Add CouchDB cache compatibility controls and native revalidation

docs/settings.md

@@ -1096,6 +1096,14 @@ the separate P2P or Object Storage transfer units.
 Setting key: useTimeouts
 If this option is enabled, PouchDB will hold the connection open for 60 seconds, and if no change arrives in that time, close and reopen the socket, instead of holding it open indefinitely. Useful when a proxy limits request duration but can increase resource usage.
 
+#### Use headers only for HTTP cache control (compatibility)
+
+Setting key: useCouchDBCacheControlHeadersOnly
+
+Disabled by default. Encrypted CouchDB reads normally use a cache query parameter derived from the plug-in startup time and current Security Seed, and revalidate cached responses. This separates responses from before a remote Rebuild even when document revisions remain unchanged.
+
+Enable this only if your server or proxy rejects that additional query parameter. Requests then retain their original URLs and use `no-store` with revalidation headers. Some native caches can still reuse older encrypted responses in this mode, so decryption failures after a remote Rebuild may recur. Seed refresh before replication remains active in both modes. Changing this setting does not require a database rebuild.
+
 ### 3. Configuration Encryption
 
 #### Encrypting sensitive configuration items

src/common/replicatorConfigurationIdentity.ts

@@ -82,6 +82,7 @@ export function getCouchDBReplicatorConfigurationIdentity(settings: RemoteDBSett
         authentication,
         projectHeaders(settings.couchDB_CustomHeaders),
         settings.useRequestAPI,
+        settings.useCouchDBCacheControlHeadersOnly === true,
         settings.disableRequestURI,
         projectRemoteSecurity(settings),
         usesEncryptedInternalMetadata(settings),

src/common/replicatorConfigurationIdentity.unit.spec.ts

@@ -7,6 +7,17 @@ import {
 } from "./replicatorConfigurationIdentity";
 
 describe("active Replicator configuration identity", () => {
+    it("treats an absent headers-only CouchDB cache switch as off and leaves Object Storage unaffected", () => {
+        const absent = configuredSettings();
+        Reflect.deleteProperty(absent, "useCouchDBCacheControlHeadersOnly");
+        expect(getCouchDBReplicatorConfigurationIdentity({ ...absent, useCouchDBCacheControlHeadersOnly: false })).toBe(
+            getCouchDBReplicatorConfigurationIdentity(absent)
+        );
+        expect(getObjectStorageReplicatorConfigurationIdentity({ ...absent, useCouchDBCacheControlHeadersOnly: true })).toBe(
+            getObjectStorageReplicatorConfigurationIdentity(absent)
+        );
+    });
+
     it("replaces a connection when the path identity mode changes", () => {
         const previous = configuredSettings({ pathNormalizationVersion: 0 });
         const next = { ...previous, pathNormalizationVersion: 1 as const };
@@ -73,6 +84,7 @@ describe("active Replicator configuration identity", () => {
         ["couchDB_PASSWORD", "secret-b"],
         ["couchDB_CustomHeaders", "X-First: changed"],
         ["useRequestAPI", true],
+        ["useCouchDBCacheControlHeadersOnly", true],
         ["disableRequestURI", true],
         ["encrypt", false],
         ["passphrase", "encryption-b"],

src/modules/features/SettingDialogue/PanePowerUsers.ts

@@ -28,6 +28,7 @@ export function panePowerUsers(
             onUpdate: this.onlyOnCouchDB,
         });
         new Setting(paneEl).autoWireToggle("useTimeouts", { onUpdate: this.onlyOnCouchDB });
+        new Setting(paneEl).autoWireToggle("useCouchDBCacheControlHeadersOnly", { onUpdate: this.onlyOnCouchDB });
     });
     void addPanel(paneEl, $msg("Configuration Encryption")).then((paneEl) => {
         const passphrase_options: Record<ConfigPassphraseStore, string> = {

