diff --git a/scripts/verify/architecture-guard-baselines.json b/scripts/verify/architecture-guard-baselines.json
index 4ae34e22a1..5c52c8650e 100644
--- a/scripts/verify/architecture-guard-baselines.json
+++ b/scripts/verify/architecture-guard-baselines.json
@@ -130,11 +130,6 @@
     "src/firmware/FirmwareProvider.ts": 1,
     "src/gdb/GdbSessionManager.ts": 14,
     "src/gpu/GpuCodeObjectsProvider.ts": 1,
-    "src/hopper/HopperAnalysisProfile.ts": 1,
-    "src/hopper/HopperCallerReconciliation.ts": 2,
-    "src/hopper/HopperFileOffset.ts": 1,
-    "src/hopper/HopperMachOImage.ts": 10,
-    "src/hopper/HopperRegexSearch.ts": 3,
     "src/inspector/JavaScriptRuntimeScope.ts": 1,
     "src/inspector/V8InspectorProvider.ts": 2,
     "src/javascript/analysis/JavaScriptAnalysisWorker.ts": 5,
diff --git a/src/hopper/HopperAnalysisProfile.ts b/src/hopper/HopperAnalysisProfile.ts
index 7d3247685d..509d6e0737 100644
--- a/src/hopper/HopperAnalysisProfile.ts
+++ b/src/hopper/HopperAnalysisProfile.ts
@@ -31,8 +31,9 @@ import {
   type HeaderArchitecture,
 } from "../domain/binaryTargetTypes.js";
 import {
-  AnalysisCancelledError,
   AnalysisCapabilityUnavailableError,
+  cancelledBy,
+  carriedReason,
 } from "../domain/analysisErrorCore.js";
 import { BinaryTargetError } from "../domain/configurationErrors.js";
 import { ProviderAdapterError } from "../domain/providerAdapterError.js";
@@ -391,8 +392,7 @@ const readHopperProfileFile = async <Value>(
     const diagnostics = { profile_file: { kind, path }, ...completed };
     const failure =
       cancellation !== undefined
-        ? new AnalysisCancelledError("open_binary", {
-            cause: cancellation.reason,
+        ? cancelledBy("open_binary", carriedReason(cancellation.reason), {
             cleanup,
             diagnostics,
           })
diff --git a/src/hopper/HopperCallerReconciliation.ts b/src/hopper/HopperCallerReconciliation.ts
index a0c0aaa589..f1eb500b9c 100644
--- a/src/hopper/HopperCallerReconciliation.ts
+++ b/src/hopper/HopperCallerReconciliation.ts
@@ -5,6 +5,8 @@ import {
   AnalysisCancelledError,
   AnalysisOutputError,
   AnalysisResourceConstraintError,
+  cancelledBy,
+  carriedReason,
 } from "../domain/analysisErrorCore.js";
 import type { AnalysisError } from "../domain/analysisErrorBase.js";
 import type { JsonValue } from "../domain/jsonValue.js";
@@ -129,8 +131,9 @@ async function buildIndex(
     bytes = 0;
   const began = performance.now();
   let stop: HopperCallerScanStop = { code: "complete" };
+  // Called only after the caller's signal aborted.
