Use structured outputs with Pydantic models instead of text parsing

README.md

@@ -128,6 +128,7 @@ print(result.usage)   # Token counts
 ```python
 from claude_dspy import ClaudeCode, ClaudeCodeConfig
 from pydantic import BaseModel, Field
+import dspy
 
 class BugReport(BaseModel):
     severity: str = Field(description="critical, high, medium, or low")
@@ -137,9 +138,23 @@ class BugReport(BaseModel):
 # Create config with Pydantic output
 config = ClaudeCodeConfig()
 
+# Option 1: Pre-construct signature in your module (where BugReport is defined)
+sig = dspy.Signature("message:str -> report:BugReport")
 agent = ClaudeCode(
     config,
-    signature="message:str -> report:BugReport",
+    signature=sig,
+    working_directory="."
+)
+
+# Option 2: Use class-based signature (recommended)
+class BugReportSignature(dspy.Signature):
+    """Analyze bugs and generate report."""
+    message: str = dspy.InputField()
+    report: BugReport = dspy.OutputField()
+
+agent = ClaudeCode(
+    config,
+    signature=BugReportSignature,
     working_directory="."
 )
 
@@ -148,6 +163,10 @@ print(result.report.severity)       # Typed access!
 print(result.report.affected_files)
 ```
 
+**Note**: String signatures like `"message:str -> report:BugReport"` only work with built-in types unless you use `dspy.Signature()` with `custom_types`. For custom Pydantic models, either:
+- Use `dspy.Signature("...", custom_types={...})`
+- Use class-based signatures (recommended)
+
 ### Push to Modaic Hub
 
 ```python