New API features will no longer occur for the v3 API, but it still carries a lot of useful capabilties, such as the multi-channel API, and multi-account batching.

Google Anaytics V3 API examples

Consult ?google_analytics_3 and see examples below:

library(googleAnalyticsR)

## Authenticate in Google OAuth2
ga_auth()

## if you need to re-authenticate use ga_auth(new_user=TRUE)

## if you have your own Google Dev console project keys, 
## then don't run ga_auth() as that will set the authentication project to the defaults.
## instead put your options here, and run googleAuthR::gar_auth()

## get account info, including View Ids
account_list <- ga_account_list()
ga_id <- account_list$viewId[1]

## get a list of what metrics and dimensions you can use
meta <- google_analytics_meta()
head(meta)

## pick the account_list$viewId you want to see data for.
## metrics and dimensions can have or have not "ga:" prefix
gadata <- google_analytics_3(id = ga_id, 
                           start="2015-08-01", end="2015-08-02", 
                           metrics = c("sessions", "bounceRate"), 
                           dimensions = c("source", "medium"))


## if more than 10000 rows in results, auto batching
## example is setting lots of dimensions to try and create big sampled data
batch_gadata <- google_analytics_3(id = account_list$viewId[1], 
                                 start="2014-08-01", end="2015-08-02", 
                                 metrics = c("sessions", "bounceRate"), 
                                 dimensions = c("source", "medium", "landingPagePath","hour","minute"),
                                 max=99999999)

## mitigate sampling by setting samplingLevel="WALK"
## this will send lots and lots of calls to the Google API limits, beware
walk_gadata <- google_analytics_3(id = account_list$viewId[1], 
                                start="2014-08-01", end="2015-08-02", 
                                metrics = c("sessions", "bounceRate"), 
                                dimensions = c("source", "medium", "landingPagePath"), 
                                max=99999999, samplingLevel="WALK")

## multi-channel funnels set type="mcf"
mcf_gadata <- google_analytics_3(id = account_list$viewId[1], 
                               start="2015-08-01", end="2015-08-02", 
                               metrics = c("totalConversions"), 
                               dimensions = c("sourcePath"), 
                               type="mcf")

## google_analytics dataframes include these meta data attributes:
- attr(*, "containsSampledData")= logi FALSE
 - attr(*, "samplePercent")= num 100
 - attr(*, "samplingLevel")= chr "DEFAULT"
 - attr(*, "profileInfo")=List of 6
  ..$ profileId            : chr "535656"
  ..$ accountId            : chr "2748374"
  ..$ webPropertyId        : chr "UA-278374-1"
  ..$ internalWebPropertyId: chr "5279208"
  ..$ profileName          : chr "XXXXX"
  ..$ tableId              : chr "mcf:539656"
 - attr(*, "dateRange")=List of 2
  ..$ startDate: chr "2015-08-01"
  ..$ endDate  : chr "2015-08-02"
 - attr(*, "totalResults")= int 4

## reach meta-data via attr()
attr(gadata, "profileInfo")
attr(gadata, "dateRange")

Other details

For syntax of filters and dimensions, this library parses in exactly as specified in the Google Analytics v3 API docs, so check those out.

Note you do not need to encode symbols if passed into metrics or dimensions parameters, but may have to encode URLs if you are filtering for those in say ga:pagePath via utils::URLencode(url, reserved = TRUE)