diff --git a/core/internal/testutil/account.go b/core/internal/testutil/account.go
index 6c1d62b5c..3c53d84d4 100644
--- a/core/internal/testutil/account.go
+++ b/core/internal/testutil/account.go
@@ -51,6 +51,7 @@ type TestScenarios struct {
 	FileRetrieve          bool // File API retrieve functionality
 	FileDelete            bool // File API delete functionality
 	FileContent           bool // File API content download functionality
+	FileBatchInput        bool // Whether batch create supports file-based input (InputFileID)
 }
 
 // ComprehensiveTestConfig extends TestConfig with additional scenarios
diff --git a/core/internal/testutil/batch.go b/core/internal/testutil/batch.go
index 58d61e521..fe28cb253 100644
--- a/core/internal/testutil/batch.go
+++ b/core/internal/testutil/batch.go
@@ -627,10 +627,10 @@ func RunFileUnsupportedTest(t *testing.T, client *bifrost.Bifrost, ctx context.C
 
 // RunFileAndBatchIntegrationTest tests the integration between file upload and batch create
 func RunFileAndBatchIntegrationTest(t *testing.T, client *bifrost.Bifrost, ctx context.Context, testConfig ComprehensiveTestConfig) {
-	// Skip if either file upload or batch create is not supported
-	if !testConfig.Scenarios.FileUpload || !testConfig.Scenarios.BatchCreate {
-		t.Logf("[SKIPPED] File and Batch Integration: FileUpload=%v, BatchCreate=%v for provider %s",
-			testConfig.Scenarios.FileUpload, testConfig.Scenarios.BatchCreate, testConfig.Provider)
+	// Skip if file-based batch input is not supported
+	if !testConfig.Scenarios.FileBatchInput {
+		t.Logf("[SKIPPED] File and Batch Integration: FileBatchInput=%v for provider %s",
+			testConfig.Scenarios.FileBatchInput, testConfig.Provider)
 		return
 	}
 
diff --git a/core/internal/testutil/tests.go b/core/internal/testutil/tests.go
index 218f3e869..f9a7401e5 100644
--- a/core/internal/testutil/tests.go
+++ b/core/internal/testutil/tests.go
@@ -115,7 +115,7 @@ func printTestSummary(t *testing.T, testConfig ComprehensiveTestConfig) {
 		{"FileDelete", testConfig.Scenarios.FileDelete},
 		{"FileContent", testConfig.Scenarios.FileContent},
 		{"FileUnsupported", !testConfig.Scenarios.FileUpload && !testConfig.Scenarios.FileList && !testConfig.Scenarios.FileRetrieve && !testConfig.Scenarios.FileDelete && !testConfig.Scenarios.FileContent},
-		{"FileAndBatchIntegration", testConfig.Scenarios.FileUpload && testConfig.Scenarios.BatchCreate},
+		{"FileAndBatchIntegration", testConfig.Scenarios.FileBatchInput},
 	}
 
 	supported := 0
diff --git a/core/providers/anthropic/anthropic_test.go b/core/providers/anthropic/anthropic_test.go
index a50fc6b1c..615434ff7 100644
--- a/core/providers/anthropic/anthropic_test.go
+++ b/core/providers/anthropic/anthropic_test.go
@@ -57,7 +57,8 @@ func TestAnthropic(t *testing.T) {
 			FileList:              true,
 			FileRetrieve:          true,
 			FileDelete:            true,
-			FileContent:           true,
+			FileContent:           false,
+			FileBatchInput:        false, // Anthropic batch API only supports inline requests, not file-based input
 		},
 	}
 
diff --git a/core/providers/bedrock/bedrock_test.go b/core/providers/bedrock/bedrock_test.go
index 9ad550358..31c3fc227 100644
--- a/core/providers/bedrock/bedrock_test.go
+++ b/core/providers/bedrock/bedrock_test.go
@@ -79,6 +79,7 @@ func TestBedrock(t *testing.T) {
 			FileRetrieve:          true,
 			FileDelete:            true,
 			FileContent:           true,
+			FileBatchInput:        true,
 		},
 	}
 
diff --git a/core/providers/gemini/batch.go b/core/providers/gemini/batch.go
index bf02b0af2..c15a12208 100644
--- a/core/providers/gemini/batch.go
+++ b/core/providers/gemini/batch.go
@@ -64,34 +64,55 @@ func buildBatchRequestItems(requests []schemas.BatchRequestItem) []GeminiBatchRe
 			requestData = req.Params
 		}
 
