Authentication handler in drracket

README.md

@@ -87,16 +87,20 @@ The result remains two values: Git's exit code and the ordered
 
 Authentication failures are detected centrally after `run-git`, before
 command-specific result processing. `current-git-authentication-handler`
-contains a callback that receives the command, processed arguments and an
-`exn:fail:git-auth` value. If the callback handles authentication and returns a
-true value, git-cli retries the original command once. The default callback
-returns `#f`, so existing error behavior is preserved until an authentication
-handler is configured.
+defaults to `default-git-authentication-handler`.
+
+The default handler first uses an existing Git `credential.helper`. When no
+helper is configured, it asks for username and password/token with
+`input-prompt`, configures the non-persistent `cache` helper locally, approves
+the credential through `git credential approve`, and retries the original Git
+command once.
+
+A custom handler can still be installed:
 
 ```racket
 (current-git-authentication-handler
  (λ (cmd args e)
-   ;; Perform credential handling here.
+   ;; Perform custom credential handling.
    #t))
 ```