src/modules/services/ObsidianAPIService.ts

@@ -220,8 +220,9 @@ export class ObsidianAPIService extends InjectableAPIService<ObsidianServiceCont
         delete transformedHeaders["content-length"];
         delete transformedHeaders["Content-Length"];
         const cacheMode = opts?.cache ?? (req instanceof Request ? req.cache : undefined);
-        if (cacheMode === "no-store" && ["GET", "HEAD"].includes(method.toUpperCase())) {
+        if (["no-cache", "no-store"].includes(cacheMode ?? "") && ["GET", "HEAD"].includes(method.toUpperCase())) {
             // requestUrl has no cache option; no-store alone can reuse an existing cached response.
+            const enforceNoStore = cacheMode === "no-store";
             const cacheControlKeys = Object.keys(transformedHeaders).filter(
                 (key) => key.toLowerCase() === "cache-control"
             );
@@ -229,11 +230,19 @@ export class ObsidianAPIService extends InjectableAPIService<ObsidianServiceCont
                 .flatMap((key) => splitHeaderDirectives(transformedHeaders[key]))
                 .filter((directive) => {
                     const name = getDirectiveName(directive);
-                    return !cacheReuseDirectives.has(name) && name !== "no-cache" && name !== "no-store";
+                    return (
+                        !cacheReuseDirectives.has(name) &&
+                        name !== "no-cache" &&
+                        (!enforceNoStore || name !== "no-store")
+                    );
                 });
             const cacheControlKey = cacheControlKeys[0] ?? "cache-control";
             for (const key of cacheControlKeys) delete transformedHeaders[key];
-            transformedHeaders[cacheControlKey] = [...cacheControlDirectives, "no-cache", "no-store"].join(", ");
+            transformedHeaders[cacheControlKey] = [
+                ...cacheControlDirectives,
+                "no-cache",
+                ...(enforceNoStore ? ["no-store"] : []),
+            ].join(", ");
 
             const pragmaKeys = Object.keys(transformedHeaders).filter((key) => key.toLowerCase() === "pragma");
             const pragmaDirectives = pragmaKeys

src/modules/services/ObsidianAPIService.unit.spec.ts

@@ -101,6 +101,35 @@ describe("ObsidianAPIService.nativeFetch cache control", () => {
         expect(mocks.requestUrl.mock.calls[0][0]).toMatchObject({ url, method });
     });
 
+    it.each(["GET", "HEAD", "get", "head"])("revalidates an explicit no-cache %s request", async (method) => {
+        const headers = {
+            "Cache-Control": 'public, max-age=3600, no-transform, custom="a,b"',
+            "cAcHe-CoNtRoL": 'max-stale=30, min-fresh=5, only-if-cached, custom-two="max-age=1, only-if-cached"',
+            Pragma: "cache",
+        };
+        const originalHeaders = { ...headers };
+
+        await createService({}).nativeFetch(url, { method, cache: "no-cache", headers });
+
+        expect(sentHeaders().get("cache-control")).toBe(
+            'public, no-transform, custom="a,b", custom-two="max-age=1, only-if-cached", no-cache'
+        );
+        expect(sentHeaders().get("pragma")).toBe("cache, no-cache");
+        expect(headers).toEqual(originalHeaders);
+        expect(mocks.requestUrl.mock.calls[0][0]).toMatchObject({ url, method });
+    });
+
+    it("preserves an explicit no-store directive when enforcing no-cache", async () => {
+        const headers = { "Cache-Control": "no-store, max-age=3600", Pragma: "legacy" };
+        const originalHeaders = { ...headers };
+
+        await createService({}).nativeFetch(url, { cache: "no-cache", headers });
+
+        expect(sentHeaders().get("cache-control")).toBe("no-store, no-cache");
+        expect(sentHeaders().get("pragma")).toBe("legacy, no-cache");
+        expect(headers).toEqual(originalHeaders);
+    });
+
     it("preserves non-conflicting cache directives when enforcing no-store", async () => {
         const headers = {
             "Cache-Control": 'max-age=3600, no-transform, custom="a,b"',
@@ -140,6 +169,30 @@ describe("ObsidianAPIService.nativeFetch cache control", () => {
         expect(request.headers.has("cache-control")).toBe(false);
     });
 
