diff --git a/app/api/routers/users.py b/app/api/routers/users.py
index 0aefad1..8aa4622 100644
--- a/app/api/routers/users.py
+++ b/app/api/routers/users.py
@@ -10,6 +10,7 @@ from sqlalchemy.orm import Session
 from app.api.deps import get_current_user, get_password_hash
 from app.core.config import get_db
 from app.models import models
+from app.models.agent import Agent
 from app.models.role_permission import Permission, Role, RolePermission
 from app.models.worklog import WorkLog
 from app.schemas import schemas
@@ -17,6 +18,23 @@ from app.schemas import schemas
 router = APIRouter(prefix="/users", tags=["Users"])
 
 
+def _user_response(user: models.User) -> dict:
+    """Build a UserResponse-compatible dict that includes the agent_id when present."""
+    data = {
+        "id": user.id,
+        "username": user.username,
+        "email": user.email,
+        "full_name": user.full_name,
+        "is_active": user.is_active,
+        "is_admin": user.is_admin,
+        "role_id": user.role_id,
+        "role_name": user.role_name,
+        "agent_id": user.agent.agent_id if user.agent else None,
+        "created_at": user.created_at,
+    }
+    return data
+
+
 def require_admin(current_user: models.User = Depends(get_current_user)):
     if not current_user.is_admin:
         raise HTTPException(status_code=403, detail="Admin required")
@@ -69,12 +87,27 @@ def create_user(
     db: Session = Depends(get_db),
     _: models.User = Depends(require_account_creator),
 ):
+    # Validate agent_id / claw_identifier: both or neither
+    has_agent_id = bool(user.agent_id)
+    has_claw = bool(user.claw_identifier)
+    if has_agent_id != has_claw:
+        raise HTTPException(
+            status_code=400,
+            detail="agent_id and claw_identifier must both be provided or both omitted",
+        )
+
     existing = db.query(models.User).filter(
         (models.User.username == user.username) | (models.User.email == user.email)
     ).first()
     if existing:
         raise HTTPException(status_code=400, detail="Username or email already exists")
 
+    # Check agent_id uniqueness
+    if has_agent_id:
+        existing_agent = db.query(Agent).filter(Agent.agent_id == user.agent_id).first()
+        if existing_agent:
+            raise HTTPException(status_code=400, detail="agent_id already in use")
+
     assigned_role = _resolve_user_role(db, user.role_id)
     hashed_password = get_password_hash(user.password) if user.password else None
     db_user = models.User(
@@ -87,9 +120,20 @@ def create_user(
         role_id=assigned_role.id,
     )
     db.add(db_user)
+    db.flush()  # get db_user.id
+
+    # Create Agent record if agent binding is requested (BE-CAL-003)
+    if has_agent_id:
+        db_agent = Agent(
+            user_id=db_user.id,
+            agent_id=user.agent_id,
+            claw_identifier=user.claw_identifier,
+        )
+        db.add(db_agent)
+
     db.commit()
     db.refresh(db_user)
-    return db_user
+    return _user_response(db_user)
 
 
 @router.get("", response_model=List[schemas.UserResponse])
@@ -99,7 +143,8 @@ def list_users(
     db: Session = Depends(get_db),
     _: models.User = Depends(require_admin),
 ):
-    return db.query(models.User).order_by(models.User.created_at.desc()).offset(skip).limit(limit).all()
+    users = db.query(models.User).order_by(models.User.created_at.desc()).offset(skip).limit(limit).all()
+    return [_user_response(u) for u in users]
 
 
 def _find_user_by_id_or_username(db: Session, identifier: str) -> models.User | None:
@@ -120,7 +165,7 @@ def get_user(
     user = _find_user_by_id_or_username(db, identifier)
     if not user:
         raise HTTPException(status_code=404, detail="User not found")
-    return user
+    return _user_response(user)
 
 
 @router.patch("/{identifier}", response_model=schemas.UserResponse)
@@ -159,7 +204,7 @@ def update_user(
 
     db.commit()
     db.refresh(user)
-    return user
+    return _user_response(user)
 
 
 @router.delete("/{identifier}", status_code=status.HTTP_204_NO_CONTENT)
diff --git a/app/main.py b/app/main.py
index b2fd104..9627064 100644
--- a/app/main.py
+++ b/app/main.py
@@ -261,6 +261,27 @@ def _migrate_schema():
         if _has_table(db, "server_states") and not _has_column(db, "server_states", "nginx_sites_json"):
             db.execute(text("ALTER TABLE server_states ADD COLUMN nginx_sites_json TEXT NULL"))
 
