diff --git a/conductor/tracks/tier4_auto_patching_20260306/plan.md b/conductor/tracks/tier4_auto_patching_20260306/plan.md
index 96600a4..033986e 100644
--- a/conductor/tracks/tier4_auto_patching_20260306/plan.md
+++ b/conductor/tracks/tier4_auto_patching_20260306/plan.md
@@ -5,8 +5,8 @@
 ## Phase 1: Patch Generation
 Focus: Generate unified diff on test failure
 
-- [ ] Task 1.1: Initialize MMA Environment
-- [ ] Task 1.2: Extend Tier 4 prompt for patch generation
+- [x] Task 1.1: Initialize MMA Environment
+- [~] Task 1.2: Extend Tier 4 prompt for patch generation
     - WHERE: `src/mma_prompts.py` or inline in `ai_client.py`
     - WHAT: Prompt to generate unified diff
     - HOW:
diff --git a/config.toml b/config.toml
index e60e5da..dccdb94 100644
--- a/config.toml
+++ b/config.toml
@@ -16,7 +16,7 @@ paths = [
     "C:\\projects\\manual_slop\\tests\\artifacts\\temp_liveexecutionsim.toml",
     "C:\\projects\\manual_slop\\tests\\artifacts\\temp_simproject.toml",
 ]
-active = "C:\\projects\\manual_slop\\tests\\artifacts\\temp_project.toml"
+active = "C:\\projects\\manual_slop\\tests\\artifacts\\temp_livetoolssim.toml"
 
 [gui]
 separate_message_panel = false
diff --git a/src/ai_client.py b/src/ai_client.py
index bcb8981..778e6a5 100644
--- a/src/ai_client.py
+++ b/src/ai_client.py
@@ -28,6 +28,7 @@ from pathlib import Path
 from src import project_manager
 from src import file_cache
 from src import mcp_client
+from src import mma_prompts
 import anthropic
 from src.gemini_cli_adapter import GeminiCliAdapter as GeminiCliAdapter
 from google import genai
@@ -1960,6 +1961,33 @@ def run_tier4_analysis(stderr: str) -> str:
  except Exception as e:
   return f"[QA ANALYSIS FAILED] {e}"
 