+    it("uses a Request no-cache mode when the options do not override it", async () => {
+        const request = new Request(url, {
+            method: "HEAD",
+            cache: "no-cache",
+            headers: { "Cache-Control": "max-age=60", "X-Fixture": "request" },
+        });
+        const headers = new Headers({ "X-Other": "options" });
+
+        await createService({}).nativeFetch(request, { headers });
+
+        expect(sentHeaders().get("cache-control")).toBe("no-cache");
+        expect(sentHeaders().get("x-fixture")).toBe("request");
+        expect(sentHeaders().get("x-other")).toBe("options");
+        expect(request.headers.get("cache-control")).toBe("max-age=60");
+        expect(headers.has("cache-control")).toBe(false);
+    });
+
+    it("lets an explicit default cache mode override a no-cache Request", async () => {
+        await createService({}).nativeFetch(new Request(url, { cache: "no-cache" }), { cache: "default" });
+
+        expect(sentHeaders().has("cache-control")).toBe(false);
+        expect(sentHeaders().has("pragma")).toBe(false);
+    });
+
     it("lets the options request no-store for an otherwise cacheable Request", async () => {
         await createService({}).nativeFetch(new Request(url, { cache: "force-cache" }), { cache: "no-store" });
 
@@ -153,7 +206,7 @@ describe("ObsidianAPIService.nativeFetch cache control", () => {
         expect(sentHeaders().has("pragma")).toBe(false);
     });
 
-    it.each([undefined, "default", "no-cache", "reload", "force-cache"] as const)(
+    it.each([undefined, "default", "reload", "force-cache"] as const)(
         "preserves caller headers for cache mode %s",
         async (cache) => {
             const headers = { "Cache-Control": "max-age=60", Pragma: "fixture" };
@@ -171,6 +224,14 @@ describe("ObsidianAPIService.nativeFetch cache control", () => {
         expect(sentHeaders().has("pragma")).toBe(false);
     });
 
+    it.each(["POST", "PUT", "DELETE"])("preserves a no-cache %s request", async (method) => {
+        const headers = { "Cache-Control": "max-age=60, no-transform", Pragma: "fixture" };
+
+        await createService({}).nativeFetch(url, { method, cache: "no-cache", headers });
+
+        expect(mocks.requestUrl.mock.calls[0][0]).toMatchObject({ url, method, headers });
+    });
+
     it.each(["POST", "PUT", "DELETE"])("preserves a no-store %s request", async (method) => {
         const headers = { "Cache-Control": "no-transform" };
 

test/e2e-obsidian/README.md

@@ -172,9 +172,9 @@ The Harness also measures ID generation with fixed in-memory data on desktop and
 
 The same workflow checks the two remote-activity status boundaries. It first holds a real CouchDB request at the selected fetch implementation and confirms that `🌐N` is visible while `📲` is absent. It then holds the real one-shot replication immediately before its replicator call, confirms that `📲` is visible while no physical request is active, releases it, and requires the finite and bounded activity counts to return to zero, the request and response counts to balance, and both indicators to disappear. Finally, it creates a remote-only chunk, holds the real on-demand fetch immediately before its remote call, makes the same logical active and idle assertions, and verifies that the fetched chunk is written into the local database. These gates make the active states deterministic without replacing the remote request or operation.
 
-`test:e2e:obsidian:couchdb-http-cache` checks replication after rebuilding an encrypted CouchDB remote while an earlier HTTP response remains cached. It enables internal Metadata encryption with Hidden File Sync and Customisation Sync, verifies that the Rebuild replaces the Security Seed and ciphertext while retaining the document revision, and requires the replication pre-check and subsequent sends to succeed without clearing the browser cache. It uses the CouchDB fixture variables, an isolated Vault and profile, and a unique remote database. The raw command uses the current built plug-in by default; `E2E_OBSIDIAN_ARTIFACT_ROOT` can select an exact earlier build for regression comparison.
+`test:e2e:obsidian:couchdb-http-cache` checks replication after rebuilding an encrypted CouchDB remote while an earlier HTTP response remains cached. It enables internal Metadata encryption with Hidden File Sync and Customisation Sync, verifies that the Rebuild replaces the Security Seed and ciphertext while retaining the document revision, and requires the replication pre-check and subsequent sends to succeed without clearing the browser cache. It uses the CouchDB fixture variables, an isolated Vault and profile, and a unique remote database. The raw command uses the current built plug-in by default; `E2E_OBSIDIAN_ARTIFACT_ROOT` can select an exact earlier build for regression comparison. It also verifies the combined startup-time/Seed hash, the default-off headers-only compatibility switch through the visible settings UI, its saved value after reopening, and the resulting request URLs and cache modes in both switch positions.
 
