diff --git a/hindsight-api/hindsight_api/api/http.py b/hindsight-api/hindsight_api/api/http.py
index 9acdf0a0..e128de00 100644
--- a/hindsight-api/hindsight_api/api/http.py
+++ b/hindsight-api/hindsight_api/api/http.py
@@ -2290,6 +2290,23 @@ def _register_routes(app: FastAPI):
     ):
         """Get a mental model by ID."""
         try:
+            # Pre-operation validation hook
+            validator = app.state.memory._operation_validator
+            if validator:
+                from hindsight_api.extensions.operation_validator import MentalModelGetContext
+
+                ctx = MentalModelGetContext(
+                    bank_id=bank_id,
+                    mental_model_id=mental_model_id,
+                    request_context=request_context,
+                )
+                validation = await validator.validate_mental_model_get(ctx)
+                if not validation.allowed:
+                    raise OperationValidationError(
+                        validation.reason or "Operation not allowed",
+                        status_code=validation.status_code,
+                    )
+
             mental_model = await app.state.memory.get_mental_model(
                 bank_id=bank_id,
                 mental_model_id=mental_model_id,
@@ -2297,9 +2314,31 @@ def _register_routes(app: FastAPI):
             )
             if mental_model is None:
                 raise HTTPException(status_code=404, detail=f"Mental model '{mental_model_id}' not found")
+
+            # Post-operation hook
+            if validator:
+                from hindsight_api.extensions.operation_validator import MentalModelGetResult
+
+                content = mental_model.get("content", "")
+                output_tokens = len(content) // 4 if content else 0
+
+                result_ctx = MentalModelGetResult(
+                    bank_id=bank_id,
+                    mental_model_id=mental_model_id,
+                    request_context=request_context,
+                    output_tokens=output_tokens,
+                    success=True,
+                )
+                try:
+                    await validator.on_mental_model_get_complete(result_ctx)
+                except Exception as hook_err:
+                    logger.warning(f"Post-mental-model-get hook error (non-fatal): {hook_err}")
+
             return MentalModelResponse(**mental_model)
         except (AuthenticationError, HTTPException):
             raise
+        except OperationValidationError as e:
+            raise HTTPException(status_code=e.status_code, detail=e.reason)
         except Exception as e:
             import traceback
 
diff --git a/hindsight-api/hindsight_api/engine/memory_engine.py b/hindsight-api/hindsight_api/engine/memory_engine.py
index 65572e2e..6d697dfb 100644
--- a/hindsight-api/hindsight_api/engine/memory_engine.py
+++ b/hindsight-api/hindsight_api/engine/memory_engine.py
@@ -597,7 +597,13 @@ class MemoryEngine(MemoryEngineInterface):
 
         from hindsight_api.models import RequestContext
 
-        internal_context = RequestContext(internal=True)
+        # Restore tenant_id/api_key_id from task payload so extensions can
+        # attribute the mental_model_refresh operation to the correct org.
+        internal_context = RequestContext(
+            internal=True,
+            tenant_id=task_dict.get("_tenant_id"),
+            api_key_id=task_dict.get("_api_key_id"),
+        )
 
         # Get the current mental model to get source_query
         mental_model = await self.get_mental_model(bank_id, mental_model_id, request_context=internal_context)
@@ -641,6 +647,42 @@ class MemoryEngine(MemoryEngineInterface):
             request_context=internal_context,
         )
 
+        # Call post-operation hook if validator is configured
+        if self._operation_validator:
+            from hindsight_api.extensions.operation_validator import MentalModelRefreshResult
+
+            # Count facts and mental models from based_on
+            facts_used = 0
+            mental_models_used = 0
+            if reflect_result.based_on:
+                for fact_type, facts in reflect_result.based_on.items():
+                    if facts:
+                        if fact_type == "mental_models":
+                            mental_models_used += len(facts)
+                        else:
+                            facts_used += len(facts)
+
+            # Estimate tokens
+            query_tokens = len(source_query) // 4 if source_query else 0
+            output_tokens = len(generated_content) // 4 if generated_content else 0
+            context_tokens = 0  # refresh doesn't use additional context
+
+            result_ctx = MentalModelRefreshResult(
+                bank_id=bank_id,
+                mental_model_id=mental_model_id,
+                request_context=internal_context,
+                query_tokens=query_tokens,
+                output_tokens=output_tokens,
+                context_tokens=context_tokens,
+                facts_used=facts_used,
+                mental_models_used=mental_models_used,
+                success=True,
+            )
+            try:
+                await self._operation_validator.on_mental_model_refresh_complete(result_ctx)
+            except Exception as hook_err:
+                logger.warning(f"Post-mental-model-refresh hook error (non-fatal): {hook_err}")
+
         logger.info(f"[REFRESH_MENTAL_MODEL_TASK] Completed for bank_id={bank_id}, mental_model_id={mental_model_id}")
 
