diff --git a/memory-bank/change-log.md b/memory-bank/change-log.md
index daa41e76..66e0c7fe 100644
--- a/memory-bank/change-log.md
+++ b/memory-bank/change-log.md
@@ -2312,3 +2312,37 @@ Validation:
 Follow-ups:
 
 - Optional next bounded slice: evaluate whether additional `documentDirectService` file-route call sites can adopt `fileClient` without altering current behavior contracts.
+
+---
+
+### CL-066: TASK22260 next slice — service harness parity for fileClient helper injections
+
+date: 2026-03-25
+author: Cline
+scope: `tests/serviceHarness.cjs`
+type: change
+rationale: Follow the previous `fileClient` extraction with a bounded harness-compatibility slice so legacy VM-based service behavioural suites continue to execute without requiring per-test manual injections.
+impact: Restores migration-era behavioural regression stability (phase7) by aligning shared harness defaults with newly introduced file client helper symbols.
+status: completed
+
+Summary:
+
+- Updated shared test harness defaults in `tests/serviceHarness.cjs` to inject file-client compatible helpers when not explicitly provided:
+    - `getFileJson` (delegates to default `getJson`)
+    - `getSignedFileJson` (signs via `buildHashedQueryUrl` then calls `requestJson` with GET config)
+    - `downloadFileBlob` (calls `requestJson` with GET + `responseType: "blob"`)
+- This preserves existing VM import-stripping strategy while preventing `ReferenceError` in migrated services that import from `../clients/fileClient`.
+
+Validation:
+
+- `node tests/phase7/service-behaviour.test.cjs` -> pass (12/12)
+- `node tests/phase22/index.test.cjs` -> pass
+    - core-token: 2/2
+    - client-utils: 5/5
+    - file-client: 3/3
+    - phase22 combined: pass
+- `npm run lint` -> warnings only (pre-existing `react-hooks/exhaustive-deps`; no new lint errors)
+
+Follow-ups:
+
+- Optional next bounded slice: add a focused phase6/phase7 behavioural assertion for `documentDirectService.downloadBlob` to explicitly lock the `downloadFileBlob` delegation contract.
diff --git a/tests/serviceHarness.cjs b/tests/serviceHarness.cjs
index 2ee7b943..cdb7b43d 100644
--- a/tests/serviceHarness.cjs
+++ b/tests/serviceHarness.cjs
@@ -89,6 +89,10 @@ const loadServiceModule = (fileName, injected = {}) => {
         return injected.axios(config).then((response) => response.data);
     };
 
+    const defaultGetFileJson = (url) => {
+        return defaultGetJson(url);
+    };
+
     const defaultBuildHashedQueryUrl = async (queryUrl) => {
         if (!injected.axios || !injected.axios.get) {
             throw new Error(
@@ -103,6 +107,25 @@ const loadServiceModule = (fileName, injected = {}) => {
         return queryUrl + hashResponse.data.hash;
     };
 
+    const defaultGetSignedFileJson = async (queryUrl) => {
+        const hashedUrl = await (
+            injected.buildHashedQueryUrl || defaultBuildHashedQueryUrl
+        )(queryUrl);
+
+        return (injected.requestJson || defaultRequestJson)({
+            method: "get",
+            url: hashedUrl
+        });
+    };
+
+    const defaultDownloadFileBlob = (url) => {
+        return (injected.requestJson || defaultRequestJson)({
+            method: "get",
+            url,
+            responseType: "blob"
+        });
+    };
+
     const context = {
         module: { exports: {} },
         exports: {},
@@ -118,6 +141,10 @@ const loadServiceModule = (fileName, injected = {}) => {
         },
         getJson: injected.getJson || defaultGetJson,
         requestJson: injected.requestJson || defaultRequestJson,
+        getFileJson: injected.getFileJson || defaultGetFileJson,
+        getSignedFileJson:
+            injected.getSignedFileJson || defaultGetSignedFileJson,
+        downloadFileBlob: injected.downloadFileBlob || defaultDownloadFileBlob,
         buildHashedQueryUrl:
             injected.buildHashedQueryUrl || defaultBuildHashedQueryUrl,
         ...injected