README.md
In gmailr: Access the 'Gmail' 'RESTful' API

This is an example of how to deploy a gmailr OAuth user token, for use in a Shiny app or similar.

This topic is also covered in the gmailr vignette "Deploy a token" (https://gmailr.r-lib.org/articles/deploy-a-token.html).

The token-setup.R script contains setup code that must be run interactively, in your primary computing environment.

This code should NOT be executed in the deployed data product. There's no reason for this code to even be part of the deployment.

token-setup.R stores the token in the file .secrets/gmailr-token.rds.

This approach relies on an encryption key, which you would create with gargle::secret_make_key(), and then store as an the environment variable ("GMAILR_DEPLOY_DEMO_KEY", in this example). Locally, you probably want to define this env var in your user-level .Renviron file. usethis::edit_r_environ() is a handy way to access that. Remember that changes to .Renviron don't take effect until you restart R.

token-setup.R is code that you run once. Or, more realistically, you run it "every now and then". There are various reasons why the cached token might become invalid and, therefore, non-refreshable. In that case, you should obtain a new token interactively and re-deploy.

send-email-byo-encrypted-token.Rmd is a Shiny document. The intent is to show how a deployed Shiny application could use an encrypted user token to send email with gmailr.

This chunk (attempts to) read the stored, encrypted token from file and tells gmailr to use it.

library(gmailr)

try(
  gm_auth(token = gm_token_read(
    ".secrets/gmailr-token.rds",
    key = "GMAILR_DEPLOY_DEMO_KEY"
  ))
)

For this to work, the encryption key must be available as a (secure) environment variable named "GMAILR_DEPLOY_DEMO_KEY" in the deployed environment.

From that point on, the gmailr usage is completely routine.

When deploying, it is important that all of these files are included:

send-email-byo-encrypted-token.Rmd or, in general, the code that creates the Shiny app
.secrets/gmailr-token.rds or, in general, the file that holds the stored, encrypted user token