Merge branch 'feat/maintenance-flows'

backend/alembic/versions/0f1ca2af3647_add_maintenance_tree_type.py

@@ -0,0 +1,33 @@
+"""add maintenance tree type
+
+Revision ID: 0f1ca2af3647
+Revises: 039
+Create Date: 2026-02-17 10:25:54.959861
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision: str = '0f1ca2af3647'
+down_revision: Union[str, None] = '039'
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.execute("ALTER TABLE trees DROP CONSTRAINT ck_trees_tree_type")
+    op.execute(
+        "ALTER TABLE trees ADD CONSTRAINT ck_trees_tree_type "
+        "CHECK (tree_type IN ('troubleshooting', 'procedural', 'maintenance'))"
+    )
+
+
+def downgrade() -> None:
+    op.execute("UPDATE trees SET tree_type = 'procedural' WHERE tree_type = 'maintenance'")
+    op.execute("ALTER TABLE trees DROP CONSTRAINT ck_trees_tree_type")
+    op.execute(
+        "ALTER TABLE trees ADD CONSTRAINT ck_trees_tree_type "
+        "CHECK (tree_type IN ('troubleshooting', 'procedural'))"
+    )

backend/alembic/versions/0fd2a90a9c2c_add_maintenance_schedules_table.py

@@ -0,0 +1,44 @@
+"""add maintenance_schedules table
+
+Revision ID: 0fd2a90a9c2c
+Revises: 6e8128ef2aa8
+Create Date: 2026-02-17
+
+"""
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects import postgresql
+
+# revision identifiers, used by Alembic.
+revision = '0fd2a90a9c2c'
+down_revision = '6e8128ef2aa8'
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.create_table(
+        'maintenance_schedules',
+        sa.Column('id', postgresql.UUID(as_uuid=True), primary_key=True),
+        sa.Column('tree_id', postgresql.UUID(as_uuid=True),
+                  sa.ForeignKey('trees.id', ondelete='CASCADE'), nullable=False),
+        sa.Column('created_by', postgresql.UUID(as_uuid=True),
+                  sa.ForeignKey('users.id', ondelete='SET NULL'), nullable=True),
+        sa.Column('cron_expression', sa.String(100), nullable=False),
+        sa.Column('timezone', sa.String(100), nullable=False, server_default='UTC'),
+        sa.Column('target_list_id', postgresql.UUID(as_uuid=True),
+                  sa.ForeignKey('target_lists.id', ondelete='SET NULL'), nullable=True),
+        sa.Column('is_active', sa.Boolean(), nullable=False, server_default='true'),
+        sa.Column('next_run_at', sa.DateTime(timezone=True), nullable=True),
+        sa.Column('last_run_at', sa.DateTime(timezone=True), nullable=True),
+        sa.Column('created_at', sa.DateTime(timezone=True), nullable=False),
+        sa.Column('updated_at', sa.DateTime(timezone=True), nullable=False),
+    )
+    op.create_index('ix_maintenance_schedules_tree_id', 'maintenance_schedules', ['tree_id'])
+    op.create_unique_constraint('uq_maintenance_schedules_tree_id', 'maintenance_schedules', ['tree_id'])
+
+
+def downgrade() -> None:
+    op.drop_constraint('uq_maintenance_schedules_tree_id', 'maintenance_schedules', type_='unique')
+    op.drop_index('ix_maintenance_schedules_tree_id', table_name='maintenance_schedules')
+    op.drop_table('maintenance_schedules')

backend/alembic/versions/5812e7df852f_add_target_lists_table.py

@@ -0,0 +1,39 @@
+"""add target_lists table
+
+Revision ID: 5812e7df852f
+Revises: 0f1ca2af3647
+Create Date: 2026-02-17 11:20:42.919564
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects import postgresql
+
+
+# revision identifiers, used by Alembic.
+revision: str = '5812e7df852f'
+down_revision: Union[str, None] = '0f1ca2af3647'
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.create_table(
+        'target_lists',
+        sa.Column('id', postgresql.UUID(as_uuid=True), primary_key=True),
+        sa.Column('team_id', postgresql.UUID(as_uuid=True), sa.ForeignKey('teams.id', ondelete='CASCADE'), nullable=False),
+        sa.Column('created_by', postgresql.UUID(as_uuid=True), sa.ForeignKey('users.id', ondelete='SET NULL'), nullable=True),
+        sa.Column('name', sa.String(255), nullable=False),
+        sa.Column('description', sa.Text(), nullable=True),
+        sa.Column('targets', postgresql.JSONB(), nullable=False, server_default='[]'),
+        sa.Column('created_at', sa.DateTime(timezone=True), nullable=False),
+        sa.Column('updated_at', sa.DateTime(timezone=True), nullable=False),
+    )
+    op.create_index('ix_target_lists_team_id', 'target_lists', ['team_id'])
+
+
+def downgrade() -> None:
+    op.drop_index('ix_target_lists_team_id', table_name='target_lists')
+    op.drop_table('target_lists')

backend/alembic/versions/6e8128ef2aa8_add_batch_id_and_target_label_to_.py

@@ -0,0 +1,28 @@
+"""add batch_id and target_label to sessions
+
+Revision ID: 6e8128ef2aa8
+Revises: 5812e7df852f
+Create Date: 2026-02-17
+
+"""
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects import postgresql
+
+# revision identifiers, used by Alembic.
+revision = '6e8128ef2aa8'
+down_revision = '5812e7df852f'
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.add_column('sessions', sa.Column('batch_id', postgresql.UUID(as_uuid=True), nullable=True))
+    op.add_column('sessions', sa.Column('target_label', sa.String(255), nullable=True))
+    op.create_index('ix_sessions_batch_id', 'sessions', ['batch_id'])
+
+
+def downgrade() -> None:
+    op.drop_index('ix_sessions_batch_id', table_name='sessions')
+    op.drop_column('sessions', 'target_label')
+    op.drop_column('sessions', 'batch_id')

backend/app/api/endpoints/maintenance_schedules.py

@@ -0,0 +1,153 @@
+"""Maintenance schedule CRUD endpoints."""
+from typing import Annotated
+from uuid import UUID
+from datetime import datetime, timezone
+from fastapi import APIRouter, Depends, HTTPException
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+from croniter import croniter
+import pytz
+
+from app.api.deps import get_current_active_user, get_db, require_engineer_or_admin
+from app.models.maintenance_schedule import MaintenanceSchedule
+from app.models.tree import Tree
+from app.models.user import User
+from app.schemas.maintenance_schedule import (
+    MaintenanceScheduleCreate,
+    MaintenanceScheduleUpdate,
+    MaintenanceScheduleResponse,
+)
+
+router = APIRouter(prefix="/maintenance-schedules", tags=["maintenance-schedules"])
+
+
+def _compute_next_run(cron_expression: str, tz_name: str) -> datetime:
+    """Compute next run time from cron expression, returned as UTC."""
+    tz = pytz.timezone(tz_name)
+    now = datetime.now(tz)
+    cron = croniter(cron_expression, now)
+    return cron.get_next(datetime).astimezone(timezone.utc)
+
+
+async def _get_tree_or_403(tree_id: UUID, current_user: User, db: AsyncSession) -> "Tree":
+    """Fetch tree and verify the current user's team owns it."""
+    result = await db.execute(select(Tree).where(Tree.id == tree_id))
+    tree = result.scalar_one_or_none()
+    if not tree:
+        raise HTTPException(status_code=404, detail="Tree not found")
+    # Super admins can access any tree; regular users must be on the same team
+    if not getattr(current_user, 'is_super_admin', False):
+        if tree.team_id != current_user.team_id:
+            raise HTTPException(status_code=403, detail="Access denied")
+    return tree
+
+
+@router.post("", response_model=MaintenanceScheduleResponse, status_code=201)
+async def create_schedule(
+    data: MaintenanceScheduleCreate,
+    current_user: Annotated[User, Depends(get_current_active_user)],
+    db: Annotated[AsyncSession, Depends(get_db)],
+    _: None = Depends(require_engineer_or_admin),
+):
+    """Create a cron schedule for a maintenance flow. One per flow."""
+    # Verify user's team owns the tree
+    await _get_tree_or_403(data.tree_id, current_user, db)
+
+    # Check no existing schedule for this tree
+    existing = await db.execute(
+        select(MaintenanceSchedule).where(MaintenanceSchedule.tree_id == data.tree_id)
+    )
+    if existing.scalar_one_or_none():
+        raise HTTPException(status_code=409, detail="Schedule already exists for this tree")
+
+    try:
+        next_run = _compute_next_run(data.cron_expression, data.timezone)
+    except (ValueError, KeyError) as e:
+        raise HTTPException(status_code=422, detail=f"Invalid cron expression or timezone: {e}")
+
+    schedule = MaintenanceSchedule(
+        tree_id=data.tree_id,
+        created_by=current_user.id,
+        cron_expression=data.cron_expression,
+        timezone=data.timezone,
+        target_list_id=data.target_list_id,
+        is_active=True,
+        next_run_at=next_run,
+    )
+    db.add(schedule)
+    await db.commit()
+    await db.refresh(schedule)
+
+    from app.core.scheduler import register_schedule
+    register_schedule(schedule)
+
+    return schedule
+
+
+@router.get("/tree/{tree_id}", response_model=MaintenanceScheduleResponse)
+async def get_schedule_for_tree(
+    tree_id: UUID,
+    current_user: Annotated[User, Depends(get_current_active_user)],
+    db: Annotated[AsyncSession, Depends(get_db)],
+):
+    """Get the schedule for a specific maintenance flow."""
+    # Verify user's team owns the tree before returning schedule data
+    await _get_tree_or_403(tree_id, current_user, db)
+
+    result = await db.execute(
+        select(MaintenanceSchedule).where(MaintenanceSchedule.tree_id == tree_id)
+    )
+    schedule = result.scalar_one_or_none()
+    if not schedule:
+        raise HTTPException(status_code=404, detail="No schedule found for this tree")
+    return schedule
+
+
+@router.patch("/{schedule_id}", response_model=MaintenanceScheduleResponse)
+async def update_schedule(
+    schedule_id: UUID,
+    data: MaintenanceScheduleUpdate,
+    current_user: Annotated[User, Depends(get_current_active_user)],
+    db: Annotated[AsyncSession, Depends(get_db)],
+    _: None = Depends(require_engineer_or_admin),
+):
+    """Update a schedule (disable, change cron, change timezone, change target list)."""
+    result = await db.execute(
+        select(MaintenanceSchedule).where(MaintenanceSchedule.id == schedule_id)
+    )
+    schedule = result.scalar_one_or_none()
+    if not schedule:
+        raise HTTPException(status_code=404, detail="Schedule not found")
+
+    # Verify user's team owns the tree this schedule belongs to
+    await _get_tree_or_403(schedule.tree_id, current_user, db)
+
+    update_fields = data.model_fields_set
+    was_active = schedule.is_active
+    if "cron_expression" in update_fields and data.cron_expression is not None:
+        schedule.cron_expression = data.cron_expression
+    if "timezone" in update_fields and data.timezone is not None:
+        schedule.timezone = data.timezone
+    if "target_list_id" in update_fields:
+        schedule.target_list_id = data.target_list_id
+    if "is_active" in update_fields and data.is_active is not None:
+        schedule.is_active = data.is_active
+
+    # Recompute next_run_at if schedule timing changed or schedule is being re-activated
+    reactivating = "is_active" in update_fields and data.is_active is True and not was_active
+    if "cron_expression" in update_fields or "timezone" in update_fields or reactivating:
+        try:
+            schedule.next_run_at = _compute_next_run(schedule.cron_expression, schedule.timezone)
+        except (ValueError, KeyError) as e:
+            raise HTTPException(status_code=422, detail=f"Invalid cron expression or timezone: {e}")
+
+    await db.commit()
+    await db.refresh(schedule)
+
+    from app.core.scheduler import register_schedule, unregister_schedule
+    if schedule.is_active:
+        register_schedule(schedule)
+    else:
+        unregister_schedule(str(schedule.id))
+
+    return schedule

backend/app/api/endpoints/sessions.py

@@ -1,8 +1,10 @@
 from datetime import datetime, timezone
 from typing import Annotated, Optional
 from uuid import UUID
+import uuid
 from fastapi import APIRouter, Depends, HTTPException, status, Query
 from fastapi.responses import PlainTextResponse
+from pydantic import BaseModel, Field as PydanticField
 from sqlalchemy.ext.asyncio import AsyncSession
 from sqlalchemy import select
 
