Authenticating API in R - r

Question

I'm trying to access Bitfinex via api but struggling to properly authenticate my request. There is a Python example of what I want to do (https://gist.github.com/jordanbaucke/5812039) but I can't seem to get it to work in R.
key <- c("MY API KEY")
secret = c("MY API SECRET")
req <- GET("https://api.bitfinex.com/v1/balances",
authenticate(key, secret))
add_headers(X-BFX-APIKEY = key))
stop_for_status(req)
content(req)
Can someone tell me what I'm doing wrong?

Answer 1

/v1/balances is a Bitfinex authenticated endpoints, thus it requires the POST request with a proper handling of payload and headers.
Here is a working example from my own script:
library(httr)
key <- "..."
secret <- "..."
# payload JSON object, the request should refer to the URL
# nonce should always be greater than for previous calls
payload_json <- list(request = '/v1/account_infos', nonce = as.character(as.numeric(as.POSIXct(Sys.time()))))
# creating string from JSON payload
payload <- jsonlite::toJSON(payload_json, auto_unbox = TRUE)
# encoding payload string
payload_str <- base64enc::base64encode(charToRaw(as.character(payload)))
# adding three Bitfinex headers:
# X-BFX-APIKEY = key
# X-BFX-PAYLOAD = base64 encoded payload string
# X-BFX-SIGNATURE = sha384 encrypted payload string with the secret key
req <- POST("https://api.bitfinex.com/v1/account_infos",
add_headers('X-BFX-APIKEY' = key,
'X-BFX-PAYLOAD' = payload_str,
'X-BFX-SIGNATURE' = openssl::sha384(payload_str, key = secret))
)
content(req)
For creating "New Order" you only need to change the payload to something, like this:
payload_json <- list(request = '/v1/account_infos',
nonce = as.character(as.numeric(as.POSIXct(Sys.time()))),
symbol = 'BTCUSD',
amount = '0.3',
price = '1000',
exchange = 'bitfinex',
side = 'sell',
type = 'exchange market'
)
The rest of the code will work without changes.
For list of payload parameters check the Bitfinex API docs, e.g. "New Order".