Network Instrumentation

Generates: Spans

Automatically captures HTTP requests made via fetch, XMLHttpRequest, and axios — zero code changes required.

Configuration

On by default. To disable:

Pulse.start({ autoDetectNetwork: false });

Capture Headers

Capture specific request or response headers alongside each span:

Pulse.start({
    networkHeaders: {
        requestHeaders:  ['x-request-id', 'authorization'],
        responseHeaders: ['x-response-time', 'cache-control'],
    },
});

Attributes

pulse.type: network.<status_code> — e.g. network.200, network.404, network.0

Attribute	Description	Example
http.method	HTTP method	"GET", "POST"
http.url	Full request URL	"https://api.example.com/users/123"
http.status_code	Response status	200, 404
http.host	Hostname	"api.example.com"
http.target	Path + query	"/users/123"
error	true on 4xx/5xx or network failure	true
graphql.operation.name	GraphQL operation name (auto-detected)	"GetUser"
graphql.operation.type	GraphQL operation type (auto-detected)	"query"
http.request.body.size	Request body size in bytes	42
http.response.body.size	Response body size in bytes	2048

GraphQL attributes are added automatically when the URL contains "graphql". Operation name and type are extracted from the request body.

http.request.body.size and http.response.body.size prioritize the Content-Length header. As a fallback, byte counts are calculated for strings, Blob, ArrayBuffer/typed views, and Document.

All requests — including fetch and axios — are intercepted via XMLHttpRequest since that's what they use internally in React Native.

Image & FastImage (OkHttp on Android)

Built-in Image, FastImage, and other native OkHttp traffic bypass the JS layer above. On Android, start from OkHttp Guide to open the network / OkHttp guide (ByteBuddy + artifacts). On iOS, URLSession is instrumented by default — use URLSession to reach the iOS network doc for filters and headers.

Native Side

Use the platform docs for URL filters, header capture, and connectivity-related behavior:

• Android APIs — Gateway to the Android network (OkHttp/ByteBuddy) guide
• iOS APIs — Gateway to the iOS network (URLSession) guide