@@ -485,3 +487,95 @@ async def save_session_as_tree(
         tree_name=new_tree.name,
         message=f"Session saved as {'published' if request_data.status == 'published' else 'draft'} tree"
     )
+
+
+# ── Batch Launch (Maintenance Flows) ──────────────────────────────────────
+
+
+class _BatchTarget(BaseModel):
+    label: str = PydanticField(..., min_length=1, max_length=255)
+
+
+class _BatchLaunchRequest(BaseModel):
+    tree_id: UUID
+    targets: list[_BatchTarget] = PydanticField(..., min_length=1, max_length=100)
+
+
+class _BatchLaunchResponse(BaseModel):
+    batch_id: str
+    count: int
+    sessions: list[dict]
+
+
+@router.post("/batch", status_code=201, response_model=_BatchLaunchResponse)
+async def batch_launch_sessions(
+    data: _BatchLaunchRequest,
+    current_user: Annotated[User, Depends(get_current_active_user)],
+    db: Annotated[AsyncSession, Depends(get_db)],
+):
+    """Create one session per target for a maintenance flow batch run."""
+    tree_result = await db.execute(select(Tree).where(Tree.id == data.tree_id))
+    tree = tree_result.scalar_one_or_none()
+    if not tree:
+        raise HTTPException(status_code=404, detail="Tree not found")
+
+    if not can_access_tree(current_user, tree):
+        raise HTTPException(status_code=403, detail="Access denied")
+
+    if not tree.is_active:
+        raise HTTPException(status_code=400, detail="Cannot batch-launch an inactive flow")
+
+    if tree.status == 'draft':
+        raise HTTPException(status_code=400, detail="Cannot batch-launch a draft flow")
+
+    if not current_user.is_super_admin and tree.team_id != current_user.team_id:
+        raise HTTPException(status_code=403, detail="Access denied")
+
+    if tree.tree_type != "maintenance":
+        raise HTTPException(status_code=400, detail="Batch launch is only for maintenance flows")
+
+    batch_id = uuid.uuid4()
+    created_sessions = []
+
+    # Hoist snapshot computation out of the loop — same tree for all targets
+    tree_snapshot = {
+        **tree.tree_structure,
+        "name": tree.name,
+        "description": tree.description,
+        "tree_type": tree.tree_type,
+    }
+
+    for target in data.targets:
+        session = Session(
+            tree_id=tree.id,
+            user_id=current_user.id,
+            tree_snapshot=tree_snapshot,
+            path_taken=[],
+            decisions=[],
+            custom_steps=[],
+            session_variables={},
+            batch_id=batch_id,
+            target_label=target.label,
+        )
+        db.add(session)
+        created_sessions.append(session)
+
+    await db.flush()
+    session_ids = [s.id for s in created_sessions]
+    result = await db.execute(select(Session).where(Session.id.in_(session_ids)))
+    created_sessions = result.scalars().all()
+    await db.commit()
+
+    return _BatchLaunchResponse(
+        batch_id=str(batch_id),
+        count=len(created_sessions),
+        sessions=[
+            {
+                "id": str(s.id),
+                "batch_id": str(s.batch_id),
+                "target_label": s.target_label,
+                "tree_id": str(s.tree_id),
+            }
+            for s in created_sessions
+        ],
+    )

backend/app/api/endpoints/target_lists.py

@@ -0,0 +1,119 @@
+"""Target lists CRUD endpoints."""
+from typing import Annotated
+from uuid import UUID
+from fastapi import APIRouter, Depends, HTTPException, status
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.api.deps import get_current_active_user, get_db, require_engineer_or_admin
+from app.models.target_list import TargetList
+from app.models.user import User
+from app.schemas.target_list import TargetListCreate, TargetListUpdate, TargetListResponse
+
+router = APIRouter(prefix="/target-lists", tags=["target-lists"])
+
+
+@router.get("/", response_model=list[TargetListResponse])
+async def list_target_lists(
+    current_user: Annotated[User, Depends(get_current_active_user)],
+    db: Annotated[AsyncSession, Depends(get_db)],
+):
+    """List all target lists for the current user's team."""
+    if not current_user.team_id:
+        return []
+    result = await db.execute(
+        select(TargetList)
+        .where(TargetList.team_id == current_user.team_id)
+        .order_by(TargetList.name)
+    )
+    return result.scalars().all()
+
+
+@router.post("/", response_model=TargetListResponse, status_code=201)
+async def create_target_list(
+    data: TargetListCreate,
+    current_user: Annotated[User, Depends(get_current_active_user)],
+    db: Annotated[AsyncSession, Depends(get_db)],
+    _: None = Depends(require_engineer_or_admin),
+):
+    """Create a new target list for the current team."""
+    if not current_user.team_id:
+        raise HTTPException(status_code=400, detail="User must belong to a team")
+    target_list = TargetList(
+        team_id=current_user.team_id,
+        created_by=current_user.id,
+        name=data.name,
+        description=data.description,
+        targets=[t.model_dump() for t in data.targets],
+    )
+    db.add(target_list)
+    await db.commit()
+    await db.refresh(target_list)
+    return target_list
+
+
+@router.get("/{list_id}", response_model=TargetListResponse)
+async def get_target_list(
+    list_id: UUID,
+    current_user: Annotated[User, Depends(get_current_active_user)],
+    db: Annotated[AsyncSession, Depends(get_db)],
+):
+    result = await db.execute(
+        select(TargetList).where(
+            TargetList.id == list_id,
+            TargetList.team_id == current_user.team_id,
+        )
+    )
+    target_list = result.scalar_one_or_none()
+    if not target_list:
+        raise HTTPException(status_code=404, detail="Target list not found")
+    return target_list
+
+
+@router.put("/{list_id}", response_model=TargetListResponse)
+async def update_target_list(
+    list_id: UUID,
+    data: TargetListUpdate,
+    current_user: Annotated[User, Depends(get_current_active_user)],
+    db: Annotated[AsyncSession, Depends(get_db)],
+    _: None = Depends(require_engineer_or_admin),
+):
+    result = await db.execute(
+        select(TargetList).where(
+            TargetList.id == list_id,
+            TargetList.team_id == current_user.team_id,
+        )
+    )
+    target_list = result.scalar_one_or_none()
+    if not target_list:
+        raise HTTPException(status_code=404, detail="Target list not found")
+    update_fields = data.model_fields_set
+    if "name" in update_fields and data.name is not None:
+        target_list.name = data.name
+    if "description" in update_fields:
+        target_list.description = data.description  # allow setting to None
+    if "targets" in update_fields and data.targets is not None:
+        target_list.targets = [t.model_dump() for t in data.targets]
+    await db.commit()
+    await db.refresh(target_list)
+    return target_list
+
+
+@router.delete("/{list_id}", status_code=204)
+async def delete_target_list(
+    list_id: UUID,
+    current_user: Annotated[User, Depends(get_current_active_user)],
+    db: Annotated[AsyncSession, Depends(get_db)],
+    _: None = Depends(require_engineer_or_admin),
+):
+    result = await db.execute(
+        select(TargetList).where(
+            TargetList.id == list_id,
+            TargetList.team_id == current_user.team_id,
+        )
+    )
+    target_list = result.scalar_one_or_none()
+    if not target_list:
+        raise HTTPException(status_code=404, detail="Target list not found")
+    await db.delete(target_list)
+    await db.commit()

backend/app/api/router.py

@@ -2,6 +2,8 @@ from fastapi import APIRouter
 from app.api.endpoints import auth, trees, sessions, invite, categories, tags, folders, step_categories, steps, admin, accounts, webhooks, shares, shared, tree_markdown
 from app.api.endpoints import admin_dashboard, admin_audit, admin_plan_limits, admin_feature_flags, admin_settings, admin_categories
 from app.api.endpoints import ratings, analytics
+from app.api.endpoints import target_lists
+from app.api.endpoints import maintenance_schedules
 
 api_router = APIRouter()
 
@@ -28,3 +30,5 @@ api_router.include_router(shared.router)  # Public endpoints (no auth)
 api_router.include_router(tree_markdown.router)
 api_router.include_router(ratings.router)
 api_router.include_router(analytics.router)
+api_router.include_router(target_lists.router)
+api_router.include_router(maintenance_schedules.router)

backend/app/core/scheduler.py

@@ -0,0 +1,144 @@
+"""APScheduler integration for maintenance flow auto-session creation."""
+import logging
+import uuid
+from datetime import datetime, timezone
+
+from apscheduler.schedulers.asyncio import AsyncIOScheduler
+from apscheduler.schedulers.base import SchedulerNotRunningError
+from apscheduler.jobstores.base import JobLookupError
+from apscheduler.triggers.cron import CronTrigger
+import pytz
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+logger = logging.getLogger(__name__)
+
+scheduler = AsyncIOScheduler()
+
+
+async def _fire_maintenance_schedule(schedule_id: str) -> None:
+    """Create batch sessions for a scheduled maintenance run."""
+    # Import all models first to ensure SQLAlchemy mapper relationships resolve
+    import app.models  # noqa: F401
+    from app.core.database import async_session_maker
+    from app.models.maintenance_schedule import MaintenanceSchedule
+    from app.models.session import Session
+    from app.models.target_list import TargetList
+    from app.models.tree import Tree
+
+    async with async_session_maker() as db:
+        try:
+            result = await db.execute(
+                select(MaintenanceSchedule).where(
+                    MaintenanceSchedule.id == uuid.UUID(schedule_id),
+                    MaintenanceSchedule.is_active == True,
+                )
+            )
+            schedule = result.scalar_one_or_none()
+            if not schedule:
+                logger.warning(f"Schedule {schedule_id} not found or inactive")
+                return
+
+            tree_result = await db.execute(
+                select(Tree).where(Tree.id == schedule.tree_id)
+            )
+            tree = tree_result.scalar_one_or_none()
+            if not tree:
+                logger.error(f"Tree {schedule.tree_id} not found for schedule {schedule_id}")
+                return
+
+            # Resolve targets
+            targets: list[dict] = []
+            if schedule.target_list_id:
+                list_result = await db.execute(
+                    select(TargetList).where(TargetList.id == schedule.target_list_id)
+                )
+                target_list = list_result.scalar_one_or_none()
+                if target_list:
+                    targets = list(target_list.targets)
+
+            if not targets:
+                targets = [{"label": "Unassigned"}]
+
+            batch_id = uuid.uuid4()
+            tree_snapshot = tree.tree_structure
+
+            sessions_to_add = []
+            for target in targets:
+                session = Session(
+                    tree_id=tree.id,
+                    user_id=schedule.created_by,
+                    tree_snapshot=tree_snapshot,
+                    path_taken=[],
+                    decisions=[],
+                    custom_steps=[],
+                    session_variables={},
+                    batch_id=batch_id,
+                    target_label=target.get("label", ""),
+                )
+                sessions_to_add.append(session)
+
+            for s in sessions_to_add:
+                db.add(s)
+
+            # Update schedule tracking
+            schedule.last_run_at = datetime.now(timezone.utc)
+            from croniter import croniter
+            tz = pytz.timezone(schedule.timezone)
+            now = datetime.now(tz)
+            cron = croniter(schedule.cron_expression, now)
+            schedule.next_run_at = cron.get_next(datetime).astimezone(timezone.utc)
+
+            await db.commit()
+            logger.info(
+                f"Schedule {schedule_id} fired: created {len(sessions_to_add)} sessions "
+                f"(batch {batch_id}) for tree '{tree.name}'"
+            )
+        except Exception:
+            logger.exception(f"Error firing maintenance schedule {schedule_id}")
+            await db.rollback()
+
+
+async def load_all_schedules(db: AsyncSession) -> None:
+    """Load all active schedules into APScheduler on startup."""
+    # Import all models to ensure SQLAlchemy mapper relationships resolve
+    # before any ORM queries are executed.
+    import app.models  # noqa: F401
+    from app.models.maintenance_schedule import MaintenanceSchedule
+    result = await db.execute(
+        select(MaintenanceSchedule).where(MaintenanceSchedule.is_active == True)
+    )
+    schedules = result.scalars().all()
+    for schedule in schedules:
+        register_schedule(schedule)
+    logger.info(f"Loaded {len(schedules)} active maintenance schedule(s)")
+
+
+def register_schedule(schedule) -> None:
+    """Register or update a schedule in APScheduler."""
+    job_id = f"maintenance_{schedule.id}"
+    try:
+        tz = pytz.timezone(schedule.timezone)
+        trigger = CronTrigger.from_crontab(schedule.cron_expression, timezone=tz)
+        scheduler.add_job(
+            _fire_maintenance_schedule,
+            trigger=trigger,
+            id=job_id,
+            args=[str(schedule.id)],
+            replace_existing=True,
+            misfire_grace_time=3600,
+        )
+        logger.info(f"Registered schedule {schedule.id} ({schedule.cron_expression})")
+    except Exception:
+        logger.exception(f"Failed to register schedule {schedule.id}")
+
+
+def unregister_schedule(schedule_id: str) -> None:
+    """Remove a schedule from APScheduler."""
+    job_id = f"maintenance_{schedule_id}"
+    if scheduler.get_job(job_id):
+        try:
+            scheduler.remove_job(job_id)
+            logger.info(f"Unregistered schedule {schedule_id}")
+        except (SchedulerNotRunningError, JobLookupError):
+            logger.warning(f"Could not remove job {job_id}: scheduler not running or job already removed")

backend/app/core/tree_validation.py

@@ -1,6 +1,8 @@
 """Tree validation helper module for draft/published workflow."""
 from typing import Any
 