-		// Extract messages from the request data
+		// Extract messages from the request data - handle multiple possible types
+		// Go type assertions don't work across slice types, so we handle each case
 		if requestData != nil {
-			if msgs, ok := requestData["messages"].([]interface{}); ok {
-				for _, msg := range msgs {
-					if msgMap, ok := msg.(map[string]interface{}); ok {
-						role := "user"
-						if r, ok := msgMap["role"].(string); ok {
-							if r == "assistant" {
-								role = "model"
-							} else if r == "system" {
-								// System messages are handled separately in Gemini
-								continue
-							} else {
-								role = r
-							}
-						}
+			var messages []map[string]interface{}
 
-						parts := []*Part{}
-						if c, ok := msgMap["content"].(string); ok {
-							parts = append(parts, &Part{Text: c})
-						}
+			// Try []interface{} first (generic JSON unmarshaling)
+			if msgsInterface, ok := requestData["messages"].([]interface{}); ok {
+				for _, m := range msgsInterface {
+					if msgMap, ok := m.(map[string]interface{}); ok {
+						messages = append(messages, msgMap)
+					}
+				}
+			} else if msgsTyped, ok := requestData["messages"].([]map[string]interface{}); ok {
+				// Try []map[string]interface{} (typed maps)
+				messages = msgsTyped
+			} else if msgsString, ok := requestData["messages"].([]map[string]string); ok {
+				// Try []map[string]string (test case format)
+				for _, m := range msgsString {
+					msgMap := make(map[string]interface{})
+					for k, v := range m {
+						msgMap[k] = v
+					}
+					messages = append(messages, msgMap)
+				}
+			}
 
-						contents = append(contents, Content{
-							Role:  role,
-							Parts: parts,
-						})
+			// Process extracted messages
+			for _, msgMap := range messages {
+				role := "user"
+				if r, ok := msgMap["role"].(string); ok {
+					if r == "assistant" {
+						role = "model"
+					} else if r == "system" {
+						// System messages are handled separately in Gemini
+						continue
+					} else {
+						role = r
 					}
 				}
+
+				parts := []*Part{}
+				if c, ok := msgMap["content"].(string); ok {
+					parts = append(parts, &Part{Text: c})
+				}
+
+				contents = append(contents, Content{
+					Role:  role,
+					Parts: parts,
+				})
 			}
 		}
 
diff --git a/core/providers/gemini/gemini_test.go b/core/providers/gemini/gemini_test.go
index a39645016..3498f5e36 100644
--- a/core/providers/gemini/gemini_test.go
+++ b/core/providers/gemini/gemini_test.go
@@ -63,7 +63,8 @@ func TestGemini(t *testing.T) {
 			FileList:              true,
 			FileRetrieve:          true,
 			FileDelete:            true,
-			FileContent:           true,
+			FileContent:           false,
+			FileBatchInput:        true,
 		},
 	}
 
diff --git a/core/providers/openai/openai_test.go b/core/providers/openai/openai_test.go
index ff40595b1..19077b809 100644
--- a/core/providers/openai/openai_test.go
+++ b/core/providers/openai/openai_test.go
@@ -70,6 +70,7 @@ func TestOpenAI(t *testing.T) {
 			FileRetrieve:          true,
 			FileDelete:            true,
 			FileContent:           true,
+			FileBatchInput:        true,
 		},
 	}