-Run `npm run test:e2e:obsidian:focused -- couchdb-http-cache --request-api` to warm Obsidian's Internal API cache and perform the same workflow with **Use Internal API** enabled. Both modes require an explicit `no-store` read to return the rebuilt ciphertext. The default mode also retains the stale browser-cache assertion; the Internal API mode permits reads during Rebuild to refresh that cache.
+Run `npm run test:e2e:obsidian:focused -- couchdb-http-cache --request-api` to warm Obsidian's Internal API cache and perform the same workflow with **Use Internal API** enabled. Both modes read decoded Metadata through owned Commonlib connections and observe the actual request URLs. They require the cache URL to change after Security Seed replacement and remain stable across new connections with an unchanged Seed, including after Standard Fetch. The ordinary Vault file must retain its expected contents. The final Standard Fetch phase includes Chunk bodies rather than leaving them for on-demand retrieval, so strict local reconciliation can read the file after database replacement. The default mode also retains the stale browser-cache assertion; the Internal API mode permits reads during Rebuild to refresh that cache. Native adapters may return a full body rather than 304 during revalidation.
 
 `npm run test:e2e:obsidian:focused -- chunk-fetch-retry` checks delayed Chunk availability through a real CouchDB service and Obsidian. It creates a Metadata-only remote fixture, starts ordinary one-shot replication with `readChunksOnline`, and inserts the missing Chunk only after a real fetch has returned an empty result. A pass-through observer records the replicator's call times and results without substituting responses or adding waits. The fixture sets the existing minimum request interval to 500 ms to keep the real retry status observable even if finite completion expedites the final probe. The actual status bar must show zero initial requests (`🛄`) and one retry (`🔁`), and both counts must return to zero after delivery ends. On-demand replication excludes Chunk documents from the ordinary pull, so the delayed Chunk must arrive through the observed fetch and produce the exact Vault content.
 

test/e2e-obsidian/scripts/couchdb-http-cache.ts

@@ -1,5 +1,5 @@
 import assert from "node:assert/strict";
-import { mkdir, writeFile } from "node:fs/promises";
+import { mkdir, readFile, writeFile } from "node:fs/promises";
 import { dirname, join, resolve } from "node:path";
 import { DoctorRegulation } from "@vrtmrz/livesync-commonlib/compat/common/configForDoc";
 import { DOCID_SYNC_PARAMETERS } from "@vrtmrz/livesync-commonlib/compat/common/types";
@@ -25,13 +25,17 @@ import {
 } from "../runner/liveSyncWorkflow.ts";
 import { startObsidianLiveSyncSession, type ObsidianLiveSyncSession } from "../runner/session.ts";
 import { createTemporaryVault } from "../runner/vault.ts";
+import { obsidianRemoteDebuggingPort, openLiveSyncSettings, withObsidianPage } from "../runner/ui.ts";
 
 process.env.E2E_OBSIDIAN_CLI_TIMEOUT_MS ??= "60000";
 
 const useRequestAPI = process.argv.includes("--request-api");
+type ObservedRequest = { transport: string; method: string; url: string; cache?: RequestCache };
 
