title: "Guide for migrating from RESP2 to RESP3 replies"

linkTitle: "RESP3 migration guide"

weight: 6

description: JSON RESP2 to RESP3 replies reference for client developers

In RESP3, the default value of the optional path argument was changed from `.` to `$`.

Due to this change, the replies of some commands have slightly changed.

This page provides a brief comparison between RESP2 and RESP3 responses for JSON commands to help developers in migrating their clients from RESP2 to RESP3.

The types are described using a [“TypeScript-like” syntax](https://www.typescriptlang.org/docs/handbook/2/everyday-types.html). `Array<a>` denotes an [array](https://www.typescriptlang.org/docs/handbook/2/everyday-types.html#arrays) where the type of elements is known, but the number of elements is not.

| Command | RESP2 | RESP3 |

|---------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

| All JSON commands | **Default value of optional `path` argument**: `.` | **Default value of optional `path` argument:** `$` |

| JSON.ARRAPPEND<br/>JSON.ARRINDEX<br/>JSON.ARRINSERT<br/>JSON.ARRLEN<br/>JSON.ARRTRIM<br/>JSON.OBJLEN<br/>JSON.STRAPPEND<br/>JSON.STRLEN<br/>JSON.TOGGLE | *`$`-based path argument:* <br/> Reply: Array\<BulkString &#124; null> <br/><br/> *`.`-based path argument :*&nbsp;<br/> Reply: BulkString | *`$`-based path argument:*&nbsp; <br/> Reply: Array\<number &#124; null> <br/><br/> *`.`-based path argument :* <br/> Reply: number |

| JSON.GET | Reply: JSON encoded string <br/> Example: <br/> ```> JSON.SET k $ "[1,2,3]"```<br/> ```> JSON.GET k```<br/>```"[1,2,3]"``` | Reply: JSON encoded string with a top-level array <br/> Example: <br/> ```> JSON.SET k $ "[1,2,3]"```<br/> ```> JSON.GET k```<br/>```"[[1,2,3]]"``` |

| JSON.NUMINCRBY<br/>JSON.NUMMULTBY | *`$`-based path argument:* <br/> Reply: JSON-encoded BulkString &#124; null <br/><br/> *`.`-based path argument :*&nbsp;<br/> Reply: BulkString &#124; null &#124; error | *`$`-based path argument:* <br/> Reply: Array\<number &#124; null> &#124; error <br/><br/> *`.`-based path argument :*&nbsp;<br/> Reply: number &#124; null &#124; error |

| JSON.OBJKEYS | *`$`-based path argument:* <br/> Reply: Array\<Array\<BulkString\>> <br/><br/> *`.`-based path argument :*&nbsp;<br/> Reply: Array\<BulkString> | *`$`-based path argument:* <br/> Reply: Array\<Array\<BulkString\>> <br/><br/> *`.`-based path argument :*&nbsp;<br/> Reply: Array\<BulkString> |

| JSON.TYPE | *`$`-based path argument:* <br/> Reply: Array\<BulkString\> <br/> Example: <br />```> JSON.TYPE k $```<br />```1) "array"``` <br/><br/> *`.`-based path argument :*&nbsp;<br/> Reply: BulkString | *`$`-based path argument:* <br/> Reply: Array\<Array\<BulkString\>> <br/> Example: <br />```> JSON.TYPE k $```<br />```1) 1) "array"``` <br/><br/> *`.`-based path argument :*&nbsp;<br/> Reply: Array\<BulkString> |