+PROCEDURAL_TREE_TYPES = {"procedural", "maintenance"}
+
 
 class TreeValidationError(Exception):
     """Custom exception for tree validation errors."""
@@ -224,14 +226,14 @@ def can_publish_tree(
         errors.append({"field": "name", "message": "Tree must have a name to be published"})
 
     # Validate structure based on tree type
-    if tree_type == "procedural":
+    if tree_type in PROCEDURAL_TREE_TYPES:
         structure_valid, structure_errors = validate_procedural_structure(tree_structure)
     else:
         structure_valid, structure_errors = validate_tree_structure(tree_structure)
     errors.extend(structure_errors)
 
     # Validate intake form if present (procedural only)
-    if intake_form and tree_type == "procedural":
+    if intake_form and tree_type in PROCEDURAL_TREE_TYPES:
         form_valid, form_errors = _validate_intake_form(intake_form)
         errors.extend(form_errors)
 

backend/app/main.py

@@ -6,11 +6,12 @@ from slowapi import _rate_limit_exceeded_handler
 from slowapi.errors import RateLimitExceeded
 
 from app.core.config import settings
-from app.core.database import init_db
+from app.core.database import init_db, async_session_maker
 from app.core.logging_config import setup_logging
 from app.core.middleware import RequestLoggingMiddleware, ErrorLoggingMiddleware
 from app.core.rate_limit import limiter
 from app.api.router import api_router
+from app.core.scheduler import scheduler, load_all_schedules
 
 # Initialize logging configuration
 setup_logging()
@@ -26,8 +27,16 @@ async def lifespan(app: FastAPI):
     logger.info(f"ALLOW_RAILWAY_ORIGINS: {settings.ALLOW_RAILWAY_ORIGINS}")
     # Note: In production, use Alembic migrations instead of init_db
     # await init_db()
+
+    # Start maintenance schedule runner
+    scheduler.start()
+    async with async_session_maker() as db:
+        await load_all_schedules(db)
+
     yield
+
     # Shutdown
+    scheduler.shutdown(wait=False)
     logger.info("Shutting down ResolutionFlow API server...")
 
 

backend/app/models/__init__.py

@@ -5,6 +5,7 @@ from .subscription import Subscription
 from .plan_limits import PlanLimits
 from .account_invite import AccountInvite
 from .tree import Tree
+from .tree_share import TreeShare
 from .session import Session
 from .attachment import Attachment
 from .invite_code import InviteCode
@@ -22,6 +23,8 @@ from .account_limit_override import AccountLimitOverride
 from .feature_flag import FeatureFlag, PlanFeatureDefault, AccountFeatureOverride
 from .platform_setting import PlatformSetting
 from .user_pinned_tree import UserPinnedTree
+from .target_list import TargetList
+from .maintenance_schedule import MaintenanceSchedule
 
 __all__ = [
     "User",
@@ -31,6 +34,7 @@ __all__ = [
     "PlanLimits",
     "AccountInvite",
     "Tree",
+    "TreeShare",
     "Session",
     "Attachment",
     "InviteCode",
@@ -55,4 +59,6 @@ __all__ = [
     "AccountFeatureOverride",
     "PlatformSetting",
     "UserPinnedTree",
+    "TargetList",
+    "MaintenanceSchedule",
 ]

backend/app/models/maintenance_schedule.py

@@ -0,0 +1,45 @@
+import uuid
+from datetime import datetime, timezone
+from typing import Optional
+from sqlalchemy import String, DateTime, ForeignKey, Boolean, UniqueConstraint
+from sqlalchemy.orm import Mapped, mapped_column
+from sqlalchemy.dialects.postgresql import UUID
+from app.core.database import Base
+
+
+class MaintenanceSchedule(Base):
+    __tablename__ = "maintenance_schedules"
+    __table_args__ = (
+        UniqueConstraint("tree_id", name="uq_maintenance_schedules_tree_id"),
+    )
+
+    id: Mapped[uuid.UUID] = mapped_column(
+        UUID(as_uuid=True), primary_key=True, default=uuid.uuid4
+    )
+    tree_id: Mapped[uuid.UUID] = mapped_column(
+        UUID(as_uuid=True), ForeignKey("trees.id", ondelete="CASCADE"),
+        nullable=False, index=True
+    )
+    created_by: Mapped[Optional[uuid.UUID]] = mapped_column(
+        UUID(as_uuid=True), ForeignKey("users.id", ondelete="SET NULL"), nullable=True
+    )
+    cron_expression: Mapped[str] = mapped_column(String(100), nullable=False)
+    timezone: Mapped[str] = mapped_column(String(100), nullable=False, default="UTC")
+    target_list_id: Mapped[Optional[uuid.UUID]] = mapped_column(
+        UUID(as_uuid=True), ForeignKey("target_lists.id", ondelete="SET NULL"), nullable=True
+    )
+    is_active: Mapped[bool] = mapped_column(Boolean, nullable=False, default=True)
+    next_run_at: Mapped[Optional[datetime]] = mapped_column(
+        DateTime(timezone=True), nullable=True
+    )
+    last_run_at: Mapped[Optional[datetime]] = mapped_column(
+        DateTime(timezone=True), nullable=True
+    )
+    created_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), default=lambda: datetime.now(timezone.utc)
+    )
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True),
+        default=lambda: datetime.now(timezone.utc),
+        onupdate=lambda: datetime.now(timezone.utc),
+    )

backend/app/models/session.py

@@ -65,3 +65,11 @@ class Session(Base):
     user: Mapped["User"] = relationship("User", back_populates="sessions")
     attachments: Mapped[list["Attachment"]] = relationship("Attachment", back_populates="session")
     shares: Mapped[list["SessionShare"]] = relationship("SessionShare", back_populates="session", cascade="all, delete-orphan")
+
+    # Batch tracking (maintenance flows)
+    batch_id: Mapped[Optional[uuid.UUID]] = mapped_column(
+        UUID(as_uuid=True), nullable=True, index=True
+    )
+    target_label: Mapped[Optional[str]] = mapped_column(
+        String(255), nullable=True
+    )

backend/app/models/target_list.py

@@ -0,0 +1,38 @@
+import uuid
+from datetime import datetime, timezone
+from typing import Optional, TYPE_CHECKING
+from sqlalchemy import String, Text, DateTime, ForeignKey
+from sqlalchemy.orm import Mapped, mapped_column
+from sqlalchemy.dialects.postgresql import UUID, JSONB
+from app.core.database import Base
+
+if TYPE_CHECKING:
+    from app.models.user import User
+    from app.models.team import Team
+
+
+class TargetList(Base):
+    __tablename__ = "target_lists"
+
+    id: Mapped[uuid.UUID] = mapped_column(
+        UUID(as_uuid=True), primary_key=True, default=uuid.uuid4
+    )
+    team_id: Mapped[uuid.UUID] = mapped_column(
+        UUID(as_uuid=True), ForeignKey("teams.id", ondelete="CASCADE"),
+        nullable=False, index=True
+    )
+    created_by: Mapped[Optional[uuid.UUID]] = mapped_column(
+        UUID(as_uuid=True), ForeignKey("users.id", ondelete="SET NULL"), nullable=True
+    )
+    name: Mapped[str] = mapped_column(String(255), nullable=False)
+    description: Mapped[Optional[str]] = mapped_column(Text, nullable=True)
+    # targets: [{"label": "RDS-01", "notes": "optional notes"}, ...]
+    targets: Mapped[list] = mapped_column(JSONB, nullable=False, default=list)
+    created_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), default=lambda: datetime.now(timezone.utc)
+    )
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True),
+        default=lambda: datetime.now(timezone.utc),
+        onupdate=lambda: datetime.now(timezone.utc),
+    )

backend/app/models/tree.py

@@ -29,7 +29,7 @@ class Tree(Base):
             name='ck_trees_status'
         ),
         CheckConstraint(
-            "tree_type IN ('troubleshooting', 'procedural')",
+            "tree_type IN ('troubleshooting', 'procedural', 'maintenance')",
             name='ck_trees_tree_type'
         ),
     )

backend/app/schemas/maintenance_schedule.py

@@ -0,0 +1,34 @@
+from datetime import datetime
+from typing import Optional
+from uuid import UUID
+from pydantic import BaseModel, Field
+
+
+class MaintenanceScheduleCreate(BaseModel):
+    tree_id: UUID
+    cron_expression: str = Field(..., min_length=9, max_length=100)
+    timezone: str = Field("UTC", max_length=100)
+    target_list_id: Optional[UUID] = None
+
+
+class MaintenanceScheduleUpdate(BaseModel):
+    cron_expression: Optional[str] = Field(None, min_length=9, max_length=100)
+    timezone: Optional[str] = Field(None, max_length=100)
+    target_list_id: Optional[UUID] = None
+    is_active: Optional[bool] = None
+
+
+class MaintenanceScheduleResponse(BaseModel):
+    id: UUID
+    tree_id: UUID
+    created_by: Optional[UUID]
+    cron_expression: str
+    timezone: str
+    target_list_id: Optional[UUID]
+    is_active: bool
+    next_run_at: Optional[datetime]
+    last_run_at: Optional[datetime]
+    created_at: datetime
+    updated_at: datetime
+
+    model_config = {"from_attributes": True}

backend/app/schemas/session.py

@@ -78,6 +78,9 @@ class SessionResponse(BaseModel):
     def normalize_text_fields(cls, v):
         return v or ""
 
+    batch_id: Optional[UUID] = None
+    target_label: Optional[str] = None
+
     class Config:
         from_attributes = True
 

backend/app/schemas/target_list.py

@@ -0,0 +1,34 @@
+from datetime import datetime
+from typing import Optional
+from uuid import UUID
+from pydantic import BaseModel, Field
+
+
+class TargetEntry(BaseModel):
+    label: str = Field(..., min_length=1, max_length=255)
+    notes: Optional[str] = Field(None, max_length=500)
+
+
+class TargetListCreate(BaseModel):
+    name: str = Field(..., min_length=1, max_length=255)
+    description: Optional[str] = None
+    targets: list[TargetEntry] = Field(..., min_length=1)
+
+
+class TargetListUpdate(BaseModel):
+    name: Optional[str] = Field(None, min_length=1, max_length=255)
+    description: Optional[str] = None
+    targets: Optional[list[TargetEntry]] = Field(None, min_length=1)
+
+
+class TargetListResponse(BaseModel):
+    id: UUID
+    team_id: UUID
+    created_by: Optional[UUID]
+    name: str
+    description: Optional[str]
+    targets: list[TargetEntry]
+    created_at: datetime
+    updated_at: datetime
+
+    model_config = {"from_attributes": True}

backend/app/schemas/tree.py

@@ -7,7 +7,7 @@ import re
 
 # --- Tree Type ---
 
-TreeType = Literal['troubleshooting', 'procedural']
+TreeType = Literal['troubleshooting', 'procedural', 'maintenance']
 