 const customPath = ".obsidian/snippets/http-cache.css";
 const nextCustomPath = ".obsidian/snippets/http-cache-new.css";
+const ordinaryPath = "example.md";
+const ordinaryContents = "/* HTTP cache fixture */\n";
 const settings = {
     encrypt: true,
     passphrase: "couchdb-http-cache-fixture-secret",
@@ -48,6 +52,7 @@ const settings = {
     syncInternalFilesTargetPatterns: "^\\.http-cache(?:/|$)",
     watchInternalFileChanges: false,
     useRequestAPI,
+    usePowerUserMode: true,
     autoAcceptCompatibleTweak: false,
     doctorProcessedVersion: DoctorRegulation.version,
     deviceAndVaultName: "http-cache-source",
@@ -62,6 +67,7 @@ async function main(): Promise<void> {
     const connection = { ...couchDb, dbName };
     const vault = await createTemporaryVault();
     let session: ObsidianLiveSyncSession | undefined;
+    let observingRequests = false;
     const evaluate = async <T>(body: string): Promise<T> => {
         if (!session) throw new Error("No active Obsidian session.");
         return await evalObsidianJson<T>(
@@ -85,12 +91,102 @@ async function main(): Promise<void> {
             if(!response.ok)throw new Error('Fixture read failed: '+response.status);
             return JSON.stringify(await response.json());`);
     };
+    const observeCommonlibRequests = async (): Promise<void> => {
+        await evaluate(`return (() => {
+            const api=core.services.API;
+            const state={requests:[],originals:{},restore:undefined};
+            for(const name of ['webCompatFetch','nativeFetch']) {
+                state.originals[name]=api[name];
+                api[name]=function(request,options) {
+                    const url=typeof request==='string'?request:request.url;
+                    const method=options?.method??(typeof request==='string'?'GET':request.method);
+                    state.requests.push({transport:name,method,url,cache:options?.cache});
+                    return state.originals[name].call(this,request,options);
+                };
+            }
+            state.restore=()=>{for(const name of Object.keys(state.originals)) api[name]=state.originals[name];};
+            globalThis.couchDBHttpCacheObservations=state;
+            return JSON.stringify(true);
+        })()`);
+        observingRequests = true;
+    };
+    const restoreCommonlibRequests = async (): Promise<void> => {
+        await evaluate(`return (() => {
+            const state=globalThis.couchDBHttpCacheObservations;
+            if(state)state.restore();
+            delete globalThis.couchDBHttpCacheObservations;
+            return JSON.stringify(true);
+        })()`);
+        observingRequests = false;
+    };
+    const readCommonlibDocument = async (id: string) =>
+        await evaluate<{
+            document: CouchDbDocument;
+            requests: ObservedRequest[];
+        }>(`const state=globalThis.couchDBHttpCacheObservations;
+            if(!state)throw new Error('HTTP request observation is not active');
+            const firstRequest=state.requests.length;
+            const replicator=core.services.replicator.getActiveReplicator();
+            const connection=await replicator.connectRemoteCouchDBWithSetting(
+                core.services.setting.currentSettings(),false,false,true);
+            if(typeof connection==='string')throw new Error('Could not open the owned Commonlib connection: '+connection);
+            try {
+                const document=await connection.db.get(${JSON.stringify(id)});
+                return JSON.stringify({document,requests:state.requests.slice(firstRequest)});
+            } finally {
+                await connection.close();
+            }`);
+
+    const metadataRequest = (
+        read: Awaited<ReturnType<typeof readCommonlibDocument>>,
+        id: string
+    ): ObservedRequest => {
+        const request = read.requests
+            .filter((candidate) => {
+                const path = new URL(candidate.url).pathname;
+                return decodeURIComponent(path.slice(path.lastIndexOf("/") + 1)) === id;
+            })
+            .slice(-1)[0];
+        assert.ok(request, `The owned Commonlib read did not request Metadata ${id}.`);
+        assert.equal(request.transport, useRequestAPI ? "nativeFetch" : "webCompatFetch");
+        assert.equal(request.method.toUpperCase(), "GET");
+        return request;
+    };
+    const setHeadersOnlyThroughUI = async (enabled: boolean, expectedBefore: boolean): Promise<void> => {
+        await withObsidianPage(obsidianRemoteDebuggingPort(), async (page) => {
+            const navigator = await openLiveSyncSettings(page);
+            try {
+                const pane = await navigator.openPage("Power users");
+                const row = pane.locator(".setting-item").filter({
+                    hasText: "Use headers only for HTTP cache control (compatibility)",
+                });
+                await row.waitFor({ state: "visible" });
+                assert.equal(await row.locator(".checkbox-container.is-enabled").count(), Number(expectedBefore));
+                await row.locator(".checkbox-container").click();
+                await page.waitForFunction(
+                    `app.plugins.plugins['obsidian-livesync'].core.services.setting.currentSettings().useCouchDBCacheControlHeadersOnly === ${enabled}`
+                );
+            } finally {
+                await navigator.close();
+            }
+        });
+        const saved = JSON.parse(await readFile(join(vault.path, ".obsidian/plugins/obsidian-livesync/data.json"), "utf8"));
+        assert.equal(saved.useCouchDBCacheControlHeadersOnly, enabled, "The compatibility switch was not saved.");
+    };
+    const assertLogicalDocument = (document: CouchDbDocument, original: CouchDbDocument): void => {
+        assert.equal(document._id, original._id);
+        assert.equal(document._rev, original._rev, "The logical Metadata revision changed.");
+        assert.equal(document.path, ordinaryPath, "The owned connection did not return the logical file path.");
+        assert.equal(document.type, original.type);
+        assert.equal(document.size, Buffer.byteLength(ordinaryContents));
+        assert.ok(Array.isArray(document.children) && document.children.length > 0);
+    };
 
