Autodek Forge Tutorial - autodesk-forge

Question

I have been working through the Autodesk Forge Sample App tutorial.
WHen I click the button to connect with my account I get this error;
{"developerMessage":"The required parameter(s) redirect_uri not present in the request","errorCode":"AUTH-008","more info":"https://forge.autodesk.com/en/docs/oauth/v2/developers_guide/error_handling/"}

Answer 1

If you get this error, you probably trying a 3 legged oauth flow. And it means that you did not provide the callback url in the request. Since you did not say which tutorial you have been using, let me point you to 2 sources - the Forge documentation tutorial here or the Learn Forge tutorial here
In both case, it is important to have the callback url defined in the application page on the Forge portal - If you are using your local machine, it should be something like http://localhost:3000/mycallback. The learnforge material tells you to define it as (see here):
http://localhost:3000/api/forge/callback/oauth
where the documentation tutorial says to use
http://sampleapp.com/oauth/callback
but here they assume you own the domain sampleapp.com which is probably not true. You need to replace sampleapp.com by your own domain or the localhost:port when developing your webserver on your local machine. Note it is important to use your true domain vs localhost when you'll run the code on your server, and update both your application page and your code to use the same definition. I usually setup 3 applications (dev: with localhost:3001, staging: with myapp-staging.autod3sk.net, and production: with myapp.autod3sk.net) - this is to avoid to have to edits keys all the time and make the application deployment a lot easier.
Now that your application is setup, you need to use that URL in your request as documented in the Oauth API. But all parameters should be URL encoded, otherwise the / character will be misinterpreted by the server. Failing to pass the correct and encoded URL parameter in the request will result in the error you are seeing.
Here is an example:
https://developer.api.autodesk.com/authentication/v1/authorize \
?response_type=code \
&client_id=MYCLIENT_ID \
&redirect_uri=MY_ENCODE_CALLBACKURL \
&scope=REQUIRED_SCOPES
after replacing the placeholders, it should look like this
https://developer.api.autodesk.com/authentication/v1/authorize\
?response_type=code\
&client_id=oz9f...k2d\
&redirect_uri=http%3a%2f%2flocalhost%3a3000%2fapi%2fforge%2fcallback%2foauth\
&scope=data%3aread
Copy this in your browser, and after logging and the consent page, the service should return to your browser with a URL like this:
http://localhost:3000/api/forge/callback/oauth?code=wroM1vFA4E-Aj241-quh_LVjm7UldawnNgYEHQ8I
Because, we do not have a server yet, the browser will error, but you can clearly see the URL returned to you with a code. You know need to copy that code into another request to get the final token. Here, we will use curl, but ideally both request and the callback should be handled by your server code.
curl 'https://developer.api.autodesk.com/authentication/v1/gettoken' \
-X 'POST' \
-H 'Content-Type: application/x-www-form-urlencoded' \
-d 'client_id=oz9f...k2d' \
-d 'client_secret=eUr...Q1e' \
-d 'grant_type=authorization_code' \
-d 'code=wroM1vFA4E-Aj241-quh_LVjm7UldawnNgYEHQ8I' \
-d 'redirect_uri=http://localhost:3000/api/forge/callback/oauth'
Ideally, all this needs to be done in your server code, like the learnforge tutorial teach you to do.