   const cancelled = (): AnalysisCancelledError =>
-    new AnalysisCancelledError(operation, { cause: options?.signal?.reason });
+    cancelledBy(operation, carriedReason(options?.signal?.reason));
   const fail = (
     error: AnalysisError,
     failureStop: HopperCallerScanStop,
@@ -428,12 +431,10 @@ export const reconcileHopperCallers = async (
     );
   if (options?.signal?.aborted)
     return err(
-      retainNative(
-        new AnalysisCancelledError(operation, {
-          cause: options.signal.reason,
-        }),
-        { scan: null, destinations: null },
-      ),
+      retainNative(cancelledBy(operation, options.signal), {
+        scan: null,
+        destinations: null,
+      }),
     );
   const selected =
     base !== undefined
diff --git a/src/hopper/HopperFileOffset.ts b/src/hopper/HopperFileOffset.ts
index 0b1014da8f..e915ac7736 100644
--- a/src/hopper/HopperFileOffset.ts
+++ b/src/hopper/HopperFileOffset.ts
@@ -9,6 +9,9 @@ import {
   AnalysisArtifactChangedError,
   AnalysisCancelledError,
   AnalysisCapabilityUnavailableError,
+  cancelledBy,
+  carriedReason,
+  type CancellationReason,
 } from "../domain/analysisErrorCore.js";
 import { BinaryTargetError } from "../domain/configurationErrors.js";
 import { ProviderCleanupError } from "../domain/providerCleanupError.js";
@@ -71,7 +74,7 @@ export async function mapHopperFileOffset(
       "The selected database digest does not identify its original executable bytes. Open that executable to verify original-file coordinates; read_bytes still exposes the database's native bytes.",
     );
   const signal = ownership.signal;
-  if (signal?.aborted) return err(cancelled(partial, signal.reason));
+  if (signal?.aborted) return err(cancelled(partial, signal));
   const publish = (marker: ProviderCleanupError): ProviderCleanupError => {
     ownership.onCleanupMarker(marker);
     return marker;
@@ -117,7 +120,7 @@ export async function mapHopperFileOffset(
         );
       return err(
         retainSnapshot(
-          cancelled(partial, cause.reason),
+          cancelled(partial, carriedReason(cause.reason)),
           captured.value,
           verification.observation,
           verified.fileOffset,
@@ -161,10 +164,9 @@ const isSourceRead = (
 
 const cancelled = (
   partial: (reason: string) => FileOffsetPartialObservation,
-  cause?: unknown,
+  reason: CancellationReason,
 ): AnalysisCancelledError =>
-  new AnalysisCancelledError(OPERATION, {
-    ...(cause === undefined ? {} : { cause }),
+  cancelledBy(OPERATION, reason, {
     partialObservation: partial("Source verification was cancelled"),
   });
 
@@ -184,7 +186,7 @@ const sourceAccessFailure = (
   partial: (reason: string) => FileOffsetPartialObservation,
 ): AnalysisError => {
   if (cause instanceof RegularFileOperationCancelled)
-    return cancelled(partial, cause.reason);
+    return cancelled(partial, carriedReason(cause.reason));
   const reason = `Cannot verify original source bytes: ${cause instanceof Error ? cause.message : String(cause)}`;
   const code =
     typeof cause === "object" && cause !== null && "code" in cause
@@ -266,7 +268,10 @@ const cleanupAfterSnapshot = (
     return err(
       withCleanup(
         retainSnapshot(
-          cancelled(partial, failure.completionCancellation.reason),
+          cancelled(
+            partial,
+            carriedReason(failure.completionCancellation.reason),
+          ),
           captured.value,
           verification.observation,
           verified.fileOffset,
diff --git a/src/hopper/HopperMachOImage.ts b/src/hopper/HopperMachOImage.ts
index ef9d79855a..b1513eedd6 100644
--- a/src/hopper/HopperMachOImage.ts
+++ b/src/hopper/HopperMachOImage.ts
@@ -11,7 +11,11 @@ import type { RetainedResourceScope } from "../application/AnalysisProvider.js";
 import type { AnalysisError } from "../domain/analysisErrorBase.js";
 import type { BinaryTarget } from "../domain/binaryTargetTypes.js";
 import { BinaryTargetError } from "../domain/configurationErrors.js";
-import { AnalysisCancelledError } from "../domain/analysisErrorCore.js";
+import {
+  AnalysisCancelledError,
+  cancelledBy,
+  carriedReason,
+} from "../domain/analysisErrorCore.js";
 import { ProviderCleanupError } from "../domain/providerCleanupError.js";
 import {
   findOverlappingFatSlices,
@@ -95,11 +99,7 @@ export const resolveHopperMachOImage = async (
       ),
     );
   if (options.signal?.aborted)
-    return err(
-      new AnalysisCancelledError("open_binary", {
-        cause: options.signal.reason,
-      }),
-    );
+    return err(cancelledBy("open_binary", options.signal));
   if (target.format !== "mach-o" && target.format !== "mach-o-universal")
     return invalid("Hopper image preparation requires a Mach-O target");
   let opened: FileHandle;
@@ -158,11 +158,7 @@ const inspectAndFinalizeHopperMachOImage = async (
   }
   if (closeOutcome.kind === "closed") {
     if (result.ok && options.signal?.aborted)
-      return err(
-        new AnalysisCancelledError("open_binary", {
-          cause: options.signal.reason,
-        }),
-      );
+      return err(cancelledBy("open_binary", options.signal));
     return result;
   }
   return retainHopperPreflightCloseFailure({
@@ -225,15 +221,20 @@ const retainHopperPreflightCloseFailure = (options: {
               cleanup,
             },
           )
-        : new AnalysisCancelledError("open_binary", {
-            cause: options.result.error.cause,
-            cleanup,
-          });
+        : cancelledBy(
+            "open_binary",
+            carriedReason(options.result.error.cause),
+            { cleanup },
+          );
   } else if (options.cancellationBeforeClose) {
-    failure = new AnalysisCancelledError("open_binary", {
-      cause: options.signal?.reason,
-      cleanup,
-    });
+    // cancellationBeforeClose records that the caller's signal had aborted.
