X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/8ae04bc41c256e89a835f8ce6ea81bd28031ae26..1fca88a96c086d7d1c22690ad2659781a5b2f5e9:/README.md

diff --git a/README.md b/README.md
index f396949535..510ae817e9 100644
--- a/README.md
+++ b/README.md
@@ -15,6 +15,10 @@
 The Google API Ruby Client makes it trivial to discover and access supported
 APIs.
 
+## Alpha
+
+This library is in Alpha. We will make an effort to support the library, but we reserve the right to make incompatible changes when necessary.
+
 ## Install
 
 Be sure `https://rubygems.org/` is in your gem sources.
@@ -83,8 +87,13 @@ drive = client.discovered_api('drive', 'v2')
 Locally cached discovery documents may be used as well. To load an API from a local file:
 
 ```ruby
+# Output discovery document to JSON
+File.open('my-api.json', 'w') do |f| f.puts MultiJson.dump(client.discovery_document('myapi', 'v1')) end
+
+# Read discovery document and load API
 doc = File.read('my-api.json')
-my_api = client.register_discovery_document('myapi', 'v1', doc)
+client.register_discovery_document('myapi', 'v1', doc)
+my_api = client.discovered_api('myapi', 'v1')
 ```
 
 ### Authorization
@@ -95,6 +104,19 @@ Credentials can be managed at the connection level, as shown, or supplied on a p
 
 For server-to-server interactions, like those between a web application and Google Cloud Storage, Prediction, or BigQuery APIs, use service accounts.
 
+As of version 0.8.3, service accounts can be configured using
+[Application Default Credentials][1], which rely on the credentials being
+available in a well-known location.  If the credentials are not present
+and it's being used on a Compute Engine VM,  it will use the VM's default credentials.
+
+```ruby
+client.authorization = :google_app_default  # in a later version, this will become the default
+client.authorization.fetch_access_token!
+client.execute(...)
+```
+
+This is simpler API to use than in previous versions, although that is still available:
+
 ```ruby
 key = Google::APIClient::KeyUtils.load_from_pkcs12('client.p12', 'notasecret')
 client.authorization = Signet::OAuth2::Client.new(
@@ -114,6 +136,8 @@ in the credentials. Detailed instructions on how to enable delegation for your d
 
 The API client can automatically retry requests for recoverable errors. To enable retries, set the `client.retries` property to
 the number of additional attempts. To avoid flooding servers, retries invovle a 1 second delay that increases on each subsequent retry.
+In the case of authentication token expiry, the API client will attempt to refresh the token and retry the failed operation - this
+is a specific exception to the retry rules.
 
 The default value for retries is 0, but will be enabled by default in future releases.
 
@@ -126,7 +150,7 @@ Example:
 
 ```ruby
 client = Google::APIClient.new
-urlshortener = client.discovered_api('urlshortner')
+urlshortener = client.discovered_api('urlshortener')
 
 batch = Google::APIClient::BatchRequest.new do |result|
     puts result.data
@@ -190,3 +214,5 @@ See the full list of [samples on Github](https://github.com/google/google-api-ru
 ## Support
 
 Please [report bugs at the project on Github](https://github.com/google/google-api-ruby-client/issues). Don't hesitate to [ask questions](http://stackoverflow.com/questions/tagged/google-api-ruby-client) about the client or APIs on [StackOverflow](http://stackoverflow.com).
+
+[1]: https://developers.google.com/accounts/docs/application-default-credentials