Every report carries a single chronological chain, captured automatically.
{
"t": 1765800000123,
"seq": 42,
"kind": "network",
"level": "error",
"message": "POST /api/cart",
"data": {
"reqId": 17,
"status": 500
}
}Kinds
| Kind | Recorded when |
|---|---|
navigation | A screen transition. UIKit is automatic; see Screen tracking. |
tap | The user interacts with a control. |
console | Your app writes to stderr. See Console & network. |
network | A request completes on a URLSession you built with networkCaptureConfiguration(). |
lifecycle | The app enters the background or returns to the foreground. |
error | An uncaught NSException. See Crash reporting. |
custom | You called addBreadcrumb. |
Adding your own
TraceItX.shared.addBreadcrumb(
message: "Coupon applied",
kind: "custom",
level: "info",
data: ["code": "SUMMER25"]
)addBreadcrumb never throws. An unknown kind coerces to custom and an
invalid level is dropped rather than passed through — instrumentation must not
be able to break the app it is instrumenting.
Put identifiers in data, not in message. data survives as structured
fields an agent can filter on; message is prose, and prose is truncated first.
Thread safety
addBreadcrumb and recordScreen are safe to call from any thread — the buffer
is lock-guarded internally. You do not need to hop to the main queue to record
something that happened on a background one, and doing so would misorder the
chain relative to what actually occurred.
The shared clock
t is absolute epoch milliseconds, on the same clock as the session replay,
so a viewer can line a crumb up against the frame that was on screen when it
fired. seq breaks ties inside the same millisecond.
Uncaught exceptions
The SDK’s exception handler records an uncaught NSException as an error
crumb and then hands the exception to whatever handler was installed before it.
The chain lives in memory, so it does not outlive the process — native iOS files
no unattended crash reports today. See Crash reporting.
Limits
Caps and trimming behaviour are in Errors & limits.