diff --git a/promptlens/models/config.py b/promptlens/models/config.py
index 7c85798..0645f07 100644
--- a/promptlens/models/config.py
+++ b/promptlens/models/config.py
@@ -2,7 +2,7 @@
 
 from typing import Any, Dict, List, Optional
 
-from pydantic import BaseModel, Field
+from pydantic import BaseModel, ConfigDict, Field
 
 
 class ProviderConfig(BaseModel):
@@ -114,9 +114,8 @@ class RunConfig(BaseModel):
     execution: ExecutionConfig = Field(default_factory=ExecutionConfig)
     output: OutputConfig = Field(default_factory=OutputConfig)
 
-    class Config:
-        """Pydantic config."""
-        json_schema_extra = {
+    model_config = ConfigDict(
+        json_schema_extra={
             "example": {
                 "golden_set": "./examples/golden_sets/customer_support.yaml",
                 "models": [
@@ -143,3 +142,4 @@ class Config:
                 },
             }
         }
+    )
diff --git a/promptlens/models/test_case.py b/promptlens/models/test_case.py
index 931208f..4861929 100644
--- a/promptlens/models/test_case.py
+++ b/promptlens/models/test_case.py
@@ -2,7 +2,7 @@
 
 from typing import Any, Dict, List, Optional
 
-from pydantic import BaseModel, Field
+from pydantic import BaseModel, ConfigDict, Field
 
 from promptlens.models.tools import ToolDefinition, ExpectedToolCall
 
@@ -50,9 +50,8 @@ class TestCase(BaseModel):
         description="Whether to actually execute tools (default: False, evaluation only)"
     )
 
-    class Config:
-        """Pydantic config."""
-        json_schema_extra = {
+    model_config = ConfigDict(
+        json_schema_extra={
             "example": {
                 "id": "cs-001",
                 "query": "How do I reset my password?",
@@ -61,6 +60,7 @@ class Config:
                 "tags": ["password", "account"],
             }
         }
+    )
 
 
 class GoldenSet(BaseModel):
@@ -80,9 +80,8 @@ class GoldenSet(BaseModel):
     test_cases: List[TestCase]
     metadata: Dict[str, Any] = Field(default_factory=dict)
 
-    class Config:
-        """Pydantic config."""
-        json_schema_extra = {
+    model_config = ConfigDict(
+        json_schema_extra={
             "example": {
                 "name": "Customer Support Tests",
                 "description": "Test cases for customer support chatbot",
@@ -98,3 +97,4 @@ class Config:
                 ],
             }
         }
+    )
diff --git a/promptlens/models/tools.py b/promptlens/models/tools.py
index bd7d52b..011447f 100644
--- a/promptlens/models/tools.py
+++ b/promptlens/models/tools.py
@@ -8,7 +8,7 @@
 """
 
 from typing import Any, Dict, List, Optional
-from pydantic import BaseModel, Field
+from pydantic import BaseModel, ConfigDict, Field
 
 
 class ToolParameter(BaseModel):
@@ -24,8 +24,7 @@ class ToolParameter(BaseModel):
     properties: Optional[Dict[str, "ToolParameter"]] = Field(None, description="For object types, nested properties")
     items: Optional["ToolParameter"] = Field(None, description="For array types, the item schema")
 
-    class Config:
-        extra = "allow"  # Allow additional JSON Schema fields
+    model_config = ConfigDict(extra="allow")  # Allow additional JSON Schema fields
 
 
 class ToolDefinition(BaseModel):
diff --git a/tests/test_pydantic_configdict.py b/tests/test_pydantic_configdict.py
new file mode 100644
index 0000000..0569d72
--- /dev/null
+++ b/tests/test_pydantic_configdict.py
@@ -0,0 +1,39 @@
+"""Regression tests for Pydantic v2 model_config migration."""
+
+from promptlens.models.config import RunConfig
+from promptlens.models.test_case import GoldenSet, TestCase as PromptLensTestCase
+from promptlens.models.tools import ToolParameter
+
+
+def test_tool_parameter_allows_additional_json_schema_fields() -> None:
+    param = ToolParameter(
+        type="string",
+        description="User locale",
+        format="email",
+        minLength=3,
+    )
+
+    dumped = param.model_dump()
+    assert dumped["format"] == "email"
+    assert dumped["minLength"] == 3
+
+
+def test_test_case_schema_keeps_example_metadata() -> None:
+    schema = PromptLensTestCase.model_json_schema()
+
+    assert "example" in schema
+    assert schema["example"]["id"] == "cs-001"
+
+
+def test_run_config_schema_keeps_example_metadata() -> None:
+    schema = RunConfig.model_json_schema()
+
+    assert "example" in schema
+    assert schema["example"]["golden_set"].endswith("customer_support.yaml")
+
+
+def test_golden_set_schema_keeps_example_metadata() -> None:
+    schema = GoldenSet.model_json_schema()
+
+    assert "example" in schema
+    assert schema["example"]["name"] == "Customer Support Tests"