Gmail node with an external application

Santosh_Srinivas · January 19, 2021, 12:45pm

Hello,

I am wondering if this is possible.

I am creating a customer facing webapp (nodejs) and would be using Google login along with permissions to read emails.

Is it possible to use the permissions granted there to trigger requests using the gmail node in n8n.
In other words, I want to avoid having to authorize the n8n gmail node explicitly.

Thanks in advance!

jan · January 20, 2021, 6:53am

Uh no sorry. It is currently sadly not possible to inject custom credentials at runtime.

If you want to make it work anyway you would have to:

Create the credentials via the API (currently undocumented as it is only meant to be used by the Editor-UI).
Add the name of the credentials into to the JSON of the workflow (that part would be simple as it is literally just one string)
Execute that workflow via the Execute-Workflow Node

Santosh_Srinivas · January 20, 2021, 7:34am

Thanks @jan. That’s pretty much what I am looking for.

I need to figure out how create separate credentials for every user of my app and then inject it into the workflow at runtime.

I’ll try to look up the source code to figure out. Please point me to any relevant places if possible.

Thank you!

jan · January 20, 2021, 7:55am

Good to hear that it was helpful.

The easiest would be to create/update credentials via the UI and then looking at what kind of data does get sent. You can find the code which creates the credentials here:

github.com

n8n-io/n8n/blob/master/packages/cli/src/Server.ts#L822

      
        
            							`The parameter "url" is missing!`,
            							undefined,
            							400,
            						);
            					}
            					if (!/^http[s]?:\/\/.*\.json$/i.exec(req.query.url as string)) {
            						throw new ResponseHelper.ResponseError(
            							`The parameter "url" is not valid! It does not seem to be a URL pointing to a n8n workflow JSON file.`,
            							undefined,
            							400,
            						);
            					}
            					const data = await requestPromise.get(req.query.url as string);
            
            
					let workflowData: IWorkflowResponse | undefined;
            					try {
            						workflowData = JSON.parse(data);
            					} catch (error) {
            						throw new ResponseHelper.ResponseError(
            							`The URL does not point to valid JSON file!`,
            							undefined,

Additionally, can you find the OAuth2 related code here:

github.com

n8n-io/n8n/blob/master/packages/cli/src/Server.ts#L1217

      
        
            
            
					// Start the workflow
            					const data: IWorkflowExecutionDataProcess = {
            						destinationNode,
            						executionMode,
            						runData,
            						sessionId,
            						startNodes,
            						workflowData,
            						userId: req.user.id,
            					};
            					const workflowRunner = new WorkflowRunner();
            					const executionId = await workflowRunner.run(data);
            
            
					return {
            						executionId,
            					};
            				},
            			),
            		);

If you authenticate via OAuth2 with Google and output some information there, before it updates the credentials, you should be able to figure out quite fast how to make that work.

Good luck!

Alexandre_Cognard · October 13, 2024, 7:38pm

Hi,

I’m just wondering about the same question.

So currently, N8N can serve natively as a backend for a SAAS where external users login using gmail.

This node has not been updated for this purpose, correct ?
Do you know some other tool that can handle this part for n8n ? (because if I want to access emails of my users, I can then send info to any workflow).

And in your proposed solution I need to host my own solution and update the source code, right ?

Thanks

Chandresh · June 9, 2025, 7:07am

I have the same problem. Is there any workaround that automatically does the gmail authentication during runtime?