diff --git a/src/options/index.ts b/src/options/index.ts
index f731d06..1da0038 100644
--- a/src/options/index.ts
+++ b/src/options/index.ts
@@ -7,20 +7,39 @@ const filterEnum = ($enum: PlainObject<any>, blacklist: string[] = []) => Object
   }, {}
 )
 
+let _options: Partial<IOption>
+
+export function getOption() {
+  const {constants, conf, ...others} = _options
+  Object.assign(constants, require('byteballcore/constants'))
+  Object.assign(conf, require('byteballcore/conf'))
+  return {...others, conf, constants}
+}
+
 /**
  * This function do all necessary thing for merging the option
  * It make it possible to set `byteballcore/constants` and `bytballcore/conf` programatically
  */
-export default function (option: Partial<IOption> = {}) {
+export function setOption(option: Partial<IOption> = {}) {
   if (!option.constants) option.constants = {}
+
   if (!option.conf) option.conf = {}
+  else throw new Error(`\`Bot.setOption({ conf: {} })\` not yet implemented (needs workaround)
+  please consider using "conf.js" file 😉`)
 
   // default conf regardless LIVENET or TESTNET
   option.conf = {
-    bServeAsHub: false,
-    bLight: true
+    bLight: true,
+    ...option.conf
   }
 
+  // #region TODO: remove this if not buggy
+  const {bLight, storage} = option.conf
+  if (bLight && (!storage || storage === 'sqlite')) option.conf.database = {
+    filename: 'byteball-light.sqlite', ...option.conf.database
+  }
+  // #endregion
+
   const conf_keys = ['hub', 'port']
 
   //#region begin merging option `conf` and `constants`
@@ -52,11 +71,16 @@ export default function (option: Partial<IOption> = {}) {
       ...option.conf
     }
   }
+  _options = option
   //#endregion
 
   // don't place this 👇 on top because it immediately print something upon require() 😓
   Object.assign(require('byteballcore/constants'), option.constants)
-  Object.assign(require('byteballcore/conf'), option.conf)
+
+  /// can't merge it maybe because of https://github.com/byteball/byteballcore/blame/cd764e9bd1edd00e93ee46c2e2ec029c6a52210b/conf.js#L73-L103
+  /// or https://github.com/byteball/byteballcore/blame/cd764e9bd1edd00e93ee46c2e2ec029c6a52210b/conf.js#L3
+  // Object.assign(require('byteballcore/conf'), option.conf) //👈🤔 TODO: need workaround
+
 }
 
 export * from './types'
diff --git a/src/options/types.ts b/src/options/types.ts
index a6b1c97..117aaa0 100644
--- a/src/options/types.ts
+++ b/src/options/types.ts
@@ -17,6 +17,10 @@ export enum TESTNET {
   attestedInDefinitionUpgradeMci = 616000,
   altBranchByBestParentUpgradeMci = 642000,
   //#endregion
+
+  //#region botbyte
+  explorer = 'https://testnetexplorer.byteball.org/#',
+  //#endregion
 }
 
 export enum LIVENET {
@@ -36,6 +40,10 @@ export enum LIVENET {
   attestedInDefinitionUpgradeMci = spendUnconfirmedUpgradeMci,
   altBranchByBestParentUpgradeMci = 3009824,
   //#endregion
+
+  //#region botbyte
+  explorer = 'https://explorer.byteball.org/#',
+  //#endregion
 }
 
 // #region Database config
@@ -43,7 +51,7 @@ export enum LIVENET {
  * @see https://github.com/byteball/byteballcore/blob/master/conf.js#L105-L116
  */
 interface IDatabase {
-  max_connections: number
+  max_connections?: number
 }
 
 interface IMySql extends IDatabase {