     async def execute_task(self, task_dict: dict[str, Any]):
@@ -5482,13 +5524,21 @@ class MemoryEngine(MemoryEngineInterface):
         if not mental_model:
             raise ValueError(f"Mental model {mental_model_id} not found in bank {bank_id}")
 
+        # Pass tenant_id and api_key_id through task payload so the worker
+        # can provide request context to extension hooks.
+        task_payload: dict[str, Any] = {
+            "mental_model_id": mental_model_id,
+        }
+        if request_context.tenant_id:
+            task_payload["_tenant_id"] = request_context.tenant_id
+        if request_context.api_key_id:
+            task_payload["_api_key_id"] = request_context.api_key_id
+
         return await self._submit_async_operation(
             bank_id=bank_id,
             operation_type="refresh_mental_model",
             task_type="refresh_mental_model",
-            task_payload={
-                "mental_model_id": mental_model_id,
-            },
+            task_payload=task_payload,
             result_metadata={"mental_model_id": mental_model_id, "name": mental_model["name"]},
             dedupe_by_bank=False,
         )
diff --git a/hindsight-api/hindsight_api/extensions/__init__.py b/hindsight-api/hindsight_api/extensions/__init__.py
index 592d0f8d..5a7dabeb 100644
--- a/hindsight-api/hindsight_api/extensions/__init__.py
+++ b/hindsight-api/hindsight_api/extensions/__init__.py
@@ -24,6 +24,10 @@ from hindsight_api.extensions.operation_validator import (
     # Consolidation operation
     ConsolidateContext,
     ConsolidateResult,
+    # Mental Model operations
+    MentalModelGetContext,
+    MentalModelGetResult,
+    MentalModelRefreshResult,
     # Core operations
     OperationValidationError,
     OperationValidatorExtension,
@@ -65,6 +69,10 @@ __all__ = [
     # Operation Validator - Consolidation
     "ConsolidateContext",
     "ConsolidateResult",
+    # Operation Validator - Mental Model
+    "MentalModelGetContext",
+    "MentalModelGetResult",
+    "MentalModelRefreshResult",
     # Tenant/Auth
     "ApiKeyTenantExtension",
     "AuthenticationError",
diff --git a/hindsight-api/hindsight_api/extensions/operation_validator.py b/hindsight-api/hindsight_api/extensions/operation_validator.py
index de4fb814..0b778ca7 100644
--- a/hindsight-api/hindsight_api/extensions/operation_validator.py
+++ b/hindsight-api/hindsight_api/extensions/operation_validator.py
@@ -196,6 +196,48 @@ class ConsolidateResult:
     error: str | None = None
 