 # --- Intake Form Schemas ---
 

backend/requirements.txt

@@ -30,3 +30,6 @@ resend==2.21.0
 
 # Utilities
 python-dotenv==1.0.1
+croniter>=2.0.0
+pytz>=2024.1
+apscheduler>=3.10.4

backend/tests/test_batch_sessions.py

@@ -0,0 +1,132 @@
+"""Tests for batch session launching (maintenance flows)."""
+import pytest
+from httpx import AsyncClient
+
+
+async def _create_maintenance_tree(client, headers):
+    """Helper: create a published maintenance tree."""
+    resp = await client.post(
+        "/api/v1/trees",
+        json={
+            "name": "Patch RDS Servers",
+            "tree_type": "maintenance",
+            "tree_structure": {
+                "steps": [
+                    {"id": "s1", "type": "procedure_step", "title": "Install patch",
+                     "description": "Run installer", "content_type": "action"},
+                    {"id": "end", "type": "procedure_end", "title": "Done"},
+                ]
+            },
+        },
+        headers=headers,
+    )
+    assert resp.status_code == 201, resp.text
+    return resp.json()["id"]
+
+
+@pytest.mark.asyncio
+async def test_batch_launch_creates_one_session_per_target(client: AsyncClient, auth_headers: dict):
+    tree_id = await _create_maintenance_tree(client, auth_headers)
+    resp = await client.post(
+        "/api/v1/sessions/batch",
+        json={
+            "tree_id": tree_id,
+            "targets": [
+                {"label": "RDS-01"},
+                {"label": "RDS-02"},
+                {"label": "RDS-03"},
+            ],
+        },
+        headers=auth_headers,
+    )
+    assert resp.status_code == 201, resp.text
+    data = resp.json()
+    assert data["count"] == 3
+    assert data["batch_id"] is not None
+    sessions = data["sessions"]
+    assert len(sessions) == 3
+    # All share the same batch_id
+    batch_ids = {s["batch_id"] for s in sessions}
+    assert len(batch_ids) == 1
+    # Each has a distinct target_label
+    labels = {s["target_label"] for s in sessions}
+    assert labels == {"RDS-01", "RDS-02", "RDS-03"}
+
+
+@pytest.mark.asyncio
+async def test_batch_launch_rejects_empty_targets(client: AsyncClient, auth_headers: dict):
+    tree_id = await _create_maintenance_tree(client, auth_headers)
+    resp = await client.post(
+        "/api/v1/sessions/batch",
+        json={"tree_id": tree_id, "targets": []},
+        headers=auth_headers,
+    )
+    assert resp.status_code == 422
+
+
+@pytest.mark.asyncio
+async def test_batch_launch_rejects_non_maintenance_tree(client: AsyncClient, auth_headers: dict):
+    """Batch launch only works for maintenance flows."""
+    # Create a procedural tree
+    resp = await client.post(
+        "/api/v1/trees",
+        json={
+            "name": "Regular Project",
+            "tree_type": "procedural",
+            "tree_structure": {
+                "steps": [
+                    {"id": "s1", "type": "procedure_step", "title": "Step",
+                     "description": "Do it", "content_type": "action"},
+                    {"id": "end", "type": "procedure_end", "title": "Done"},
+                ]
+            },
+        },
+        headers=auth_headers,
+    )
+    tree_id = resp.json()["id"]
+    batch_resp = await client.post(
+        "/api/v1/sessions/batch",
+        json={"tree_id": tree_id, "targets": [{"label": "SRV-01"}]},
+        headers=auth_headers,
+    )
+    assert batch_resp.status_code == 400
+
+
+@pytest.mark.asyncio
+async def test_batch_launch_requires_auth(client: AsyncClient):
+    """Unauthenticated batch launch returns 401."""
+    resp = await client.post(
+        "/api/v1/sessions/batch",
+        json={"tree_id": "00000000-0000-0000-0000-000000000000", "targets": [{"label": "SRV-01"}]},
+    )
+    assert resp.status_code == 401
+
+
+@pytest.mark.asyncio
+async def test_batch_launch_rejects_draft_tree(client: AsyncClient, auth_headers: dict):
+    """Batch launch against a draft maintenance tree returns 400."""
+    # Create a maintenance tree — trees default to 'published', so we explicitly set draft
+    resp = await client.post(
+        "/api/v1/trees",
+        json={
+            "name": "Draft Maintenance",
+            "tree_type": "maintenance",
+            "status": "draft",
+            "tree_structure": {
+                "steps": [
+                    {"id": "s1", "type": "procedure_step", "title": "Step",
+                     "description": "Do it", "content_type": "action"},
+                    {"id": "end", "type": "procedure_end", "title": "Done"},
+                ]
+            },
+        },
+        headers=auth_headers,
+    )
+    assert resp.status_code == 201, resp.text
+    tree_id = resp.json()["id"]
+    batch_resp = await client.post(
+        "/api/v1/sessions/batch",
+        json={"tree_id": tree_id, "targets": [{"label": "SRV-01"}]},
+        headers=auth_headers,
+    )
+    assert batch_resp.status_code == 400

backend/tests/test_maintenance_schedules.py

@@ -0,0 +1,140 @@
+"""Tests for maintenance schedule CRUD."""
+import pytest
+from httpx import AsyncClient
+
+
+async def _create_maintenance_tree(client, headers):
+    resp = await client.post(
+        "/api/v1/trees",
+        json={
+            "name": "Scheduled Patch",
+            "tree_type": "maintenance",
+            "tree_structure": {
+                "steps": [
+                    {"id": "s1", "type": "procedure_step", "title": "Step",
+                     "description": "Do it", "content_type": "action"},
+                    {"id": "end", "type": "procedure_end", "title": "Done"},
+                ]
+            },
+        },
+        headers=headers,
+    )
+    assert resp.status_code == 201, resp.text
+    return resp.json()["id"]
+
+
+@pytest.mark.asyncio
+async def test_create_schedule(client: AsyncClient, auth_headers: dict):
+    tree_id = await _create_maintenance_tree(client, auth_headers)
+    resp = await client.post(
+        "/api/v1/maintenance-schedules",
+        json={
+            "tree_id": tree_id,
+            "cron_expression": "0 9 15 * *",
+            "timezone": "America/New_York",
+        },
+        headers=auth_headers,
+    )
+    assert resp.status_code == 201, resp.text
+    data = resp.json()
+    assert data["cron_expression"] == "0 9 15 * *"
+    assert data["timezone"] == "America/New_York"
+    assert data["is_active"] is True
+    assert data["next_run_at"] is not None
+
+
+@pytest.mark.asyncio
+async def test_duplicate_schedule_rejected(client: AsyncClient, auth_headers: dict):
+    """Cannot create two schedules for the same tree."""
+    tree_id = await _create_maintenance_tree(client, auth_headers)
+    await client.post(
+        "/api/v1/maintenance-schedules",
+        json={"tree_id": tree_id, "cron_expression": "0 0 1 * *", "timezone": "UTC"},
+        headers=auth_headers,
+    )
+    resp = await client.post(
+        "/api/v1/maintenance-schedules",
+        json={"tree_id": tree_id, "cron_expression": "0 6 1 * *", "timezone": "UTC"},
+        headers=auth_headers,
+    )
+    assert resp.status_code == 409
+
+
+@pytest.mark.asyncio
+async def test_get_schedule_for_tree(client: AsyncClient, auth_headers: dict):
+    tree_id = await _create_maintenance_tree(client, auth_headers)
+    await client.post(
+        "/api/v1/maintenance-schedules",
+        json={"tree_id": tree_id, "cron_expression": "0 0 1 * *", "timezone": "UTC"},
+        headers=auth_headers,
+    )
+    resp = await client.get(f"/api/v1/maintenance-schedules/tree/{tree_id}", headers=auth_headers)
+    assert resp.status_code == 200
+    assert resp.json()["cron_expression"] == "0 0 1 * *"
+
+
+@pytest.mark.asyncio
+async def test_disable_schedule(client: AsyncClient, auth_headers: dict):
+    tree_id = await _create_maintenance_tree(client, auth_headers)
+    create = await client.post(
+        "/api/v1/maintenance-schedules",
+        json={"tree_id": tree_id, "cron_expression": "0 6 * * 1", "timezone": "UTC"},
+        headers=auth_headers,
+    )
+    sched_id = create.json()["id"]
+    resp = await client.patch(
+        f"/api/v1/maintenance-schedules/{sched_id}",
+        json={"is_active": False},
+        headers=auth_headers,
+    )
+    assert resp.status_code == 200
+    assert resp.json()["is_active"] is False
+
+
+@pytest.mark.asyncio
+async def test_get_schedule_not_found(client: AsyncClient, auth_headers: dict):
+    tree_id = await _create_maintenance_tree(client, auth_headers)
+    resp = await client.get(f"/api/v1/maintenance-schedules/tree/{tree_id}", headers=auth_headers)
+    assert resp.status_code == 404
+
+
+@pytest.mark.asyncio
+async def test_cannot_schedule_other_teams_tree(client: AsyncClient, auth_headers: dict, test_db):
+    """User cannot create a schedule for a tree belonging to another team."""
+    import uuid as _uuid
+    from app.models.team import Team
+    from app.models.tree import Tree
+
+    # Create a tree belonging to a DIFFERENT team directly in DB
+    other_team = Team(name=f"Other Team {_uuid.uuid4()}")
+    test_db.add(other_team)
+    await test_db.flush()
+
+    other_tree = Tree(
+        name="Other Team Tree",
+        tree_type="maintenance",
+        team_id=other_team.id,
+        tree_structure={
+            "steps": [
+                {"id": "s1", "type": "procedure_step", "title": "Step",
+                 "description": "Do it", "content_type": "action"},
+                {"id": "end", "type": "procedure_end", "title": "Done"},
+            ]
+        },
+        status="published",
+        visibility="team",
+    )
+    test_db.add(other_tree)
+    await test_db.flush()
+
+    # Current user (from auth_headers) tries to schedule it
+    resp = await client.post(
+        "/api/v1/maintenance-schedules",
+        json={
+            "tree_id": str(other_tree.id),
+            "cron_expression": "0 9 1 * *",
+            "timezone": "UTC",
+        },
+        headers=auth_headers,
+    )
+    assert resp.status_code in (403, 404)  # either is acceptable

backend/tests/test_maintenance_tree_type.py

@@ -0,0 +1,73 @@
+"""Tests for maintenance tree type."""
+import pytest
+from httpx import AsyncClient
+
+
+@pytest.mark.asyncio
+async def test_create_maintenance_tree(client: AsyncClient, auth_headers: dict):
+    """Maintenance tree type is accepted by the API."""
+    resp = await client.post(
+        "/api/v1/trees",
+        json={
+            "name": "Update FSLogix",
+            "description": "Monthly FSLogix update procedure",
+            "tree_type": "maintenance",
+            "tree_structure": {
+                "steps": [
+                    {"id": "step-1", "type": "procedure_step", "title": "Download installer",
+                     "description": "Get latest FSLogix from Microsoft", "content_type": "action"},
+                    {"id": "step-end", "type": "procedure_end", "title": "Complete"},
+                ]
+            },
+        },
+        headers=auth_headers,
+    )
+    assert resp.status_code == 201, resp.text
+    data = resp.json()
+    assert data["tree_type"] == "maintenance"
+
+
+@pytest.mark.asyncio
+async def test_list_maintenance_trees_filter(client: AsyncClient, auth_headers: dict):
+    """Filtering by tree_type=maintenance returns only maintenance trees."""
+    await client.post(
+        "/api/v1/trees",
+        json={
+            "name": "Maintenance Only",
+            "tree_type": "maintenance",
+            "tree_structure": {
+                "steps": [
+                    {"id": "s1", "type": "procedure_step", "title": "Step",
+                     "description": "Do it", "content_type": "action"},
+                    {"id": "end", "type": "procedure_end", "title": "Done"},
+                ]
+            },
+        },
+        headers=auth_headers,
+    )
+    resp = await client.get("/api/v1/trees?tree_type=maintenance", headers=auth_headers)
+    assert resp.status_code == 200
+    trees = resp.json()
+    assert all(t["tree_type"] == "maintenance" for t in trees)
+    assert len(trees) >= 1
+
+
+@pytest.mark.asyncio
+async def test_invalid_tree_type_rejected(client: AsyncClient, auth_headers: dict):
+    """An unrecognized tree_type value is rejected with 422."""
+    resp = await client.post(
+        "/api/v1/trees",
+        json={
+            "name": "Bad Type",
+            "tree_type": "garbage",
+            "tree_structure": {
+                "steps": [
+                    {"id": "s1", "type": "procedure_step", "title": "Step",
+                     "description": "Do it", "content_type": "action"},
+                    {"id": "end", "type": "procedure_end", "title": "Done"},
+                ]
+            },
+        },
+        headers=auth_headers,
+    )
+    assert resp.status_code == 422

