diff --git a/src/artifacts/apple/AppleAssetCatalogAnalysis.ts b/src/artifacts/apple/AppleAssetCatalogAnalysis.ts
index cae0295898..98016f124e 100644
--- a/src/artifacts/apple/AppleAssetCatalogAnalysis.ts
+++ b/src/artifacts/apple/AppleAssetCatalogAnalysis.ts
@@ -337,6 +337,7 @@ const inspectAssetCatalogEntry = async (input: {
     throw new ArtifactReaderFailure(
       "integrity",
       `Asset catalog changed before inspection: ${entry.path}`,
+      { integrityCheck: "member-identity" },
     );
   let output: string;
   try {
@@ -353,6 +354,7 @@ const inspectAssetCatalogEntry = async (input: {
     throw new ArtifactReaderFailure(
       "integrity",
       `Asset catalog changed during inspection: ${entry.path}`,
+      { integrityCheck: "member-identity" },
     );
   const capturedOutput: AnalysisCapturedOutput = {
     stdout: output,
diff --git a/src/artifacts/apple/DylibFileAccess.ts b/src/artifacts/apple/DylibFileAccess.ts
index 448b5476c1..00e650a860 100644
--- a/src/artifacts/apple/DylibFileAccess.ts
+++ b/src/artifacts/apple/DylibFileAccess.ts
@@ -18,6 +18,7 @@ import {
   mapArtifactFileFailure,
   withArtifactRegularFile,
 } from "../ArtifactFileOperation.js";
+import type { ArtifactIntegrityCheck } from "../../domain/artifactOperationError.js";
 import type { ArtifactResourceScope } from "../ArtifactResourceScope.js";
 import { readArtifactFileChunks } from "../readArtifactFileChunks.js";
 import { hasMachoMagic } from "../../domain/apple/machoContainer.js";
@@ -80,7 +81,7 @@ export class DylibFileAccess {
       for await (const chunk of source) hash.update(chunk);
       const coverage = source.readCoverage();
       if (coverage.kind !== "complete" || coverage.bytes !== initial.size)
-        throw changed(path);
+        throw changed(path, undefined, "read-coverage");
       return hash.digest("hex");
     });
   }
@@ -164,9 +165,13 @@ const deniedDisplayPath = (root: string, path: string): string => {
   return inside === "" || outside ? path : inside;
 };
 
-const changed = (path: string, cause?: unknown): ArtifactReaderFailure =>
+const changed = (
+  path: string,
+  cause?: unknown,
+  integrityCheck: ArtifactIntegrityCheck = "member-identity",
+): ArtifactReaderFailure =>
   new ArtifactReaderFailure(
     "integrity",
     `${path} changed while its dyld load commands were traced`,
-    cause === undefined ? undefined : { cause },
+    cause === undefined ? { integrityCheck } : { cause, integrityCheck },
   );
diff --git a/src/artifacts/apple/DylibResolutionReader.ts b/src/artifacts/apple/DylibResolutionReader.ts
index 98d11741a8..5732480ffe 100644
--- a/src/artifacts/apple/DylibResolutionReader.ts
+++ b/src/artifacts/apple/DylibResolutionReader.ts
@@ -23,6 +23,7 @@ import {
 } from "../ArtifactReader.js";
 import { ArtifactTraversalObservation } from "../ArtifactTraversalObservation.js";
 import { DirectoryArtifactReader } from "../DirectoryArtifactReader.js";
+import { targetDigestChangedFailure } from "../withArtifactTargetIdentity.js";
 import { consumeWithOrderedReads } from "../OrderedReads.js";
 import {
   DylibFileAccess,
@@ -209,9 +210,10 @@ export const traceDylibResolution = async (options: {
         digests.get(target) ??