 
+# =============================================================================
+# Mental Model Contexts
+# =============================================================================
+
+
+@dataclass
+class MentalModelGetContext:
+    """Context for a mental model GET operation validation (pre-operation)."""
+
+    bank_id: str
+    mental_model_id: str
+    request_context: "RequestContext"
+
+
+@dataclass
+class MentalModelGetResult:
+    """Result context for post-mental-model-GET hook."""
+
+    bank_id: str
+    mental_model_id: str
+    request_context: "RequestContext"
+    output_tokens: int  # tokens in the returned content
+    success: bool = True
+    error: str | None = None
+
+
+@dataclass
+class MentalModelRefreshResult:
+    """Result context for post-mental-model-refresh hook."""
+
+    bank_id: str
+    mental_model_id: str
+    request_context: "RequestContext"
+    query_tokens: int  # tokens in source_query
+    output_tokens: int  # tokens in generated content
+    context_tokens: int  # tokens in context (if any)
+    facts_used: int  # facts referenced in based_on
+    mental_models_used: int  # mental models referenced in based_on
+    success: bool = True
+    error: str | None = None
+
+
 class OperationValidatorExtension(Extension, ABC):
     """
     Validates and hooks into retain/recall/reflect/consolidate operations.
@@ -402,3 +444,64 @@ class OperationValidatorExtension(Extension, ABC):
                 - error: Error message (if failed)
         """
         pass
+
+    # =========================================================================
+    # Mental Model - Pre-operation validation hook (optional - override to implement)
+    # =========================================================================
+
+    async def validate_mental_model_get(self, ctx: MentalModelGetContext) -> ValidationResult:
+        """
+        Validate a mental model GET operation before execution.
+
+        Override to implement custom validation logic for mental model retrieval.
+
+        Args:
+            ctx: Context containing:
+                - bank_id: Bank identifier
+                - mental_model_id: Mental model identifier
+                - request_context: Request context with auth info
+
+        Returns:
+            ValidationResult indicating whether the operation is allowed.
+        """
+        return ValidationResult.accept()
+
+    # =========================================================================
+    # Mental Model - Post-operation hooks (optional - override to implement)
+    # =========================================================================
+
+    async def on_mental_model_get_complete(self, result: MentalModelGetResult) -> None:
+        """
+        Called after a mental model GET operation completes (success or failure).
+
+        Override to implement post-operation logic such as tracking or audit logging.
+
+        Args:
+            result: Result context containing:
+                - bank_id: Bank identifier
+                - mental_model_id: Mental model identifier
+                - output_tokens: Token count of the returned content
+                - success: Whether the operation succeeded
+                - error: Error message (if failed)
+        """
+        pass
+
+    async def on_mental_model_refresh_complete(self, result: MentalModelRefreshResult) -> None:
+        """
+        Called after a mental model refresh operation completes (success or failure).
+
+        Override to implement post-operation logic such as tracking or audit logging.
+
+        Args:
+            result: Result context containing:
+                - bank_id: Bank identifier
+                - mental_model_id: Mental model identifier
+                - query_tokens: Tokens in source_query
+                - output_tokens: Tokens in generated content
+                - context_tokens: Tokens in context
+                - facts_used: Number of facts referenced
+                - mental_models_used: Number of mental models referenced
+                - success: Whether the operation succeeded
+                - error: Error message (if failed)
+        """
+        pass
diff --git a/hindsight-api/tests/test_mental_model_hooks.py b/hindsight-api/tests/test_mental_model_hooks.py
new file mode 100644
index 00000000..c88655c5
--- /dev/null
+++ b/hindsight-api/tests/test_mental_model_hooks.py
@@ -0,0 +1,206 @@
+"""Unit tests for mental model operation validator hooks.
+
+Tests that the operation validator hooks are called correctly for
+mental model GET and refresh operations.
+"""
+
+import pytest
+
+from hindsight_api.extensions.operation_validator import (
+    MentalModelGetContext,
+    MentalModelGetResult,
+    MentalModelRefreshResult,
+    OperationValidatorExtension,
+    ValidationResult,
+)
+
+
+class TestMentalModelGetContextDataclass:
+    """Tests for MentalModelGetContext dataclass."""
+
+    def test_create_context(self):
+        """Test creating a MentalModelGetContext."""
+        from unittest.mock import MagicMock
+
+        request_context = MagicMock()
+        ctx = MentalModelGetContext(
+            bank_id="bank-1",
+            mental_model_id="mm-1",
+            request_context=request_context,
+        )
+
+        assert ctx.bank_id == "bank-1"
+        assert ctx.mental_model_id == "mm-1"
+        assert ctx.request_context is request_context
+
+
+class TestMentalModelGetResultDataclass:
+    """Tests for MentalModelGetResult dataclass."""
+
+    def test_create_result_success(self):
