# HOWTO: JSON3 read json path value as Custom type or Convert JSON3.Object as Custom type
**URL:** https://discourse.julialang.org/t/howto-json3-read-json-path-value-as-custom-type-or-convert-json3-object-as-custom-type/115014
**Category:** New to Julia
**Tags:** question
**Created:** [May 31, 2024, 2:15pm UTC](https://discourse.julialang.org/t/howto-json3-read-json-path-value-as-custom-type-or-convert-json3-object-as-custom-type/115014 "2024-05-31T14:15:25Z")
**Posts on this page:** 9
**Page:** 1
### Author:  [@listenmmm](https://discourse.julialang.org/u/listenmmm)
#### Post date: [May 31, 2024, 2:15pm UTC](https://discourse.julialang.org/t/howto-json3-read-json-path-value-as-custom-type-or-convert-json3-object-as-custom-type/115014/1 "2024-05-31T14:15:25Z")
```julia-auto
begin
struct Book
name
price
tags
end
StructTypes.StructType(::Type{Book}) = StructTypes.Struct()
request_body_io = IOBuffer()
response_body_io = IOBuffer()
JSON3.write(request_body_io, Book("the julia", 11.11, ["programming", "julia"]))
request_body_io |> seekstart
response = request(
"https://httpbin.org/post",
method="POST",
headers=Dict("accept" => "application/json", "content-type" => "application/json"),
verbose=false,
input=request_body_io,
output=response_body_io,
)
@show response.status
@show response.message
body = response_body_io |> seekstart |> JSON3.read
# => how to convert the JSON3.Object as type Book or how to read json path (e.g. root.json) and convert it's value as Type Book directly
#
@show body["json"]
end
```
# UPDATE (provided by @Jeff_Emanuel )
```julia-auto
book = response_body_io |> seekstart |> JSON3.read |> x -> StructTypes.constructfrom(Book, x["json"])
@show typeof(book) # => typeof(book) = Book
@show book # => book = Book("the julia", 11.11, ["programming", "julia"])
```
---
### Author:  [@Jeff\_Emanuel](https://discourse.julialang.org/u/Jeff_Emanuel)
#### Post date: [May 31, 2024, 2:23pm UTC](https://discourse.julialang.org/t/howto-json3-read-json-path-value-as-custom-type-or-convert-json3-object-as-custom-type/115014/2 "2024-05-31T14:23:22Z")
[https://quinnj.github.io/JSON3.jl/stable/#Read-JSON-into-a-type](https://quinnj.github.io/JSON3.jl/stable/#Read-JSON-into-a-type)
---
### Author:  [@listenmmm](https://discourse.julialang.org/u/listenmmm)
#### Post date: [May 31, 2024, 2:27pm UTC](https://discourse.julialang.org/t/howto-json3-read-json-path-value-as-custom-type-or-convert-json3-object-as-custom-type/115014/3 "2024-05-31T14:27:11Z")
I’ve looked at this but couldn’t find what I was looking for, or I didn’t know how to apply it to my needs
---
### Author:  [@Jeff\_Emanuel](https://discourse.julialang.org/u/Jeff_Emanuel)
#### Post date: [May 31, 2024, 2:28pm UTC](https://discourse.julialang.org/t/howto-json3-read-json-path-value-as-custom-type-or-convert-json3-object-as-custom-type/115014/4 "2024-05-31T14:28:51Z")
Use the 2-arg JSON3.read which takes a type instead of the single argument JSON3.read you have at the end of your code. Something like
```julia
body = JSON3.read( response_body_io |> seekstart, Book )
```
You might need to read the body into a String first.
---
### Author:  [@listenmmm](https://discourse.julialang.org/u/listenmmm)
#### Post date: [May 31, 2024, 2:30pm UTC](https://discourse.julialang.org/t/howto-json3-read-json-path-value-as-custom-type-or-convert-json3-object-as-custom-type/115014/5 "2024-05-31T14:30:41Z")
I don’t want to convert the entire response body to type Book, but to convert its json field (root.json) to type Book
---
### Author:  [@Jeff\_Emanuel](https://discourse.julialang.org/u/Jeff_Emanuel)
#### Post date: [May 31, 2024, 2:33pm UTC](https://discourse.julialang.org/t/howto-json3-read-json-path-value-as-custom-type-or-convert-json3-object-as-custom-type/115014/6 "2024-05-31T14:33:53Z")
If you don’t have a type for the entire JSON structure, it may be simplest (if not fastest) to re-encode just the part that constitutes a book and the re-decode that as a Book. I’d look at defining a type for the entire structure.
---
### Author:  [@listenmmm](https://discourse.julialang.org/u/listenmmm)
#### Post date: [May 31, 2024, 2:37pm UTC](https://discourse.julialang.org/t/howto-json3-read-json-path-value-as-custom-type-or-convert-json3-object-as-custom-type/115014/7 "2024-05-31T14:37:19Z")
could JSON3 Intermediate Type（e.g. JSON3.Object) convert as custom type ?
---
### Author:  [@Jeff\_Emanuel](https://discourse.julialang.org/u/Jeff_Emanuel)
#### Post date: [May 31, 2024, 2:39pm UTC](https://discourse.julialang.org/t/howto-json3-read-json-path-value-as-custom-type-or-convert-json3-object-as-custom-type/115014/8 "2024-05-31T14:39:48Z")
I’m not aware of any way to do that automatically. I haven’t used this, but you could experiment with [Home · StructTypes.jl](https://juliadata.org/StructTypes.jl/stable/#StructTypes.constructfrom)
---
### Author:  [@listenmmm](https://discourse.julialang.org/u/listenmmm)
#### Post date: [May 31, 2024, 3:00pm UTC](https://discourse.julialang.org/t/howto-json3-read-json-path-value-as-custom-type-or-convert-json3-object-as-custom-type/115014/9 "2024-05-31T15:00:37Z")
It works fine, thanks!
I don’t know if this takes advantage of the lazy parse feature of JSON3.