diff --git a/implementation_plan.md b/implementation_plan.md
index 205215b..b6069eb 100644
--- a/implementation_plan.md
+++ b/implementation_plan.md
@@ -28,6 +28,9 @@ Transition the system from a functional prototype to a scalable, production-read
 -   **SessionRecoveryManager** (`src/core/recovery.py`):
     -   Implemented logic for handling `cf_clearance_expired`, `rate_limit`, etc.
 
+### Maintenance & Hotfixes
+-   **requirements.txt**: Added missing runtime dependencies (`prometheus-client`, `redis`, `msgpack`) to resolve `ModuleNotFoundError` in worker containers.
+
 ### Documentation
 -   **README.md**: Updated with Production Usage, Scaling, and Monitoring instructions.
 
diff --git a/requirements.txt b/requirements.txt
index d5035df..527c5eb 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -6,3 +6,4 @@ pydantic==2.5.3
 pytest>=8.0.0
 pytest-asyncio>=0.23.0
 aiohttp==3.9.1
+prometheus-client==0.19.0
diff --git a/walkthrough.md b/walkthrough.md
index 410b130..7a79fce 100644
--- a/walkthrough.md
+++ b/walkthrough.md
@@ -109,6 +109,7 @@ tests/unit/test_session_core.py .. [100%]
     - Removed `shm_size` conflict and legacy version tag.
 - **Worker**: Implemented `src/orchestrator/worker.py` for continuous task processing.
 - **Monitoring**: Implemented `src/core/monitoring.py` exposing metrics on port 8000.
+- **Hotfix: Runtime Dependencies**: Resolved `ModuleNotFoundError` crashes by adding `prometheus-client`, `redis`, and `msgpack` to `requirements.txt`.
 - **Documentation**: Updated `README.md` with production operations guide.
 
 ## Conclusion