         (await files.sha256(join(root, target), undefined));
       if (targetDigest !== options.targetSha256)
-        throw new ArtifactReaderFailure(
-          "integrity",
-          `Active target digest changed: expected ${options.targetSha256}, observed ${targetDigest}`,
+        throw targetDigestChangedFailure(
+          "target",
+          options.targetSha256,
+          targetDigest,
         );
       assertArtifactReadActive(options.signal);
       return dylibResolutionResultSchema.parse({
diff --git a/src/artifacts/apple/KeyedArchiveReader.ts b/src/artifacts/apple/KeyedArchiveReader.ts
index 7fbe7a14e6..4835e3a693 100644
--- a/src/artifacts/apple/KeyedArchiveReader.ts
+++ b/src/artifacts/apple/KeyedArchiveReader.ts
@@ -1,4 +1,5 @@
 import { HOST_PLATFORM } from "../../platform/HostPlatform.js";
+import { targetDigestChangedFailure } from "../withArtifactTargetIdentity.js";
 import { createHash } from "node:crypto";
 import {
   decodeLimit,
@@ -302,9 +303,10 @@ export const inspectStandaloneKeyedArchive = (input: {
       input.signal,
     );
     if (snapshot.sha256 !== input.targetSha256)
-      throw new ArtifactReaderFailure(
-        "integrity",
-        `Active archive digest changed: expected ${input.targetSha256}, observed ${snapshot.sha256}`,
+      throw targetDigestChangedFailure(
+        "archive",
+        input.targetSha256,
+        snapshot.sha256,
       );
     return decodeSelectedArchive(snapshot.bytes, {
       targetSha256: input.targetSha256,
diff --git a/src/artifacts/extraction/ArtifactExtraction.ts b/src/artifacts/extraction/ArtifactExtraction.ts
index e90fa4284a..9afbd65a54 100644
--- a/src/artifacts/extraction/ArtifactExtraction.ts
+++ b/src/artifacts/extraction/ArtifactExtraction.ts
@@ -187,7 +187,7 @@ export const materializeArtifactInventoryInScope = async (
         throw new ArtifactReaderFailure(
           "integrity",
           `Inventoried source changed: ${sourcePath}`,
-          { cause },
+          { cause, integrityCheck: "container-identity" },
         );
       throw cause;
     }
@@ -288,6 +288,7 @@ export const materializeArtifactInventoryInScope = async (
       throw new ArtifactReaderFailure(
         "integrity",
         `Selected occurrence has no inventory node: ${occurrence.occurrence_id}`,
+        { integrityCheck: "inventory-node" },
       );
     return { occurrence, node };
   });
@@ -493,6 +494,7 @@ const writeSelectedEntries = async ({
       throw new ArtifactReaderFailure(
         "integrity",
         `Regular artifact entry is missing from inventory: ${path}`,
+        { integrityCheck: "inventory-node" },
       );
     }
     queue.next += 1;
@@ -526,6 +528,7 @@ const writeSelectedEntries = async ({
     throw new ArtifactReaderFailure(
       "integrity",
       `Inventoried regular artifact entries were not materialized: ${[...expected.keys()].sort(compareUnicodeCodePoints).join(", ")}`,
+      { integrityCheck: "traversal-coverage" },
     );
 };
 
@@ -750,7 +753,7 @@ const createReader = async (
         throw new ArtifactReaderFailure(
           "integrity",
           `Inventoried source changed: ${path}`,
-          { cause },
+          { cause, integrityCheck: "container-identity" },
         );
       throw cause;
     }
diff --git a/src/artifacts/inventory/hashStableRootArtifact.ts b/src/artifacts/inventory/hashStableRootArtifact.ts
index 37f6ded9c6..1d11fc1ae6 100644
--- a/src/artifacts/inventory/hashStableRootArtifact.ts
+++ b/src/artifacts/inventory/hashStableRootArtifact.ts
@@ -166,7 +166,7 @@ export const hashStableRootArtifactHandle = async (
       throw new ArtifactReaderFailure(
         "integrity",
         `Root artifact changed during inventory: ${path}`,
-        { cause: cause.cause ?? cause },
+        { cause: cause.cause ?? cause, integrityCheck: "container-identity" },
       );
     throw artifactOperationCause(cause);
   }
@@ -174,6 +174,7 @@ export const hashStableRootArtifactHandle = async (
     throw new ArtifactReaderFailure(
       "integrity",
       `Root artifact changed during inventory: ${path}`,
+      { integrityCheck: "container-identity" },
     );
   abortIfNeeded(signal);
   return digest;
diff --git a/src/artifacts/withArtifactTargetIdentity.ts b/src/artifacts/withArtifactTargetIdentity.ts
index b6ad882d69..ffebd5984b 100644
--- a/src/artifacts/withArtifactTargetIdentity.ts
+++ b/src/artifacts/withArtifactTargetIdentity.ts
@@ -3,6 +3,21 @@ import { ArtifactReaderFailure } from "./ArtifactReader.js";
 import type { ArtifactResourceScope } from "./ArtifactResourceScope.js";
 import { hashStableRootArtifact } from "./inventory/hashStableRootArtifact.js";
 
+/**
+ * The `container-identity` failure for a selected target whose observed
+ * digest no longer matches the one the session admitted.
