Learn more about what Sentry uses to create a trail of events (breadcrumbs) that happened prior to an issue.

Sentry uses breadcrumbs to create a trail of events that happened prior to an issue. These events are very similar to traditional logs, but can record more rich structured data.

This page provides an overview of manual breadcrumb recording and customization. Learn more about the information that displays on the Issue Details page and how you can filter breadcrumbs to quickly resolve issues in Using Breadcrumbs.

You can manually add breadcrumbs whenever something interesting happens. For example, you might manually record a breadcrumb if the user authenticates or another state change occurs.

Manually record a breadcrumb:

#include <sentry.h>

sentry_value_t crumb = sentry_value_new_breadcrumb("default", "Authenticated user");
sentry_value_set_by_key(crumb, "category", sentry_value_new_string("auth"));
sentry_value_set_by_key(crumb, "level", sentry_value_new_string("info"));

// to add `data` to a breadcrumb you must create a wrapping `object` which maps
// to the expected dictionary structure:
sentry_value_t http_data = sentry_value_new_object();
sentry_value_set_by_key(http_data, "url", sentry_value_new_string(""));
sentry_value_set_by_key(http_data, "method", sentry_value_new_string("GET"));
sentry_value_set_by_key(http_data, "status_code", sentry_value_new_int32(200));
sentry_value_set_by_key(http_data, "reason", sentry_value_new_string("OK"));

sentry_value_t http_crumb = sentry_value_new_breadcrumb("http", NULL);
sentry_value_set_by_key(http_crumb, "category", sentry_value_new_string("xhr"));
sentry_value_set_by_key(http_crumb, "data", http_data);

The available breadcrumb keys are type, category, message, level, timestamp (which many SDKs will set automatically for you), and data, which is the place to put any additional information you'd like the breadcrumb to include. Using keys other than these six won't cause an error, but will result in the data being dropped when the event is processed by Sentry.

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