue unique identifier (same errors are grouped into the same issue) |
| `error.fingerprint` | String | Fingerprint for uniquely identifying the error |
| `error.handling` | String | Error handling method (`handled`, `unhandled`) |
| `error.handling_stack` | String | Stack trace when error was handled |
| `error.causes` | Array | Information about other errors that caused this error |
**Network Error Attributes**
Network errors contain information about failed HTTP requests:
| Attribute | Type | Description |
| -------------------------------- | ------ | ---------------------------------------------------------------------- |
| `error.resource.status_code` | Number | HTTP response status code |
| `error.resource.method` | String | HTTP method (e.g., `GET`, `POST`) |
| `error.resource.url` | String | Resource URL |
| `error.resource.url_host` | String | URL host part |
| `error.resource.url_path` | String | URL path part |
| `error.resource.url_scheme` | String | URL scheme |
| `error.resource.provider.name` | String | Resource provider name, defaults to `unknown` |
| `error.resource.provider.domain` | String | Resource provider domain |
| `error.resource.provider.type` | String | Resource provider type (e.g., `first-party`, `cdn`, `ad`, `analytics`) |
For more information about different JavaScript error types, see [MDN documentation](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error).
**Action Timing Attributes**
| Attribute | Type | Description |
| ------------------------ | ----------- | --------------------------------------------- |
| `action.loading_time` | Number (ns) | Action loading time |
| `action.long_task.count` | Number | Number of long tasks triggered by this action |
| `action.resource.count` | Number | Number of resources triggered by this action |
| `action.error.count` | Number | Number of errors triggered by this action |
**Action Identification Attributes**
| Attribute | Type | Description |
| -------------------- | ------ | ----------------------------------------------------------------------------------------------------------- |
| `action.id` | String | User action unique identifier (UUID) |
| `action.type` | String | User action type (e.g., `click`, `custom`). Set to `custom` for custom user actions |
| `action.target.name` | String | Element user interacted with. Only for auto-collected actions |
| `action.name` | String | User-friendly name (e.g., `Click on #checkout`). For custom user actions, the action name given in API call |
RUM automatically detects user frustration signals, helping you understand problems users encounter in your application.
| Attribute | Type | Description |
| ------------------------------------- | ------ | --------------------------------------------------------------- |
| `session.frustration.count` | Number | Total frustration signals in session |
| `view.frustration.count` | Number | Total frustration signals in view |
| `action.frustration.type:dead_click` | String | Dead click detected by RUM SDK (click with no response) |
| `action.frustration.type:rage_click` | String | Rage click detected by RUM SDK (rapid consecutive clicks) |
| `action.frustration.type:error_click` | String | Error click detected by RUM SDK (click that triggered an error) |
Frustration signals are important indicators for identifying user experience issues. Dead clicks and rage clicks typically indicate UI response delays or interaction design problems.
If the URL contains UTM parameters, RUM automatically captures the following attributes for tracking marketing campaigns:
| Attribute | Type | Description |
| ----------------------------- | ------ | ------------------------------------------------------------------------------- |
| `view.url_query.utm_source` | String | URL parameter tracking traffic source |
| `view.url_query.utm_medium` | String | URL parameter tracking which channel traffic came from |
| `view.url_query.utm_campaign` | String | URL parameter identifying specific marketing campaign associated with this view |
| `view.url_query.utm_content` | String | URL parameter identifying specific element user clicked in marketing campaign |
| `view.url_query.utm_term` | String | URL parameter tracking keyword user searched to trigger given campaign |
## Data Storage
Before uploading to FlashCat, data is temporarily stored in plaintext in the browser's local storage (LocalStorage or SessionStorage).
SDK adds events to an in-memory batch buffer.
When network is unavailable, batches are retained in local storage.
When network is available, data is sent to server in batches.
Data exceeding certain time limits is automatically cleaned up to avoid excessive storage usage.
Sensitive data should not be included in RUM events, or should be obfuscated or filtered via the `beforeSend` callback before sending.
## Data Upload
Web RUM SDK uploads collected events to the server in batches to optimize network performance and reduce impact on user experience.
### Batch Upload Triggers
* Event count in batch reaches threshold
* Batch size reaches threshold
* Periodic upload (e.g., every 10 seconds)
* Page unload (`beforeunload` event)
### Upload Strategy
| Strategy | Description |
| ---------------------- | --------------------------------------------------------------------------- |
| **Beacon API** | Preferred, ensures data isn't lost when page unloads |
| **XHR/Fetch Fallback** | If Beacon API unavailable, uses XMLHttpRequest or Fetch API |
| **Failure Retry** | If upload fails, batch is retained in local storage until successfully sent |
| **Data Compression** | Batch data is compressed before upload to reduce network traffic |
## Privacy and Compliance
SDK can be configured to anonymize IP addresses
Use `beforeSend` callback to filter or obfuscate sensitive information
Configurable whether to use cookies and local storage
Supports user privacy opt-out mechanism
For detailed privacy configuration information, see [Advanced Configuration](/en/rum/sdk/web/advanced-config#user-tracking-consent).
## More Information
Learn how to integrate RUM SDK in Web applications
Learn how to configure advanced SDK features
Learn about SDK browser and framework compatibility