Network spans forwarding

Network spans forwarding

Network spans forwarding adds a W3C traceparent header to your app's network requests, so you can trace the same request in Embrace and in your backend observability platform. For an overview, see Network spans forwarding.

Enable network spans forwarding

1. Enable network spans forwarding for your app in the Embrace dashboard. See Enable network spans forwarding.

2. On Android, add enable_network_span_forwarding to android/app/src/main/embrace-config.json. iOS needs no app changes.

   {
     "app_id": "xxxxx",
     "api_token": "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx",
     "sdk_config": {
       "app_framework": "react_native",
       "networking": {
         "enable_network_span_forwarding": true
       }
     }
   }

   For more on this file, see Android configuration file.

Limit forwarding to specific domains

By default, the Embrace SDK adds the header to every captured request. To add it only to your own domains, set an allowlist on each platform.

iOS

In your EmbraceInitializer.swift file, pass traceparent options to the URLSession capture service:

let captureServices = CaptureServicesOptionsBuilder()
    .addUrlSessionCaptureService(withOptions: URLSessionCaptureService.Options(
        traceparent: .init(onlyAllowDomains: ["example.com"])
    ))
    .addDefaults()
    .build()

try EmbraceIO.setup(
    options: .withAppId(
        "__APP_ID__", // 5 digits string
        platform: .reactNative,
        captureServices: captureServices
    )
)
try EmbraceIO.shared.start()

Each entry is a bare hostname that matches the host and its subdomains. For the full rules, see Limiting injection to specific domains.

Android

Add traceparent_only_allow_domains to embrace-config.json. Each entry is an exact hostname (example.com) or a subdomain suffix (.example.com):

"networking": {
  "enable_network_span_forwarding": true,
  "traceparent_only_allow_domains": ["example.com", ".example.com"]
}

Disable network spans forwarding

1. Remove your app from network spans forwarding in the Embrace dashboard.
2. Stop header injection in your app:

iOS

In your EmbraceInitializer.swift file, set onlyAllowDomains to an empty array:

.addUrlSessionCaptureService(withOptions: URLSessionCaptureService.Options(
    traceparent: .init(onlyAllowDomains: [])
))

Android

Set enable_network_span_forwarding to false, or remove it.