+        """Test creating a successful MentalModelGetResult."""
+        from unittest.mock import MagicMock
+
+        request_context = MagicMock()
+        result = MentalModelGetResult(
+            bank_id="bank-1",
+            mental_model_id="mm-1",
+            request_context=request_context,
+            output_tokens=250,
+        )
+
+        assert result.bank_id == "bank-1"
+        assert result.mental_model_id == "mm-1"
+        assert result.output_tokens == 250
+        assert result.success is True
+        assert result.error is None
+
+    def test_create_result_failure(self):
+        """Test creating a failed MentalModelGetResult."""
+        from unittest.mock import MagicMock
+
+        result = MentalModelGetResult(
+            bank_id="bank-1",
+            mental_model_id="mm-1",
+            request_context=MagicMock(),
+            output_tokens=0,
+            success=False,
+            error="Not found",
+        )
+
+        assert result.success is False
+        assert result.error == "Not found"
+
+
+class TestMentalModelRefreshResultDataclass:
+    """Tests for MentalModelRefreshResult dataclass."""
+
+    def test_create_result_with_all_fields(self):
+        """Test creating a MentalModelRefreshResult with all fields."""
+        from unittest.mock import MagicMock
+
+        result = MentalModelRefreshResult(
+            bank_id="bank-1",
+            mental_model_id="mm-1",
+            request_context=MagicMock(),
+            query_tokens=50,
+            output_tokens=500,
+            context_tokens=0,
+            facts_used=10,
+            mental_models_used=2,
+        )
+
+        assert result.query_tokens == 50
+        assert result.output_tokens == 500
+        assert result.context_tokens == 0
+        assert result.facts_used == 10
+        assert result.mental_models_used == 2
+        assert result.success is True
+        assert result.error is None
+
+    def test_create_result_failure(self):
+        """Test creating a failed MentalModelRefreshResult."""
+        from unittest.mock import MagicMock
+
+        result = MentalModelRefreshResult(
+            bank_id="bank-1",
+            mental_model_id="mm-1",
+            request_context=MagicMock(),
+            query_tokens=50,
+            output_tokens=0,
+            context_tokens=0,
+            facts_used=0,
+            mental_models_used=0,
+            success=False,
+            error="Reflect failed",
+        )
+
+        assert result.success is False
+        assert result.error == "Reflect failed"
+
+
+class TestDefaultHookBehavior:
+    """Tests for default (no-op) behavior of mental model hooks on OperationValidatorExtension."""
+
+    @pytest.fixture
+    def validator(self):
+        """Create a concrete subclass for testing default behavior."""
+        from unittest.mock import MagicMock
+
+        # Create a concrete subclass that implements the abstract methods
+        class TestValidator(OperationValidatorExtension):
+            async def validate_retain(self, ctx):
+                return ValidationResult.accept()
+
+            async def validate_recall(self, ctx):
+                return ValidationResult.accept()
+
+            async def validate_reflect(self, ctx):
+                return ValidationResult.accept()
+
+        return TestValidator(config={})
+
+    @pytest.mark.asyncio
+    async def test_validate_mental_model_get_default_accepts(self, validator):
+        """Test that default validate_mental_model_get accepts."""
+        from unittest.mock import MagicMock
+
+        ctx = MentalModelGetContext(
+            bank_id="bank-1",
+            mental_model_id="mm-1",
+            request_context=MagicMock(),
+        )
+
+        result = await validator.validate_mental_model_get(ctx)
+
+        assert result.allowed is True
+
+    @pytest.mark.asyncio
+    async def test_on_mental_model_get_complete_default_noop(self, validator):
+        """Test that default on_mental_model_get_complete is a no-op."""
+        from unittest.mock import MagicMock
+
+        result = MentalModelGetResult(
+            bank_id="bank-1",
+            mental_model_id="mm-1",
+            request_context=MagicMock(),
+            output_tokens=100,
+        )
+
+        # Should not raise
+        await validator.on_mental_model_get_complete(result)
+
+    @pytest.mark.asyncio
+    async def test_on_mental_model_refresh_complete_default_noop(self, validator):
+        """Test that default on_mental_model_refresh_complete is a no-op."""
+        from unittest.mock import MagicMock
+
+        result = MentalModelRefreshResult(
+            bank_id="bank-1",
+            mental_model_id="mm-1",
+            request_context=MagicMock(),
+            query_tokens=50,
+            output_tokens=500,
+            context_tokens=0,
+            facts_used=5,
+            mental_models_used=1,
+        )
+
+        # Should not raise
+        await validator.on_mental_model_refresh_complete(result)
+
+
+class TestExportsAvailable:
+    """Test that mental model hooks are properly exported."""
+
+    def test_imports_from_extensions_package(self):
+        """Test that all mental model types can be imported from hindsight_api.extensions."""
+        from hindsight_api.extensions import (
+            MentalModelGetContext,
+            MentalModelGetResult,
+            MentalModelRefreshResult,
+        )
+
+        assert MentalModelGetContext is not None
+        assert MentalModelGetResult is not None
+        assert MentalModelRefreshResult is not None