backend/tests/test_target_lists.py

@@ -0,0 +1,153 @@
+"""Tests for target lists CRUD."""
+import pytest
+from httpx import AsyncClient
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.models.team import Team
+from app.models.user import User
+from sqlalchemy import select
+
+
+@pytest.fixture
+async def auth_headers(client: AsyncClient, test_db: AsyncSession, test_user: dict):
+    """Override auth_headers to ensure the test user has a team_id assigned."""
+    # Fetch the user from DB and assign a team
+    result = await test_db.execute(select(User).where(User.email == test_user["email"]))
+    user = result.scalar_one()
+
+    # Create a team and assign the user to it
+    team = Team(name="Test Team")
+    test_db.add(team)
+    await test_db.flush()
+
+    user.team_id = team.id
+    await test_db.commit()
+
+    # Re-login to get a fresh token
+    login_data = {
+        "email": test_user["email"],
+        "password": test_user["password"],
+    }
+    resp = await client.post("/api/v1/auth/login/json", json=login_data)
+    assert resp.status_code == 200
+    token_data = resp.json()
+    return {"Authorization": f"Bearer {token_data['access_token']}"}
+
+
+@pytest.mark.asyncio
+async def test_create_target_list(client: AsyncClient, auth_headers: dict):
+    resp = await client.post(
+        "/api/v1/target-lists/",
+        json={
+            "name": "RDS Farm A",
+            "description": "Production RDS servers",
+            "targets": [
+                {"label": "RDS-01", "notes": "192.168.1.10"},
+                {"label": "RDS-02", "notes": "192.168.1.11"},
+            ],
+        },
+        headers=auth_headers,
+    )
+    assert resp.status_code == 201, resp.text
+    data = resp.json()
+    assert data["name"] == "RDS Farm A"
+    assert len(data["targets"]) == 2
+
+
+@pytest.mark.asyncio
+async def test_list_target_lists(client: AsyncClient, auth_headers: dict):
+    resp = await client.get("/api/v1/target-lists/", headers=auth_headers)
+    assert resp.status_code == 200
+    assert isinstance(resp.json(), list)
+
+
+@pytest.mark.asyncio
+async def test_get_target_list(client: AsyncClient, auth_headers: dict):
+    create = await client.post(
+        "/api/v1/target-lists/",
+        json={"name": "Get Test", "targets": [{"label": "SRV-01"}]},
+        headers=auth_headers,
+    )
+    list_id = create.json()["id"]
+    resp = await client.get(f"/api/v1/target-lists/{list_id}", headers=auth_headers)
+    assert resp.status_code == 200
+    assert resp.json()["name"] == "Get Test"
+
+
+@pytest.mark.asyncio
+async def test_update_target_list(client: AsyncClient, auth_headers: dict):
+    create = await client.post(
+        "/api/v1/target-lists/",
+        json={"name": "Old Name", "targets": [{"label": "SRV-01"}]},
+        headers=auth_headers,
+    )
+    list_id = create.json()["id"]
+    resp = await client.put(
+        f"/api/v1/target-lists/{list_id}",
+        json={"name": "New Name", "targets": [{"label": "SRV-01"}, {"label": "SRV-02"}]},
+        headers=auth_headers,
+    )
+    assert resp.status_code == 200
+    assert resp.json()["name"] == "New Name"
+    assert len(resp.json()["targets"]) == 2
+
+
+@pytest.mark.asyncio
+async def test_delete_target_list(client: AsyncClient, auth_headers: dict):
+    create = await client.post(
+        "/api/v1/target-lists/",
+        json={"name": "To Delete", "targets": [{"label": "X"}]},
+        headers=auth_headers,
+    )
+    list_id = create.json()["id"]
+    resp = await client.delete(f"/api/v1/target-lists/{list_id}", headers=auth_headers)
+    assert resp.status_code == 204
+
+    get = await client.get(f"/api/v1/target-lists/{list_id}", headers=auth_headers)
+    assert get.status_code == 404
+
+@pytest.mark.asyncio
+async def test_cannot_access_other_teams_list(client: AsyncClient, auth_headers: dict, test_db):
+    """User from team B cannot access team A's list."""
+    import uuid
+    from app.models.team import Team
+    from app.models.user import User
+    from app.core.security import get_password_hash
+
+    # Create team A list using existing auth_headers
+    create = await client.post(
+        "/api/v1/target-lists/",
+        json={"name": "Team A List", "targets": [{"label": "SRV-A"}]},
+        headers=auth_headers,
+    )
+    assert create.status_code == 201
+    list_id = create.json()["id"]
+
+    # Create a separate team B with its own user
+    team_b = Team(name=f"Team B {uuid.uuid4()}")
+    test_db.add(team_b)
+    await test_db.flush()
+
+    user_b = User(
+        email=f"userb_{uuid.uuid4()}@test.com",
+        password_hash=get_password_hash("password123"),
+        name="User B",
+        is_active=True,
+        team_id=team_b.id,
+        role="engineer",
+    )
+    test_db.add(user_b)
+    await test_db.flush()
+
+    # Get auth token for user B
+    login = await client.post(
+        "/api/v1/auth/login/json",
+        json={"email": user_b.email, "password": "password123"},
+    )
+    assert login.status_code == 200
+    token_b = login.json()["access_token"]
+    headers_b = {"Authorization": f"Bearer {token_b}"}
+
+    # Team B cannot access Team A's list
+    resp = await client.get(f"/api/v1/target-lists/{list_id}", headers=headers_b)
+    assert resp.status_code == 404

frontend/src/api/index.ts

@@ -13,3 +13,5 @@ export { default as adminApi } from './admin'
 export { treeMarkdownApi } from './treeMarkdown'
 export { default as pinnedFlowsApi } from './pinnedFlows'
 export { default as analyticsApi } from './analytics'
+export { targetListsApi } from './targetLists'
+export { maintenanceSchedulesApi, batchLaunchApi } from './maintenanceSchedules'

frontend/src/api/maintenanceSchedules.ts

@@ -0,0 +1,24 @@
+import { apiClient } from './client'
+import type {
+  MaintenanceSchedule,
+  MaintenanceScheduleCreate,
+  MaintenanceScheduleUpdate,
+  BatchLaunchRequest,
+  BatchLaunchResponse,
+} from '@/types'
+
+export const maintenanceSchedulesApi = {
+  getForTree: (treeId: string): Promise<MaintenanceSchedule> =>
+    apiClient.get(`/maintenance-schedules/tree/${treeId}`).then(r => r.data),
+
+  create: (data: MaintenanceScheduleCreate): Promise<MaintenanceSchedule> =>
+    apiClient.post('/maintenance-schedules', data).then(r => r.data),
+
+  update: (id: string, data: MaintenanceScheduleUpdate): Promise<MaintenanceSchedule> =>
+    apiClient.patch(`/maintenance-schedules/${id}`, data).then(r => r.data),
+}
+
+export const batchLaunchApi = {
+  launch: (data: BatchLaunchRequest): Promise<BatchLaunchResponse> =>
+    apiClient.post('/sessions/batch', data).then(r => r.data),
+}

frontend/src/api/targetLists.ts

@@ -0,0 +1,19 @@
+import { apiClient } from './client'
+import type { TargetList, TargetListCreate } from '@/types'
+
+export const targetListsApi = {
+  list: (): Promise<TargetList[]> =>
+    apiClient.get('/target-lists/').then(r => r.data),
+
+  get: (id: string): Promise<TargetList> =>
+    apiClient.get(`/target-lists/${id}`).then(r => r.data),
+
+  create: (data: TargetListCreate): Promise<TargetList> =>
+    apiClient.post('/target-lists/', data).then(r => r.data),
+
+  update: (id: string, data: Partial<TargetListCreate>): Promise<TargetList> =>
+    apiClient.put(`/target-lists/${id}`, data).then(r => r.data),
+
+  delete: (id: string): Promise<void> =>
+    apiClient.delete(`/target-lists/${id}`).then(() => undefined),
+}

frontend/src/components/layout/Sidebar.tsx

@@ -29,7 +29,7 @@ export function Sidebar() {
   const [activeTags, setActiveTags] = useState<string[]>([])
   const [activeSessionCount, setActiveSessionCount] = useState(0)
   const [pinnedFlows, setPinnedFlows] = useState<PinnedFlow[]>([])
-  const [treeCounts, setTreeCounts] = useState({ total: 0, troubleshooting: 0, procedural: 0 })
+  const [treeCounts, setTreeCounts] = useState({ total: 0, troubleshooting: 0, procedural: 0, maintenance: 0 })
 
   // Fetch sidebar data on mount
   useEffect(() => {
@@ -55,7 +55,8 @@ export function Sidebar() {
         const total = allTrees.length
         const troubleshooting = allTrees.filter(t => t.tree_type === 'troubleshooting').length
         const procedural = allTrees.filter(t => t.tree_type === 'procedural').length
-        setTreeCounts({ total, troubleshooting, procedural })
+        const maintenance = allTrees.filter(t => t.tree_type === 'maintenance').length
+        setTreeCounts({ total, troubleshooting, procedural, maintenance })
       } catch {
         // Silently handle errors
       }
@@ -145,6 +146,7 @@ export function Sidebar() {
               children={[
                 { href: '/trees?type=troubleshooting', label: 'Troubleshooting', count: treeCounts.troubleshooting || undefined },
                 { href: '/trees?type=procedural', label: 'Projects', count: treeCounts.procedural || undefined },
+                { href: '/trees?type=maintenance', label: 'Maintenance', count: treeCounts.maintenance || undefined },
               ]}
             />
             <NavItem href="/my-trees" icon={PenLine} label="Flow Editor" />

frontend/src/components/library/TreeGridView.tsx

@@ -1,5 +1,5 @@
 import { Link } from 'react-router-dom'
-import { Pencil, Globe, Lock, Trash2, GitBranch, FileText } from 'lucide-react'
+import { Pencil, Globe, Lock, Trash2, GitBranch, FileText, Wrench } from 'lucide-react'
 import type { TreeListItem } from '@/types'
 import { TagBadges } from '@/components/common/TagBadges'
 import { AddToFolderMenu } from './AddToFolderMenu'
@@ -41,6 +41,12 @@ export function TreeGridView({
                   Draft
                 </span>
               )}
+              {tree.tree_type === 'maintenance' && (
+                <span className="inline-flex items-center gap-1 rounded-full border border-amber-500/30 bg-amber-500/10 px-2 py-0.5 font-label text-[0.625rem] uppercase tracking-wide text-amber-400">
+                  <Wrench className="h-3 w-3" />
+                  Maintenance
+                </span>
+              )}
             </div>
             <div className="flex items-center gap-2">
               {tree.is_public ? (

frontend/src/components/library/TreeListView.tsx

@@ -1,5 +1,5 @@
 import { Link } from 'react-router-dom'
-import { Pencil, Globe, Lock, GitBranch, FileText, Trash2 } from 'lucide-react'
+import { Pencil, Globe, Lock, GitBranch, FileText, Trash2, Wrench } from 'lucide-react'
 import type { TreeListItem } from '@/types'
 import { TagBadges } from '@/components/common/TagBadges'
 import { AddToFolderMenu } from './AddToFolderMenu'
@@ -42,6 +42,12 @@ export function TreeListView({
                   Draft
                 </span>
               )}
+              {tree.tree_type === 'maintenance' && (
+                <span className="inline-flex items-center gap-1 rounded-full border border-amber-500/30 bg-amber-500/10 px-2 py-0.5 font-label text-[0.625rem] uppercase tracking-wide text-amber-400 flex-shrink-0">
+                  <Wrench className="h-3 w-3" />
+                  Maintenance
+                </span>
+              )}
               {tree.is_public ? (
                 <span title="Public tree">
                   <Globe className="h-3.5 w-3.5 text-muted-foreground flex-shrink-0" />

