diff --git a/relaykit/relayconvert/internal/oai_chat/to_claude_messages_req.go b/relaykit/relayconvert/internal/oai_chat/to_claude_messages_req.go
index fec9d95e..ee4722f5 100644
--- a/relaykit/relayconvert/internal/oai_chat/to_claude_messages_req.go
+++ b/relaykit/relayconvert/internal/oai_chat/to_claude_messages_req.go
@@ -32,25 +32,14 @@ func OpenAIChatRequestToClaudeMessages(c context.Context, info convmeta.Meta, te
 	claudeTools := make([]any, 0, len(textRequest.Tools))
 
 	for _, tool := range textRequest.Tools {
-		if params, ok := tool.Function.Parameters.(map[string]any); ok {
-			claudeTool := dto.Tool{
-				Name:        tool.Function.Name,
-				Description: tool.Function.Description,
-			}
-			claudeTool.InputSchema = make(map[string]interface{})
-			if params["type"] != nil {
-				claudeTool.InputSchema["type"] = params["type"].(string)
-			}
-			claudeTool.InputSchema["properties"] = params["properties"]
-			claudeTool.InputSchema["required"] = params["required"]
-			for key, value := range params {
-				if key == "type" || key == "properties" || key == "required" {
-					continue
-				}
-				claudeTool.InputSchema[key] = value
-			}
-			claudeTools = append(claudeTools, &claudeTool)
+		if _, ok := tool.Function.Parameters.(map[string]any); !ok && tool.Type != "function" {
+			continue
 		}
+		claudeTools = append(claudeTools, &dto.Tool{
+			Name:        tool.Function.Name,
+			Description: tool.Function.Description,
+			InputSchema: sharedclaude.FunctionParametersToInputSchema(tool.Function.Parameters),
+		})
 	}
 
 	if textRequest.WebSearchOptions != nil {
diff --git a/relaykit/relayconvert/internal/oai_chat/to_claude_messages_req_test.go b/relaykit/relayconvert/internal/oai_chat/to_claude_messages_req_test.go
new file mode 100644
index 00000000..c718bd25
--- /dev/null
+++ b/relaykit/relayconvert/internal/oai_chat/to_claude_messages_req_test.go
@@ -0,0 +1,81 @@
+package oaichat
+
+import (
+	"context"
+	"testing"
+
+	"github.com/QuantumNous/new-api/relaykit/dto"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestOpenAIChatRequestToClaudeMessagesNormalizesToolInputSchema(t *testing.T) {
+	tests := []struct {
+		name       string
+		parameters any
+		wantSchema map[string]any
+	}{
+		{
+			name:       "omitted parameters",
+			parameters: nil,
+			wantSchema: map[string]any{
+				"type":       "object",
+				"properties": map[string]any{},
+			},
+		},
+		{
+			name: "missing type and properties",
+			parameters: map[string]any{
+				"additionalProperties": false,
+			},
+			wantSchema: map[string]any{
+				"type":                 "object",
+				"properties":           map[string]any{},
+				"additionalProperties": false,
+			},
+		},
+		{
+			name: "non-string type",
+			parameters: map[string]any{
+				"type":       123,
+				"properties": map[string]any{},
+			},
+			wantSchema: map[string]any{
+				"type":       123,
+				"properties": map[string]any{},
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			maxTokens := uint(1024)
+			got, err := OpenAIChatRequestToClaudeMessages(context.Background(), nil, dto.GeneralOpenAIRequest{
+				Model:     "claude-test",
+				MaxTokens: &maxTokens,
+				Messages: []dto.Message{
+					{Role: "user", Content: "Call the tool."},
+				},
+				Tools: []dto.ToolCallRequest{
+					{
+						Type: "function",
+						Function: dto.FunctionRequest{
+							Name:        "get_current_time",
+							Description: "Get the current time",
+							Parameters:  tt.parameters,
+						},
+					},
+				},
+			})
+
+			require.NoError(t, err)
+			tools, ok := got.Tools.([]any)
+			require.True(t, ok)
+			require.Len(t, tools, 1)
+			tool, ok := tools[0].(*dto.Tool)
+			require.True(t, ok)
+			assert.Equal(t, "get_current_time", tool.Name)
+			assert.Equal(t, tt.wantSchema, tool.InputSchema)
+		})
+	}
+}
diff --git a/relaykit/relayconvert/internal/oai_responses/to_claude_messages_req.go b/relaykit/relayconvert/internal/oai_responses/to_claude_messages_req.go
index 53aa674c..3695449f 100644
--- a/relaykit/relayconvert/internal/oai_responses/to_claude_messages_req.go
+++ b/relaykit/relayconvert/internal/oai_responses/to_claude_messages_req.go
@@ -134,32 +134,12 @@ func responsesFunctionDeclarationsToClaudeTools(functions []dto.FunctionRequest)
 		tools = append(tools, &dto.Tool{
 			Name:        function.Name,
 			Description: function.Description,
-			InputSchema: responsesFunctionParametersToClaudeInputSchema(function.Parameters),
+			InputSchema: sharedclaude.FunctionParametersToInputSchema(function.Parameters),
 		})
 	}
 	return tools
 }
 
-func responsesFunctionParametersToClaudeInputSchema(parameters any) map[string]interface{} {
-	if params, ok := parameters.(map[string]any); ok {
-		schema := make(map[string]interface{}, len(params))
-		for key, value := range params {
-			schema[key] = value
-		}
-		if schema["type"] == nil {
-			schema["type"] = "object"
-		}
-		if schema["properties"] == nil {
-			schema["properties"] = map[string]interface{}{}
-		}
-		return schema
-	}
-	return map[string]interface{}{
-		"type":       "object",
-		"properties": map[string]interface{}{},
-	}
-}
-
 func applyResponsesReasoningToClaude(req *dto.OpenAIResponsesRequest, claudeRequest *dto.ClaudeRequest) {
 	effort := ReasoningEffort(req)
 	switch effort {
diff --git a/relaykit/relayconvert/internal/shared/claude/schema.go b/relaykit/relayconvert/internal/shared/claude/schema.go
new file mode 100644
index 00000000..4878130d
--- /dev/null
+++ b/relaykit/relayconvert/internal/shared/claude/schema.go
@@ -0,0 +1,16 @@
+package claude
+
+func FunctionParametersToInputSchema(parameters any) map[string]any {
+	params, _ := parameters.(map[string]any)
+	schema := make(map[string]any, len(params)+2)
+	for key, value := range params {
+		schema[key] = value
+	}
+	if schema["type"] == nil {
+		schema["type"] = "object"
+	}
+	if schema["properties"] == nil {
+		schema["properties"] = map[string]any{}
+	}
+	return schema
+}