+    failure = cancelledBy(
+      "open_binary",
+      carriedReason(options.signal?.reason),
+      {
+        cleanup,
+      },
+    );
   } else {
     failure = new BinaryTargetError(
       options.target.path,
@@ -256,11 +257,7 @@ const retainHopperPreflightCloseFailure = (options: {
     failure.retainSecondaryFailure(cleanupError);
   }
   if (options.signal?.aborted && !cancellationIsPrimary)
-    failure.retainSecondaryFailure(
-      new AnalysisCancelledError("open_binary", {
-        cause: options.signal.reason,
-      }),
-    );
+    failure.retainSecondaryFailure(cancelledBy("open_binary", options.signal));
   new AnalysisCleanupLeaseGroup(failure, [lease]);
   return err(failure);
 };
@@ -280,10 +277,7 @@ const inspectHopperMachOImage = async (
     );
   const read = (offset: number, length: number): Promise<Buffer> =>
     readFileHandleRange(file, offset, length, () => {
-      if (signal?.aborted)
-        throw new AnalysisCancelledError("open_binary", {
-          cause: signal.reason,
-        });
+      if (signal?.aborted) throw cancelledBy("open_binary", signal);
     });
   const header = await read(0, 8);
   const fatPrefix = readFatHeaderPrefix(header);
@@ -298,14 +292,9 @@ const inspectHopperMachOImage = async (
     for await (const chunk of readFileHandleChunks(file, {
       ...(signal === undefined ? {} : { signal }),
       cancellationFailure: (reason) =>
-        new AnalysisCancelledError("open_binary", { cause: reason }),
+        cancelledBy("open_binary", carriedReason(reason)),
     })) {
-      if (signal?.aborted)
-        return err(
-          new AnalysisCancelledError("open_binary", {
-            cause: signal.reason,
-          }),
-        );
+      if (signal?.aborted) return err(cancelledBy("open_binary", signal));
       const bytes = Buffer.from(chunk);
       hash.update(bytes);
       size += bytes.length;
@@ -317,10 +306,7 @@ const inspectHopperMachOImage = async (
         prefixLength += copied;
       }
     }
-    if (signal?.aborted)
-      return err(
-        new AnalysisCancelledError("open_binary", { cause: signal.reason }),
-      );
+    if (signal?.aborted) return err(cancelledBy("open_binary", signal));
     if (prefixLength !== prefix.length)
       return invalid("Thin Mach-O header is truncated");
     const observedSha256 = hash.digest("hex");
@@ -372,10 +358,7 @@ const inspectHopperMachOImage = async (
   const admitted = target.universalSlice;
   const matches: FatSliceDeclaration[] = [];
   for (const slice of parsed.slices) {
-    if (signal?.aborted)
-      return err(
-        new AnalysisCancelledError("open_binary", { cause: signal.reason }),
-      );
+    if (signal?.aborted) return err(cancelledBy("open_binary", signal));
     const rangeError = validateFatSlice(slice, size, tableEnd);
     if (rangeError !== null) return invalid(rangeError);
     if (slice.reserved !== null && slice.reserved !== 0)
diff --git a/src/hopper/HopperRegexSearch.test.ts b/src/hopper/HopperRegexSearch.test.ts
index 61674f8e3f..2dc4a23fc5 100644
--- a/src/hopper/HopperRegexSearch.test.ts
+++ b/src/hopper/HopperRegexSearch.test.ts
@@ -1,7 +1,10 @@
 import { expect, it, vi } from "vitest";
 import { HopperRegexSearch } from "./HopperRegexSearch.js";
 import { err, ok } from "../domain/result.js";
-import { AnalysisCapabilityUnavailableError } from "../domain/analysisErrorCore.js";
+import {
+  AnalysisCapabilityUnavailableError,
+  OwnerCancellation,
+} from "../domain/analysisErrorCore.js";
 import {
   HopperRemoteError,
   HopperTimeoutError,
@@ -247,6 +250,45 @@ it.each(
   },
 );
 
+it.each([false, true])(
