iOS SDK Data Collection

iOS RUM SDK automatically generates events with relevant metrics and attributes. Each RUM event includes default attributes (such as view.url, device.type, geo.country) as well as event-specific metrics and attributes (such as view.time_spent, resource.method).

App Startup Metrics

During app startup, the iOS SDK automatically records app startup time and creates corresponding views.

Startup time measures the time interval from process start to the first applicationDidBecomeActive notification.

Attribute	Type	Description
`view.is_start_view`	Boolean	Identifies if this view is the initial view created at app startup
`action.type`	String	Type of app startup action, value is `application_start`
`action.loading_time`	Number (ns)	Time required for app startup

View Monitoring

In iOS apps, views are automatically created when users visit different screens. Views start recording when users open a screen and stop when the view is no longer visible.

View Lifecycle Management:

Views don’t end immediately when stopped, but remain in inactive state for a period
If a new view starts during this period, the previous view will completely end
If no new view starts, the previous view will resume to active state

Background Behavior:

When app enters background, SDK retains the last active view and monitors background events
Background time is not counted toward the active view’s time_spent metric
If user returns to app immediately, SDK resumes the original time_spent measurement

Default Attributes

iOS RUM SDK automatically attaches default attributes to all events, helping you understand user devices, network status, and app context.

Core Attributes

Attribute	Type	Description
`date`	Integer	Event timestamp (milliseconds)
`type`	String	Event type (e.g., `session`, `view`, `resource`, `error`, `action`)
`service`	String	Service name that generated this event
`application.id`	String	Application unique identifier

Device Attributes

The following device-related attributes are automatically attached to all events:

Attribute	Type	Description
`device.type`	String	Device type (e.g., `Mobile`, `Tablet`, `TV`, `Desktop`, `Other`)
`device.brand`	String	Device brand, `Apple` for iOS devices
`device.model`	String	Device model (e.g., `iPhone`, `iPad`, `iPod Touch`, `Apple TV`)
`device.name`	String	Device name

Operating System Attributes

The following OS-related attributes are automatically attached to all events:

Attribute	Type	Description
`os.name`	String	Operating system name (e.g., `iOS`, `iPadOS`, `tvOS`)
`os.version`	String	Operating system version (e.g., `15.4.1`, `16.0`)
`os.version_major`	String	Operating system major version (e.g., `15`, `16`)

Network Connectivity Attributes

The following network-related attributes are automatically attached to resource and error events:

Attribute	Type	Description
`connectivity.status`	String	Device network connection status (e.g., `connected`, `not_connected`)
`connectivity.interfaces`	String Array	Available network interface types (e.g., `wifi`, `cellular`, `ethernet`)
`connectivity.cellular.technology`	String	Cellular network technology type (e.g., `3G`, `4G`, `LTE`, `5G`)
`connectivity.cellular.carrier_name`	String	Cellular network carrier name

Geo-location Attributes

The following attributes relate to IP address geo-location:

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`)
`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.

Global User Attributes

You can enable user tracking on all RUM events to correlate user sessions and simplify troubleshooting.

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
`usr.anonymous_id`	String	Anonymous user identifier

User attributes are optional but we recommend providing at least one. See Track User Information.

Only the standard user fields above are supported. Other user attributes are not supported. If needed, configure them under context.

Event-Specific Attributes

Different event types have specific attributes and metrics.

Session Attributes

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_crash`	Boolean	Whether session contains crash events
`session.has_replay`	Boolean	Whether session has replay enabled

View Attributes

Attribute	Type	Description
`view.id`	String	View unique identifier
`view.url`	String	View URL, corresponds to UIViewController class name
`view.name`	String	Customizable view name
`view.referrer`	String	Previous view URL
`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.time_spent`	Number (ns)	Time user spent on this view
`view.network_settled_time`	Number (ns)	Time for view to fully initialize at startup
`view.is_active`	Boolean	Whether view is active
`view.is_slow_rendered`	Boolean	Whether view rendering is slow
`view.crash.count`	Number	Number of crashes in this view
`view.frozen_frame.count`	Number	Number of frozen frames in this view
`view.refresh_rate_average`	Number	View average refresh rate
`view.refresh_rate_min`	Number	View minimum refresh rate
`view.memory_average`	Number	View average memory usage
`view.memory_max`	Number	View maximum memory usage
`view.cpu_ticks_count`	Number	View CPU tick count
`view.cpu_ticks_per_second`	Number	View CPU ticks per second

Resource Attributes

Attribute	Type	Description
`resource.id`	String	Resource unique identifier
`resource.url`	String	Resource URL
`resource.method`	String	HTTP method (e.g., `GET`, `POST`, `PATCH`, `DELETE`)
`resource.type`	String	Resource type (e.g., `xhr`, `image`, `font`, `css`, `js`)
`resource.status_code`	Number	HTTP response status code
`resource.size`	Number (bytes)	Resource size
`resource.duration`	Number (ns)	Total time to load resource
`resource.connect.duration`	Number (ns)	Time to establish server connection (connectEnd - connectStart)
`resource.ssl.duration`	Number (ns)	Time for TLS handshake
`resource.dns.duration`	Number (ns)	Time for DNS resolution (domainLookupEnd - domainLookupStart)
`resource.first_byte.duration`	Number (ns)	Time waiting for first byte response (responseStart - requestStart)
`resource.download.duration`	Number (ns)	Time to download response (responseEnd - responseStart)
`resource.redirect.duration`	Number (ns)	Time for subsequent HTTP requests (redirectEnd - redirectStart)

Error Attributes

Attribute	Type	Description
`error.id`	String	Error unique identifier
`error.message`	String	Concise, human-readable one-line error message
`error.source`	String	Error source (e.g., `network`, `source`, `console`, `webview`)
`error.stack`	String	Error stack trace or supplementary information
`error.type`	String	Error type or error code
`error.is_crash`	Boolean	Whether this error caused app crash

Action Attributes

Attribute	Type	Description
`action.id`	String	User action UUID
`action.type`	String	User action type (e.g., `tap`, `scroll`, `swipe`, `application_start`)
`action.name`	String	User action name
`action.target.name`	String	Element user interacted with
`action.loading_time`	Number (ns)	Action loading time
`action.resource.count`	Number	Number of resources triggered by this action
`action.error.count`	Number	Number of errors triggered by this action

Data Storage

Before data is uploaded to Flashcat, it is stored in plaintext in the app’s cache directory.

Security Protection:

Cache folder is protected by iOS app sandbox
Other apps cannot read this data

Security Notes:

If device is jailbroken, stored data may become readable
Sensitive data should not be included in RUM events, or should be obfuscated or filtered via Event Mapper before sending

SDK Integration

Learn how to integrate the iOS SDK

Advanced Configuration

Configure custom attributes, sampling, and event filtering

Insights

View and analyze collected RUM data

Quick Start

Analytics

SDK Integration

Performance

Error Tracking

Explorer

Session Replay

Best Practices

Others

App Startup Metrics

View Monitoring

Default Attributes

Event-Specific Attributes

Data Storage

SDK Integration

Advanced Configuration

Insights

​App Startup Metrics

​View Monitoring

​Default Attributes

​Event-Specific Attributes

​Data Storage

​Related Documentation

SDK Integration

Advanced Configuration

Insights

App Startup Metrics

View Monitoring

Default Attributes

Event-Specific Attributes

Data Storage

Related Documentation