frontend/src/components/library/TreeTableView.tsx

@@ -1,6 +1,6 @@
 import { useState } from 'react'
 import { Link } from 'react-router-dom'
-import { Pencil, Globe, Lock, ChevronUp, ChevronDown, GitBranch, FileText, Trash2 } from 'lucide-react'
+import { Pencil, Globe, Lock, ChevronUp, ChevronDown, GitBranch, FileText, Trash2, Wrench } from 'lucide-react'
 import type { TreeListItem } from '@/types'
 import { TagBadges } from '@/components/common/TagBadges'
 import { AddToFolderMenu } from './AddToFolderMenu'
@@ -144,6 +144,12 @@ export function TreeTableView({
                       Draft
                     </span>
                   )}
+                  {tree.tree_type === 'maintenance' && (
+                    <span className="inline-flex items-center gap-1 rounded-full border border-amber-500/30 bg-amber-500/10 px-2 py-0.5 font-label text-[0.625rem] uppercase tracking-wide text-amber-400 flex-shrink-0">
+                      <Wrench className="h-3 w-3" />
+                      Maintenance
+                    </span>
+                  )}
                   {tree.is_public ? (
                     <span title="Public tree">
                       <Globe className="h-3.5 w-3.5 text-muted-foreground flex-shrink-0" />

frontend/src/components/maintenance/BatchLaunchModal.tsx

@@ -0,0 +1,202 @@
+import { useState, useEffect } from 'react'
+import { X, List, Clock, PenLine, ExternalLink } from 'lucide-react'
+import { cn } from '@/lib/utils'
+import { toast } from '@/lib/toast'
+import { targetListsApi, batchLaunchApi } from '@/api'
+import type { TargetList, TargetEntry } from '@/types'
+
+interface BatchLaunchModalProps {
+  treeId: string
+  treeName: string
+  onClose: () => void
+  onLaunched: (batchId: string, count: number) => void
+}
+
+type TabId = 'manual' | 'saved' | 'previous' | 'psa'
+
+export function BatchLaunchModal({ treeId, treeName, onClose, onLaunched }: BatchLaunchModalProps) {
+  const [activeTab, setActiveTab] = useState<TabId>('manual')
+  const [savedLists, setSavedLists] = useState<TargetList[] | null>(null)
+  const [selectedListId, setSelectedListId] = useState<string | null>(null)
+  const [manualInput, setManualInput] = useState('')
+  const [isLaunching, setIsLaunching] = useState(false)
+
+  useEffect(() => {
+    if (activeTab === 'saved' && savedLists === null) {
+      targetListsApi.list()
+        .then(setSavedLists)
+        .catch(() => toast.error('Failed to load saved lists'))
+    }
+  }, [activeTab, savedLists])
+
+  const getTargets = (): TargetEntry[] => {
+    if (activeTab === 'saved' && selectedListId && savedLists) {
+      const list = savedLists.find(l => l.id === selectedListId)
+      return list?.targets ?? []
+    }
+    if (activeTab === 'manual') {
+      return manualInput
+        .split('\n')
+        .map(l => l.trim())
+        .filter(Boolean)
+        .map(label => ({ label }))
+    }
+    return []
+  }
+
+  const targets = getTargets()
+
+  const handleLaunch = async () => {
+    if (targets.length === 0) {
+      toast.error('Add at least one target before launching')
+      return
+    }
+    if (targets.length > 100) {
+      toast.error('Maximum 100 targets per batch')
+      return
+    }
+    setIsLaunching(true)
+    try {
+      const result = await batchLaunchApi.launch({ tree_id: treeId, targets })
+      toast.success(`${result.count} sessions created`)
+      onLaunched(result.batch_id, result.count)
+    } catch {
+      toast.error('Failed to launch batch')
+    } finally {
+      setIsLaunching(false)
+    }
+  }
+
+  const tabs: { id: TabId; label: string; icon: React.ReactNode }[] = [
+    { id: 'manual', label: 'Manual Entry', icon: <PenLine className="h-3.5 w-3.5" /> },
+    { id: 'saved', label: 'Saved List', icon: <List className="h-3.5 w-3.5" /> },
+    { id: 'previous', label: 'Previous Run', icon: <Clock className="h-3.5 w-3.5" /> },
+    { id: 'psa', label: 'PSA / RMM', icon: <ExternalLink className="h-3.5 w-3.5" /> },
+  ]
+
+  return (
+    <div className="fixed inset-0 z-50 flex items-center justify-center bg-black/60 backdrop-blur-sm">
+      <div className="w-full max-w-lg rounded-xl border border-border bg-card shadow-2xl">
+        {/* Header */}
+        <div className="flex items-center justify-between border-b border-border px-6 py-4">
+          <div>
+            <h2 className="text-base font-semibold text-foreground">Batch Launch</h2>
+            <p className="text-[0.8125rem] text-muted-foreground">{treeName}</p>
+          </div>
+          <button onClick={onClose} className="rounded-lg p-1.5 text-muted-foreground hover:bg-accent hover:text-foreground">
+            <X className="h-4 w-4" />
+          </button>
+        </div>
+
+        {/* Tabs */}
+        <div className="flex border-b border-border px-4 pt-2">
+          {tabs.map(tab => (
+            <button
+              key={tab.id}
+              onClick={() => setActiveTab(tab.id)}
+              className={cn(
+                "flex items-center gap-1.5 px-3 py-2 font-label text-[0.6875rem] uppercase tracking-wide transition-colors",
+                activeTab === tab.id
+                  ? "border-b-2 border-primary text-foreground"
+                  : "text-muted-foreground hover:text-foreground"
+              )}
+            >
+              {tab.icon}
+              {tab.label}
+            </button>
+          ))}
+        </div>
+
+        {/* Content */}
+        <div className="p-6">
+          {activeTab === 'manual' && (
+            <div className="space-y-2">
+              <label className="font-label text-[0.6875rem] uppercase tracking-wide text-muted-foreground">
+                Server names (one per line)
+              </label>
+              <textarea
+                className="h-40 w-full rounded-lg border border-border bg-card px-3 py-2 text-[0.875rem] text-foreground placeholder:text-muted-foreground focus:border-primary focus:outline-none focus:ring-1 focus:ring-primary/20"
+                placeholder={"RDS-01\nRDS-02\nRDS-03"}
+                value={manualInput}
+                onChange={e => setManualInput(e.target.value)}
+              />
+            </div>
+          )}
+
+          {activeTab === 'saved' && (
+            <div className="space-y-2">
+              {savedLists === null ? (
+                <div className="flex h-24 items-center justify-center">
+                  <div className="h-4 w-4 animate-spin rounded-full border-2 border-primary border-t-transparent" />
+                </div>
+              ) : savedLists.length === 0 ? (
+                <p className="text-[0.875rem] text-muted-foreground">
+                  No saved lists yet. Create one in Team Settings &rarr; Target Lists.
+                </p>
+              ) : (
+                savedLists.map(list => (
+                  <button
+                    key={list.id}
+                    onClick={() => setSelectedListId(list.id)}
+                    className={cn(
+                      "w-full rounded-lg border px-4 py-3 text-left transition-colors",
+                      selectedListId === list.id
+                        ? "border-primary/30 bg-primary/10 text-foreground"
+                        : "border-border text-muted-foreground hover:bg-accent hover:text-foreground"
+                    )}
+                  >
+                    <div className="font-medium">{list.name}</div>
+                    <div className="text-[0.8125rem]">{list.targets.length} targets</div>
+                  </button>
+                ))
+              )}
+            </div>
+          )}
+
+          {activeTab === 'previous' && (
+            <p className="text-[0.875rem] text-muted-foreground">Previous run history coming soon.</p>
+          )}
+
+          {activeTab === 'psa' && (
+            <div className="rounded-lg border border-border bg-accent/30 p-6 text-center">
+              <ExternalLink className="mx-auto mb-2 h-8 w-8 text-muted-foreground" />
+              <p className="font-medium text-foreground">PSA / RMM Import</p>
+              <p className="mt-1 text-[0.8125rem] text-muted-foreground">
+                ConnectWise, Kaseya, and RMM integrations coming soon.
+              </p>
+            </div>
+          )}
+        </div>
+
+        {/* Preview */}
+        {targets.length > 0 && (
+          <div className="border-t border-border px-6 py-3">
+            <p className="text-[0.8125rem] text-muted-foreground">
+              Will create{' '}
+              <span className="font-semibold text-foreground">{targets.length} sessions</span>:{' '}
+              {targets.slice(0, 5).map(t => t.label).join(', ')}
+              {targets.length > 5 && ` +${targets.length - 5} more`}
+            </p>
+          </div>
+        )}
+
+        {/* Footer */}
+        <div className="flex justify-end gap-2 border-t border-border px-6 py-4">
+          <button
+            onClick={onClose}
+            className="rounded-lg border border-border px-4 py-2 text-[0.875rem] text-muted-foreground hover:bg-accent hover:text-foreground"
+          >
+            Cancel
+          </button>
+          <button
+            onClick={handleLaunch}
+            disabled={isLaunching || targets.length === 0}
+            className="rounded-lg bg-gradient-brand px-4 py-2 text-[0.875rem] font-medium text-white shadow-lg shadow-primary/20 hover:opacity-90 disabled:opacity-50"
+          >
+            {isLaunching ? 'Launching\u2026' : targets.length > 0 ? `Launch ${targets.length} Sessions` : 'Launch'}
+          </button>
+        </div>
+      </div>
+    </div>
+  )
+}

frontend/src/lib/routing.ts

@@ -1,7 +1,7 @@
 /**
  * Shared routing helpers for tree/session navigation.
  * Centralizes the logic for determining the correct navigation path
- * based on tree type (troubleshooting vs procedural).
+ * based on tree type (troubleshooting vs procedural vs maintenance).
  */
 
 /**
@@ -14,6 +14,9 @@ export function getTreeNavigatePath(
   if (treeType === 'procedural') {
     return `/flows/${treeId}/navigate`
   }
+  if (treeType === 'maintenance') {
+    return `/flows/${treeId}/maintenance`
+  }
   return `/trees/${treeId}/navigate`
 }
 
@@ -24,7 +27,7 @@ export function getTreeEditorPath(
   treeId: string,
   treeType?: string
 ): string {
-  if (treeType === 'procedural') {
+  if (treeType === 'procedural' || treeType === 'maintenance') {
     return `/flows/${treeId}/edit`
   }
   return `/trees/${treeId}/edit`

frontend/src/pages/AccountSettingsPage.tsx

@@ -1,6 +1,6 @@
 import { useEffect, useState } from 'react'
 import { Link } from 'react-router-dom'
-import { Building2, Users, Mail, Crown, Loader2, AlertCircle, Check, X, Settings, FolderTree, RefreshCw } from 'lucide-react'
+import { Building2, Users, Mail, Crown, Loader2, AlertCircle, Check, X, Settings, FolderTree, Server, RefreshCw } from 'lucide-react'
 import { accountsApi } from '@/api/accounts'
 import type { Account, AccountMember, AccountInvite } from '@/types'
 import { cn } from '@/lib/utils'
@@ -496,6 +496,23 @@ export function AccountSettingsPage() {
           </Link>
         )}
 
