diff --git a/src/error.ts b/src/error.ts
index e04b074..4fb86bb 100644
--- a/src/error.ts
+++ b/src/error.ts
@@ -6,3 +6,6 @@ export function errorExit(msg: string): void {
 }
 
 export const ERR_NOT_READY = "NOT_READY";
+export const ERR_INVALID_CHAIN = "INVALID_CHAIN";
+export const ERR_ENDPOINT_INVALID = "ENDPOINT_INVALID";
+export const ERR_METHOD_INVALID = "METHOD_INVALID";