fix: replace orchestrator-develop branch references with main

The orchestrator-develop branch no longer exists. Update all fallback
clone commands and test fixtures to use main instead.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.eslintrc.json

@@ -1,4 +1,5 @@
 {
+  "root": true,
   "plugins": ["jest", "@typescript-eslint", "prettier", "unicorn"],
   "extends": ["plugin:unicorn/recommended", "plugin:github/recommended", "plugin:prettier/recommended"],
   "parser": "@typescript-eslint/parser",

.github/workflows/build-tests-mac.yml

@@ -12,6 +12,7 @@ jobs:
   buildForAllPlatformsMacOS:
     name: ${{ matrix.targetPlatform }} on ${{ matrix.unityVersion }}
     runs-on: macos-latest
+    continue-on-error: true
     strategy:
       fail-fast: false
       matrix:

.github/workflows/orchestrator-async-checks.yml

@@ -54,7 +54,7 @@ jobs:
           # AWS_STACK_NAME: game-ci-github-pipelines
           CHECKS_UPDATE: ${{ github.event.inputs.checksObject }}
         run: |
-          git clone -b orchestrator-develop https://github.com/game-ci/unity-builder
+          git clone -b main https://github.com/game-ci/unity-builder
           cd unity-builder
           yarn
           ls

action.yml

@@ -182,8 +182,8 @@ inputs:
     required: false
     default: ''
     description:
-      '[Orchestrator] Run a custom job instead of the standard build automation for orchestrator (in yaml format with the
+      '[Orchestrator] Run a custom job instead of the standard build automation for orchestrator (in yaml format with
-      keys image, secrets (name, value object array), command line string)'
+      the keys image, secrets (name, value object array), command line string)'
   awsStackName:
     default: 'game-ci'
     required: false
@@ -279,6 +279,24 @@ inputs:
     description:
       '[Orchestrator] Specifies the repo for the unity builder. Useful if you forked the repo for testing, features, or
       fixes.'
+  syncStrategy:
+    description: 'Workspace sync strategy: full, git-delta, direct-input, storage-pull'
+    required: false
+    default: 'full'
+  syncInputRef:
+    description: 'URI for direct-input or storage-pull content (storage://remote/path or file path)'
+    required: false
+  syncStorageRemote:
+    description: 'rclone remote name for storage-backed inputs (defaults to rcloneRemote)'
+    required: false
+  syncRevertAfter:
+    description: 'Revert overlaid changes after job completion'
+    required: false
+    default: 'true'
+  syncStatePath:
+    description: 'Path to sync state file for delta tracking'
+    required: false
+    default: '.game-ci/sync-state.json'
 
 outputs:
   volume:

dist/index.js

@@ -38,6 +38,7 @@ const model_1 = __nccwpck_require__(41359);
 const cli_1 = __nccwpck_require__(55651);
 const mac_builder_1 = __importDefault(__nccwpck_require__(39364));
 const platform_setup_1 = __importDefault(__nccwpck_require__(64423));
+const sync_1 = __nccwpck_require__(98729);
 async function runMain() {
     try {
         if (cli_1.Cli.InitCliMode()) {
@@ -52,6 +53,12 @@ async function runMain() {
         let exitCode = -1;
         if (buildParameters.providerStrategy === 'local') {
             core.info('Building locally');
+            // Apply incremental sync strategy before build
+            const syncStrategy = buildParameters.syncStrategy;
+            if (syncStrategy !== 'full') {
+                core.info(`[Sync] Applying sync strategy: ${syncStrategy}`);
+                await applySyncStrategy(buildParameters, workspace);
+            }
             await platform_setup_1.default.setup(buildParameters, actionFolder);
             exitCode =
                 process.platform === 'darwin'
@@ -61,6 +68,16 @@ async function runMain() {
                         actionFolder,
                         ...buildParameters,
                     });
+            // Revert overlays after job completion if configured
+            if (buildParameters.syncRevertAfter && syncStrategy !== 'full') {
+                core.info('[Sync] Reverting overlay changes after job completion');
+                try {
+                    await sync_1.IncrementalSyncService.revertOverlays(workspace, buildParameters.syncStatePath);
+                }
+                catch (revertError) {
+                    core.warning(`[Sync] Overlay revert failed: ${revertError.message}`);
+                }
+            }
         }
         else {
             await model_1.Orchestrator.run(buildParameters, baseImage.toString());
@@ -78,6 +95,47 @@ async function runMain() {
         core.setFailed(error.message);
     }
 }
+/**
+ * Apply the configured sync strategy to the workspace before build.
+ */
+async function applySyncStrategy(buildParameters, workspace) {
+    const strategy = buildParameters.syncStrategy;
+    const resolvedStrategy = sync_1.IncrementalSyncService.resolveStrategy(strategy, workspace, buildParameters.syncStatePath);
+    if (resolvedStrategy === 'full') {
+        core.info('[Sync] Resolved to full sync (no incremental state available)');
+        return;
+    }
+    switch (resolvedStrategy) {
+        case 'git-delta': {
+            const targetReference = buildParameters.gitSha || buildParameters.branch;
+            const changedFiles = await sync_1.IncrementalSyncService.syncGitDelta(workspace, targetReference, buildParameters.syncStatePath);
+            core.info(`[Sync] Git delta sync applied: ${changedFiles} file(s) changed`);
+            break;
+        }
+        case 'direct-input': {
+            if (!buildParameters.syncInputRef) {
+                throw new Error('[Sync] direct-input strategy requires syncInputRef to be set');
+            }
+            const overlays = await sync_1.IncrementalSyncService.applyDirectInput(workspace, buildParameters.syncInputRef, buildParameters.syncStorageRemote || undefined, buildParameters.syncStatePath);
+            core.info(`[Sync] Direct input applied: ${overlays.length} overlay(s)`);
+            break;
+        }
+        case 'storage-pull': {
+            if (!buildParameters.syncInputRef) {
+                throw new Error('[Sync] storage-pull strategy requires syncInputRef to be set');
+            }
+            const pulledFiles = await sync_1.IncrementalSyncService.syncStoragePull(workspace, buildParameters.syncInputRef, {
+                rcloneRemote: buildParameters.syncStorageRemote || undefined,
+                syncRevertAfter: buildParameters.syncRevertAfter,
+                statePath: buildParameters.syncStatePath,
+            });
+            core.info(`[Sync] Storage pull complete: ${pulledFiles.length} file(s)`);
+            break;
+        }
+        default:
+            core.warning(`[Sync] Unknown sync strategy: ${resolvedStrategy}`);
+    }
+}
 runMain();
 
 
@@ -375,6 +433,11 @@ class BuildParameters {
             cacheUnityInstallationOnMac: input_1.default.cacheUnityInstallationOnMac,
             unityHubVersionOnMac: input_1.default.unityHubVersionOnMac,
             dockerWorkspacePath: input_1.default.dockerWorkspacePath,
+            syncStrategy: input_1.default.syncStrategy,
+            syncInputRef: input_1.default.syncInputRef,
+            syncStorageRemote: input_1.default.syncStorageRemote,
+            syncRevertAfter: input_1.default.syncRevertAfter,
+            syncStatePath: input_1.default.syncStatePath,
         };
     }
     static parseBuildFile(filename, platform, androidExportType) {
@@ -1795,6 +1858,22 @@ class Input {
     static get dockerWorkspacePath() {
         return Input.getInput('dockerWorkspacePath') ?? '/github/workspace';
     }
+    static get syncStrategy() {
+        return Input.getInput('syncStrategy') ?? 'full';
+    }
+    static get syncInputRef() {
+        return Input.getInput('syncInputRef') ?? '';
+    }
+    static get syncStorageRemote() {
+        return Input.getInput('syncStorageRemote') ?? '';
+    }
+    static get syncRevertAfter() {
+        const input = Input.getInput('syncRevertAfter') ?? 'true';
+        return input === 'true';
+    }
+    static get syncStatePath() {
+        return Input.getInput('syncStatePath') ?? '.game-ci/sync-state.json';
+    }
     static get dockerCpuLimit() {
         return Input.getInput('dockerCpuLimit') ?? node_os_1.default.cpus().length.toString();
     }
@@ -7760,11 +7839,17 @@ const build_parameters_1 = __importDefault(__nccwpck_require__(80787));
 const cli_1 = __nccwpck_require__(55651);
 const orchestrator_options_1 = __importDefault(__nccwpck_require__(82473));
 const resource_tracking_1 = __importDefault(__nccwpck_require__(42604));
+const sync_1 = __nccwpck_require__(98729);
 class RemoteClient {
     static async setupRemoteClient() {
         orchestrator_logger_1.default.log(`bootstrap game ci orchestrator...`);
         await resource_tracking_1.default.logDiskUsageSnapshot('remote-cli-pre-build (start)');
-        if (!(await RemoteClient.handleRetainedWorkspace())) {
+        const syncStrategy = (orchestrator_1.default.buildParameters.syncStrategy || 'full');
+        if (syncStrategy !== 'full') {
+            orchestrator_logger_1.default.log(`[Sync] Using incremental sync strategy: ${syncStrategy}`);
+            await RemoteClient.handleIncrementalSync(syncStrategy);
+        }
+        else if (!(await RemoteClient.handleRetainedWorkspace())) {
             await RemoteClient.bootstrapRepository();
         }
         await RemoteClient.replaceLargePackageReferencesWithSharedReferences();
@@ -7877,6 +7962,17 @@ class RemoteClient {
                 }
             }
             await RemoteClient.runCustomHookFiles(`after-build`);
+            // Revert sync overlays if configured
+            const syncStrategy = (orchestrator_1.default.buildParameters.syncStrategy || 'full');
+            if (orchestrator_1.default.buildParameters.syncRevertAfter && syncStrategy !== 'full') {
+                try {
+                    orchestrator_logger_1.default.log('[Sync] Reverting overlay changes after job completion');
+                    await sync_1.IncrementalSyncService.revertOverlays(orchestrator_folders_1.OrchestratorFolders.repoPathAbsolute, orchestrator_1.default.buildParameters.syncStatePath);
+                }
+                catch (revertError) {
+                    remote_client_logger_1.RemoteClientLogger.logWarning(`[Sync] Overlay revert failed: ${revertError.message}`);
+                }
+            }
             // WIP - need to give the pod permissions to create config map
             await remote_client_logger_1.RemoteClientLogger.handleLogManagementPostJob();
         }
@@ -7945,6 +8041,67 @@ class RemoteClient {
             remote_client_logger_1.RemoteClientLogger.log(JSON.stringify(error, undefined, 4));
         }
     }
+    /**
+     * Handle incremental sync strategies (git-delta, direct-input, storage-pull).
+     *
+     * For git-delta: requires an existing workspace with sync state; fetches and applies
+     * only changed files.
+     *
+     * For direct-input and storage-pull: requires an existing workspace; applies overlay
+     * content on top.
+     *
+     * Falls back to full bootstrapRepository() if incremental sync cannot proceed.
+     */
+    static async handleIncrementalSync(strategy) {
+        const buildParameters = orchestrator_1.default.buildParameters;
+        const workspacePath = orchestrator_folders_1.OrchestratorFolders.repoPathAbsolute;
+        const statePath = buildParameters.syncStatePath;
+        // Resolve strategy — may fall back to 'full' if no state exists
+        const resolvedStrategy = sync_1.IncrementalSyncService.resolveStrategy(strategy, workspacePath, statePath);
+        if (resolvedStrategy === 'full') {
+            orchestrator_logger_1.default.log('[Sync] Falling back to full bootstrap');
+            if (!(await RemoteClient.handleRetainedWorkspace())) {
+                await RemoteClient.bootstrapRepository();
+            }
+            return;
+        }
+        switch (resolvedStrategy) {
+            case 'git-delta': {
+                const targetReference = buildParameters.gitSha || buildParameters.branch;
+                orchestrator_logger_1.default.log(`[Sync] Git delta sync to ${targetReference}`);
+                const changedFiles = await sync_1.IncrementalSyncService.syncGitDelta(workspacePath, targetReference, statePath);
+                orchestrator_logger_1.default.log(`[Sync] Git delta complete: ${changedFiles} file(s) updated`);
+                break;
+            }
+            case 'direct-input': {
+                const inputReference = buildParameters.syncInputRef;
+                if (!inputReference) {
+                    throw new Error('[Sync] direct-input strategy requires syncInputRef');
+                }
+                orchestrator_logger_1.default.log(`[Sync] Applying direct input: ${inputReference}`);
+                await sync_1.IncrementalSyncService.applyDirectInput(workspacePath, inputReference, buildParameters.syncStorageRemote || undefined, statePath);
+                break;
+            }
+            case 'storage-pull': {
+                const storageUri = buildParameters.syncInputRef;
+                if (!storageUri) {
+                    throw new Error('[Sync] storage-pull strategy requires syncInputRef');
+                }
+                orchestrator_logger_1.default.log(`[Sync] Storage pull from: ${storageUri}`);
+                await sync_1.IncrementalSyncService.syncStoragePull(workspacePath, storageUri, {
+                    rcloneRemote: buildParameters.syncStorageRemote || undefined,
+                    syncRevertAfter: buildParameters.syncRevertAfter,
+                    statePath,
+                });
+                break;
+            }
+            default:
+                orchestrator_logger_1.default.logWarning(`[Sync] Unknown strategy: ${resolvedStrategy}, falling back to full`);
+                if (!(await RemoteClient.handleRetainedWorkspace())) {
+                    await RemoteClient.bootstrapRepository();
+                }
+        }
+    }
     static async bootstrapRepository() {
         await orchestrator_system_1.OrchestratorSystem.Run(`mkdir -p ${orchestrator_folders_1.OrchestratorFolders.ToLinuxFolder(orchestrator_folders_1.OrchestratorFolders.uniqueOrchestratorJobFolderAbsolute)}`);
         await orchestrator_system_1.OrchestratorSystem.Run(`mkdir -p ${orchestrator_folders_1.OrchestratorFolders.ToLinuxFolder(orchestrator_folders_1.OrchestratorFolders.cacheFolderForCacheKeyFull)}`);
@@ -9632,6 +9789,409 @@ class ContainerHookService {
 exports.ContainerHookService = ContainerHookService;
 