+        {/* Target Lists Link (owners only) */}
+        {isAccountOwner && (
+          <Link
+            to="/account/target-lists"
+            className="bg-card border border-border rounded-xl p-4 sm:p-6 flex items-center justify-between group hover:border-border transition-all"
+          >
+            <div className="flex items-center gap-3">
+              <Server className="h-5 w-5 text-muted-foreground" />
+              <div>
+                <h2 className="text-lg font-semibold text-foreground">Target Lists</h2>
+                <p className="text-sm text-muted-foreground">Saved server lists for maintenance flow batch launching</p>
+              </div>
+            </div>
+            <span className="text-muted-foreground group-hover:text-foreground transition-colors">&rarr;</span>
+          </Link>
+        )}
+
         {/* Preferences Section */}
         <div className="bg-card border border-border rounded-xl p-4 sm:p-6">
           <div className="flex items-center gap-2">

frontend/src/pages/MaintenanceFlowDetailPage.tsx

@@ -0,0 +1,198 @@
+import { useEffect, useState } from 'react'
+import { useParams, useNavigate } from 'react-router-dom'
+import { Wrench, Calendar, Play, Settings, Clock, CheckCircle, AlertCircle } from 'lucide-react'
+import { treesApi } from '@/api/trees'
+import { sessionsApi } from '@/api/sessions'
+import { maintenanceSchedulesApi } from '@/api/maintenanceSchedules'
+import { BatchLaunchModal } from '@/components/maintenance/BatchLaunchModal'
+import { toast } from '@/lib/toast'
+import { cn } from '@/lib/utils'
+import type { Tree, MaintenanceSchedule, Session } from '@/types'
+
+export default function MaintenanceFlowDetailPage() {
+  const { id } = useParams<{ id: string }>()
+  const navigate = useNavigate()
+  const [tree, setTree] = useState<Tree | null>(null)
+  const [schedule, setSchedule] = useState<MaintenanceSchedule | null>(null)
+  const [recentSessions, setRecentSessions] = useState<Session[]>([])
+  const [showBatchModal, setShowBatchModal] = useState(false)
+  const [isLoading, setIsLoading] = useState(true)
+
+  useEffect(() => {
+    if (!id) return
+    const load = async () => {
+      try {
+        const treeData = await treesApi.get(id)
+        setTree(treeData)
+
+        // Load recent sessions for this tree
+        try {
+          const sessionData = await sessionsApi.list({ tree_id: id, size: 30 })
+          setRecentSessions(Array.isArray(sessionData) ? sessionData : [])
+        } catch {
+          // Sessions load is optional
+        }
+
+        // Try to load schedule (404 is fine)
+        try {
+          const sched = await maintenanceSchedulesApi.getForTree(id)
+          setSchedule(sched)
+        } catch {
+          // No schedule yet is fine
+        }
+      } catch {
+        toast.error('Failed to load maintenance flow')
+        navigate('/trees?type=maintenance')
+      } finally {
+        setIsLoading(false)
+      }
+    }
+    load()
+  }, [id, navigate])
+
+  const handleLaunched = (_batchId: string, count: number) => {
+    setShowBatchModal(false)
+    toast.success(`${count} sessions created — view them in Sessions`)
+    navigate('/sessions')
+  }
+
+  if (isLoading) {
+    return (
+      <div className="flex h-64 items-center justify-center">
+        <div className="h-6 w-6 animate-spin rounded-full border-2 border-primary border-t-transparent" />
+      </div>
+    )
+  }
+
+  if (!tree) return null
+
+  // Group sessions by batch_id for run history
+  const batchMap = new Map<string, Session[]>()
+  for (const s of recentSessions) {
+    const key = s.batch_id ?? s.id
+    const existing = batchMap.get(key) ?? []
+    batchMap.set(key, [...existing, s])
+  }
+  const batches = Array.from(batchMap.entries()).slice(0, 10)
+
+  return (
+    <div className="mx-auto max-w-4xl space-y-6 p-6">
+      {/* Header */}
+      <div className="flex items-start justify-between">
+        <div className="flex items-center gap-3">
+          <div className="flex h-10 w-10 items-center justify-center rounded-lg bg-amber-500/10 text-amber-400">
+            <Wrench className="h-5 w-5" />
+          </div>
+          <div>
+            <h1 className="text-xl font-semibold text-foreground">{tree.name}</h1>
+            {tree.description && (
+              <p className="text-[0.8125rem] text-muted-foreground">{tree.description}</p>
+            )}
+          </div>
+        </div>
+        <div className="flex gap-2">
+          <button
+            onClick={() => navigate(`/flows/${id}/edit`)}
+            className="flex items-center gap-1.5 rounded-lg border border-border px-3 py-2 text-[0.875rem] text-muted-foreground hover:bg-accent hover:text-foreground"
+          >
+            <Settings className="h-3.5 w-3.5" />
+            Edit Flow
+          </button>
+          <button
+            onClick={() => setShowBatchModal(true)}
+            className="flex items-center gap-1.5 rounded-lg bg-gradient-brand px-4 py-2 text-[0.875rem] font-medium text-white shadow-lg shadow-primary/20 hover:opacity-90"
+          >
+            <Play className="h-3.5 w-3.5" />
+            Batch Launch
+          </button>
+        </div>
+      </div>
+
+      {/* Schedule Panel */}
+      <div className="rounded-xl border border-border bg-card p-5">
+        <div className="flex items-center gap-2 mb-3">
+          <Calendar className="h-4 w-4 text-muted-foreground" />
+          <h2 className="font-semibold text-foreground">Schedule</h2>
+        </div>
+        {schedule ? (
+          <div className="space-y-2 text-[0.875rem]">
+            <div className="flex flex-wrap items-center gap-2">
+              <span className={cn(
+                "inline-flex items-center gap-1 rounded-full px-2 py-0.5 font-label text-[0.625rem] uppercase tracking-wide",
+                schedule.is_active
+                  ? "bg-emerald-500/10 text-emerald-400"
+                  : "bg-muted text-muted-foreground"
+              )}>
+                {schedule.is_active
+                  ? <CheckCircle className="h-3 w-3" />
+                  : <AlertCircle className="h-3 w-3" />}
+                {schedule.is_active ? 'Active' : 'Paused'}
+              </span>
+              <code className="rounded bg-accent px-1.5 py-0.5 text-[0.8125rem] text-foreground">
+                {schedule.cron_expression}
+              </code>
+              <span className="text-muted-foreground">({schedule.timezone})</span>
+            </div>
+            {schedule.next_run_at && (
+              <p className="text-muted-foreground">
+                Next run: {new Date(schedule.next_run_at).toLocaleString()}
+              </p>
+            )}
+          </div>
+        ) : (
+          <p className="text-[0.875rem] text-muted-foreground">
+            No schedule configured. Sessions can still be launched manually via Batch Launch.
+          </p>
+        )}
+      </div>
+
+      {/* Run History */}
+      <div className="rounded-xl border border-border bg-card p-5">
+        <div className="flex items-center gap-2 mb-4">
+          <Clock className="h-4 w-4 text-muted-foreground" />
+          <h2 className="font-semibold text-foreground">Run History</h2>
+        </div>
+        {batches.length === 0 ? (
+          <p className="text-[0.875rem] text-muted-foreground">No runs yet. Launch a batch to get started.</p>
+        ) : (
+          <div className="space-y-2">
+            {batches.map(([batchKey, sessions]) => {
+              const completed = sessions.filter(s => s.completed_at).length
+              const total = sessions.length
+              const date = sessions[0]?.started_at
+              return (
+                <div key={batchKey} className="flex items-center justify-between rounded-lg border border-border px-4 py-3">
+                  <div>
+                    <p className="text-[0.875rem] font-medium text-foreground">
+                      {total} target{total !== 1 ? 's' : ''}
+                    </p>
+                    {date && (
+                      <p className="text-[0.8125rem] text-muted-foreground">
+                        {new Date(date).toLocaleDateString()}
+                      </p>
+                    )}
+                  </div>
+                  <span className={cn(
+                    "font-label text-[0.75rem] uppercase tracking-wide",
+                    completed === total ? "text-emerald-400" : "text-amber-400"
+                  )}>
+                    {completed}/{total} complete
+                  </span>
+                </div>
+              )
+            })}
+          </div>
+        )}
+      </div>
+
+      {showBatchModal && (
+        <BatchLaunchModal
+          treeId={id!}
+          treeName={tree.name}
+          onClose={() => setShowBatchModal(false)}
+          onLaunched={handleLaunched}
+        />
+      )}
+    </div>
+  )
+}

frontend/src/pages/TreeLibraryPage.tsx

@@ -37,14 +37,14 @@ export function TreeLibraryPage() {
 
   // Read type filter from URL query params (e.g. /trees?type=procedural)
   const urlType = searchParams.get('type')
-  const [typeFilter, setTypeFilter] = useState<'all' | 'troubleshooting' | 'procedural'>(
+  const [typeFilter, setTypeFilter] = useState<'all' | 'troubleshooting' | 'procedural' | 'maintenance'>(
-    urlType === 'troubleshooting' || urlType === 'procedural' ? urlType : 'all'
+    urlType === 'troubleshooting' || urlType === 'procedural' || urlType === 'maintenance' ? urlType : 'all'
   )
 
   // Sync filters when URL changes (e.g. clicking sidebar categories/tags or nav sub-items)
   useEffect(() => {
     const t = searchParams.get('type')
-    if (t === 'troubleshooting' || t === 'procedural') {
+    if (t === 'troubleshooting' || t === 'procedural' || t === 'maintenance') {
       setTypeFilter(t)
     } else {
       setTypeFilter('all')
@@ -253,13 +253,15 @@ export function TreeLibraryPage() {
           <div className="mb-6 flex flex-col gap-4 sm:mb-8 sm:flex-row sm:items-start sm:justify-between">
             <div>
               <h1 className="text-2xl font-bold font-heading text-foreground sm:text-3xl">
-                {typeFilter === 'procedural' ? 'Projects' : typeFilter === 'troubleshooting' ? 'Troubleshooting Flows' : 'Flow Library'}
+                {typeFilter === 'procedural' ? 'Projects' : typeFilter === 'troubleshooting' ? 'Troubleshooting Flows' : typeFilter === 'maintenance' ? 'Maintenance Flows' : 'Flow Library'}
               </h1>
               <p className="mt-2 text-muted-foreground">
                 {typeFilter === 'procedural'
                   ? 'Step-by-step projects and runbooks'
                   : typeFilter === 'troubleshooting'
                     ? 'Branching decision flows for troubleshooting'
+                    : typeFilter === 'maintenance'
+                      ? 'Scheduled maintenance procedures run across targets'
                       : 'Browse and start troubleshooting flows and projects'}
               </p>
             </div>
@@ -326,7 +328,7 @@ export function TreeLibraryPage() {
             <div className="flex flex-col gap-3 sm:flex-row sm:items-center sm:justify-between">
               <div className="flex items-center gap-4">
                 <div className="flex rounded-lg border border-border p-0.5">
-                  {(['all', 'troubleshooting', 'procedural'] as const).map((t) => (
+                  {(['all', 'troubleshooting', 'procedural', 'maintenance'] as const).map((t) => (
                     <button
                       key={t}
                       onClick={() => setTypeFilter(t)}
@@ -337,7 +339,7 @@ export function TreeLibraryPage() {
                           : 'text-muted-foreground hover:text-foreground'
                       )}
                     >
-                      {t === 'all' ? 'All' : t === 'troubleshooting' ? 'Troubleshooting' : 'Projects'}
+                      {t === 'all' ? 'All' : t === 'troubleshooting' ? 'Troubleshooting' : t === 'procedural' ? 'Projects' : 'Maintenance'}
                     </button>
                   ))}
                 </div>

