# How to use own defined struct in .api file **URL:** \ **Category:** Legato Application Framework\ **Created:** [July 11, 2018, 8:54am UTC](https://forum.legato.io/t/how-to-use-own-defined-struct-in-api-file/3430 "2018-07-11T08:54:24Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![sowvikroy](https://avatars.discourse-cdn.com/v4/letter/s/8baadc/32.png) [@sowvikroy](https://forum.legato.io/u/sowvikroy)\ **Post date:** [July 11, 2018, 8:54am UTC](https://forum.legato.io/t/how-to-use-own-defined-struct-in-api-file/3430/1 "2018-07-11T08:54:25Z")
Hello, I have a requirement to use my own defined structure in the .api file. Somehow I am successfully doing this like below: **File: abc.api** REFERENCE Params; FUNCTION Info(Params params OUT); **File: abcd.h** typedef struct { //Common parameters int32\_t signal\_strength; int32\_t temperature; uint32\_t level; }abc\_Params; **File: abcde.c** void abc\_Info(abc\_ParamsRef\_t\* params) { //Here I can’t access the struct members } Could anyone please help ---
**Author:** ![flu](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.legato.io/flu/32/813_2.png) [@flu](https://forum.legato.io/u/flu)\ **Post date:** [July 11, 2018, 9:12am UTC](https://forum.legato.io/t/how-to-use-own-defined-struct-in-api-file/3430/2 "2018-07-11T09:12:15Z")
Hello sowviroy \*.api files do not support structures Solution #1: Use different functions to pass the difference structure fields Solution #2: abc\_Params myStruc; Use le\_event\_Report ( myEvtId, & myStruc, sizeof ( myStruc ) ); KR. ---
**Author:** ![Madan](https://avatars.discourse-cdn.com/v4/letter/m/6a8cbe/32.png) [@Madan](https://forum.legato.io/u/Madan)\ **Post date:** [October 25, 2018, 4:16am UTC](https://forum.legato.io/t/how-to-use-own-defined-struct-in-api-file/3430/3 "2018-10-25T04:16:45Z")
I do need to use a structure in an API call. Legato documentation shows there is a provision for STRUCT. But it is not recognised by compiler. Wasnt it supposed to work? ---
**Author:** ![davidc](https://avatars.discourse-cdn.com/v4/letter/d/a183cd/32.png) [@davidc](https://forum.legato.io/u/davidc)\ **Post date:** [October 25, 2018, 7:06am UTC](https://forum.legato.io/t/how-to-use-own-defined-struct-in-api-file/3430/4 "2018-10-25T07:06:18Z")
Hiya, API doesn’t support a struct as a ‘datatype’. The `struct` you see mentioned in the docs are just how the IPC library deals with `references` - they’re actually an opaque data type that you treat as a void pointer. This has caused me grief for a couple of years… ciao, Dave ---
**Author:** ![Kalai](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.legato.io/kalai/32/1135_2.png) [@Kalai](https://forum.legato.io/u/Kalai)\ **Post date:** [September 16, 2021, 6:10am UTC](https://forum.legato.io/t/how-to-use-own-defined-struct-in-api-file/3430/5 "2021-09-16T06:10:59Z")
hi any samples available how to use struct in user defined api.thanks in advance ---
**Author:** ![jyijyi](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.legato.io/jyijyi/32/822_2.png) [@jyijyi](https://forum.legato.io/u/jyijyi)\ **Post date:** [September 16, 2021, 7:02am UTC](https://forum.legato.io/t/how-to-use-own-defined-struct-in-api-file/3430/6 "2021-09-16T07:02:57Z")
how about this? > [@In legato 19.02 api is not supporting more than 2 string](https://forum.legato.io/t/in-legato-19-02-api-is-not-supporting-more-than-2-string/5716/2): > > how about making the API file like this? STRUCT ARRAY123 { string Array1[10]; int32 port1; string Array2[10]; int32 port2; string Array3[10]; int32 port3; string Array4[10]; int32 port4; string Array5[10]; int32 port5; }; FUNCTION arraySend ( ARRAY123 asd IN ); It is working on my side with vscode leaf swi-wp76\_4.7.0. You can use my code: [IPC\_step1.rar](https://forum.legato.io/uploads/short-url/dgUwkVXIXDa6sS6CbPxzjqn2x7a.rar) (2.4 KB) ---