+        # --- agents table (BE-CAL-003) ---
+        if not _has_table(db, "agents"):
+            db.execute(text("""
+                CREATE TABLE agents (
+                    id INTEGER NOT NULL AUTO_INCREMENT,
+                    user_id INTEGER NOT NULL,
+                    agent_id VARCHAR(128) NOT NULL,
+                    claw_identifier VARCHAR(128) NOT NULL,
+                    status ENUM('idle','on_call','busy','exhausted','offline') NOT NULL DEFAULT 'idle',
+                    last_heartbeat DATETIME NULL,
+                    exhausted_at DATETIME NULL,
+                    recovery_at DATETIME NULL,
+                    exhaust_reason ENUM('rate_limit','billing') NULL,
+                    created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
+                    PRIMARY KEY (id),
+                    UNIQUE INDEX idx_agents_user_id (user_id),
+                    UNIQUE INDEX idx_agents_agent_id (agent_id),
+                    CONSTRAINT fk_agents_user_id FOREIGN KEY (user_id) REFERENCES users(id)
+                ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4
+            """))
+
         # --- essentials table (BE-PR-003) ---
         if not _has_table(db, "essentials"):
             db.execute(text("""
@@ -316,7 +337,7 @@ def _sync_default_user_roles(db):
 @app.on_event("startup")
 def startup():
     from app.core.config import Base, engine, SessionLocal
-    from app.models import models, webhook, apikey, activity, milestone, notification, worklog, monitor, role_permission, task, support, meeting, proposal, propose, essential
+    from app.models import models, webhook, apikey, activity, milestone, notification, worklog, monitor, role_permission, task, support, meeting, proposal, propose, essential, agent, calendar
     Base.metadata.create_all(bind=engine)
     _migrate_schema()
 
diff --git a/app/models/agent.py b/app/models/agent.py
new file mode 100644
index 0000000..289e2d9
--- /dev/null
+++ b/app/models/agent.py
@@ -0,0 +1,140 @@
+"""Agent model — tracks OpenClaw agents linked to HarborForge users.
+
+An Agent represents an AI agent (identified by its OpenClaw ``agent_id``)
+that is bound to exactly one HarborForge User.  The Calendar system uses
+Agent status to decide whether to wake an agent for scheduled slots.
+
+See: NEXT_WAVE_DEV_DIRECTION.md §1.4 (Agent table) and §6 (Agent wakeup)
+Implements: BE-CAL-003
+"""
+
+from sqlalchemy import (
+    Column,
+    Integer,
+    String,
+    DateTime,
+    Enum,
+    ForeignKey,
+)
+from sqlalchemy.orm import relationship
+from sqlalchemy.sql import func
+from app.core.config import Base
+import enum
+
+
+# ---------------------------------------------------------------------------
+# Enums
+# ---------------------------------------------------------------------------
+
+class AgentStatus(str, enum.Enum):
+    """Runtime status of an Agent."""
+    IDLE = "idle"
+    ON_CALL = "on_call"
+    BUSY = "busy"
+    EXHAUSTED = "exhausted"
+    OFFLINE = "offline"
+
+
+class ExhaustReason(str, enum.Enum):
+    """Why an agent entered the Exhausted state."""
+    RATE_LIMIT = "rate_limit"
+    BILLING = "billing"
+
+
+# ---------------------------------------------------------------------------
+# Agent model
+# ---------------------------------------------------------------------------
+
+class Agent(Base):
+    """An OpenClaw agent bound to a HarborForge user.
+
+    Fields
+    ------
+    user_id : int
+        One-to-one FK to ``users.id``.  Each user has at most one agent.
+    agent_id : str
+        The ``$AGENT_ID`` value from OpenClaw (globally unique).
+    claw_identifier : str
+        The OpenClaw instance identifier (matches ``MonitoredServer.identifier``
+        by convention, but has no FK — they are independent concepts).
+    status : AgentStatus
+        Current runtime status, managed by heartbeat / calendar wakeup logic.
+    last_heartbeat : datetime | None
+        Timestamp of the most recent heartbeat received from this agent.
+    exhausted_at : datetime | None
+        When the agent entered the ``EXHAUSTED`` state.
+    recovery_at : datetime | None
+        Estimated time the agent will recover from ``EXHAUSTED`` → ``IDLE``.
+    exhaust_reason : ExhaustReason | None
+        Why the agent became exhausted (rate-limit vs billing).
+    """
+
+    __tablename__ = "agents"
+
+    id = Column(Integer, primary_key=True, index=True)
+
+    user_id = Column(
+        Integer,
+        ForeignKey("users.id"),
+        nullable=False,
+        unique=True,
+        index=True,
+        comment="1-to-1 link to the owning HarborForge user",
+    )
+
+    agent_id = Column(
+        String(128),
+        nullable=False,
+        unique=True,
+        index=True,
+        comment="OpenClaw $AGENT_ID",
+    )
+
+    claw_identifier = Column(
+        String(128),
+        nullable=False,
+        comment="OpenClaw instance identifier (same value as MonitoredServer.identifier by convention)",
+    )
+
+    # -- runtime status fields ----------------------------------------------
+
+    status = Column(
+        Enum(AgentStatus, values_callable=lambda x: [e.value for e in x]),
+        nullable=False,
+        default=AgentStatus.IDLE,
+        comment="Current agent status: idle | on_call | busy | exhausted | offline",
+    )
+
+    last_heartbeat = Column(
+        DateTime(timezone=True),
+        nullable=True,
+        comment="Timestamp of the most recent heartbeat",
+    )
+
+    # -- exhausted state detail ---------------------------------------------
+
+    exhausted_at = Column(
+        DateTime(timezone=True),
+        nullable=True,
+        comment="When the agent entered EXHAUSTED state",
+    )
+
+    recovery_at = Column(
+        DateTime(timezone=True),
+        nullable=True,
+        comment="Estimated recovery time from EXHAUSTED → IDLE",
+    )
+
+    exhaust_reason = Column(
+        Enum(ExhaustReason, values_callable=lambda x: [e.value for e in x]),
+        nullable=True,
+        comment="rate_limit | billing — why the agent is exhausted",
+    )
+
+    # -- timestamps ---------------------------------------------------------
+
+    created_at = Column(DateTime(timezone=True), server_default=func.now())
+
+    # -- relationships ------------------------------------------------------
+
+    user = relationship("User", back_populates="agent", uselist=False)
diff --git a/app/models/models.py b/app/models/models.py
index 24c0b12..b790154 100644
--- a/app/models/models.py
+++ b/app/models/models.py
@@ -81,6 +81,7 @@ class User(Base):
     owned_projects = relationship("Project", back_populates="owner")
     comments = relationship("Comment", back_populates="author")
     project_memberships = relationship("ProjectMember", back_populates="user")
+    agent = relationship("Agent", back_populates="user", uselist=False)
 