+  "joins an active search on close and preserves earlier caller cancellation: %s",
+  async (callerFirst) => {
+    let release!: () => void;
+    const gate = new Promise<void>((resolve) => {
+      release = resolve;
+    });
+    const controller = new AbortController();
+    const search = new HopperRegexSearch({
+      callTool: async () => {
+        await gate;
+        return ok([]);
+      },
+    });
+    const pending = search.execute(
+      "search_strings",
+      { pattern: "fixture", mode: "regex", case_sensitive: false },
+      { signal: controller.signal },
+    );
+    if (callerFirst) controller.abort("caller stopped");
+    let finished = false;
+    const closing = search.close().then(() => {
+      finished = true;
+    });
+    await Promise.resolve();
+    expect(finished).toBe(false);
+    release();
+    expect(await pending).toMatchObject({
+      ok: false,
+      error: {
+        _tag: "AnalysisCancelledError",
+        cause: callerFirst ? "caller stopped" : OwnerCancellation.ownerClosed,
+      },
+    });
+    await closing;
+    expect(finished).toBe(true);
+  },
+);
+
 it.each(
   [null, "caller stopped", { requested: "stop" }].flatMap((reason) =>
     (["inventory", "progress"] as const).map((stage) => ({ reason, stage })),
diff --git a/src/hopper/HopperRegexSearch.ts b/src/hopper/HopperRegexSearch.ts
index c830fd88a8..ed56f6d484 100644
--- a/src/hopper/HopperRegexSearch.ts
+++ b/src/hopper/HopperRegexSearch.ts
@@ -2,7 +2,7 @@ import { z } from "zod";
 
 import type { ExecutionOptions } from "../application/AnalysisProvider.js";
 import type { AnalysisError } from "../domain/analysisErrorBase.js";
-import { AnalysisCancelledError } from "../domain/analysisErrorCore.js";
+import { cancelledBy, OwnerCancellation } from "../domain/analysisErrorCore.js";
 import { HopperRemoteError } from "../domain/hopperErrors.js";
 import type { JsonValue } from "../domain/jsonValue.js";
 import { err, ok, type Result } from "../domain/result.js";
@@ -61,7 +61,8 @@ export class HopperRegexSearch {
 
   /** Abort matching workers before their provider session closes. */
   async close(): Promise<void> {
-    for (const controller of this.#active.keys()) controller.abort();
+    for (const controller of this.#active.keys())
+      controller.abort(OwnerCancellation.ownerClosed);
     await Promise.all(this.#active.values());
   }
 
@@ -115,9 +116,7 @@ export class HopperRegexSearch {
     if (!parsed.ok) return parsed;
     const rows: readonly (typeof parsed.value)[number][] = parsed.value;
     if (options.signal?.aborted)
-      return err(
-        new AnalysisCancelledError(operation, { cause: options.signal.reason }),
-      );
+      return err(cancelledBy(operation, options.signal));
     await options.progress
       ?.report({
         phase: "hopper_regex",
@@ -127,9 +126,7 @@ export class HopperRegexSearch {
       })
       .catch(() => undefined);
     if (options.signal?.aborted)
-      return err(
-        new AnalysisCancelledError(operation, { cause: options.signal.reason }),
-      );
+      return err(cancelledBy(operation, options.signal));
     const matched = await matchRegexValues({
       operation,
       pattern: input.data.pattern,
@@ -141,9 +138,7 @@ export class HopperRegexSearch {
     });
     if (!matched.ok) return matched;
     if (options.signal?.aborted)
-      return err(
-        new AnalysisCancelledError(operation, { cause: options.signal.reason }),
-      );
+      return err(cancelledBy(operation, options.signal));
     const selected = new Set(matched.value);
     return ok(rows.filter((_, index) => selected.has(index)));
   }