Workflow Skills

Persistent history and rollback system for AI operations ("Time Machine"). Allows tagging tasks, snapshotting objects before modification, and undoing specific tasks even after Editor restarts.

NEW: Session-level undo - Group all changes from a conversation and undo them together.

Operating Mode

• Approval：本模块大部分 skill 标 SkillMode.SemiAuto（bookmark / history / task / session 系列里的纯读查询 + workflow_plan，后者 ReadOnly=true 仅生成聚合计划），可直接执行。有副作用的 skill (bookmark_set / bookmark_goto / workflow_snapshot_object / workflow_snapshot_created / batch_retry_failed) 走默认 SkillMode.FullAuto，需 grant。
• Auto / Bypass：FullAuto 直接执行。
• 含 NeverInSemi 高危 skill：bookmark_delete / workflow_delete_task（标 Operation.Delete，删除书签/任务记录）、workflow_clear_history（Operation.Delete + RiskLevel=high，清空全部历史+redo栈+文件存储，不可逆）。这些在 Approval/Auto 下返 MODE_FORBIDDEN，仅 Bypass 或 Allowlist 命中可调。

注意：workflow_undo_task / workflow_session_undo 不是 Delete operation（标的是 Modify/Execute），它们能在 Approval/Auto 直接撤销已记录任务。

DO NOT (common hallucinations):

• workflow_save does not exist → use workflow_task_end to end and save a task
• workflow_rollback does not exist → use workflow_undo_task (by taskId) or workflow_session_undo (by sessionId)
• workflow_create does not exist → use workflow_task_start
• workflow_revert_task is deprecated → use workflow_undo_task

Routing:

• For simple undo/redo (1 step) → editor_undo / editor_redo (editor module)
• For multi-step undo → history_undo with steps parameter (this module)
• For conversation-level undo → workflow_session_undo (this module)

Bookmark Skills

bookmark_set

Save current selection and scene view position as a bookmark.

Returns: { success, bookmark, selectedCount, hasSceneView, note }

bookmark_goto

Restore selection and scene view from a bookmark.

Returns: { success, bookmark, restoredSelection, note }

bookmark_list

List all saved bookmarks.

No parameters.

Returns: { success, count, bookmarks: [{ name, selectedCount, hasSceneView, note, createdAt }] }

bookmark_delete

Delete a bookmark.

Returns: { success, deleted }

History Skills

history_undo

Undo the last operation (or multiple steps).

Returns: { success, undoneSteps }

history_redo

Redo the last undone operation (or multiple steps).

Returns: { success, redoneSteps }

history_get_current

Get the name of the current undo group.

No parameters.

Returns: { success, currentGroup, groupIndex }

Planning And Batch Governance

workflow_plan

Generate a combined execution plan for multiple skills on the server side.

Returns: { totalSteps, totalRisk, steps, dependencies, warnings, mayDisconnect }

batch_query_assets

Query project assets with filters that are useful before batch cleanup or migration work.

Returns: { count, totalMatched, summary, assets }

batch_retry_failed

Retry only the failed items from an earlier batch execution report. This now reuses the original operation context stored in the report.

Returns: { status, jobId?, retryCount, originalReportId, reportId? }

Session Management (Conversation-Level Undo)

workflow_session_start

Start a new session (conversation-level). All changes will be tracked and can be undone together. Call this at the beginning of each conversation.

Returns: { success, sessionId, message }

workflow_session_end

End the current session and save all tracked changes. Call this at the end of each conversation.

No parameters.

Returns: { success, sessionId, message }

workflow_session_undo

Undo all changes made during a specific session (conversation-level undo).

Returns: { success, sessionId, message }

workflow_session_list

List all recorded sessions (conversation-level history).

No parameters.

Returns: { success, count, currentSessionId, sessions: [{ sessionId, taskCount, totalChanges, startTime, endTime, tags }] }

workflow_session_status

Get the current session status.

No parameters.

Returns: { success, hasActiveSession, currentSessionId, isRecording, currentTaskId, currentTaskTag, currentTaskDescription, snapshotCount }

Task-Level Skills

workflow_task_start

Start a new persistent workflow task to track changes for undo. Call workflow_task_end when done.

Returns: { success, taskId, message }

workflow_task_end

End the current workflow task and save it. Requires an active task (call workflow_task_start first).

No parameters.

Returns: { success, taskId, snapshotCount, message }

workflow_snapshot_object

Manually snapshot an object's state before modification. Requires an active task (call workflow_task_start first). Call this BEFORE component_set_property, gameobject_set_transform, etc.

Returns: { success, objectName, type }

workflow_snapshot_created

Record a newly created object for undo tracking. Requires an active task (call workflow_task_start first). Note: component_add and gameobject_create automatically record created objects, so you typically don't need to call this manually.