+
+def run_tier4_patch_generation(error: str, file_context: str) -> str:
+ if not error or not error.strip():
+  return ""
+ try:
+  _ensure_gemini_client()
+  if not _gemini_client:
+   return ""
+  prompt = (
+   f"{mma_prompts.TIER4_PATCH_PROMPT}\n\n"
+   f"Error:\n```\n{error}\n```\n\n"
+   f"File Context:\n```\n{file_context}\n```\n"
+  )
+  model_name = "gemini-2.5-flash-lite"
+  resp = _gemini_client.models.generate_content(
+   model=model_name,
+   contents=prompt,
+   config=types.GenerateContentConfig(
+    temperature=0.0,
+    max_output_tokens=2048,
+   )
+  )
+  patch = resp.text.strip() if resp.text else ""
+  return patch
+ except Exception as e:
+  return f"[PATCH GENERATION FAILED] {e}"
+
 def get_token_stats(md_content: str) -> dict[str, Any]:
  global _provider, _gemini_client, _model, _CHARS_PER_TOKEN
  total_tokens = 0
diff --git a/src/mma_prompts.py b/src/mma_prompts.py
index e68e4ba..b7b15ef 100644
--- a/src/mma_prompts.py
+++ b/src/mma_prompts.py
@@ -153,3 +153,28 @@ PROMPTS: Dict[str, str] = {
  "tier2_track_finalization": TIER2_TRACK_FINALIZATION,
  "tier2_contract_first": TIER2_CONTRACT_FIRST,
 }
+
+TIER4_PATCH_PROMPT: str = """You are a Tier 4 QA Agent specializing in error analysis and patch generation.
+When a test or command fails, analyze the error and generate a unified diff patch to fix it.
+
+OUTPUT FORMAT: Unified diff format (diff -u)
+```
+--- a/path/to/file.py
++++ b/path/to/file.py
+@@ -start,count +start,count @@
+ context line
+-removed line
++added line
+ context line
+```
+
+RULES:
+1. Use "--- a/" and "+++ b/" prefixes with the actual file path
+2. Include sufficient context lines (3 above/below minimum)
+3. Use @@ -X,Y +X,Y @@ format for hunk headers
+4. Only include changes necessary to fix the error
+5. If multiple files need changes, include each in the patch
+6. Output ONLY the unified diff - no explanations, no markdown code blocks
+
+Analyze this error and generate the patch:
+"""
diff --git a/tests/test_tier4_patch_generation.py b/tests/test_tier4_patch_generation.py
new file mode 100644
index 0000000..b86bfef
--- /dev/null
+++ b/tests/test_tier4_patch_generation.py
@@ -0,0 +1,67 @@
+from unittest.mock import MagicMock, patch
+import pytest
+from src import ai_client
+from src import mma_prompts
+
+def test_tier4_patch_prompt_exists() -> None:
+  """Test that TIER4_PATCH_PROMPT is defined in mma_prompts.py."""
+  assert hasattr(mma_prompts, "TIER4_PATCH_PROMPT")
+  prompt = mma_prompts.TIER4_PATCH_PROMPT
+  assert "unified diff" in prompt.lower() or "diff -u" in prompt.lower()
+  assert "---" in prompt
+  assert "+++" in prompt
+  assert "@@" in prompt
+
+def test_tier4_patch_prompt_format_instructions() -> None:
+  """Test that the patch prompt includes format instructions for unified diff."""
+  prompt = mma_prompts.TIER4_PATCH_PROMPT
+  assert "--- a/" in prompt or "---" in prompt
+  assert "+++ b/" in prompt or "+++" in prompt
+
+def test_run_tier4_patch_generation_exists() -> None:
+  """Test that run_tier4_patch_generation function exists in ai_client."""
+  assert hasattr(ai_client, "run_tier4_patch_generation")
+  assert callable(ai_client.run_tier4_patch_generation)
+
+def test_run_tier4_patch_generation_empty_error() -> None:
+  """Test that run_tier4_patch_generation returns empty string on empty error."""
+  with patch("src.ai_client._ensure_gemini_client"), \
+     patch("src.ai_client._gemini_client") as mock_client:
+    mock_resp = MagicMock()
+    mock_resp.text = ""
+    mock_client.models.generate_content.return_value = mock_resp
+    
+    result = ai_client.run_tier4_patch_generation("", "file context")
+    assert result == ""
+
+def test_run_tier4_patch_generation_calls_ai() -> None:
+  """Test that run_tier4_patch_generation calls the AI with the correct prompt."""
+  with patch("src.ai_client._ensure_gemini_client"), \
+     patch("src.ai_client._gemini_client", create=True) as mock_client, \
+     patch("src.ai_client.types") as mock_types:
+    mock_resp = MagicMock()
+    mock_resp.text = "--- a/test.py\n+++ b/test.py\n@@ -1 +1 @@\n-old\n+new"
+    mock_client.models.generate_content.return_value = mock_resp
+    mock_types.GenerateContentConfig = MagicMock()
+    
+    error = "TypeError: unsupported operand"
+    file_context = "def foo():\n    pass"
+    result = ai_client.run_tier4_patch_generation(error, file_context)
+    
+    mock_client.models.generate_content.assert_called()
+
+def test_run_tier4_patch_generation_returns_diff() -> None:
+  """Test that run_tier4_patch_generation returns diff text."""
+  with patch("src.ai_client._ensure_gemini_client"), \
+     patch("src.ai_client._gemini_client", create=True) as mock_client, \
+     patch("src.ai_client.types") as mock_types:
+    expected_diff = "--- a/src/test.py\n+++ b/src/test.py\n@@ -10,5 +10,6 @@\n def test_func():\n-    old_value = 1\n+    old_value = 1\n+    new_value = 2"
+    mock_resp = MagicMock()
+    mock_resp.text = expected_diff
+    mock_client.models.generate_content.return_value = mock_resp
+    mock_types.GenerateContentConfig = MagicMock()
+    
+    result = ai_client.run_tier4_patch_generation("error", "context")
+    assert "---" in result
+    assert "+++" in result
+    assert "@@" in result
\ No newline at end of file