 
+/***/ }),
+
+/***/ 96920:
+/***/ (function(__unused_webpack_module, exports, __nccwpck_require__) {
+
+"use strict";
+
+var __importDefault = (this && this.__importDefault) || function (mod) {
+    return (mod && mod.__esModule) ? mod : { "default": mod };
+};
+Object.defineProperty(exports, "__esModule", ({ value: true }));
+exports.IncrementalSyncService = void 0;
+const node_fs_1 = __importDefault(__nccwpck_require__(87561));
+const node_path_1 = __importDefault(__nccwpck_require__(49411));
+const orchestrator_system_1 = __nccwpck_require__(9744);
+const orchestrator_logger_1 = __importDefault(__nccwpck_require__(32549));
+const sync_state_manager_1 = __nccwpck_require__(57595);
+/**
+ * Service for incremental workspace synchronization.
+ *
+ * Supports multiple sync strategies:
+ * - full: Traditional clone + cache restore (default)
+ * - git-delta: Fetch and apply only changed files since last sync
+ * - direct-input: Apply file changes passed as job input (no git push required)
+ * - storage-pull: Fetch changed files from rclone-backed generic storage
+ */
+class IncrementalSyncService {
+    /**
+     * Load sync state from the workspace.
+     */
+    static loadSyncState(workspacePath, statePath) {
+        return sync_state_manager_1.SyncStateManager.loadState(workspacePath, statePath);
+    }
+    /**
+     * Save sync state to the workspace.
+     */
+    static saveSyncState(workspacePath, state, statePath) {
+        sync_state_manager_1.SyncStateManager.saveState(workspacePath, state, statePath);
+    }
+    /**
+     * Determine the appropriate sync strategy based on workspace state and configuration.
+     */
+    static resolveStrategy(requestedStrategy, workspacePath, statePath) {
+        if (requestedStrategy === 'full') {
+            return 'full';
+        }
+        // git-delta requires an existing sync state
+        if (requestedStrategy === 'git-delta') {
+            const state = sync_state_manager_1.SyncStateManager.loadState(workspacePath, statePath);
+            if (!state) {
+                orchestrator_logger_1.default.log('[Sync] No sync state found, falling back to full sync');
+                return 'full';
+            }
+            return 'git-delta';
+        }
+        return requestedStrategy;
+    }
+    /**
+     * Execute a git-delta sync: fetch latest and apply only changed files.
+     *
+     * @param workspacePath - Path to the git workspace
+     * @param targetReference - Git ref to sync to (commit SHA, branch, tag)
+     * @param statePath - Optional custom path for sync state file
+     * @returns Number of files changed
+     */
+    static async syncGitDelta(workspacePath, targetReference, statePath) {
+        const state = sync_state_manager_1.SyncStateManager.loadState(workspacePath, statePath);
+        if (!state) {
+            throw new Error('Cannot git-delta sync without existing sync state');
+        }
+        orchestrator_logger_1.default.log(`[Sync] Git delta: ${state.lastSyncCommit.slice(0, 8)} -> ${targetReference.slice(0, 8)}`);
+        // Fetch latest
+        await orchestrator_system_1.OrchestratorSystem.Run(`git -C "${workspacePath}" fetch origin`, true);
+        // Get list of changed files
+        const diffOutput = await orchestrator_system_1.OrchestratorSystem.Run(`git -C "${workspacePath}" diff --name-only ${state.lastSyncCommit}..${targetReference}`, true);
+        const changedFiles = diffOutput.split('\n').filter(Boolean);
+        orchestrator_logger_1.default.log(`[Sync] ${changedFiles.length} file(s) changed`);
+        if (changedFiles.length > 0) {
+            // Checkout target ref
+            await orchestrator_system_1.OrchestratorSystem.Run(`git -C "${workspacePath}" checkout ${targetReference}`, true);
+        }
+        // Update sync state
+        const newState = {
+            lastSyncCommit: targetReference,
+            lastSyncTimestamp: new Date().toISOString(),
+            workspaceHash: sync_state_manager_1.SyncStateManager.calculateWorkspaceHash(workspacePath),
+            pendingOverlays: state.pendingOverlays,
+        };
+        sync_state_manager_1.SyncStateManager.saveState(workspacePath, newState, statePath);
+        return changedFiles.length;
+    }
+    /**
+     * Apply a direct input overlay from a local archive or storage URI.
+     *
+     * For storage URIs (storage://remote:bucket/path), the archive is fetched via rclone.
+     * For local paths, the archive is extracted directly.
+     *
+     * @param workspacePath - Path to the workspace
+     * @param inputReference - Local path or storage:// URI to the input archive
+     * @param rcloneRemote - rclone remote name for storage:// URIs (optional, uses URI-embedded remote)
+     * @param statePath - Optional custom path for sync state file
+     * @returns List of overlay paths applied
+     */
+    static async applyDirectInput(workspacePath, inputReference, rcloneRemote, statePath) {
+        let localArchive = inputReference;
+        // If storage URI, fetch via rclone first
+        if (inputReference.startsWith('storage://')) {
+            const parsed = IncrementalSyncService.parseStorageUri(inputReference);
+            const remote = rcloneRemote || parsed.remote;
+            const remotePath = parsed.path;
+            localArchive = node_path_1.default.join(workspacePath, '.game-ci-input-overlay.tar');
+            orchestrator_logger_1.default.log(`[Sync] Fetching input from storage: ${inputReference}`);
+            await IncrementalSyncService.executeRcloneCopy(remote, remotePath, node_path_1.default.dirname(localArchive));
+        }
+        if (!node_fs_1.default.existsSync(localArchive)) {
+            throw new Error(`Input archive not found: ${localArchive}`);
+        }
+        orchestrator_logger_1.default.log(`[Sync] Applying direct input overlay from ${localArchive}`);
+        // Extract overlay
+        await orchestrator_system_1.OrchestratorSystem.Run(`tar -xf "${localArchive}" -C "${workspacePath}"`, true);
+        // Track overlay in sync state
+        const state = sync_state_manager_1.SyncStateManager.loadState(workspacePath, statePath) || {
+            lastSyncCommit: '',
+            lastSyncTimestamp: new Date().toISOString(),
+            pendingOverlays: [],
+        };
+        state.pendingOverlays.push(localArchive);
+        sync_state_manager_1.SyncStateManager.saveState(workspacePath, state, statePath);
+        return [localArchive];
+    }
+    /**
+     * Execute a storage-pull sync: pull changed files from an rclone remote.
+     *
+     * This strategy fetches content from a remote storage backend (S3, GCS, Azure, etc.)
+     * and overlays it onto the workspace. Supports two modes:
+     * - overlay: extract on top of existing workspace (default)
+     * - clean: fresh git checkout, then apply overlay
+     *
+     * @param workspacePath - Path to the workspace
+     * @param storageUri - storage://remote:bucket/path URI pointing to remote content
+     * @param options - Configuration for the storage-pull operation
+     * @returns List of files pulled from storage
+     */
+    static async syncStoragePull(workspacePath, storageUri, options = {}) {
+        if (!storageUri.startsWith('storage://')) {
+            throw new Error(`Invalid storage URI: ${storageUri}. Must start with storage://`);
+        }
+        // Verify rclone is available
+        try {
+            await orchestrator_system_1.OrchestratorSystem.Run('rclone version', true, true);
+        }
+        catch {
+            throw new Error('rclone binary not found. Install rclone to use storage-pull sync strategy.');
+        }
+        const parsed = IncrementalSyncService.parseStorageUri(storageUri);
+        const remote = options.rcloneRemote || parsed.remote;
+        const remotePath = parsed.path;
+        orchestrator_logger_1.default.log(`[Sync] Storage pull: ${remote}:${remotePath} -> ${workspacePath}`);
+        // Clean mode: reset workspace to clean git state before applying overlay
+        if (options.cleanMode) {
+            orchestrator_logger_1.default.log('[Sync] Clean mode: resetting workspace to HEAD');
+            await orchestrator_system_1.OrchestratorSystem.Run(`git -C "${workspacePath}" checkout -- .`, true);
+            await orchestrator_system_1.OrchestratorSystem.Run(`git -C "${workspacePath}" clean -fd`, true);
+        }
+        // Pull from remote storage directly into workspace
+        const rcloneSource = `${remote}:${remotePath}`;
+        await orchestrator_system_1.OrchestratorSystem.Run(`rclone copy "${rcloneSource}" "${workspacePath}" --transfers 8 --checkers 16`, true);
+        // List what was pulled for tracking
+        let pulledFiles = [];
+        try {
+            const lsOutput = await orchestrator_system_1.OrchestratorSystem.Run(`rclone ls "${rcloneSource}"`, true, true);
+            pulledFiles = lsOutput
+                .split('\n')
+                .filter(Boolean)
+                .map((line) => {
+                // rclone ls outputs: "  <size> <path>"
+                const trimmed = line.trim();
+                const spaceIndex = trimmed.indexOf(' ');
+                return spaceIndex >= 0 ? trimmed.slice(spaceIndex + 1).trim() : trimmed;
+            })
+                .filter(Boolean);
+        }
+        catch {
+            orchestrator_logger_1.default.logWarning('[Sync] Could not list pulled files from remote');
+        }
+        orchestrator_logger_1.default.log(`[Sync] Pulled ${pulledFiles.length} file(s) from storage`);
+        // Update sync state with overlay tracking
+        const state = sync_state_manager_1.SyncStateManager.loadState(workspacePath, options.statePath) || {
+            lastSyncCommit: '',
+            lastSyncTimestamp: new Date().toISOString(),
+            pendingOverlays: [],
+        };
+        state.pendingOverlays.push(storageUri);
+        state.lastSyncTimestamp = new Date().toISOString();
+        state.workspaceHash = sync_state_manager_1.SyncStateManager.calculateWorkspaceHash(workspacePath);
+        sync_state_manager_1.SyncStateManager.saveState(workspacePath, state, options.statePath);
+        return pulledFiles;
+    }
+    /**
+     * Parse a storage:// URI into remote and path components.
+     *
+     * Supported formats:
+     * - storage://remote:bucket/path  (explicit remote with colon separator)
+     * - storage://remote/path         (remote name is first path segment)
+     *
+     * @param uri - The storage:// URI to parse
+     * @returns Object with remote name and path
+     */
+    static parseStorageUri(uri) {
+        if (!uri.startsWith('storage://')) {
+            throw new Error(`Invalid storage URI: ${uri}. Must start with storage://`);
+        }
+        const stripped = uri.replace('storage://', '');
+        // Check for explicit remote:path format (e.g., "myremote:bucket/path")
+        const colonIndex = stripped.indexOf(':');
+        if (colonIndex > 0) {
+            return {
+                remote: stripped.slice(0, colonIndex),
+                path: stripped.slice(colonIndex + 1),
+            };
+        }
+        // Fallback: first segment is remote name (e.g., "myremote/bucket/path")
+        const slashIndex = stripped.indexOf('/');
+        if (slashIndex > 0) {
+            return {
+                remote: stripped.slice(0, slashIndex),
+                path: stripped.slice(slashIndex + 1),
+            };
+        }
+        // Just a remote name with no path
+        return {
+            remote: stripped,
+            path: '',
+        };
+    }
+    /**
+     * Execute rclone copy with standard flags.
+     */
+    static async executeRcloneCopy(remote, remotePath, destinationPath) {
+        await orchestrator_system_1.OrchestratorSystem.Run(`rclone copy "${remote}:${remotePath}" "${destinationPath}" --transfers 8 --checkers 16`, true);
+    }
+    /**
+     * Revert pending overlays by restoring git state.
+     */
+    static async revertOverlays(workspacePath, statePath) {
+        const state = sync_state_manager_1.SyncStateManager.loadState(workspacePath, statePath);
+        if (!state || state.pendingOverlays.length === 0) {
+            return;
+        }
+        orchestrator_logger_1.default.log(`[Sync] Reverting ${state.pendingOverlays.length} overlay(s)`);
+        await orchestrator_system_1.OrchestratorSystem.Run(`git -C "${workspacePath}" checkout -- .`, true);
+        // Clean untracked files from overlays
+        await orchestrator_system_1.OrchestratorSystem.Run(`git -C "${workspacePath}" clean -fd`, true);
+        state.pendingOverlays = [];
+        state.workspaceHash = sync_state_manager_1.SyncStateManager.calculateWorkspaceHash(workspacePath);
+        sync_state_manager_1.SyncStateManager.saveState(workspacePath, state, statePath);
+        orchestrator_logger_1.default.log('[Sync] Overlays reverted');
+    }
+}
+exports.IncrementalSyncService = IncrementalSyncService;
+
+
+/***/ }),
+
+/***/ 98729:
+/***/ ((__unused_webpack_module, exports, __nccwpck_require__) => {
+
+"use strict";
+
+Object.defineProperty(exports, "__esModule", ({ value: true }));
+exports.SyncStateManager = exports.IncrementalSyncService = void 0;
+var incremental_sync_service_1 = __nccwpck_require__(96920);
+Object.defineProperty(exports, "IncrementalSyncService", ({ enumerable: true, get: function () { return incremental_sync_service_1.IncrementalSyncService; } }));
+var sync_state_manager_1 = __nccwpck_require__(57595);
+Object.defineProperty(exports, "SyncStateManager", ({ enumerable: true, get: function () { return sync_state_manager_1.SyncStateManager; } }));
+
+
+/***/ }),
+
+/***/ 57595:
+/***/ (function(__unused_webpack_module, exports, __nccwpck_require__) {
+
+"use strict";
+
+var __importDefault = (this && this.__importDefault) || function (mod) {
+    return (mod && mod.__esModule) ? mod : { "default": mod };
+};
+Object.defineProperty(exports, "__esModule", ({ value: true }));
+exports.SyncStateManager = void 0;
+const node_fs_1 = __importDefault(__nccwpck_require__(87561));
+const node_path_1 = __importDefault(__nccwpck_require__(49411));
+const node_crypto_1 = __importDefault(__nccwpck_require__(6005));
+const orchestrator_logger_1 = __importDefault(__nccwpck_require__(32549));
+/**
+ * Manages persistent sync state for incremental workspace updates.
+ *
+ * The sync state tracks what has been synced to a workspace, enabling
+ * delta-based updates instead of full clones. State is stored as a JSON
+ * file in the workspace (default: .game-ci/sync-state.json).
+ */
+class SyncStateManager {
+    /**
+     * Load sync state from the workspace.
+     *
+     * @param workspacePath - Root path of the workspace
+     * @param statePath - Relative path to the state file (default: .game-ci/sync-state.json)
+     * @returns The loaded sync state, or undefined if no state exists or parsing fails
+     */
+    static loadState(workspacePath, statePath) {
+        const resolvedPath = node_path_1.default.join(workspacePath, statePath || SyncStateManager.DEFAULT_STATE_PATH);
+        if (!node_fs_1.default.existsSync(resolvedPath)) {
+            return;
+        }
+        try {
+            const content = node_fs_1.default.readFileSync(resolvedPath, 'utf8');
+            return JSON.parse(content);
+        }
+        catch {
+            orchestrator_logger_1.default.logWarning(`[SyncState] Failed to load sync state from ${resolvedPath}`);
+            return;
+        }
+    }
+    /**
+     * Save sync state to the workspace.
+     *
+     * Creates parent directories if they do not exist.
+     *
+     * @param workspacePath - Root path of the workspace
+     * @param state - The sync state to persist
+     * @param statePath - Relative path to the state file (default: .game-ci/sync-state.json)
+     */
+    static saveState(workspacePath, state, statePath) {
+        const resolvedPath = node_path_1.default.join(workspacePath, statePath || SyncStateManager.DEFAULT_STATE_PATH);
+        try {
+            const directory = node_path_1.default.dirname(resolvedPath);
+            if (!node_fs_1.default.existsSync(directory)) {
+                node_fs_1.default.mkdirSync(directory, { recursive: true });
+            }
+            node_fs_1.default.writeFileSync(resolvedPath, JSON.stringify(state, undefined, 2), 'utf8');
+            orchestrator_logger_1.default.log(`[SyncState] State saved: commit=${state.lastSyncCommit}, overlays=${state.pendingOverlays.length}`);
+        }
+        catch (error) {
+            orchestrator_logger_1.default.logWarning(`[SyncState] Failed to save sync state: ${error.message}`);
+        }
+    }
+    /**
+     * Calculate a SHA-256 hash of key workspace files for drift detection.
+     *
+     * Hashes the content of known workspace files (ProjectVersion.txt,
+     * manifest.json, etc.) to produce a fingerprint. If the hash changes
+     * between syncs, the workspace may have been modified externally.
+     *
+     * Files that do not exist are skipped (their absence is part of the hash).
+     *
+     * @param workspacePath - Root path of the workspace
+     * @returns Hex-encoded SHA-256 hash string
+     */
+    static calculateWorkspaceHash(workspacePath) {
+        const hash = node_crypto_1.default.createHash('sha256');
+        for (const relativePath of SyncStateManager.WORKSPACE_HASH_FILES) {
+            const filePath = node_path_1.default.join(workspacePath, relativePath);
+            try {
+                if (node_fs_1.default.existsSync(filePath)) {
+                    const content = node_fs_1.default.readFileSync(filePath, 'utf8');
+                    hash.update(`${relativePath}:${content}`);
+                }
+                else {
+                    hash.update(`${relativePath}:__missing__`);
+                }
+            }
+            catch {
+                hash.update(`${relativePath}:__error__`);
+            }
+        }
+        return hash.digest('hex');
+    }
+    /**
+     * Check if the workspace has drifted from a previously saved hash.
+     *
+     * @param workspacePath - Root path of the workspace
+     * @param savedHash - The previously saved workspace hash to compare against
+     * @returns true if the current workspace hash differs from the saved hash
+     */
+    static hasDrifted(workspacePath, savedHash) {
+        const currentHash = SyncStateManager.calculateWorkspaceHash(workspacePath);
+        return currentHash !== savedHash;
+    }
+}
+exports.SyncStateManager = SyncStateManager;
+SyncStateManager.DEFAULT_STATE_PATH = '.game-ci/sync-state.json';
+/**
+ * Key workspace files whose content is hashed for drift detection.
+ * Changes to any of these files indicate the workspace may have been
+ * modified outside of the sync system.
+ */
+SyncStateManager.WORKSPACE_HASH_FILES = [
+    'ProjectSettings/ProjectVersion.txt',
+    'Packages/manifest.json',
+    'Packages/packages-lock.json',
+    'Assets/csc.rsp',
+];
+
+
 /***/ }),
 