+ */
+export const targetDigestChangedFailure = (
+  subject: string,
+  expected: string,
+  observed: string,
+): ArtifactReaderFailure =>
+  new ArtifactReaderFailure(
+    "integrity",
+    `Active ${subject} digest changed: expected ${expected}, observed ${observed}`,
+    { integrityCheck: "container-identity" },
+  );
+
 /** Bind live resource reads to the target identity established by the session. */
 export const withArtifactTargetIdentity = async <T>(
   target: BinaryTarget,
@@ -13,10 +28,7 @@ export const withArtifactTargetIdentity = async <T>(
   const verify = async () => {
     const digest = await hashStableRootArtifact(target.path, resources, signal);
     if (digest.sha256 !== target.sha256)
-      throw new ArtifactReaderFailure(
-        "integrity",
-        `Active target digest changed: expected ${target.sha256}, observed ${digest.sha256}`,
-      );
+      throw targetDigestChangedFailure("target", target.sha256, digest.sha256);
   };
   await verify();
   const result = await read();
diff --git a/src/domain/artifactOperationError.ts b/src/domain/artifactOperationError.ts
index 093055114e..9f1e203c0f 100644
--- a/src/domain/artifactOperationError.ts
+++ b/src/domain/artifactOperationError.ts
@@ -32,7 +32,8 @@ export interface ArtifactAdmissionLimit {
  * or place an entry outside the artifact, entries that do not reassemble into
  * the source, an inventory node or verified state a later read relies on
  * that is missing, output bytes that do not read back as written, or an
- * output tree used after commit or whose cleanup could not be verified.
+ * output tree used after commit or whose cleanup could not be verified,
+ * or a verification traversal that did not reproduce every inventoried entry.
  */
 export type ArtifactIntegrityCheck =
   | "foreign-entry"
@@ -49,7 +50,8 @@ export type ArtifactIntegrityCheck =
   | "reconstruction"
   | "inventory-node"
   | "output-readback"
-  | "output-lifecycle";
+  | "output-lifecycle"
+  | "traversal-coverage";
 
 /** Artifact inventory or extraction failed a typed safety boundary. */
 export class ArtifactOperationError extends AnalysisError {
diff --git a/src/native/NativeMachoSource.test.ts b/src/native/NativeMachoSource.test.ts
index 85ea4b7ce4..8af92e5415 100644
--- a/src/native/NativeMachoSource.test.ts
+++ b/src/native/NativeMachoSource.test.ts
@@ -84,7 +84,10 @@ it("refuses wrong initial digest and a changed selected file even after a return
         undefined,
         run,
       ),
-    ).rejects.toMatchObject({ reason: "integrity" });
+    ).rejects.toMatchObject({
+      reason: "integrity",
+      integrityCheck: "container-identity",
+    });
     expect(run).not.toHaveBeenCalled();
     await expect(
       withNativeMachoSource(f, scope, undefined, async () => {
@@ -111,7 +114,10 @@ it("refuses a path replacement during the producer callback", async () => {
         await writeFile(f.path, f.bytes);
         return "result";
       }),
-    ).rejects.toMatchObject({ reason: "integrity" });
+    ).rejects.toMatchObject({
+      reason: "integrity",
+      integrityCheck: "container-identity",
+    });
   } finally {
     await scope.close();
     await rm(f.root, { recursive: true, force: true });
diff --git a/src/native/NativeMachoSource.ts b/src/native/NativeMachoSource.ts
index 6be35bc95f..6c45acdaf7 100644
--- a/src/native/NativeMachoSource.ts
+++ b/src/native/NativeMachoSource.ts
@@ -8,6 +8,7 @@ import {
 import { ArtifactReaderFailure } from "../artifacts/ArtifactReader.js";
 import type { ArtifactResourceScope } from "../artifacts/ArtifactResourceScope.js";
 import { hashStableRootArtifactHandle } from "../artifacts/inventory/hashStableRootArtifact.js";
+import { targetDigestChangedFailure } from "../artifacts/withArtifactTargetIdentity.js";
 
 /** A positional reader for one slice of the descriptor bound to the target. */
 export interface NativeMachoSource {
@@ -37,9 +38,13 @@ export class NativeMachoSourceVerificationFailure extends ArtifactReaderFailure
         : String(verificationCause),
       {
         cause: verificationCause,
-        ...(verificationCause instanceof ArtifactReaderFailure &&
-        verificationCause.cancellation !== undefined
-          ? { cancellation: verificationCause.cancellation }
+        ...(verificationCause instanceof ArtifactReaderFailure
+          ? {
+              ...verificationCause.primaryFacts(),
