Transports

The Native SDK uses Transports to send event payloads to Sentry. The default transport depends on the target platform:

• Windows: WinHTTP
• Linux: Curl
• macOS: Curl

Custom Transports

To specify a custom transport, use the sentry_options_set_transport function and supply a transport that implements the sentry_transport_t interface.

#include <sentry.h>

void custom_transport(sentry_envelope_t *envelope, void *state) {
  /*
   * Send the event here. If the transport requires state, such as an HTTP
   * client object or request queue, it can be specified in the `state`
   * parameter when configuring the transport. It will be passed as second
   * argument to this function.
   * The transport takes ownership of the `envelope`, and must free it once it
   * is done.
   */
  sentry_envelope_free(envelope);
}

int main(void) {
  void *transport_state = 0;

  sentry_options_t *options = sentry_options_new();
  sentry_transport_t *transport = sentry_transport_new(custom_transport);
  sentry_transport_set_state(transport, transport_state);

  sentry_options_set_transport(options, transport);
  sentry_init(options);

  /* ... */
}

The transport is invoked in the same thread as the call to sentry_capture_event. Consider to offload network communication to a background thread or thread pool to avoid blocking execution.

Using a Proxy

The Native SDK allows the configuration of an HTTP (CONNECT) or SOCKS5 proxy through which requests can be tunneled to our backend. It can be configured manually via the following option interface:

sentry_options_t *options = sentry_options_new();
sentry_options_set_proxy(options, "http://my.proxy:8080");
sentry_init(options);

/* ... */

The same function can also be used for the SOCKS5 proxy:

sentry_options_t *options = sentry_options_new();
sentry_options_set_proxy(options, "socks5://my.proxy:1080");
sentry_init(options);

/* ... */

Proxy behavior

We support HTTP proxies on all platforms, and SOCKS5 proxies on Linux and macOS. On Windows, https proxy servers are not supported by the default transport (WinHTTP). The proxy may also contain authentication ("http://user:password@my.proxy:8080") or be written in IPv6 format ("http://[::1]:8080").

The SDK will always automatically configure the HTTP proxy if a corresponding environment variable is set. Depending on the DSN protocol, the matching http(s)_proxy environment variable is read. So for a usual Sentry-hosted DSN, you must set the https_proxy variable .

If you don't want the SDK to configure the HTTP proxy from the environment variables automatically, you can set the proxy option to an empty string value:

sentry_options_t *options = sentry_options_new();
sentry_options_set_proxy(options, "");
sentry_init(options);

/* ... */