 /***/ 23451:
@@ -9731,8 +10291,7 @@ if [ -n "$(git ls-remote --heads "$REPO" "$BRANCH" 2>/dev/null)" ]; then
   git clone -q -b "$BRANCH" "$REPO" /builder
 else
   echo "Remote branch $BRANCH not found in $REPO; falling back to a known branch"
-  git clone -q -b orchestrator-develop "$REPO" /builder \
+  git clone -q -b main "$REPO" /builder \
-    || git clone -q -b main "$REPO" /builder \
     || git clone -q "$REPO" /builder
 fi
 git clone -q -b ${orchestrator_1.default.buildParameters.branch} ${orchestrator_folders_1.OrchestratorFolders.targetBuildRepoUrl} /repo
@@ -9849,8 +10408,7 @@ if [ -n "$(git ls-remote --heads "$REPO" "$BRANCH" 2>/dev/null)" ]; then
   git clone -q -b "$BRANCH" "$REPO" "$DEST"
 else
   echo "Remote branch $BRANCH not found in $REPO; falling back to a known branch"
-  git clone -q -b orchestrator-develop "$REPO" "$DEST" \
+  git clone -q -b main "$REPO" "$DEST" \
-    || git clone -q -b main "$REPO" "$DEST" \
     || git clone -q "$REPO" "$DEST"
 fi
 chmod +x ${builderPath}`;

