From 0655370c830a309d8808ef365dff611725ea73b1 Mon Sep 17 00:00:00 2001
From: Barry Pollard <barrypollard@google.com>
Date: Tue, 21 Apr 2026 12:43:38 +0100
Subject: [PATCH] Add onEachInteraction to onINP options

This adds an "onEachInteraction" option to onINP, which exposes to us
each interaction. It also calls attributeINP on each value given to the
callback.

---
 src/attribution/onINP.ts | 35 ++++++++++++++++++++++++++++++++++-
 src/types/inp.ts         |  1 +
 2 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/src/attribution/onINP.ts b/src/attribution/onINP.ts
index 0d6d098..3fe5050 100644
--- a/src/attribution/onINP.ts
+++ b/src/attribution/onINP.ts
@@ -260,7 +260,40 @@ export const onINP = (
     cleanupPending = false;
   };
 
-  interactionManager._onBeforeProcessingEntry = groupEntriesByRenderTime;
+  async function handleOnEachInteractionCallback(
+    entry: PerformanceEventTiming,
+  ) {
+    if (!opts.onEachInteraction) {
+      return;
+    }
+
+    // Wait a microtask so this "pre" processing callback actually
+    // becomes a "post" processing callback.
+    void (await Promise.resolve());
+    if (!entry.interactionId) {
+      return;
+    }
+
+    const interaction = attributeINP({
+      entries: [entry],
+      // The only value we really need for `attributeINP` is `entries`
+      // Everything else is included to fill out the type.
+      name: 'INP',
+      rating: 'good',
+      value: entry.duration,
+      delta: entry.duration,
+      navigationType: 'navigate',
+      id: 'N/A',
+    });
+    opts.onEachInteraction(interaction);
+  }
+
+  interactionManager._onBeforeProcessingEntry = (
+    entry: PerformanceEventTiming,
+  ) => {
+    void handleOnEachInteractionCallback(entry);
+    groupEntriesByRenderTime(entry);
+  };
   interactionManager._onAfterProcessingINPCandidate = saveInteractionTarget;
 
   const getIntersectingLoAFs = (
diff --git a/src/types/inp.ts b/src/types/inp.ts
index 6041b2d..9b6bd2e 100644
--- a/src/types/inp.ts
+++ b/src/types/inp.ts
@@ -28,6 +28,7 @@ export interface INPReportOpts extends ReportOpts {
 export interface INPAttributionReportOpts extends AttributionReportOpts {
   durationThreshold?: number;
   includeProcessedEventEntries?: boolean;
+  onEachInteraction?: (interaction: INPMetricWithAttribution) => void;
 }
 
 /**
-- 
2.50.1 (Apple Git-155)