     @property
     def role_name(self):
diff --git a/app/schemas/schemas.py b/app/schemas/schemas.py
index d1fb556..6bd1443 100644
--- a/app/schemas/schemas.py
+++ b/app/schemas/schemas.py
@@ -176,6 +176,9 @@ class UserBase(BaseModel):
 class UserCreate(UserBase):
     password: Optional[str] = None
     role_id: Optional[int] = None
+    # Agent binding (both must be provided or both omitted)
+    agent_id: Optional[str] = None
+    claw_identifier: Optional[str] = None
 
 
 class UserUpdate(BaseModel):
@@ -192,6 +195,7 @@ class UserResponse(UserBase):
     is_admin: bool
     role_id: Optional[int] = None
     role_name: Optional[str] = None
+    agent_id: Optional[str] = None
     created_at: datetime
     
     class Config:
@@ -389,6 +393,47 @@ class ProposalAcceptResponse(ProposalResponse):
         from_attributes = True
 
 
+# ---------------------------------------------------------------------------
+# Agent schemas (BE-CAL-003)
+# ---------------------------------------------------------------------------
+
+class AgentStatusEnum(str, Enum):
+    IDLE = "idle"
+    ON_CALL = "on_call"
+    BUSY = "busy"
+    EXHAUSTED = "exhausted"
+    OFFLINE = "offline"
+
+
+class ExhaustReasonEnum(str, Enum):
+    RATE_LIMIT = "rate_limit"
+    BILLING = "billing"
+
+
+class AgentResponse(BaseModel):
+    """Read-only representation of an Agent."""
+    id: int
+    user_id: int
+    agent_id: str
+    claw_identifier: str
+    status: AgentStatusEnum
+    last_heartbeat: Optional[datetime] = None
+    exhausted_at: Optional[datetime] = None
+    recovery_at: Optional[datetime] = None
+    exhaust_reason: Optional[ExhaustReasonEnum] = None
+    created_at: datetime
+
+    class Config:
+        from_attributes = True
+
+
+class AgentStatusUpdate(BaseModel):
+    """Payload for updating an agent's runtime status."""
+    status: AgentStatusEnum
+    exhaust_reason: Optional[ExhaustReasonEnum] = None
+    recovery_at: Optional[datetime] = None
+
+
 # Backward-compatible aliases
 ProposeStatusEnum = ProposalStatusEnum
 ProposeBase = ProposalBase