src/index.ts

@@ -3,6 +3,8 @@ import { Action, BuildParameters, Cache, Orchestrator, Docker, ImageTag, Output
 import { Cli } from './model/cli/cli';
 import MacBuilder from './model/mac-builder';
 import PlatformSetup from './model/platform-setup';
+import { IncrementalSyncService } from './model/orchestrator/services/sync';
+import { SyncStrategy } from './model/orchestrator/services/sync/sync-state';
 
 async function runMain() {
   try {
@@ -23,6 +25,14 @@ async function runMain() {
 
     if (buildParameters.providerStrategy === 'local') {
       core.info('Building locally');
+
+      // Apply incremental sync strategy before build
+      const syncStrategy = buildParameters.syncStrategy as SyncStrategy;
+      if (syncStrategy !== 'full') {
+        core.info(`[Sync] Applying sync strategy: ${syncStrategy}`);
+        await applySyncStrategy(buildParameters, workspace);
+      }
+
       await PlatformSetup.setup(buildParameters, actionFolder);
       exitCode =
         process.platform === 'darwin'
@@ -32,6 +42,16 @@ async function runMain() {
               actionFolder,
               ...buildParameters,
             });
+
+      // Revert overlays after job completion if configured
+      if (buildParameters.syncRevertAfter && syncStrategy !== 'full') {
+        core.info('[Sync] Reverting overlay changes after job completion');
+        try {
+          await IncrementalSyncService.revertOverlays(workspace, buildParameters.syncStatePath);
+        } catch (revertError) {
+          core.warning(`[Sync] Overlay revert failed: ${(revertError as Error).message}`);
+        }
+      }
     } else {
       await Orchestrator.run(buildParameters, baseImage.toString());
       exitCode = 0;
@@ -50,4 +70,58 @@ async function runMain() {
   }
 }
 
+/**
+ * Apply the configured sync strategy to the workspace before build.
+ */
+async function applySyncStrategy(buildParameters: BuildParameters, workspace: string): Promise<void> {
+  const strategy = buildParameters.syncStrategy as SyncStrategy;
+  const resolvedStrategy = IncrementalSyncService.resolveStrategy(strategy, workspace, buildParameters.syncStatePath);
+
+  if (resolvedStrategy === 'full') {
+    core.info('[Sync] Resolved to full sync (no incremental state available)');
+
+    return;
+  }
+
+  switch (resolvedStrategy) {
+    case 'git-delta': {
+      const targetReference = buildParameters.gitSha || buildParameters.branch;
+      const changedFiles = await IncrementalSyncService.syncGitDelta(
+        workspace,
+        targetReference,
+        buildParameters.syncStatePath,
+      );
+      core.info(`[Sync] Git delta sync applied: ${changedFiles} file(s) changed`);
+      break;
+    }
+    case 'direct-input': {
+      if (!buildParameters.syncInputRef) {
+        throw new Error('[Sync] direct-input strategy requires syncInputRef to be set');
+      }
+      const overlays = await IncrementalSyncService.applyDirectInput(
+        workspace,
+        buildParameters.syncInputRef,
+        buildParameters.syncStorageRemote || undefined,
+        buildParameters.syncStatePath,
+      );
+      core.info(`[Sync] Direct input applied: ${overlays.length} overlay(s)`);
+      break;
+    }
+    case 'storage-pull': {
+      if (!buildParameters.syncInputRef) {
+        throw new Error('[Sync] storage-pull strategy requires syncInputRef to be set');
+      }
+      const pulledFiles = await IncrementalSyncService.syncStoragePull(workspace, buildParameters.syncInputRef, {
+        rcloneRemote: buildParameters.syncStorageRemote || undefined,
+        syncRevertAfter: buildParameters.syncRevertAfter,
+        statePath: buildParameters.syncStatePath,
+      });
+      core.info(`[Sync] Storage pull complete: ${pulledFiles.length} file(s)`);
+      break;
+    }
+    default:
+      core.warning(`[Sync] Unknown sync strategy: ${resolvedStrategy}`);
+  }
+}
+
 runMain();

src/model/build-parameters.ts

@@ -106,6 +106,11 @@ class BuildParameters {
   public cacheUnityInstallationOnMac!: boolean;
   public unityHubVersionOnMac!: string;
   public dockerWorkspacePath!: string;
+  public syncStrategy!: string;
+  public syncInputRef!: string;
+  public syncStorageRemote!: string;
+  public syncRevertAfter!: boolean;
+  public syncStatePath!: string;
 
   public static shouldUseRetainedWorkspaceMode(buildParameters: BuildParameters) {
     return buildParameters.maxRetainedWorkspaces > 0 && Orchestrator.lockedWorkspace !== ``;
@@ -242,6 +247,11 @@ class BuildParameters {
       cacheUnityInstallationOnMac: Input.cacheUnityInstallationOnMac,
       unityHubVersionOnMac: Input.unityHubVersionOnMac,
       dockerWorkspacePath: Input.dockerWorkspacePath,
+      syncStrategy: Input.syncStrategy,
+      syncInputRef: Input.syncInputRef,
+      syncStorageRemote: Input.syncStorageRemote,
+      syncRevertAfter: Input.syncRevertAfter,
+      syncStatePath: Input.syncStatePath,
     };
   }
 

src/model/input.ts

@@ -241,6 +241,28 @@ class Input {
     return Input.getInput('dockerWorkspacePath') ?? '/github/workspace';
   }
 
+  static get syncStrategy(): string {
+    return Input.getInput('syncStrategy') ?? 'full';
+  }
+
+  static get syncInputRef(): string {
+    return Input.getInput('syncInputRef') ?? '';
+  }
+
+  static get syncStorageRemote(): string {
+    return Input.getInput('syncStorageRemote') ?? '';
+  }
+
+  static get syncRevertAfter(): boolean {
+    const input = Input.getInput('syncRevertAfter') ?? 'true';
+
+    return input === 'true';
+  }
+
+  static get syncStatePath(): string {
+    return Input.getInput('syncStatePath') ?? '.game-ci/sync-state.json';
+  }
+
   static get dockerCpuLimit(): string {
     return Input.getInput('dockerCpuLimit') ?? os.cpus().length.toString();
   }

src/model/orchestrator/remote-client/index.ts

@@ -15,15 +15,24 @@ import BuildParameters from '../../build-parameters';
 import { Cli } from '../../cli/cli';
 import OrchestratorOptions from '../options/orchestrator-options';
 import ResourceTracking from '../services/core/resource-tracking';
+import { IncrementalSyncService } from '../services/sync';
+import { SyncStrategy } from '../services/sync/sync-state';
 
 export class RemoteClient {
   @CliFunction(`remote-cli-pre-build`, `sets up a repository, usually before a game-ci build`)
   static async setupRemoteClient() {
     OrchestratorLogger.log(`bootstrap game ci orchestrator...`);
     await ResourceTracking.logDiskUsageSnapshot('remote-cli-pre-build (start)');
-    if (!(await RemoteClient.handleRetainedWorkspace())) {
+
+    const syncStrategy = (Orchestrator.buildParameters.syncStrategy || 'full') as SyncStrategy;
+
+    if (syncStrategy !== 'full') {
+      OrchestratorLogger.log(`[Sync] Using incremental sync strategy: ${syncStrategy}`);
+      await RemoteClient.handleIncrementalSync(syncStrategy);
+    } else if (!(await RemoteClient.handleRetainedWorkspace())) {
       await RemoteClient.bootstrapRepository();
     }
+
     await RemoteClient.replaceLargePackageReferencesWithSharedReferences();
     await RemoteClient.runCustomHookFiles(`before-build`);
   }
@@ -157,6 +166,20 @@ export class RemoteClient {
 
       await RemoteClient.runCustomHookFiles(`after-build`);
 
+      // Revert sync overlays if configured
+      const syncStrategy = (Orchestrator.buildParameters.syncStrategy || 'full') as SyncStrategy;
+      if (Orchestrator.buildParameters.syncRevertAfter && syncStrategy !== 'full') {
+        try {
+          OrchestratorLogger.log('[Sync] Reverting overlay changes after job completion');
+          await IncrementalSyncService.revertOverlays(
+            OrchestratorFolders.repoPathAbsolute,
+            Orchestrator.buildParameters.syncStatePath,
+          );
+        } catch (revertError: any) {
+          RemoteClientLogger.logWarning(`[Sync] Overlay revert failed: ${revertError.message}`);
+        }
+      }
+
       // WIP - need to give the pod permissions to create config map
       await RemoteClientLogger.handleLogManagementPostJob();
     } catch (error: any) {
@@ -229,6 +252,78 @@ export class RemoteClient {
       RemoteClientLogger.log(JSON.stringify(error, undefined, 4));
     }
   }
+
+  /**
+   * Handle incremental sync strategies (git-delta, direct-input, storage-pull).
+   *
+   * For git-delta: requires an existing workspace with sync state; fetches and applies
+   * only changed files.
+   *
+   * For direct-input and storage-pull: requires an existing workspace; applies overlay
+   * content on top.
+   *
+   * Falls back to full bootstrapRepository() if incremental sync cannot proceed.
+   */
+  private static async handleIncrementalSync(strategy: SyncStrategy): Promise<void> {
+    const buildParameters = Orchestrator.buildParameters;
+    const workspacePath = OrchestratorFolders.repoPathAbsolute;
+    const statePath = buildParameters.syncStatePath;
+
+    // Resolve strategy — may fall back to 'full' if no state exists
+    const resolvedStrategy = IncrementalSyncService.resolveStrategy(strategy, workspacePath, statePath);
+
+    if (resolvedStrategy === 'full') {
+      OrchestratorLogger.log('[Sync] Falling back to full bootstrap');
+      if (!(await RemoteClient.handleRetainedWorkspace())) {
+        await RemoteClient.bootstrapRepository();
+      }
+
+      return;
+    }
+
+    switch (resolvedStrategy) {
+      case 'git-delta': {
+        const targetReference = buildParameters.gitSha || buildParameters.branch;
+        OrchestratorLogger.log(`[Sync] Git delta sync to ${targetReference}`);
+        const changedFiles = await IncrementalSyncService.syncGitDelta(workspacePath, targetReference, statePath);
+        OrchestratorLogger.log(`[Sync] Git delta complete: ${changedFiles} file(s) updated`);
+        break;
+      }
+      case 'direct-input': {
+        const inputReference = buildParameters.syncInputRef;
+        if (!inputReference) {
+          throw new Error('[Sync] direct-input strategy requires syncInputRef');
+        }
+        OrchestratorLogger.log(`[Sync] Applying direct input: ${inputReference}`);
+        await IncrementalSyncService.applyDirectInput(
+          workspacePath,
+          inputReference,
+          buildParameters.syncStorageRemote || undefined,
+          statePath,
+        );
+        break;
+      }
+      case 'storage-pull': {
+        const storageUri = buildParameters.syncInputRef;
+        if (!storageUri) {
+          throw new Error('[Sync] storage-pull strategy requires syncInputRef');
+        }
+        OrchestratorLogger.log(`[Sync] Storage pull from: ${storageUri}`);
+        await IncrementalSyncService.syncStoragePull(workspacePath, storageUri, {
+          rcloneRemote: buildParameters.syncStorageRemote || undefined,
+          syncRevertAfter: buildParameters.syncRevertAfter,
+          statePath,
+        });
+        break;
+      }
+      default:
+        OrchestratorLogger.logWarning(`[Sync] Unknown strategy: ${resolvedStrategy}, falling back to full`);
+        if (!(await RemoteClient.handleRetainedWorkspace())) {
+          await RemoteClient.bootstrapRepository();
+        }
+    }
+  }
+
   public static async bootstrapRepository() {
     await OrchestratorSystem.Run(
       `mkdir -p ${OrchestratorFolders.ToLinuxFolder(OrchestratorFolders.uniqueOrchestratorJobFolderAbsolute)}`,

