diff --git a/libs/common/src/tools/achievements/achievement-processor.ts b/libs/common/src/tools/achievements/achievement-processor.ts
index dde4a98463e..2be603c22f9 100644
--- a/libs/common/src/tools/achievements/achievement-processor.ts
+++ b/libs/common/src/tools/achievements/achievement-processor.ts
@@ -1,11 +1,5 @@
 import { Observable, OperatorFunction, concatMap, from, map, pipe, withLatestFrom } from "rxjs";
 
-import { active } from "./achievement-manager";
-import {
-  achievementMonitors$,
-  achievementsLocal$ as achievementsLog$,
-  userActionIn$,
-} from "./inputs";
 import {
   AchievementEvent,
   AchievementId,
@@ -14,68 +8,67 @@ import {
   MetricId,
   UserActionEvent,
 } from "./types";
-import { mapProgressByName } from "./util";
+import { mapProgressByName as toMetricMap } from "./util";
 
-// the formal event processor
-function validate(
+/** Monitors a user activity stream to recognize achievements
+ *  @param validators$ validators track achievement progress and award achievements
+ *  @param captured$ the set of previously emitted achievement events
+ */
+function achievements(
   validators$: Observable<AchievementValidator[]>,
   captured$: Observable<AchievementEvent[]>,
 ): OperatorFunction<UserActionEvent, AchievementEvent> {
   return pipe(
     withLatestFrom(validators$),
+    // narrow the list of all live monitors to just those that may produce new logs
     map(([action, monitors]) => {
-      // narrow the list of all live monitors to just those that may produce new logs
       const triggered = monitors.filter((m) => m.filter(action));
       return [action, triggered] as const;
     }),
     withLatestFrom(captured$),
+    // monitor achievements
     concatMap(([[action, validators], captured]) => {
-      const results: AchievementEvent[] = [];
-      const progress = mapProgressByName(captured);
-      const measurements = new Map<AchievementId, AchievementProgressEvent[]>();
+      const achievements: AchievementEvent[] = [];
+      const metrics = toMetricMap(captured);
+      const progress = new Map<AchievementId, AchievementProgressEvent[]>();
 
       // collect measurements
       for (const validator of validators) {
-        const measured = validator.measure(action, progress);
-        measurements.set(validator.achievement, measured);
-        results.push(...measured);
+        const measured = validator.measure?.(action, metrics) ?? [];
+        progress.set(validator.achievement, measured);
+
+        achievements.push(...measured);
       }
 
       // update processor's internal progress values
       const distinct = new Map<MetricId, AchievementId>();
-      const entries = [...measurements.entries()].flatMap(([a, ms]) =>
-        ms.map((m) => [a, m] as const),
-      );
+      const entries = [...progress.entries()].flatMap(([a, ms]) => ms.map((m) => [a, m] as const));
       for (const [achievement, measured] of entries) {
         const key = measured.achievement.name;
+
+        // prevent duplicate updates
         if (distinct.has(key)) {
-          const msg = `${achievement} failed to set set ${key} value already set by ${distinct.get(key)}`;
+          const msg = `${achievement} failed to set ${key}; value already set by ${distinct.get(key)}`;
           throw new Error(msg);
         }
-
         distinct.set(key, achievement);
-        progress.set(measured.achievement.name, measured.achievement.value);
+
+        metrics.set(measured.achievement.name, measured.achievement.value);
       }
 
       // detect earned achievements
       for (const validator of validators) {
-        const measured = measurements.get(validator.achievement) ?? [];
-        const earned = validator.earn(measured, progress);
-        results.push(...earned);
+        const events = progress.get(validator.achievement) ?? [];
+        const awarded = validator.award?.(events, metrics) ?? [];
+
+        achievements.push(...awarded);
       }
 
       // deliver results as a stream containing individual records to maintain
       // the map/reduce model of the validator
-      return from(results);
+      return from(achievements);
     }),
   );
 }
 
-// monitors are lazy until their trigger condition is met
-const liveMonitors$ = achievementMonitors$.pipe(active(achievementsLog$));
-
-// pre-wired achievement stream; this is the prototype's host, and
-//  in the full version is wired by the application
-const validatedAchievements$ = userActionIn$.pipe(validate(liveMonitors$, achievementsLog$));
-
-export { validate, validatedAchievements$ };
+export { achievements as validate };
diff --git a/libs/common/src/tools/achievements/examples/example-validators.ts b/libs/common/src/tools/achievements/examples/example-validators.ts
index 6c5b89702d0..89d1f571c5e 100644
--- a/libs/common/src/tools/achievements/examples/example-validators.ts
+++ b/libs/common/src/tools/achievements/examples/example-validators.ts
@@ -20,10 +20,7 @@ const TotallyAttachedValidator = {
   filter(item) {
     return item.tags?.includes("with-attachment") ?? false;
   },
-  measure(item, progress) {
-    return [];
-  },
-  earn(progress) {
+  award(progress) {
     return [earnedEvent(TotallyAttachedAchievement)];
   },
 } satisfies AchievementValidator;
@@ -49,9 +46,6 @@ const ItemCreatedTracker = {
     const value = 1 + (progress.get(ItemCreatedProgress) ?? 0);
     return [progressEvent(ItemCreatedProgress, value)];
   },
-  earn(progress) {
-    return [];
-  },
 } satisfies AchievementValidator;
 
 const ItemCreatedValidator = {
@@ -67,7 +61,7 @@ const ItemCreatedValidator = {
   measure(item, progress) {
     return [progressEvent(ItemCreatedProgress)];
   },
-  earn(progress) {
+  award(progress) {
     return [earnedEvent(ItemCreatedAchievement)];
   },
 } satisfies AchievementValidator;
@@ -86,7 +80,7 @@ const ThreeItemsCreatedValidator = {
     const value = 1 + (progress.get(ItemCreatedProgress) ?? 0);
     return [progressEvent(ItemCreatedProgress, value)];
   },
-  earn(_measured, progress) {
+  award(_measured, progress) {
     const value = progress.get(ItemCreatedProgress) ?? 0;
     return value >= 3 ? [earnedEvent(ItemCreatedAchievement)] : [];
   },
@@ -106,7 +100,7 @@ const FiveItemsCreatedValidator = {
     const value = 1 + (progress.get(ItemCreatedProgress) ?? 0);
     return [progressEvent(ItemCreatedProgress, value)];
   },
-  earn(_measured, progress) {
+  award(_measured, progress) {
     const value = progress.get(ItemCreatedProgress) ?? 0;
     return value >= 5 ? [earnedEvent(ItemCreatedAchievement)] : [];
   },
diff --git a/libs/common/src/tools/achievements/types.ts b/libs/common/src/tools/achievements/types.ts
index 995026e47a1..e9cb59679cc 100644
--- a/libs/common/src/tools/achievements/types.ts
+++ b/libs/common/src/tools/achievements/types.ts
@@ -47,11 +47,11 @@ export type AchievementValidator = Achievement & {
   filter: (item: EventFormat) => boolean;
 
   // observe data from the event stream and produces measurements
-  measure: (item: EventFormat, progress: Map<MetricId, number>) => AchievementProgressEvent[];
+  measure?: (item: EventFormat, metrics: Map<MetricId, number>) => AchievementProgressEvent[];
 
   // monitors achievement progress and emits earned achievements
-  earn: (
-    measured: AchievementProgressEvent[],
-    progress: Map<MetricId, number>,
+  award?: (
+    events: AchievementProgressEvent[],
+    metrics: Map<MetricId, number>,
   ) => AchievementEarnedEvent[];
 };