Merge pull request #4073 from SalesforceCommerceCloud/feat/mrt-distributed-tracing

@WI-24614336: Enable tracing with MRT distributed tracing flag

Author: shethj

docs/distributed-tracing.md

@@ -33,10 +33,11 @@ DT env var**.
 | Env var | Effect |
 |---------|--------|
 | `OTEL_TRACING_ENABLED=true` | Enables DT (and `server_timing`'s OTel path). Resolved via `getOTELConfig().enabled`. |
+| `MRT_DISTRIBUTED_TRACING_ENABLED=true` | Alternative MRT-managed switch that enables the same shared tracing paths. |
 | `OTEL_SERVICE_NAME` | Affects `server_timing` only. DT's `service.name` is a hardcoded constant (`pwa-kit-react-sdk`) and ignores this var. |
 
-When `OTEL_TRACING_ENABLED` is unset (or anything other than `"true"`), DT is a
-complete no-op: no spans, no header injection, zero behavior change.
+When neither tracing flag is set to `"true"`, DT is a complete no-op: no spans,
+no header injection, zero behavior change.
 
 Set the env var via MRT environment configuration. No code change or redeploy of
 application code is required to toggle it.
@@ -101,7 +102,7 @@ packages/pwa-kit-react-sdk/src/
     mrt-console-span-exporter.js        ← stdout exporter (MRT scrape contract)
     react-rendering.js                  ← wires server + child spans into the render path
   utils/
-    opentelemetry-config.js             ← getOTELConfig(): the OTEL_TRACING_ENABLED master switch
+    opentelemetry-config.js             ← getOTELConfig(): the shared tracing master switch
   ssr/universal/components/with-react-query/
     index.js                            ← creates per-query scapi:* child spans (OTel-free; uses res.locals helper)
 

packages/pwa-kit-react-sdk/CHANGELOG.md

@@ -1,4 +1,5 @@
 ## v3.22.0-dev (Oct 09, 2026)
+-   [Feature] Enable OpenTelemetry and distributed tracing when either `OTEL_TRACING_ENABLED=true` or MRT's `MRT_DISTRIBUTED_TRACING_ENABLED=true` is set.
 ## v3.21.0 (Oct 08, 2026)
 - Version alignment release; no functional changes to `pwa-kit-react-sdk` since v3.20.0.
 

packages/pwa-kit-react-sdk/src/ssr/server/mrt-console-span-exporter.js

@@ -12,7 +12,8 @@
  * exporter's only job is to print the JSON shape MRT expects. No OTLP endpoint
  * is involved.
  *
- * @env OTEL_TRACING_ENABLED — resolved via getOTELConfig().enabled
+ * @env OTEL_TRACING_ENABLED / MRT_DISTRIBUTED_TRACING_ENABLED — resolved via
+ *      getOTELConfig().enabled
  */
 import {ConsoleSpanExporter} from '@opentelemetry/sdk-trace-base'
 import {ExportResultCode, hrTimeToTimeStamp} from '@opentelemetry/core'

packages/pwa-kit-react-sdk/src/utils/opentelemetry-config.js

@@ -13,7 +13,9 @@ const DEFAULT_SERVICE_NAME = 'pwa-kit-react-sdk'
 export const getOTELConfig = () => {
     return {
         serviceName: process.env.OTEL_SERVICE_NAME || DEFAULT_SERVICE_NAME,
-        enabled: process.env.OTEL_TRACING_ENABLED === 'true'
+        enabled:
+            process.env.OTEL_TRACING_ENABLED === 'true' ||
+            process.env.MRT_DISTRIBUTED_TRACING_ENABLED === 'true'
     }
 }
 

packages/pwa-kit-react-sdk/src/utils/opentelemetry-config.test.js

@@ -17,6 +17,8 @@ describe('OpenTelemetry Config', () => {
     beforeEach(() => {
         // Reset environment variables
         process.env = {...originalEnv}
+        delete process.env.OTEL_TRACING_ENABLED
+        delete process.env.MRT_DISTRIBUTED_TRACING_ENABLED
 
         // Clear module cache to reset _cachedConfig
         jest.resetModules()
@@ -67,6 +69,15 @@ describe('OpenTelemetry Config', () => {
                 expect(config.enabled).toBe(true)
             })
 
+            test('should return enabled as true when MRT_DISTRIBUTED_TRACING_ENABLED is "true"', () => {
+                process.env.MRT_DISTRIBUTED_TRACING_ENABLED = 'true'
+
+                const {getOTELConfig} = mockModule()
+                const config = getOTELConfig()
+
+                expect(config.enabled).toBe(true)
+            })
+
             test('should return enabled as false when OTEL_TRACING_ENABLED is not set', () => {
                 delete process.env.OTEL_TRACING_ENABLED
 
@@ -97,6 +108,16 @@ describe('OpenTelemetry Config', () => {
                     expect(config.enabled).toBe(false)
                 })
             })
+
+            test('should return enabled as false when neither tracing flag is "true"', () => {
+                process.env.OTEL_TRACING_ENABLED = 'false'
+                process.env.MRT_DISTRIBUTED_TRACING_ENABLED = '1'
+
+                const {getOTELConfig} = mockModule()
+                const config = getOTELConfig()
+
+                expect(config.enabled).toBe(false)
+            })
         })
     })
 })

packages/pwa-kit-react-sdk/src/utils/opentelemetry.js

@@ -123,7 +123,8 @@ export const createChildSpan = (name, attributes = {}) => {
                     span_name: name,
                     otel_enabled: otelConfig.enabled,
                     otel_service_name: otelConfig.serviceName,
-                    suggestion: 'Set OTEL_TRACING_ENABLED=true to enable proper timing'
+                    suggestion:
+                        'Set OTEL_TRACING_ENABLED=true or MRT_DISTRIBUTED_TRACING_ENABLED=true to enable proper timing'
                 }
             })
         }