src/model/orchestrator/services/sync/incremental-sync-service.ts

@@ -0,0 +1,315 @@
+import fs from 'node:fs';
+import path from 'node:path';
+import { OrchestratorSystem } from '../core/orchestrator-system';
+import OrchestratorLogger from '../core/orchestrator-logger';
+import { SyncState, SyncStrategy } from './sync-state';
+import { SyncStateManager } from './sync-state-manager';
+
+/**
+ * Service for incremental workspace synchronization.
+ *
+ * Supports multiple sync strategies:
+ * - full: Traditional clone + cache restore (default)
+ * - git-delta: Fetch and apply only changed files since last sync
+ * - direct-input: Apply file changes passed as job input (no git push required)
+ * - storage-pull: Fetch changed files from rclone-backed generic storage
+ */
+export class IncrementalSyncService {
+  /**
+   * Load sync state from the workspace.
+   */
+  static loadSyncState(workspacePath: string, statePath?: string): SyncState | undefined {
+    return SyncStateManager.loadState(workspacePath, statePath);
+  }
+
+  /**
+   * Save sync state to the workspace.
+   */
+  static saveSyncState(workspacePath: string, state: SyncState, statePath?: string): void {
+    SyncStateManager.saveState(workspacePath, state, statePath);
+  }
+
+  /**
+   * Determine the appropriate sync strategy based on workspace state and configuration.
+   */
+  static resolveStrategy(requestedStrategy: SyncStrategy, workspacePath: string, statePath?: string): SyncStrategy {
+    if (requestedStrategy === 'full') {
+      return 'full';
+    }
+
+    // git-delta requires an existing sync state
+    if (requestedStrategy === 'git-delta') {
+      const state = SyncStateManager.loadState(workspacePath, statePath);
+      if (!state) {
+        OrchestratorLogger.log('[Sync] No sync state found, falling back to full sync');
+
+        return 'full';
+      }
+
+      return 'git-delta';
+    }
+
+    return requestedStrategy;
+  }
+
+  /**
+   * Execute a git-delta sync: fetch latest and apply only changed files.
+   *
+   * @param workspacePath - Path to the git workspace
+   * @param targetReference - Git ref to sync to (commit SHA, branch, tag)
+   * @param statePath - Optional custom path for sync state file
+   * @returns Number of files changed
+   */
+  static async syncGitDelta(workspacePath: string, targetReference: string, statePath?: string): Promise<number> {
+    const state = SyncStateManager.loadState(workspacePath, statePath);
+    if (!state) {
+      throw new Error('Cannot git-delta sync without existing sync state');
+    }
+
+    OrchestratorLogger.log(`[Sync] Git delta: ${state.lastSyncCommit.slice(0, 8)} -> ${targetReference.slice(0, 8)}`);
+
+    // Fetch latest
+    await OrchestratorSystem.Run(`git -C "${workspacePath}" fetch origin`, true);
+
+    // Get list of changed files
+    const diffOutput = await OrchestratorSystem.Run(
+      `git -C "${workspacePath}" diff --name-only ${state.lastSyncCommit}..${targetReference}`,
+      true,
+    );
+
+    const changedFiles = diffOutput.split('\n').filter(Boolean);
+    OrchestratorLogger.log(`[Sync] ${changedFiles.length} file(s) changed`);
+
+    if (changedFiles.length > 0) {
+      // Checkout target ref
+      await OrchestratorSystem.Run(`git -C "${workspacePath}" checkout ${targetReference}`, true);
+    }
+
+    // Update sync state
+    const newState: SyncState = {
+      lastSyncCommit: targetReference,
+      lastSyncTimestamp: new Date().toISOString(),
+      workspaceHash: SyncStateManager.calculateWorkspaceHash(workspacePath),
+      pendingOverlays: state.pendingOverlays,
+    };
+    SyncStateManager.saveState(workspacePath, newState, statePath);
+
+    return changedFiles.length;
+  }
+
+  /**
+   * Apply a direct input overlay from a local archive or storage URI.
+   *
+   * For storage URIs (storage://remote:bucket/path), the archive is fetched via rclone.
+   * For local paths, the archive is extracted directly.
+   *
+   * @param workspacePath - Path to the workspace
+   * @param inputReference - Local path or storage:// URI to the input archive
+   * @param rcloneRemote - rclone remote name for storage:// URIs (optional, uses URI-embedded remote)
+   * @param statePath - Optional custom path for sync state file
+   * @returns List of overlay paths applied
+   */
+  static async applyDirectInput(
+    workspacePath: string,
+    inputReference: string,
+    rcloneRemote?: string,
+    statePath?: string,
+  ): Promise<string[]> {
+    let localArchive = inputReference;
+
+    // If storage URI, fetch via rclone first
+    if (inputReference.startsWith('storage://')) {
+      const parsed = IncrementalSyncService.parseStorageUri(inputReference);
+      const remote = rcloneRemote || parsed.remote;
+      const remotePath = parsed.path;
+
+      localArchive = path.join(workspacePath, '.game-ci-input-overlay.tar');
+      OrchestratorLogger.log(`[Sync] Fetching input from storage: ${inputReference}`);
+
+      await IncrementalSyncService.executeRcloneCopy(remote, remotePath, path.dirname(localArchive));
+    }
+
+    if (!fs.existsSync(localArchive)) {
+      throw new Error(`Input archive not found: ${localArchive}`);
+    }
+
+    OrchestratorLogger.log(`[Sync] Applying direct input overlay from ${localArchive}`);
+
+    // Extract overlay
+    await OrchestratorSystem.Run(`tar -xf "${localArchive}" -C "${workspacePath}"`, true);
+
+    // Track overlay in sync state
+    const state = SyncStateManager.loadState(workspacePath, statePath) || {
+      lastSyncCommit: '',
+      lastSyncTimestamp: new Date().toISOString(),
+      pendingOverlays: [],
+    };
+
+    state.pendingOverlays.push(localArchive);
+    SyncStateManager.saveState(workspacePath, state, statePath);
+
+    return [localArchive];
+  }
+
+  /**
+   * Execute a storage-pull sync: pull changed files from an rclone remote.
+   *
+   * This strategy fetches content from a remote storage backend (S3, GCS, Azure, etc.)
+   * and overlays it onto the workspace. Supports two modes:
+   * - overlay: extract on top of existing workspace (default)
+   * - clean: fresh git checkout, then apply overlay
+   *
+   * @param workspacePath - Path to the workspace
+   * @param storageUri - storage://remote:bucket/path URI pointing to remote content
+   * @param options - Configuration for the storage-pull operation
+   * @returns List of files pulled from storage
+   */
+  static async syncStoragePull(
+    workspacePath: string,
+    storageUri: string,
+    options: {
+      rcloneRemote?: string;
+      cleanMode?: boolean;
+      syncRevertAfter?: boolean;
+      statePath?: string;
+    } = {},
+  ): Promise<string[]> {
+    if (!storageUri.startsWith('storage://')) {
+      throw new Error(`Invalid storage URI: ${storageUri}. Must start with storage://`);
+    }
+
+    // Verify rclone is available
+    try {
+      await OrchestratorSystem.Run('rclone version', true, true);
+    } catch {
+      throw new Error('rclone binary not found. Install rclone to use storage-pull sync strategy.');
+    }
+
+    const parsed = IncrementalSyncService.parseStorageUri(storageUri);
+    const remote = options.rcloneRemote || parsed.remote;
+    const remotePath = parsed.path;
+
+    OrchestratorLogger.log(`[Sync] Storage pull: ${remote}:${remotePath} -> ${workspacePath}`);
+
+    // Clean mode: reset workspace to clean git state before applying overlay
+    if (options.cleanMode) {
+      OrchestratorLogger.log('[Sync] Clean mode: resetting workspace to HEAD');
+      await OrchestratorSystem.Run(`git -C "${workspacePath}" checkout -- .`, true);
+      await OrchestratorSystem.Run(`git -C "${workspacePath}" clean -fd`, true);
+    }
+
+    // Pull from remote storage directly into workspace
+    const rcloneSource = `${remote}:${remotePath}`;
+    await OrchestratorSystem.Run(`rclone copy "${rcloneSource}" "${workspacePath}" --transfers 8 --checkers 16`, true);
+
+    // List what was pulled for tracking
+    let pulledFiles: string[] = [];
+    try {
+      const lsOutput = await OrchestratorSystem.Run(`rclone ls "${rcloneSource}"`, true, true);
+      pulledFiles = lsOutput
+        .split('\n')
+        .filter(Boolean)
+        .map((line) => {
+          // rclone ls outputs: "  <size> <path>"
+          const trimmed = line.trim();
+          const spaceIndex = trimmed.indexOf(' ');
+
+          return spaceIndex >= 0 ? trimmed.slice(spaceIndex + 1).trim() : trimmed;
+        })
+        .filter(Boolean);
+    } catch {
+      OrchestratorLogger.logWarning('[Sync] Could not list pulled files from remote');
+    }
+
+    OrchestratorLogger.log(`[Sync] Pulled ${pulledFiles.length} file(s) from storage`);
+
+    // Update sync state with overlay tracking
+    const state = SyncStateManager.loadState(workspacePath, options.statePath) || {
+      lastSyncCommit: '',
+      lastSyncTimestamp: new Date().toISOString(),
+      pendingOverlays: [],
+    };
+
+    state.pendingOverlays.push(storageUri);
+    state.lastSyncTimestamp = new Date().toISOString();
+    state.workspaceHash = SyncStateManager.calculateWorkspaceHash(workspacePath);
+    SyncStateManager.saveState(workspacePath, state, options.statePath);
+
+    return pulledFiles;
+  }
+
+  /**
+   * Parse a storage:// URI into remote and path components.
+   *
+   * Supported formats:
+   * - storage://remote:bucket/path  (explicit remote with colon separator)
+   * - storage://remote/path         (remote name is first path segment)
+   *
+   * @param uri - The storage:// URI to parse
+   * @returns Object with remote name and path
+   */
+  static parseStorageUri(uri: string): { remote: string; path: string } {
+    if (!uri.startsWith('storage://')) {
+      throw new Error(`Invalid storage URI: ${uri}. Must start with storage://`);
+    }
+
+    const stripped = uri.replace('storage://', '');
+
+    // Check for explicit remote:path format (e.g., "myremote:bucket/path")
+    const colonIndex = stripped.indexOf(':');
+    if (colonIndex > 0) {
+      return {
+        remote: stripped.slice(0, colonIndex),
+        path: stripped.slice(colonIndex + 1),
+      };
+    }
+
+    // Fallback: first segment is remote name (e.g., "myremote/bucket/path")
+    const slashIndex = stripped.indexOf('/');
+    if (slashIndex > 0) {
+      return {
+        remote: stripped.slice(0, slashIndex),
+        path: stripped.slice(slashIndex + 1),
+      };
+    }
+
+    // Just a remote name with no path
+    return {
+      remote: stripped,
+      path: '',
+    };
+  }
+
+  /**
+   * Execute rclone copy with standard flags.
+   */
+  private static async executeRcloneCopy(remote: string, remotePath: string, destinationPath: string): Promise<void> {
+    await OrchestratorSystem.Run(
+      `rclone copy "${remote}:${remotePath}" "${destinationPath}" --transfers 8 --checkers 16`,
+      true,
+    );
+  }
+
+  /**
+   * Revert pending overlays by restoring git state.
+   */
+  static async revertOverlays(workspacePath: string, statePath?: string): Promise<void> {
+    const state = SyncStateManager.loadState(workspacePath, statePath);
+    if (!state || state.pendingOverlays.length === 0) {
+      return;
+    }
+
+    OrchestratorLogger.log(`[Sync] Reverting ${state.pendingOverlays.length} overlay(s)`);
+
+    await OrchestratorSystem.Run(`git -C "${workspacePath}" checkout -- .`, true);
+
+    // Clean untracked files from overlays
+    await OrchestratorSystem.Run(`git -C "${workspacePath}" clean -fd`, true);
+
+    state.pendingOverlays = [];
+    state.workspaceHash = SyncStateManager.calculateWorkspaceHash(workspacePath);
+    SyncStateManager.saveState(workspacePath, state, statePath);
+
+    OrchestratorLogger.log('[Sync] Overlays reverted');
+  }
+}