Returns: { success, objectName, type }

workflow_list

List persistent workflow history.

No parameters.

Returns: { success, count, history: [{ id, tag, description, time, changes }] }

workflow_undo_task

Undo changes from a specific task (restore to previous state). The undone task is saved and can be redone later.

Returns: { success, taskId }

workflow_redo_task

Redo a previously undone task (restore changes).

Returns: { success, taskId }

workflow_undone_list

List all undone tasks that can be redone.

No parameters.

Returns: { success, count, undoneStack: [{ id, tag, description, time, changes }] }

workflow_revert_task

(deprecated) Alias for workflow_undo_task. Use workflow_undo_task instead.

Returns: { success, taskId }

workflow_delete_task

Delete a task from history (does not revert changes, just removes the record).

Returns: { success, deletedId }

workflow_clear_history

Permanently clear ALL workflow history: every task, the redo (undone) stack, and every backed-up file blob in the content-addressed store. High-risk and irreversible. This ONLY deletes tracking history — it does NOT undo or revert any change already applied to your project assets, scenes, or settings. To roll changes back, use workflow_undo_task / workflow_session_undo before clearing.

Marked SkillOperation.Delete + RiskLevel="high", so it is NeverInSemi (returns MODE_FORBIDDEN in Approval/Auto; only Bypass or an Allowlist hit can call it).

Parameters: None

Returns: { success, before, after, message } where before/after each report { tasks, undoneStack, historyFileBytes, fileStoreBytes }.

Snapshot Mechanism

History is persisted to workflow_history.json (schemaVersion 5). Asset and .meta bytes are independently content-addressed in Library/UnitySkills/workflow_files/<sha1>; history keeps fileHash / metaFileHash references. Schema 2/3 histories are migrated atomically: legacy blobs are made durable before inline base64 is removed.

Snapshots are tiered by SnapshotType:

Undo/redo return per-snapshot detail (TaskUndoResult: total / succeeded / failed / details / error). Operations run in reverse order; on the first failure, failed and unprocessed snapshots stay on their source stack so they can be retried.

Auto-clean

WorkflowAutoCleanConfig (EditorPrefs keys UnitySkills.Workflow.*) trims history and the file store after EndTask and after LoadHistory. Defaults: MaxTasks=200, MaxHistoryMB=32, MaxTaskAgeDays=30, MaxStoreMB=512, StoreMaxAgeDays=7. Store age/size pruning never removes a blob referenced by retained history. A value of 0 disables that individual limit.

Settings are now truly revertible

Setting-class skills used to be one-way; they now register a restorer and can be rolled back: console_set_pause_on_error / console_set_collapse / console_set_clear_on_play, debug_set_defines, graphics_set_quality_level / graphics_set_default_render_pipeline / graphics_set_quality_render_pipeline / graphics_add_always_included_shader / graphics_remove_always_included_shader / graphics_set_shader_stripping, physics_set_gravity / physics_set_layer_collision, project_add_tag.

Cinemachine's 28 write skills now set TracksWorkflow=true (the snapshot code existed but never auto-triggered). scene_save / scene_create are now rollback-capable (scene_save over an existing scene backs up the old file as a Modified snapshot).

Known Limitations

• scene_save undo restores the on-disk .unity file; if the scene is currently open, you must Reload Scene for the restore to take effect.
• Objects created in a never-saved scene: their GlobalObjectId becomes invalid across an Editor restart, so undo will mark them as failed in the result detail.
• External side effects (Package Manager operations, etc.) cannot be rolled back.

Minimal Example

import unity_skills

# Session-level: wrap entire conversation for bulk undo
unity_skills.call_skill("workflow_session_start", tag="Build Player")
unity_skills.call_skill("gameobject_create", name="Player", primitiveType="Capsule")
unity_skills.call_skill("component_add", name="Player", componentType="Rigidbody")
unity_skills.call_skill("workflow_session_end")
# Later: undo entire session
sessions = unity_skills.call_skill("workflow_session_list")
unity_skills.call_skill("workflow_session_undo", sessionId=sessions["sessions"][0]["sessionId"])

Auto-Tracked Operations

The following operations are automatically tracked for undo when a session/task is active:

• gameobject_create / gameobject_create_batch
• gameobject_duplicate / gameobject_duplicate_batch
• component_add / component_add_batch
• ui_create_* (canvas, button, text, image, etc.)
• light_create
• prefab_instantiate / prefab_instantiate_batch
• material_create / material_duplicate
• terrain_create
• cinemachine_create_vcam

For modification operations, the system auto-snapshots target objects before changes when possible.

Exact Signatures

Exact names, parameters, defaults, and returns are defined by GET /skills/schema or unity_skills.get_skill_schema(), not by this file.