first commit: one-api base code + SAAS plan document

relay/adaptor/gemini/constants.go

@@ -0,0 +1,35 @@
+package gemini
+
+import (
+	"github.com/songquanpeng/one-api/relay/adaptor/geminiv2"
+)
+
+// https://ai.google.dev/models/gemini
+
+var ModelList = geminiv2.ModelList
+
+// ModelsSupportSystemInstruction is the list of models that support system instruction.
+//
+// https://cloud.google.com/vertex-ai/generative-ai/docs/learn/prompts/system-instructions
+var ModelsSupportSystemInstruction = []string{
+	// "gemini-1.0-pro-002",
+	// "gemini-1.5-flash", "gemini-1.5-flash-001", "gemini-1.5-flash-002",
+	// "gemini-1.5-flash-8b",
+	// "gemini-1.5-pro", "gemini-1.5-pro-001", "gemini-1.5-pro-002",
+	// "gemini-1.5-pro-experimental",
+	"gemini-2.0-flash", "gemini-2.0-flash-exp",
+	"gemini-2.0-flash-thinking-exp-01-21",
+}
+
+// IsModelSupportSystemInstruction check if the model support system instruction.
+//
+// Because the main version of Go is 1.20, slice.Contains cannot be used
+func IsModelSupportSystemInstruction(model string) bool {
+	for _, m := range ModelsSupportSystemInstruction {
+		if m == model {
+			return true
+		}
+	}
+
+	return false
+}