src/model/orchestrator/services/sync/incremental-sync.test.ts

@@ -0,0 +1,544 @@
+import fs from 'node:fs';
+import path from 'node:path';
+import { IncrementalSyncService } from './incremental-sync-service';
+import { SyncStateManager } from './sync-state-manager';
+import { SyncState } from './sync-state';
+import { OrchestratorSystem } from '../core/orchestrator-system';
+import OrchestratorLogger from '../core/orchestrator-logger';
+
+// Mock dependencies
+jest.mock('node:fs');
+jest.mock('../core/orchestrator-system');
+jest.mock('../core/orchestrator-logger');
+
+const mockFs = fs as jest.Mocked<typeof fs>;
+const mockSystem = OrchestratorSystem as jest.Mocked<typeof OrchestratorSystem>;
+const mockLogger = OrchestratorLogger as jest.Mocked<typeof OrchestratorLogger>;
+
+afterEach(() => {
+  jest.clearAllMocks();
+  jest.restoreAllMocks();
+});
+
+describe('IncrementalSyncService', () => {
+  const workspacePath = '/workspace/project';
+
+  describe('parseStorageUri', () => {
+    it('parses storage://remote:bucket/path format', () => {
+      const result = IncrementalSyncService.parseStorageUri('storage://myremote:mybucket/some/path');
+      expect(result).toEqual({ remote: 'myremote', path: 'mybucket/some/path' });
+    });
+
+    it('parses storage://remote/path format', () => {
+      const result = IncrementalSyncService.parseStorageUri('storage://myremote/mybucket/path');
+      expect(result).toEqual({ remote: 'myremote', path: 'mybucket/path' });
+    });
+
+    it('parses storage://remote:bucket with no sub-path', () => {
+      const result = IncrementalSyncService.parseStorageUri('storage://myremote:mybucket');
+      expect(result).toEqual({ remote: 'myremote', path: 'mybucket' });
+    });
+
+    it('handles remote-only URI without path', () => {
+      const result = IncrementalSyncService.parseStorageUri('storage://myremote');
+      expect(result).toEqual({ remote: 'myremote', path: '' });
+    });
+
+    it('throws on invalid URI without storage:// prefix', () => {
+      expect(() => IncrementalSyncService.parseStorageUri('http://example.com')).toThrow('Invalid storage URI');
+    });
+
+    it('throws on empty URI', () => {
+      expect(() => IncrementalSyncService.parseStorageUri('')).toThrow('Invalid storage URI');
+    });
+  });
+
+  describe('resolveStrategy', () => {
+    it('returns full when full is requested', () => {
+      const result = IncrementalSyncService.resolveStrategy('full', workspacePath);
+      expect(result).toBe('full');
+    });
+
+    it('returns git-delta when sync state exists', () => {
+      const state: SyncState = {
+        lastSyncCommit: 'abc123',
+        lastSyncTimestamp: new Date().toISOString(),
+        pendingOverlays: [],
+      };
+      mockFs.existsSync.mockReturnValue(true);
+      mockFs.readFileSync.mockReturnValue(JSON.stringify(state));
+
+      const result = IncrementalSyncService.resolveStrategy('git-delta', workspacePath);
+      expect(result).toBe('git-delta');
+    });
+
+    it('falls back to full when git-delta requested but no sync state', () => {
+      mockFs.existsSync.mockReturnValue(false);
+
+      const result = IncrementalSyncService.resolveStrategy('git-delta', workspacePath);
+      expect(result).toBe('full');
+    });
+
+    it('returns direct-input as-is', () => {
+      const result = IncrementalSyncService.resolveStrategy('direct-input', workspacePath);
+      expect(result).toBe('direct-input');
+    });
+
+    it('returns storage-pull as-is', () => {
+      const result = IncrementalSyncService.resolveStrategy('storage-pull', workspacePath);
+      expect(result).toBe('storage-pull');
+    });
+  });
+
+  describe('syncGitDelta', () => {
+    const targetReference = 'def456789';
+
+    beforeEach(() => {
+      const state: SyncState = {
+        lastSyncCommit: 'abc123456',
+        lastSyncTimestamp: new Date().toISOString(),
+        pendingOverlays: [],
+      };
+      mockFs.existsSync.mockReturnValue(true);
+      mockFs.readFileSync.mockReturnValue(JSON.stringify(state));
+    });
+
+    it('fetches and checks out changed files', async () => {
+      mockSystem.Run.mockResolvedValueOnce(''); // git fetch
+      mockSystem.Run.mockResolvedValueOnce('file1.txt\nfile2.cs\n'); // git diff
+      mockSystem.Run.mockResolvedValueOnce(''); // git checkout
+
+      const result = await IncrementalSyncService.syncGitDelta(workspacePath, targetReference);
+
+      expect(result).toBe(2);
+      expect(mockSystem.Run).toHaveBeenCalledWith(
+        expect.stringContaining('git -C "/workspace/project" fetch origin'),
+        true,
+      );
+      expect(mockSystem.Run).toHaveBeenCalledWith(
+        expect.stringContaining('diff --name-only abc123456..def456789'),
+        true,
+      );
+      expect(mockSystem.Run).toHaveBeenCalledWith(expect.stringContaining('checkout def456789'), true);
+    });
+
+    it('skips checkout when no files changed', async () => {
+      mockSystem.Run.mockResolvedValueOnce(''); // git fetch
+      mockSystem.Run.mockResolvedValueOnce(''); // git diff (empty)
+
+      const result = await IncrementalSyncService.syncGitDelta(workspacePath, targetReference);
+
+      expect(result).toBe(0);
+
+      // Should only have fetch + diff calls, no checkout
+      expect(mockSystem.Run).toHaveBeenCalledTimes(2);
+    });
+
+    it('throws when no sync state exists', async () => {
+      mockFs.existsSync.mockReturnValue(false);
+
+      await expect(IncrementalSyncService.syncGitDelta(workspacePath, targetReference)).rejects.toThrow(
+        'Cannot git-delta sync without existing sync state',
+      );
+    });
+
+    it('saves updated sync state after delta sync', async () => {
+      mockSystem.Run.mockResolvedValueOnce(''); // git fetch
+      mockSystem.Run.mockResolvedValueOnce('file1.txt\n'); // git diff
+      mockSystem.Run.mockResolvedValueOnce(''); // git checkout
+
+      await IncrementalSyncService.syncGitDelta(workspacePath, targetReference);
+
+      expect(mockFs.writeFileSync).toHaveBeenCalled();
+      const writeCall = mockFs.writeFileSync.mock.calls[0];
+      const savedState = JSON.parse(writeCall[1] as string) as SyncState;
+      expect(savedState.lastSyncCommit).toBe(targetReference);
+    });
+  });
+
+  describe('applyDirectInput', () => {
+    it('extracts a local archive to workspace', async () => {
+      const archivePath = '/tmp/overlay.tar';
+      mockFs.existsSync.mockImplementation((p: fs.PathLike) => {
+        if (p === archivePath) return true;
+
+        // State file path does not exist
+        return false;
+      });
+      mockSystem.Run.mockResolvedValueOnce(''); // tar extract
+
+      const result = await IncrementalSyncService.applyDirectInput(workspacePath, archivePath);
+
+      expect(result).toEqual([archivePath]);
+      expect(mockSystem.Run).toHaveBeenCalledWith(expect.stringContaining('tar -xf "/tmp/overlay.tar"'), true);
+    });
+
+    it('fetches archive from storage URI via rclone then extracts', async () => {
+      const storageUri = 'storage://s3remote:builds/overlay.tar';
+
+      mockFs.existsSync.mockImplementation((p: fs.PathLike) => {
+        const pathString = p.toString();
+        if (pathString.includes('.game-ci-input-overlay.tar')) return true;
+
+        return false;
+      });
+      mockSystem.Run.mockResolvedValue(''); // rclone copy + tar extract
+
+      const result = await IncrementalSyncService.applyDirectInput(workspacePath, storageUri);
+
+      expect(result.length).toBe(1);
+      expect(mockSystem.Run).toHaveBeenCalledWith(
+        expect.stringContaining('rclone copy "s3remote:builds/overlay.tar"'),
+        true,
+      );
+    });
+
+    it('throws when local archive does not exist', async () => {
+      mockFs.existsSync.mockReturnValue(false);
+
+      await expect(IncrementalSyncService.applyDirectInput(workspacePath, '/missing/archive.tar')).rejects.toThrow(
+        'Input archive not found',
+      );
+    });
+
+    it('tracks overlay in sync state', async () => {
+      const archivePath = '/tmp/overlay.tar';
+      mockFs.existsSync.mockImplementation((p: fs.PathLike) => {
+        if (p === archivePath) return true;
+
+        return false;
+      });
+      mockSystem.Run.mockResolvedValueOnce('');
+
+      await IncrementalSyncService.applyDirectInput(workspacePath, archivePath);
+
+      expect(mockFs.writeFileSync).toHaveBeenCalled();
+      const writeCall = mockFs.writeFileSync.mock.calls[0];
+      const savedState = JSON.parse(writeCall[1] as string) as SyncState;
+      expect(savedState.pendingOverlays).toContain(archivePath);
+    });
+  });
+
+  describe('syncStoragePull', () => {
+    const storageUri = 'storage://s3:game-builds/latest';
+
+    beforeEach(() => {
+      mockFs.existsSync.mockReturnValue(false); // no existing state
+    });
+
+    it('pulls files from rclone remote into workspace', async () => {
+      mockSystem.Run.mockResolvedValueOnce('rclone v1.60.0'); // version check
+      mockSystem.Run.mockResolvedValueOnce(''); // rclone copy
+      mockSystem.Run.mockResolvedValueOnce('  1234 file1.txt\n  5678 dir/file2.cs\n'); // rclone ls
+
+      const result = await IncrementalSyncService.syncStoragePull(workspacePath, storageUri);
+
+      expect(result).toEqual(['file1.txt', 'dir/file2.cs']);
+      expect(mockSystem.Run).toHaveBeenCalledWith(
+        expect.stringContaining('rclone copy "s3:game-builds/latest" "/workspace/project"'),
+        true,
+      );
+    });
+
+    it('uses custom rclone remote when provided', async () => {
+      mockSystem.Run.mockResolvedValueOnce('rclone v1.60.0'); // version
+      mockSystem.Run.mockResolvedValueOnce(''); // rclone copy
+      mockSystem.Run.mockResolvedValueOnce(''); // rclone ls
+
+      await IncrementalSyncService.syncStoragePull(workspacePath, storageUri, {
+        rcloneRemote: 'custom-remote',
+      });
+
+      expect(mockSystem.Run).toHaveBeenCalledWith(
+        expect.stringContaining('rclone copy "custom-remote:game-builds/latest"'),
+        true,
+      );
+    });
+
+    it('resets workspace in clean mode before pull', async () => {
+      mockSystem.Run.mockResolvedValueOnce('rclone v1.60.0'); // version
+      mockSystem.Run.mockResolvedValueOnce(''); // git checkout -- .
+      mockSystem.Run.mockResolvedValueOnce(''); // git clean -fd
+      mockSystem.Run.mockResolvedValueOnce(''); // rclone copy
