# Perform API GET and convert the resulting Json as tag values **URL:** \ **Category:** Ignition\ **Tags:** ignition81, scripting, perspective\ **Created:** [June 10, 2024, 10:33pm UTC](https://forum.inductiveautomation.com/t/perform-api-get-and-convert-the-resulting-json-as-tag-values/91660 "2024-06-10T22:33:04Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![cdrizzy](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/cdrizzy/32/59051_2.png) [@cdrizzy](https://forum.inductiveautomation.com/u/cdrizzy)\ **Post date:** [June 10, 2024, 10:33pm UTC](https://forum.inductiveautomation.com/t/perform-api-get-and-convert-the-resulting-json-as-tag-values/91660/1 "2024-06-10T22:33:04Z")
I have a few API GETs that I am attempting to use for communication between our machines and an ERP. Using the Postman application I am able to send the GET request and receive a response (Only the names, locations and events have been changed while the structure is still intact): [resultJsonFromAPI.json](https://forum.inductiveautomation.com/uploads/short-url/toszocmimB1lw9eiMtbNNwiCuWA.json) (2.6 KB) I plan on most of this information being useful to me in the future but for now this particular API has the "ItemNo" and "UOM" values that I need. I would like to store these values as a tag so I can use them elsewhere. I am able to perform HTTP bindings in Perspective on a TextField and then configure my transform to ```python {value}[0]["UOM"] ``` and it returns the expected value. I can also bind the http to a custom property and it will add all the objects in for me: ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/1/b/1b8c26b6b85603c8a698df8fc4b642536232234d.png) Unfortunately this does me no good apart from confirming that the API functions and it does seem to be a json. I am struggling with trying to understand how to script this. I have seen several examples where people have mentioned dictionaries but I don't know what those are or how to make them, and I tried to modify this code but I have obviously butchered the formatting (this snippet is actually from a different API but the info is similar and the concept should be the same): ```python Header1="ProdOrderNo" Header2="ProdOrderItemNo" Header3="ItemNo" Header4="ItemDesc" ##client = system.net.httpClient() wasnt working like i thought when i did client.get() response = system.net.httpGet("http://apiroutehere") data=[] for key in response.json['ProdOrderComponentItemList']: #i thought this was the name of the primary header. pretty sure im wrong. data.append([key['ProdOrderNo'],key['ProdOrderItemNo'],key['ItemNo'],key['ItemDesc']]) headers=[Header1,Header2,Header3,Header4] listing=system.dataset.toDataSet(headers, data) system.tag.writeAsync(["[default]TagImWritingTo"], [len(data),listing]) ``` I tried to make an expression tag and use `jsonGet()` but I again could not figure out the headers and I'm not even sure that I was performing the GET correctly. I will only be setting this up once and wont have to do it again (I'm not saying never though) so if I have to manually set up the tags then so be it. I would greatly appreciate some guidance with where I should even be starting and what the appropriate approach even is. My scripting/Python knowledge is limited, heck I didn't even know what an API was 2 months ago, so thanks for your patience. ----------------------------------------------------------------------------------------- ----------------------------------------------------------------------------------------- ----------------------------------------------------------------------------------------- Edit: So I have marked this as solved however I wanted to add some additional information since my API query parameter will change depending on which line I'm currently communicating from. I added two reference tags to obtain this value and keep all my stuff in one place. ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/b/7/b7bcb631a5f14a46ad87866b15af86a1e84f57d6.png) I used a Value Changed script event on the relevant tag: ```python srcTag="pathToTagA" tarTag="pathToTagB" srcVal=system.tag.readBlocking(srcTag)[0].value ##allows the parameter for the GET to be dynamic with srcVal as a substitute addressAPI="APIhttpaddress"+srcVal response=system.net.httpGet(addressAPI) system.tag.writeAsync(tarTag,response) ``` As a result I think the GET only occurs when the value changes (I made an assumption that should reduce the network traffic?) and "tarTag" is a document tag as suggested. ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/d/1/d127bf3473907e24f33d5554ecaf6d125d62aa32.png) I set up a bunch of expression tags within my UDT that use `jsonGet({[.]0jsonFGPalletList},"[0].ProdOrderNo")` and substituted `[0].ProdOrderNo` with the required header. I was having a huge roadblock because I could not wrap my head around how to translate the information from the User Manual example that had clearly defined headers to my data that had none. I don't know how I finally made the connection but I did. I tested this and if the value that is passed as a API query param is not valid it will give `Error_ExpressionEval` as the result. I am satisfied with how it is setup but would also accept critique. Thanks for all the help. ---
**Author:** ![michael.flagler](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/michael.flagler/32/26272_2.png) [@michael.flagler](https://forum.inductiveautomation.com/u/michael.flagler)\ **Post date:** [June 10, 2024, 10:37pm UTC](https://forum.inductiveautomation.com/t/perform-api-get-and-convert-the-resulting-json-as-tag-values/91660/2 "2024-06-10T22:37:06Z")
Easiest I believe is to write the entire json string to a document tag (probably in a UDT), then have other expression tags in the UDT that use jsonGet to set their values without having to use any scripting. > **[jsonGet | Ignition User Manual](https://www.docs.inductiveautomation.com/docs/8.1/appendix/expression-functions/JSON/jsonGet)** > > Takes a JSON friendly string and a path string, and returns the value of that path. ---
**Author:** ![cdrizzy](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/cdrizzy/32/59051_2.png) [@cdrizzy](https://forum.inductiveautomation.com/u/cdrizzy)\ **Post date:** [June 11, 2024, 4:28pm UTC](https://forum.inductiveautomation.com/t/perform-api-get-and-convert-the-resulting-json-as-tag-values/91660/3 "2024-06-11T16:28:35Z")
Thanks! The document tag was the key. I did edit my main post with some extra info that clarified some of the struggles I had. Thank you for the help. ---
**Author:** ![David\_Stone](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/david_stone/32/79749_2.png) [@David\_Stone](https://forum.inductiveautomation.com/u/David_Stone)\ **Post date:** [June 11, 2024, 10:41pm UTC](https://forum.inductiveautomation.com/t/perform-api-get-and-convert-the-resulting-json-as-tag-values/91660/4 "2024-06-11T22:41:55Z")
Instead of reinventing the wheel, consider using this free module from Kyvis Labs, it does all the API requests on the gateway side and is configured using a YAML file. It is a lot easier to configure as it makes a tag provider and makes the tags directly if configured to do so. Saves a lot of ad-hoc scripts and onChanges etc. Also it makes it easier for a more junior integrator to follow what is happening. > **[GitHub - Kyvis-Labs/ignition-api-client-module: An Ignition module that...](https://github.com/Kyvis-Labs/ignition-api-client-module)** > > An Ignition module that provides an easy way to interface with REST APIs without having to write scripts in Ignition. - Kyvis-Labs/ignition-api-client-module ---
**Author:** ![cdrizzy](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/cdrizzy/32/59051_2.png) [@cdrizzy](https://forum.inductiveautomation.com/u/cdrizzy)\ **Post date:** [June 12, 2024, 1:49pm UTC](https://forum.inductiveautomation.com/t/perform-api-get-and-convert-the-resulting-json-as-tag-values/91660/5 "2024-06-12T13:49:58Z")
Neat. I will look at this for the next time I need to perform API shenanigans. Thank you.