frontend/src/pages/account/TargetListsPage.tsx

@@ -0,0 +1,251 @@
+import { useEffect, useState } from 'react'
+import { Plus, Pencil, Trash2, Server } from 'lucide-react'
+import { targetListsApi } from '@/api'
+import type { TargetList, TargetListCreate, TargetEntry } from '@/types'
+import { toast } from '@/lib/toast'
+import { ConfirmDialog } from '@/components/common/ConfirmDialog'
+
+export default function TargetListsPage() {
+  const [lists, setLists] = useState<TargetList[]>([])
+  const [isLoading, setIsLoading] = useState(true)
+  const [showEditor, setShowEditor] = useState(false)
+  const [editingList, setEditingList] = useState<TargetList | null>(null)
+  const [deleteTarget, setDeleteTarget] = useState<TargetList | null>(null)
+
+  // Editor state
+  const [editorName, setEditorName] = useState('')
+  const [editorDescription, setEditorDescription] = useState('')
+  const [editorTargets, setEditorTargets] = useState('')
+  const [isSaving, setIsSaving] = useState(false)
+
+  const load = async () => {
+    try {
+      const data = await targetListsApi.list()
+      setLists(data)
+    } catch {
+      toast.error('Failed to load target lists')
+    } finally {
+      setIsLoading(false)
+    }
+  }
+
+  useEffect(() => { load() }, [])
+
+  const openEditor = (list?: TargetList) => {
+    if (list) {
+      setEditingList(list)
+      setEditorName(list.name)
+      setEditorDescription(list.description ?? '')
+      setEditorTargets(list.targets.map(t => t.notes ? `${t.label} # ${t.notes}` : t.label).join('\n'))
+    } else {
+      setEditingList(null)
+      setEditorName('')
+      setEditorDescription('')
+      setEditorTargets('')
+    }
+    setShowEditor(true)
+  }
+
+  const parseTargets = (raw: string): TargetEntry[] =>
+    raw.split('\n')
+      .map(l => l.trim())
+      .filter(Boolean)
+      .map(line => {
+        const hashIdx = line.indexOf('#')
+        if (hashIdx === -1) return { label: line }
+        return {
+          label: line.slice(0, hashIdx).trim(),
+          notes: line.slice(hashIdx + 1).trim() || undefined,
+        }
+      })
+
+  const handleSave = async () => {
+    if (!editorName.trim()) { toast.error('Name is required'); return }
+    const targets = parseTargets(editorTargets)
+    if (targets.length === 0) { toast.error('Add at least one target'); return }
+
+    setIsSaving(true)
+    try {
+      const payload: TargetListCreate = {
+        name: editorName.trim(),
+        description: editorDescription.trim() || undefined,
+        targets,
+      }
+      if (editingList) {
+        const updated = await targetListsApi.update(editingList.id, payload)
+        setLists(prev => prev.map(l => l.id === updated.id ? updated : l))
+        toast.success('Target list updated')
+      } else {
+        const created = await targetListsApi.create(payload)
+        setLists(prev => [...prev, created])
+        toast.success('Target list created')
+      }
+      setShowEditor(false)
+    } catch {
+      toast.error('Failed to save target list')
+    } finally {
+      setIsSaving(false)
+    }
+  }
+
+  const handleDelete = async () => {
+    if (!deleteTarget) return
+    try {
+      await targetListsApi.delete(deleteTarget.id)
+      setLists(prev => prev.filter(l => l.id !== deleteTarget.id))
+      toast.success('Target list deleted')
+    } catch {
+      toast.error('Failed to delete target list')
+    } finally {
+      setDeleteTarget(null)
+    }
+  }
+
+  return (
+    <div className="space-y-6">
+      <div className="flex items-center justify-between">
+        <div>
+          <h1 className="text-xl font-semibold text-foreground">Target Lists</h1>
+          <p className="text-[0.8125rem] text-muted-foreground">
+            Saved server lists for maintenance flow batch launching
+          </p>
+        </div>
+        <button
+          onClick={() => openEditor()}
+          className="flex items-center gap-1.5 rounded-lg bg-gradient-brand px-4 py-2 text-[0.875rem] font-medium text-white shadow-lg shadow-primary/20 hover:opacity-90"
+        >
+          <Plus className="h-4 w-4" />
+          New List
+        </button>
+      </div>
+
+      {isLoading ? (
+        <div className="flex h-32 items-center justify-center">
+          <div className="h-5 w-5 animate-spin rounded-full border-2 border-primary border-t-transparent" />
+        </div>
+      ) : lists.length === 0 ? (
+        <div className="flex flex-col items-center justify-center rounded-xl border border-border bg-card py-12 text-center">
+          <Server className="mb-3 h-10 w-10 text-muted-foreground" />
+          <p className="font-medium text-foreground">No target lists yet</p>
+          <p className="mt-1 text-[0.8125rem] text-muted-foreground">
+            Create lists of servers to reuse across maintenance runs
+          </p>
+        </div>
+      ) : (
+        <div className="space-y-3">
+          {lists.map(list => (
+            <div
+              key={list.id}
+              className="flex items-center justify-between rounded-xl border border-border bg-card px-5 py-4"
+            >
+              <div>
+                <p className="font-medium text-foreground">{list.name}</p>
+                {list.description && (
+                  <p className="text-[0.8125rem] text-muted-foreground">{list.description}</p>
+                )}
+                <p className="mt-0.5 font-label text-[0.6875rem] uppercase tracking-wide text-muted-foreground">
+                  {list.targets.length} target{list.targets.length !== 1 ? 's' : ''}
+                  {list.targets.length > 0 && (
+                    <> &middot; {list.targets.slice(0, 3).map(t => t.label).join(', ')}{list.targets.length > 3 ? '\u2026' : ''}</>
+                  )}
+                </p>
+              </div>
+              <div className="flex items-center gap-1">
+                <button
+                  onClick={() => openEditor(list)}
+                  className="rounded-lg p-2 text-muted-foreground hover:bg-accent hover:text-foreground"
+                  title="Edit"
+                >
+                  <Pencil className="h-4 w-4" />
+                </button>
+                <button
+                  onClick={() => setDeleteTarget(list)}
+                  className="rounded-lg p-2 text-muted-foreground hover:bg-accent hover:text-red-400"
+                  title="Delete"
+                >
+                  <Trash2 className="h-4 w-4" />
+                </button>
+              </div>
+            </div>
+          ))}
+        </div>
+      )}
+
+      {/* Editor Modal */}
+      {showEditor && (
+        <div className="fixed inset-0 z-50 flex items-center justify-center bg-black/60 backdrop-blur-sm">
+          <div className="w-full max-w-md rounded-xl border border-border bg-card p-6 shadow-2xl">
+            <h2 className="mb-4 text-base font-semibold text-foreground">
+              {editingList ? 'Edit Target List' : 'New Target List'}
+            </h2>
+            <div className="space-y-4">
+              <div>
+                <label className="mb-1 block font-label text-[0.6875rem] uppercase tracking-wide text-muted-foreground">
+                  Name
+                </label>
+                <input
+                  type="text"
+                  value={editorName}
+                  onChange={e => setEditorName(e.target.value)}
+                  className="w-full rounded-lg border border-border bg-card px-3 py-2 text-[0.875rem] text-foreground placeholder:text-muted-foreground focus:border-primary focus:outline-none focus:ring-1 focus:ring-primary/20"
+                  placeholder="e.g. RDS Farm A"
+                />
+              </div>
+              <div>
+                <label className="mb-1 block font-label text-[0.6875rem] uppercase tracking-wide text-muted-foreground">
+                  Description (optional)
+                </label>
+                <input
+                  type="text"
+                  value={editorDescription}
+                  onChange={e => setEditorDescription(e.target.value)}
+                  className="w-full rounded-lg border border-border bg-card px-3 py-2 text-[0.875rem] text-foreground placeholder:text-muted-foreground focus:border-primary focus:outline-none focus:ring-1 focus:ring-primary/20"
+                  placeholder="e.g. Production RDS servers"
+                />
+              </div>
+              <div>
+                <label className="mb-1 block font-label text-[0.6875rem] uppercase tracking-wide text-muted-foreground">
+                  Targets &mdash; one per line (add notes after #)
+                </label>
+                <textarea
+                  value={editorTargets}
+                  onChange={e => setEditorTargets(e.target.value)}
+                  rows={6}
+                  className="w-full rounded-lg border border-border bg-card px-3 py-2 text-[0.875rem] text-foreground placeholder:text-muted-foreground focus:border-primary focus:outline-none focus:ring-1 focus:ring-primary/20"
+                  placeholder={"RDS-01 # 192.168.1.10\nRDS-02\nRDS-03 # Backup server"}
+                />
+              </div>
+            </div>
+            <div className="mt-6 flex justify-end gap-2">
+              <button
+                onClick={() => setShowEditor(false)}
+                className="rounded-lg border border-border px-4 py-2 text-[0.875rem] text-muted-foreground hover:bg-accent hover:text-foreground"
+              >
+                Cancel
+              </button>
+              <button
+                onClick={handleSave}
+                disabled={isSaving}
+                className="rounded-lg bg-gradient-brand px-4 py-2 text-[0.875rem] font-medium text-white shadow-lg shadow-primary/20 hover:opacity-90 disabled:opacity-50"
+              >
+                {isSaving ? 'Saving\u2026' : 'Save'}
+              </button>
+            </div>
+          </div>
+        </div>
+      )}
+
+      {deleteTarget && (
+        <ConfirmDialog
+          isOpen={!!deleteTarget}
+          onClose={() => setDeleteTarget(null)}
+          onConfirm={handleDelete}
+          title="Delete Target List"
+          message={`Delete "${deleteTarget.name}"? This cannot be undone.`}
+          confirmLabel="Delete"
+          confirmVariant="destructive"
+        />
+      )}
+    </div>
+  )
+}

frontend/src/router.tsx

@@ -24,6 +24,7 @@ const TreeNavigationPage = lazy(() => import('@/pages/TreeNavigationPage'))
 const TreeEditorPage = lazy(() => import('@/pages/TreeEditorPage'))
 const ProceduralEditorPage = lazy(() => import('@/pages/ProceduralEditorPage'))
 const ProceduralNavigationPage = lazy(() => import('@/pages/ProceduralNavigationPage'))
+const MaintenanceFlowDetailPage = lazy(() => import('@/pages/MaintenanceFlowDetailPage'))
 const SessionHistoryPage = lazy(() => import('@/pages/SessionHistoryPage'))
 const SessionDetailPage = lazy(() => import('@/pages/SessionDetailPage'))
 const MySharesPage = lazy(() => import('@/pages/MySharesPage'))
@@ -45,6 +46,7 @@ const AdminGlobalCategoriesPage = lazy(() => import('@/pages/admin/GlobalCategor
 // Account pages
 const AccountLayout = lazy(() => import('@/components/account/AccountLayout'))
 const TeamCategoriesPage = lazy(() => import('@/pages/account/TeamCategoriesPage'))
+const TargetListsPage = lazy(() => import('@/pages/account/TargetListsPage'))
 
 export const router = createBrowserRouter([
   {
@@ -168,6 +170,14 @@ export const router = createBrowserRouter([
           </Suspense>
         ),
       },
+      {
+        path: 'flows/:id/maintenance',
+        element: (
+          <Suspense fallback={<PageLoader />}>
+            <MaintenanceFlowDetailPage />
+          </Suspense>
+        ),
+      },
       {
         path: 'trees/:id/navigate',
         element: (
@@ -328,6 +338,14 @@ export const router = createBrowserRouter([
               </Suspense>
             ),
           },
+          {
+            path: 'target-lists',
+            element: (
+              <Suspense fallback={<PageLoader />}>
+                <TargetListsPage />
+              </Suspense>
+            ),
+          },
         ],
       },
     ],

frontend/src/types/index.ts

@@ -23,3 +23,14 @@ export interface PaginatedResponse<T> {
 export interface ApiError {
   detail: string
 }
+
+export type {
+  TargetEntry,
+  TargetList,
+  TargetListCreate,
+  MaintenanceSchedule,
+  MaintenanceScheduleCreate,
+  MaintenanceScheduleUpdate,
+  BatchLaunchRequest,
+  BatchLaunchResponse,
+} from './maintenance'

frontend/src/types/maintenance.ts

@@ -0,0 +1,65 @@
+export interface TargetEntry {
+  label: string
+  notes?: string
+}
+
+export interface TargetList {
+  id: string
+  team_id: string
+  created_by?: string
+  name: string
+  description?: string
+  targets: TargetEntry[]
+  created_at: string
+  updated_at: string
+}
+
+export interface TargetListCreate {
+  name: string
+  description?: string
+  targets: TargetEntry[]
+}
+
+export interface MaintenanceSchedule {
+  id: string
+  tree_id: string
+  created_by?: string
+  cron_expression: string
+  timezone: string
+  target_list_id?: string
+  is_active: boolean
+  next_run_at?: string
+  last_run_at?: string
+  created_at: string
+  updated_at: string
+}
+
+export interface MaintenanceScheduleCreate {
+  tree_id: string
+  cron_expression: string
+  timezone: string
+  target_list_id?: string
+}
+
+export interface MaintenanceScheduleUpdate {
+  cron_expression?: string
+  timezone?: string
+  target_list_id?: string
+  is_active?: boolean
+}
+
+export interface BatchLaunchRequest {
+  tree_id: string
+  targets: TargetEntry[]
+}
+
+export interface BatchLaunchResponse {
+  batch_id: string
+  count: number
+  sessions: Array<{
+    id: string
+    batch_id: string
+    target_label: string
+    tree_id: string
+  }>
+}

frontend/src/types/session.ts

@@ -60,6 +60,8 @@ export interface Session {
   scratchpad: string
   next_steps: string
   session_variables: Record<string, string>
+  batch_id?: string
+  target_label?: string
 }
 
 export interface SessionCreate {

frontend/src/types/tree.ts

@@ -58,7 +58,7 @@ export interface TreeStructure {
 
 // --- Procedural Flow Types ---
 
-export type TreeType = 'troubleshooting' | 'procedural'
+export type TreeType = 'troubleshooting' | 'procedural' | 'maintenance'
 
 export type IntakeFieldType =
   | 'text' | 'textarea' | 'number' | 'ip_address' | 'email' | 'url'