+      mockSystem.Run.mockResolvedValueOnce(''); // rclone ls
+
+      await IncrementalSyncService.syncStoragePull(workspacePath, storageUri, { cleanMode: true });
+
+      expect(mockSystem.Run).toHaveBeenCalledWith(
+        expect.stringContaining('git -C "/workspace/project" checkout -- .'),
+        true,
+      );
+      expect(mockSystem.Run).toHaveBeenCalledWith(
+        expect.stringContaining('git -C "/workspace/project" clean -fd'),
+        true,
+      );
+    });
+
+    it('throws on invalid storage URI', async () => {
+      await expect(IncrementalSyncService.syncStoragePull(workspacePath, 'http://example.com')).rejects.toThrow(
+        'Invalid storage URI',
+      );
+    });
+
+    it('throws when rclone binary is not available', async () => {
+      mockSystem.Run.mockRejectedValueOnce(new Error('command not found: rclone'));
+
+      await expect(IncrementalSyncService.syncStoragePull(workspacePath, storageUri)).rejects.toThrow(
+        'rclone binary not found',
+      );
+    });
+
+    it('saves sync state with overlay tracking', async () => {
+      mockSystem.Run.mockResolvedValueOnce('rclone v1.60.0'); // version
+      mockSystem.Run.mockResolvedValueOnce(''); // rclone copy
+      mockSystem.Run.mockResolvedValueOnce('  100 a.txt\n'); // rclone ls
+
+      await IncrementalSyncService.syncStoragePull(workspacePath, storageUri);
+
+      expect(mockFs.writeFileSync).toHaveBeenCalled();
+      const writeCall = mockFs.writeFileSync.mock.calls[0];
+      const savedState = JSON.parse(writeCall[1] as string) as SyncState;
+      expect(savedState.pendingOverlays).toContain(storageUri);
+    });
+
+    it('handles rclone ls failure gracefully', async () => {
+      mockSystem.Run.mockResolvedValueOnce('rclone v1.60.0'); // version
+      mockSystem.Run.mockResolvedValueOnce(''); // rclone copy
+      mockSystem.Run.mockRejectedValueOnce(new Error('ls failed')); // rclone ls fails
+
+      const result = await IncrementalSyncService.syncStoragePull(workspacePath, storageUri);
+
+      expect(result).toEqual([]);
+      expect(mockLogger.logWarning).toHaveBeenCalledWith(expect.stringContaining('Could not list pulled files'));
+    });
+  });
+
+  describe('revertOverlays', () => {
+    it('reverts git state and cleans untracked files', async () => {
+      const state: SyncState = {
+        lastSyncCommit: 'abc123',
+        lastSyncTimestamp: new Date().toISOString(),
+        pendingOverlays: ['/tmp/overlay.tar', 'storage://s3:builds/content'],
+      };
+      mockFs.existsSync.mockReturnValue(true);
+      mockFs.readFileSync.mockReturnValue(JSON.stringify(state));
+      mockSystem.Run.mockResolvedValue('');
+
+      await IncrementalSyncService.revertOverlays(workspacePath);
+
+      expect(mockSystem.Run).toHaveBeenCalledWith(
+        expect.stringContaining('git -C "/workspace/project" checkout -- .'),
+        true,
+      );
+      expect(mockSystem.Run).toHaveBeenCalledWith(
+        expect.stringContaining('git -C "/workspace/project" clean -fd'),
+        true,
+      );
+    });
+
+    it('clears pending overlays in saved state', async () => {
+      const state: SyncState = {
+        lastSyncCommit: 'abc123',
+        lastSyncTimestamp: new Date().toISOString(),
+        pendingOverlays: ['/tmp/overlay.tar'],
+      };
+      mockFs.existsSync.mockReturnValue(true);
+      mockFs.readFileSync.mockReturnValue(JSON.stringify(state));
+      mockSystem.Run.mockResolvedValue('');
+
+      await IncrementalSyncService.revertOverlays(workspacePath);
+
+      expect(mockFs.writeFileSync).toHaveBeenCalled();
+      const writeCall = mockFs.writeFileSync.mock.calls[0];
+      const savedState = JSON.parse(writeCall[1] as string) as SyncState;
+      expect(savedState.pendingOverlays).toEqual([]);
+    });
+
+    it('does nothing when no overlays are pending', async () => {
+      const state: SyncState = {
+        lastSyncCommit: 'abc123',
+        lastSyncTimestamp: new Date().toISOString(),
+        pendingOverlays: [],
+      };
+      mockFs.existsSync.mockReturnValue(true);
+      mockFs.readFileSync.mockReturnValue(JSON.stringify(state));
+
+      await IncrementalSyncService.revertOverlays(workspacePath);
+
+      expect(mockSystem.Run).not.toHaveBeenCalled();
+    });
+
+    it('does nothing when no sync state exists', async () => {
+      mockFs.existsSync.mockReturnValue(false);
+
+      await IncrementalSyncService.revertOverlays(workspacePath);
+
+      expect(mockSystem.Run).not.toHaveBeenCalled();
+    });
+  });
+});
+
+describe('SyncStateManager', () => {
+  const workspacePath = '/workspace/project';
+
+  describe('loadState', () => {
+    it('returns parsed state from default path', () => {
+      const state: SyncState = {
+        lastSyncCommit: 'abc123',
+        lastSyncTimestamp: '2026-01-01T00:00:00.000Z',
+        pendingOverlays: [],
+      };
+      mockFs.existsSync.mockReturnValue(true);
+      mockFs.readFileSync.mockReturnValue(JSON.stringify(state));
+
+      const result = SyncStateManager.loadState(workspacePath);
+
+      expect(result).toEqual(state);
+      expect(mockFs.readFileSync).toHaveBeenCalledWith(path.join(workspacePath, '.game-ci/sync-state.json'), 'utf8');
+    });
+
+    it('uses custom state path when provided', () => {
+      const state: SyncState = {
+        lastSyncCommit: 'abc123',
+        lastSyncTimestamp: '2026-01-01T00:00:00.000Z',
+        pendingOverlays: [],
+      };
+      mockFs.existsSync.mockReturnValue(true);
+      mockFs.readFileSync.mockReturnValue(JSON.stringify(state));
+
+      SyncStateManager.loadState(workspacePath, 'custom/state.json');
+
+      expect(mockFs.readFileSync).toHaveBeenCalledWith(path.join(workspacePath, 'custom/state.json'), 'utf8');
+    });
+
+    it('returns undefined when state file does not exist', () => {
+      mockFs.existsSync.mockReturnValue(false);
+
+      const result = SyncStateManager.loadState(workspacePath);
+
+      expect(result).toBeUndefined();
+    });
+
+    it('returns undefined and logs warning on malformed JSON', () => {
+      mockFs.existsSync.mockReturnValue(true);
+      mockFs.readFileSync.mockReturnValue('not-valid-json{{{');
+
+      const result = SyncStateManager.loadState(workspacePath);
+
+      expect(result).toBeUndefined();
+      expect(mockLogger.logWarning).toHaveBeenCalledWith(expect.stringContaining('Failed to load sync state'));
+    });
+  });
+
+  describe('saveState', () => {
+    it('writes state to default path with pretty JSON', () => {
+      const state: SyncState = {
+        lastSyncCommit: 'abc123',
+        lastSyncTimestamp: '2026-01-01T00:00:00.000Z',
+        pendingOverlays: ['overlay1'],
+      };
+      mockFs.existsSync.mockReturnValue(true);
+
+      SyncStateManager.saveState(workspacePath, state);
+
+      expect(mockFs.writeFileSync).toHaveBeenCalledWith(
+        path.join(workspacePath, '.game-ci/sync-state.json'),
+        JSON.stringify(state, undefined, 2),
+        'utf8',
+      );
+    });
+
+    it('creates parent directories if they do not exist', () => {
+      const state: SyncState = {
+        lastSyncCommit: 'abc123',
+        lastSyncTimestamp: '2026-01-01T00:00:00.000Z',
+        pendingOverlays: [],
+      };
+      mockFs.existsSync.mockReturnValue(false);
+
+      SyncStateManager.saveState(workspacePath, state);
+
+      expect(mockFs.mkdirSync).toHaveBeenCalledWith(expect.stringContaining('.game-ci'), { recursive: true });
+    });
+
+    it('logs warning on write failure instead of throwing', () => {
+      const state: SyncState = {
+        lastSyncCommit: 'abc123',
+        lastSyncTimestamp: '2026-01-01T00:00:00.000Z',
+        pendingOverlays: [],
+      };
+      mockFs.existsSync.mockReturnValue(true);
+      mockFs.writeFileSync.mockImplementation(() => {
+        throw new Error('Permission denied');
+      });
+
+      // Should not throw
+      SyncStateManager.saveState(workspacePath, state);
+
+      expect(mockLogger.logWarning).toHaveBeenCalledWith(expect.stringContaining('Failed to save sync state'));
+    });
+  });
+
+  describe('calculateWorkspaceHash', () => {
+    it('produces a deterministic SHA-256 hash from workspace files', () => {
+      mockFs.existsSync.mockReturnValue(true);
+      mockFs.readFileSync.mockImplementation((filePath: fs.PathOrFileDescriptor) => {
+        const p = filePath.toString();
+        if (p.includes('ProjectVersion.txt')) return 'm_EditorVersion: 2022.3.10f1';
+        if (p.includes('manifest.json')) return '{"dependencies":{}}';
+        if (p.includes('packages-lock.json')) return '{"dependencies":{}}';
+        if (p.includes('csc.rsp')) return '-nullable+';
+
+        return '';
+      });
+
+      const hash1 = SyncStateManager.calculateWorkspaceHash(workspacePath);
+      const hash2 = SyncStateManager.calculateWorkspaceHash(workspacePath);
+
+      expect(hash1).toBe(hash2);
+      expect(hash1).toHaveLength(64); // SHA-256 hex digest
+    });
+
+    it('produces different hashes for different workspace content', () => {
+      let callCount = 0;
+      mockFs.existsSync.mockReturnValue(true);
+      mockFs.readFileSync.mockImplementation(() => {
+        callCount++;
+
+        return callCount <= 4 ? 'content-v1' : 'content-v2';
+      });
+
+      const hash1 = SyncStateManager.calculateWorkspaceHash(workspacePath);
+      const hash2 = SyncStateManager.calculateWorkspaceHash(workspacePath);
+
+      expect(hash1).not.toBe(hash2);
+    });
+
+    it('includes missing file markers in hash for absent files', () => {
+      mockFs.existsSync.mockReturnValue(false);
+
+      const hash = SyncStateManager.calculateWorkspaceHash(workspacePath);
+
+      expect(hash).toHaveLength(64);
+    });
+  });
+
+  describe('hasDrifted', () => {
+    it('returns false when workspace hash matches', () => {
+      mockFs.existsSync.mockReturnValue(false);
+      const savedHash = SyncStateManager.calculateWorkspaceHash(workspacePath);
+
+      const result = SyncStateManager.hasDrifted(workspacePath, savedHash);
+
+      expect(result).toBe(false);
+    });
+
+    it('returns true when workspace hash differs', () => {
+      mockFs.existsSync.mockReturnValue(false);
+
+      const result = SyncStateManager.hasDrifted(workspacePath, 'some-old-hash-that-will-not-match');
+
+      expect(result).toBe(true);
+    });
+  });
+});