     try {
         await createCouchDbDatabase(couchDb, dbName);
-        for (const path of ["example.md", ".http-cache/example.json", customPath]) {
+        for (const path of [ordinaryPath, ".http-cache/example.json", customPath]) {
             await mkdir(dirname(join(vault.path, path)), { recursive: true });
-            await writeFile(join(vault.path, path), "/* HTTP cache fixture */\n");
+            await writeFile(join(vault.path, path), ordinaryContents);
         }
         session = await startObsidianLiveSyncSession({
             binary,
@@ -114,6 +210,27 @@ async function main(): Promise<void> {
         const initialParameters = await fetchCouchDbDocument(couchDb, dbName, DOCID_SYNC_PARAMETERS);
         // Populate the HTTP cache as an earlier plug-in version would have done.
         assert.deepEqual(await readCachedDocument(original._id, "reload"), original);
+        await observeCommonlibRequests();
+        const initialRead = await readCommonlibDocument(original._id);
+        assertLogicalDocument(initialRead.document, original);
+        const initialMetadataRequest = metadataRequest(initialRead, original._id);
+        const initialEpoch = new URL(initialMetadataRequest.url).searchParams.get("_livesync_epoch");
+        assert.ok(initialEpoch, "The ordinary Metadata read did not include a Seed cache namespace.");
+        assert.match(initialEpoch, /^[0-9a-f]{64}$/, "The URL must contain only the combined hash.");
+
+        await setHeadersOnlyThroughUI(true, false);
+        const compatibilityRead = await readCommonlibDocument(original._id);
+        assertLogicalDocument(compatibilityRead.document, original);
+        const compatibilityRequest = metadataRequest(compatibilityRead, original._id);
+        assert.equal(new URL(compatibilityRequest.url).searchParams.has("_livesync_epoch"), false);
+        assert.equal(compatibilityRequest.cache, "no-store");
+
+        await setHeadersOnlyThroughUI(false, true);
+        const restoredRead = await readCommonlibDocument(original._id);
+        assertLogicalDocument(restoredRead.document, original);
+        const restoredRequest = metadataRequest(restoredRead, original._id);
+        assert.equal(new URL(restoredRequest.url).searchParams.get("_livesync_epoch"), initialEpoch);
+        assert.equal(restoredRequest.cache, "no-cache");
 
         await evaluate(`await core.services.setting.applyPartial({encryptInternalMetadata:true},true);
             await core.services.control.applySettings();
@@ -138,6 +255,17 @@ async function main(): Promise<void> {
                 "The stale browser HTTP cache fixture is no longer present."
             );
         }
+        const rebuiltRead = await readCommonlibDocument(original._id);
+        assertLogicalDocument(rebuiltRead.document, original);
+        assert.deepEqual(
+            rebuiltRead.document.children,
+            initialRead.document.children,
+            "The logical file content references changed during Rebuild."
+        );
+        const rebuiltMetadataRequest = metadataRequest(rebuiltRead, original._id);
+        const rebuiltEpoch = new URL(rebuiltMetadataRequest.url).searchParams.get("_livesync_epoch");
+        assert.ok(rebuiltEpoch, "The post-Rebuild Metadata read did not include a Seed cache namespace.");
+        assert.notEqual(rebuiltEpoch, initialEpoch, "The cache namespace did not change with the Security Seed.");
 
