HTTP Headers in Globe

Globe automatically adds several HTTP headers to each request reaching your application. These headers provide valuable information about the request context, execution environment, and geographic details that you can use for customizing behavior and diagnostics.

Request headers provided by Globe

The following headers are added to each request before it reaches your Dart application:

Header	Type	Description
`x-globe-request-id`	String	Unique identifier for the current request, useful for debugging and tracing
`x-globe-dc-id`	String?	IATA code of the compute region where the request is executing
`x-globe-dc-eu`	String?	`true` or `false` indicating whether the request is executing in an EU data center
`x-globe-dc-city`	String?	City name where the request is being executed
`x-globe-dc-country`	String	ISO-3166-1 alpha-2 country code of the executing data center (e.g., "US")
`x-globe-dc-continent`	String	Continent of the executing data center (e.g., "Europe")
`x-globe-dc-latitude`	String	Latitude coordinate of the executing data center
`x-globe-dc-longitude`	String	Longitude coordinate of the executing data center
`x-globe-eu`	String?	`true` or `false` indicating whether the request originated from within the EU
`x-globe-latitude`	String?	Latitude coordinate of the request origin
`x-globe-longitude`	String?	Longitude coordinate of the request origin
`x-globe-city`	String?	City name where the request originated from
`x-globe-country`	String?	ISO-3166-1 alpha-2 country code of the request origin (e.g., "US")
`x-globe-region`	String?	Region or state where the request originated from (e.g., "Texas")
`x-globe-region-code`	String?	ISO-3166-2 region code of the request origin (e.g., "TX")
`x-globe-continent`	String?	Continent where the request originated from (e.g., "Europe")
`x-globe-tz`	String?	Timezone of the request origin (e.g., "America/Chicago")

Additionally, Globe includes standard forwarding headers:

Header	Description
`x-forwarded-for`	Original IP address of the client
`x-forwarded-proto`	Protocol used by the client (http or https)

Response headers added by Globe

Globe adds these headers to responses sent back to clients:

Header	Description
`x-globe-temperature`	Container start state: `cold`, `warm`, or `hot`

Using headers in your Dart application

Accessing request headers

Here's how to access Globe headers in a typical Shelf application:

import 'package:shelf/shelf.dart';

Response handleRequest(Request request) {
  final requestId = request.headers['x-globe-request-id'] ?? 'unknown';
  final region = request.headers['x-globe-dc-id'] ?? 'unknown';
  final city = request.headers['x-globe-city'] ?? 'unknown';

  // Use header values in your application logic
  return Response.ok('Request $requestId from $city, processed in $region');
}

Common use cases for Globe headers

Geolocation-based customization

Use location headers to provide regionalized content without additional geolocation services:

Response handleRequest(Request request) {
  final country = request.headers['x-globe-country'];
  final language = _determineLanguageForCountry(country);

  return Response.ok(_getLocalizedContent(language));
}

Deployment debugging

Headers can help identify where and how your code is executing:

Response debugInfo(Request request) {
  return Response.ok({
    'requestId': request.headers['x-globe-request-id'],
    'datacenter': request.headers['x-globe-dc-city'],
    'country': request.headers['x-globe-dc-country'],
    'temperature': request.headers['x-globe-temperature']  // Checked in response
  }.toString());
}

GDPR and data residency compliance

EU-specific headers help implement compliance requirements:

bool isRequestFromEU(Request request) {
  return request.headers['x-globe-eu'] == 'true';
}

Response handleRequest(Request request) {
  if (isRequestFromEU(request)) {
    // Apply EU-specific data handling
  }

  return Response.ok('Handled with appropriate compliance');
}

Monitoring cold starts

You can monitor the x-globe-temperature response header to track cold start frequency and impact.

Best practices

Don't assume all headers will be present; always provide fallback values
For location-specific features, use the headers as a convenience, but provide user options to override
Include the x-globe-request-id in logs to simplify request tracking
Consider storing region information in analytics to identify performance patterns

Getting Started

Core Concepts

Frameworks

Storage

Infrastructure