+              ...(verificationCause.cancellation === undefined
+                ? {}
+                : { cancellation: verificationCause.cancellation }),
+            }
           : {}),
       },
       verificationCause instanceof ArtifactReaderFailure
@@ -82,14 +87,15 @@ export const withNativeMachoSource = <T>(
             throw new ArtifactReaderFailure(
               "integrity",
               `Active Mach-O target changed: ${target.path}`,
-              { cause },
+              { cause, integrityCheck: "container-identity" },
             );
           throw cause;
         });
         if (digest.sha256 !== target.sha256)
-          throw new ArtifactReaderFailure(
-            "integrity",
-            `Active Mach-O target digest changed: expected ${target.sha256}, observed ${digest.sha256}`,
+          throw targetDigestChangedFailure(
+            "Mach-O target",
+            target.sha256,
+            digest.sha256,
           );
       };
       await verify();
@@ -122,6 +128,7 @@ export const withNativeMachoSource = <T>(
             throw new ArtifactReaderFailure(
               "integrity",
               "Mach-O source changed during slice read.",
+              { integrityCheck: "read-coverage" },
             );
           return bytes;
         },
diff --git a/tests/boundary/filesystem/keyedArchiveStandaloneSelection.test.ts b/tests/boundary/filesystem/keyedArchiveStandaloneSelection.test.ts
index 628fccfe8c..6810a548b7 100644
--- a/tests/boundary/filesystem/keyedArchiveStandaloneSelection.test.ts
+++ b/tests/boundary/filesystem/keyedArchiveStandaloneSelection.test.ts
@@ -129,7 +129,7 @@ it.skipIf(process.platform === "win32")(
         ok: false,
         error: {
           reason: "integrity",
-          detail: expect.stringContaining("Active archive digest changed"),
+          integrityCheck: "container-identity",
         },
       });
       await truncate(stored, 64 * 1024 * 1024 + 1);
diff --git a/tests/boundary/mcp/dylibResolutionMcp.test.ts b/tests/boundary/mcp/dylibResolutionMcp.test.ts
index 5ea20698d0..db6f9378dd 100644
--- a/tests/boundary/mcp/dylibResolutionMcp.test.ts
+++ b/tests/boundary/mcp/dylibResolutionMcp.test.ts
@@ -111,7 +111,12 @@ it("traces dylib resolution for an opened app bundle and rejects a changed targe
       arguments: {},
     });
     expect(changed.isError).toBe(true);
-    expect(JSON.stringify(parseMcpToolError(changed))).toContain("integrity");
+    expect(parseMcpToolError(changed)).toMatchObject({
+      error: {
+        category: "integrity_mismatch",
+        details: { reason: "integrity", integrity_check: "container-identity" },
+      },
+    });
   });
 });
 
diff --git a/tests/boundary/providers/native/artifactProvider.extractionCompleteness.test.ts b/tests/boundary/providers/native/artifactProvider.extractionCompleteness.test.ts
index 26fa178edc..8ea9b49efe 100644
--- a/tests/boundary/providers/native/artifactProvider.extractionCompleteness.test.ts
+++ b/tests/boundary/providers/native/artifactProvider.extractionCompleteness.test.ts
@@ -104,7 +104,8 @@ it.each(["file", "directory"] as const)(
     );
     await expect(materialize()).rejects.toMatchObject({
       reason: "integrity",
-      message: expect.stringMatching(/not materialized.*z\/missing\.txt/iu),
+      integrityCheck: "traversal-coverage",
+      message: expect.stringContaining("z/missing.txt"),
     });
     await expect(access(output)).rejects.toThrow();
     expect(
@@ -129,9 +130,8 @@ it.skipIf(process.platform === "win32" || process.getuid?.() === 0)(
     onTestFinished(() => chmod(child, 0o755));
     await expect(materialize()).rejects.toMatchObject({
       reason: "integrity",
-      message: expect.stringMatching(
-        /not materialized.*child\/selected\.txt/iu,
-      ),
+      integrityCheck: "traversal-coverage",
+      message: expect.stringContaining("child/selected.txt"),
     });
     await expect(access(output)).rejects.toThrow();
     await chmod(child, 0o755);
@@ -151,7 +151,8 @@ it("still refuses a regular file added after inventory and rolls back", async ()
   await writeFile(join(source, "z.txt"), "new\n");
   await expect(materialize()).rejects.toMatchObject({
     reason: "integrity",
-    message: "Regular artifact entry is missing from inventory: z.txt",
+    integrityCheck: "inventory-node",
+    message: expect.stringContaining("z.txt"),
   });
   await expect(access(output)).rejects.toThrow();
 });