         await evaluate(`await core.services.setting.applyPartial({usePluginSync:true,syncInternalFiles:true},true);
             await core.services.control.applySettings();return JSON.stringify(true);`);
@@ -148,13 +276,59 @@ async function main(): Promise<void> {
             if(opened)await opened.close();return JSON.stringify({admitted:!!opened});
             }catch(error){return JSON.stringify({admitted:false,error:error.name});}`);
         assert.ok(admission.admitted, `Replication admission failed: ${JSON.stringify(admission)}`);
-        assert.equal((await readCachedDocument(original._id, "no-store")).path, rebuilt.path);
+        const repeatedRead = await readCommonlibDocument(original._id);
+        assertLogicalDocument(repeatedRead.document, original);
+        assert.deepEqual(
+            repeatedRead.document.children,
+            initialRead.document.children,
+            "The logical file content references changed after replication admission."
+        );
+        const repeatedMetadataRequest = metadataRequest(repeatedRead, original._id);
+        const repeatedEpoch = new URL(repeatedMetadataRequest.url).searchParams.get("_livesync_epoch");
+        assert.equal(
+            repeatedEpoch,
+            rebuiltEpoch,
+            "A new connection at the same Seed did not reuse its cache namespace."
+        );
         await pushLocalChanges(cliBinary, session.cliEnv);
         await pushLocalChanges(cliBinary, session.cliEnv);
+        // Include Chunk bodies for strict reconciliation after replacing the local database.
+        await evaluate(
+            `await core.services.setting.applyPartial({readChunksOnline:false},true);return JSON.stringify(true);`
+        );
+        const fetchAttempt = await evaluate<{ succeeded: boolean; error?: string; diagnostics?: unknown }>(`try {
+            await core.rebuilder.fetchLocal(false,true);return JSON.stringify({succeeded:true});
+            } catch(error) {
+                await core.services.API.showWindow('log-log');
+                await new Promise(resolve=>setTimeout(resolve,100));
+                const log=Array.from(document.querySelectorAll('.logpane .log pre')).map(e=>e.textContent??'').join('\\n').slice(-16000);
+                return JSON.stringify({succeeded:false,error:String(error),diagnostics:{
+                    databaseReady:core.services.database.isDatabaseReady(),appReady:core.services.appLifecycle.isReady(),
+                    unresolvedMessages:(await core.services.appLifecycle.getUnresolvedMessages()).flat(),log}});
+            }`);
+        assert.ok(fetchAttempt.succeeded, `Standard Fetch failed: ${JSON.stringify(fetchAttempt)}`);
+        await waitForLiveSyncCoreReady(cliBinary, session.cliEnv);
+        const fetchedRead = await readCommonlibDocument(original._id);
+        assertLogicalDocument(fetchedRead.document, original);
+        assert.deepEqual(fetchedRead.document.children, initialRead.document.children);
+        assert.equal(
+            new URL(metadataRequest(fetchedRead, original._id).url).searchParams.get("_livesync_epoch"),
+            rebuiltEpoch
+        );
+        assert.equal(await readFile(join(vault.path, ordinaryPath), "utf8"), ordinaryContents);
+        await pushLocalChanges(cliBinary, session.cliEnv);
+        await restoreCommonlibRequests();
         console.log(
-            `Rebuild and subsequent replication succeeded after warming the ${useRequestAPI ? "Internal API" : "browser"} HTTP cache.`
+            `Cache compatibility switch persistence, Rebuild, Standard Fetch, and subsequent replication succeeded with the ${useRequestAPI ? "Internal API" : "browser"} HTTP cache.`
         );
     } finally {
+        if (observingRequests && session) {
+            try {
+                await restoreCommonlibRequests();
+            } catch {
+                // The isolated Obsidian process is stopped immediately below.
+            }
+        }
         await session?.app.stop();
         await vault.dispose();
         await deleteCouchDbDatabase(couchDb, dbName);

updates.md

@@ -14,6 +14,12 @@ Earlier releases remain available in the 1.0 release history, the 1.0 preview hi
 
 ### Fixed
 
+#### Synchronisation
+
+- We can synchronise and Fetch an encrypted CouchDB remote when the Internal API retains responses from before a Rebuild. (#1234)
+    - Metadata and Chunk reads use a cache URL derived from the startup time and Security Seed together. The URL remains stable within the same startup and Seed.
+    - The advanced CouchDB setting **Use headers only for HTTP cache control (compatibility)** is disabled by default. Enable it only if your server or proxy rejects the additional query parameter; affected native caches may then reuse stale encrypted responses after Rebuild.
+
 #### Translations
 
 - The notice shown when a translation is available now displays the **Display Language** setting label correctly in English, French, Hebrew, Russian, and Simplified Chinese. (#1298) Thank you to @cwatanab for the contribution!