**Author:** ![Kalai](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.legato.io/kalai/32/1135_2.png) [@Kalai](https://forum.legato.io/u/Kalai)\ **Post date:** [September 16, 2021, 10:35am UTC](https://forum.legato.io/t/how-to-use-own-defined-struct-in-api-file/3430/7 "2021-09-16T10:35:38Z")
[StructApi.tar.gz](https://forum.legato.io/uploads/short-url/rSq0yuFxpuIO2boggioLiABPiwP.gz) (3.0 KB) am getting the following error, can u guide me how to pass input to the struct and my sample is attached for your refernce Jan 6 10:27:00 swi-mdm9x28-wp user.info Legato: INFO | ClientCompExe[4274]/ClientComp T=main | ClientComp.c \_ClientComp\_COMPONENT\_INIT() 17 | LOG\_CLIENT\> start Jan 6 10:27:00 swi-mdm9x28-wp user.info Legato: INFO | ClientCompExe[4274]/ClientComp T=main | ClientComp.c \_ClientComp\_COMPONENT\_INIT() 24 | LOG\_CLIENT\> make the request no 1 to server Jan 6 10:27:00 swi-mdm9x28-wp user.info Legato: INFO | StructApiComponentExe[4273]/StructApiComponent T=main | StructApiComponent.c Sample\_logMessage() 26 | LOG\_SERVER\> received the message “log from client : request no 1” from a client. Jan 6 10:27:10 swi-mdm9x28-wp user.emerg Legato: _EMR_ | ClientCompExe[4274]/framework T=main | Sample\_client.c Sample\_arraySend() 667 | Assert Failed: ‘Sample\_PackARRAY123( &\_msgBufPtr, &\_msgBufSize, asdPtr )’ Jan 6 10:27:10 swi-mdm9x28-wp user.info Legato: INFO | supervisor[4058]/supervisor T=main | proc.c proc\_SigChildHandler() 2051 | Process ‘ClientCompExe’ (PID: 4274) has exited with exit code 1. Jan 6 10:27:10 swi-mdm9x28-wp user.warn Legato: -WRN- | supervisor[4058]/supervisor T=main | app.c app\_SigChildHandler() 4031 | Process ‘ClientCompExe’ in app ‘StructApi’ faulted: Ignored. ---
**Author:** ![jyijyi](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.legato.io/jyijyi/32/822_2.png) [@jyijyi](https://forum.legato.io/u/jyijyi)\ **Post date:** [September 16, 2021, 11:02am UTC](https://forum.legato.io/t/how-to-use-own-defined-struct-in-api-file/3430/8 "2021-09-16T11:02:31Z")
Can yoy use the sample code in the link which is proven to be working fine ---
**Author:** ![Kalai](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.legato.io/kalai/32/1135_2.png) [@Kalai](https://forum.legato.io/u/Kalai)\ **Post date:** [September 16, 2021, 11:04am UTC](https://forum.legato.io/t/how-to-use-own-defined-struct-in-api-file/3430/9 "2021-09-16T11:04:29Z")
i exactly use the same program but getting error , the only change made is instead of two app i used two component ---
**Author:** ![jyijyi](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.legato.io/jyijyi/32/822_2.png) [@jyijyi](https://forum.legato.io/u/jyijyi)\ **Post date:** [September 16, 2021, 11:06am UTC](https://forum.legato.io/t/how-to-use-own-defined-struct-in-api-file/3430/10 "2021-09-16T11:06:00Z")
How about just running my app with two app ---
**Author:** ![Kalai](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.legato.io/kalai/32/1135_2.png) [@Kalai](https://forum.legato.io/u/Kalai)\ **Post date:** [September 16, 2021, 11:28am UTC](https://forum.legato.io/t/how-to-use-own-defined-struct-in-api-file/3430/11 "2021-09-16T11:28:24Z")
getting same error, dont know what am missing ---
**Author:** ![jyijyi](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.legato.io/jyijyi/32/822_2.png) [@jyijyi](https://forum.legato.io/u/jyijyi)\ **Post date:** [September 16, 2021, 11:30am UTC](https://forum.legato.io/t/how-to-use-own-defined-struct-in-api-file/3430/12 "2021-09-16T11:30:19Z")
Are you using swi-wp76\_4.7.0 ---
**Author:** ![Kalai](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.legato.io/kalai/32/1135_2.png) [@Kalai](https://forum.legato.io/u/Kalai)\ **Post date:** [September 16, 2021, 11:32am UTC](https://forum.legato.io/t/how-to-use-own-defined-struct-in-api-file/3430/13 "2021-09-16T11:32:19Z")
no its swi-wp76\_4.0.1 ---
**Author:** ![jyijyi](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.legato.io/jyijyi/32/822_2.png) [@jyijyi](https://forum.legato.io/u/jyijyi)\ **Post date:** [September 16, 2021, 11:41am UTC](https://forum.legato.io/t/how-to-use-own-defined-struct-in-api-file/3430/14 "2021-09-16T11:41:25Z")
Can you try the same