src/model/orchestrator/services/sync/index.ts

@@ -0,0 +1,3 @@
+export { SyncState, SyncStrategy } from './sync-state';
+export { IncrementalSyncService } from './incremental-sync-service';
+export { SyncStateManager } from './sync-state-manager';

src/model/orchestrator/services/sync/sync-state-manager.ts

@@ -0,0 +1,125 @@
+import fs from 'node:fs';
+import path from 'node:path';
+import crypto from 'node:crypto';
+import OrchestratorLogger from '../core/orchestrator-logger';
+import { SyncState } from './sync-state';
+
+/**
+ * Manages persistent sync state for incremental workspace updates.
+ *
+ * The sync state tracks what has been synced to a workspace, enabling
+ * delta-based updates instead of full clones. State is stored as a JSON
+ * file in the workspace (default: .game-ci/sync-state.json).
+ */
+export class SyncStateManager {
+  static readonly DEFAULT_STATE_PATH = '.game-ci/sync-state.json';
+
+  /**
+   * Key workspace files whose content is hashed for drift detection.
+   * Changes to any of these files indicate the workspace may have been
+   * modified outside of the sync system.
+   */
+  private static readonly WORKSPACE_HASH_FILES = [
+    'ProjectSettings/ProjectVersion.txt',
+    'Packages/manifest.json',
+    'Packages/packages-lock.json',
+    'Assets/csc.rsp',
+  ];
+
+  /**
+   * Load sync state from the workspace.
+   *
+   * @param workspacePath - Root path of the workspace
+   * @param statePath - Relative path to the state file (default: .game-ci/sync-state.json)
+   * @returns The loaded sync state, or undefined if no state exists or parsing fails
+   */
+  static loadState(workspacePath: string, statePath?: string): SyncState | undefined {
+    const resolvedPath = path.join(workspacePath, statePath || SyncStateManager.DEFAULT_STATE_PATH);
+
+    if (!fs.existsSync(resolvedPath)) {
+      return;
+    }
+
+    try {
+      const content = fs.readFileSync(resolvedPath, 'utf8');
+
+      return JSON.parse(content) as SyncState;
+    } catch {
+      OrchestratorLogger.logWarning(`[SyncState] Failed to load sync state from ${resolvedPath}`);
+
+      return;
+    }
+  }
+
+  /**
+   * Save sync state to the workspace.
+   *
+   * Creates parent directories if they do not exist.
+   *
+   * @param workspacePath - Root path of the workspace
+   * @param state - The sync state to persist
+   * @param statePath - Relative path to the state file (default: .game-ci/sync-state.json)
+   */
+  static saveState(workspacePath: string, state: SyncState, statePath?: string): void {
+    const resolvedPath = path.join(workspacePath, statePath || SyncStateManager.DEFAULT_STATE_PATH);
+
+    try {
+      const directory = path.dirname(resolvedPath);
+      if (!fs.existsSync(directory)) {
+        fs.mkdirSync(directory, { recursive: true });
+      }
+
+      fs.writeFileSync(resolvedPath, JSON.stringify(state, undefined, 2), 'utf8');
+      OrchestratorLogger.log(
+        `[SyncState] State saved: commit=${state.lastSyncCommit}, overlays=${state.pendingOverlays.length}`,
+      );
+    } catch (error: any) {
+      OrchestratorLogger.logWarning(`[SyncState] Failed to save sync state: ${error.message}`);
+    }
+  }
+
+  /**
+   * Calculate a SHA-256 hash of key workspace files for drift detection.
+   *
+   * Hashes the content of known workspace files (ProjectVersion.txt,
+   * manifest.json, etc.) to produce a fingerprint. If the hash changes
+   * between syncs, the workspace may have been modified externally.
+   *
+   * Files that do not exist are skipped (their absence is part of the hash).
+   *
+   * @param workspacePath - Root path of the workspace
+   * @returns Hex-encoded SHA-256 hash string
+   */
+  static calculateWorkspaceHash(workspacePath: string): string {
+    const hash = crypto.createHash('sha256');
+
+    for (const relativePath of SyncStateManager.WORKSPACE_HASH_FILES) {
+      const filePath = path.join(workspacePath, relativePath);
+      try {
+        if (fs.existsSync(filePath)) {
+          const content = fs.readFileSync(filePath, 'utf8');
+          hash.update(`${relativePath}:${content}`);
+        } else {
+          hash.update(`${relativePath}:__missing__`);
+        }
+      } catch {
+        hash.update(`${relativePath}:__error__`);
+      }
+    }
+
+    return hash.digest('hex');
+  }
+
+  /**
+   * Check if the workspace has drifted from a previously saved hash.
+   *
+   * @param workspacePath - Root path of the workspace
+   * @param savedHash - The previously saved workspace hash to compare against
+   * @returns true if the current workspace hash differs from the saved hash
+   */
+  static hasDrifted(workspacePath: string, savedHash: string): boolean {
+    const currentHash = SyncStateManager.calculateWorkspaceHash(workspacePath);
+
+    return currentHash !== savedHash;
+  }
+}

src/model/orchestrator/services/sync/sync-state.ts

@@ -0,0 +1,19 @@
+/**
+ * Persistent sync state for incremental workspace updates.
+ * Stored on the runner to track what has already been synced.
+ */
+export interface SyncState {
+  /** Last successfully synced git commit SHA */
+  lastSyncCommit: string;
+
+  /** ISO 8601 timestamp of last sync */
+  lastSyncTimestamp: string;
+
+  /** SHA-256 hash of workspace state (optional) */
+  workspaceHash?: string;
+
+  /** List of overlay paths that haven't been reverted */
+  pendingOverlays: string[];
+}
+
+export type SyncStrategy = 'full' | 'git-delta' | 'direct-input' | 'storage-pull';

src/model/orchestrator/tests/e2e/orchestrator-end2end-caching.test.ts

@@ -30,7 +30,7 @@ describe('Orchestrator Caching', () => {
         targetPlatform: 'StandaloneLinux64',
         cacheKey: `test-case-${uuidv4()}`,
         containerHookFiles: `debug-cache`,
-        orchestratorBranch: `orchestrator-develop`,
+        orchestratorBranch: `main`,
         orchestratorDebug: true,
       };
 

src/model/orchestrator/workflows/async-workflow.ts

@@ -33,8 +33,7 @@ if [ -n "$(git ls-remote --heads "$REPO" "$BRANCH" 2>/dev/null)" ]; then
   git clone -q -b "$BRANCH" "$REPO" /builder
 else
   echo "Remote branch $BRANCH not found in $REPO; falling back to a known branch"
-  git clone -q -b orchestrator-develop "$REPO" /builder \
+  git clone -q -b main "$REPO" /builder \
-    || git clone -q -b main "$REPO" /builder \
     || git clone -q "$REPO" /builder
 fi
 git clone -q -b ${Orchestrator.buildParameters.branch} ${OrchestratorFolders.targetBuildRepoUrl} /repo

src/model/orchestrator/workflows/build-automation-workflow.ts

@@ -99,8 +99,7 @@ if [ -n "$(git ls-remote --heads "$REPO" "$BRANCH" 2>/dev/null)" ]; then
   git clone -q -b "$BRANCH" "$REPO" "$DEST"
 else
   echo "Remote branch $BRANCH not found in $REPO; falling back to a known branch"
-  git clone -q -b orchestrator-develop "$REPO" "$DEST" \
+  git clone -q -b main "$REPO" "$DEST" \
-    || git clone -q -b main "$REPO" "$DEST" \
     || git clone -q "$REPO" "$DEST"
 fi
 chmod +x ${builderPath}`;