firstrally v0.0.1

First Rally API

Install

npm install firstrally

Usage

Require the package

FirstRally = require "firstrally"

You can use the API wrapper by calling the functions below. See example.coffee for a quick example.

Authentication

All functions require authentication unless otherwise specified. Before you're able to call an authenticated function, you must first set your api_key and api_key_secret. If you don't set these correctly, you'll receive a 401 Unauthorized error response from the server.

Set your API key and Secret

FirstRally.set
  api_key: "... your api key ..."
  api_key_secret: "... your api key secret ..."

Both your api key and secret can be generated within your account page on firstrally.com

Real-time Data

Most users will want to use this API wrapper to subscribe to real-time data streams. First Rally monitors hundreds of streams from dozens of exchanges. Streams are identified using the following naming scheme:

exchange_id/base_currency/secondary_currency

An example stream id would be "coinbase_exchange/usd/btc". This would denote a data stream tracking the value of Bitcoin in U.S. Dollars on Coinbase Exchange. You can list all available data streams by performing the following:

FirstRally.DataStream.list (error, json) ->
  if !error?
    console.log json # list all streams

See DataStream.list below for detailed information about the response.

Subscribing to a stream is just as easy

Historical Data

In addition to real-time data, you can use our API to make requests for historical data. Historical data is requested in batches, which when processed will produce a data file for download. Batch requests are specified by a stream_id, as well as the start_date and end_date representing the timespan of the resultant data.

Before requesting a data batch, you must first request a price quote from our servers. Once receiving a quote, you can then queue the data batch:

moment = require "moment"

FirstRally.DataBatch.quote "coinbase/usd/btc", moment().subtract(1, "day"), moment(), (error, quote) ->
  if !error?
    # quote contains a server-signed object specifying the price, currency and batch
    # information you can then use to create the data batch.

    # Do something with the price
    price_in_dollars = quote.price

    FirstRally.DataBatch.create quote, (error, data_batch) ->
      if !error?
        # data_batch contains information about the data batch that was just queued.
        # When returned, it'll contain an id that you can then use to request the 
        # status of the data batch and download the resultant data file. See 
        # DataBatch.status() for more information.
      

CAUTION: Requesting a data batch through DataBatch.create() will subtract the price of that data batch from your account when successfully processed. We require a server-signed quote as a security mechanism so you know exactly how much will be deducted from your account. Make sure you’ve reviewed the price of the desired data batch before requesting it.

To download a successfully processed batch file, perform the following. Note that the API differs slightly here in that you’ll receive a single response object that you can then stream. See BatchFile.download() for more details.

fs = require "fs"

# Assume the batch file is 23. You can get the batch file's id
# by calling DataBatch.status()
batch_file_id = 23

FirstRally.BatchFile.download batch_file_id, (response) ->
  response.on 'error', (err) ->
    console.log(err)
  .pipe(fs.createWriteStream("data_file.json.gz"))

API Methods

Public methods:

• Conversion.current
• DataStream.list
• User.login

Private methods (requires authentication):

• User.balance
• User.update_profile
• User.change_password
• Notification.create
• Notification.delete
• DataStream.subscribe
• DataStream.unsubscribe
• DataBatch.quote
• DataBatch.create
• DataBatch.status
• BatchFile.download
• Subscription.quote
• Subscription.frequency

Handling Responses

Each method takes a done parameter as the last argument. This is a callback function of the form function(error, json) which you can use to process the response. If error is null, your response was successful.

Alternatively, you can pass a done callback that takes a single response object which you can use to stream the response. See the Historical Data section above for an example.

Handling Errors

When using the first form of the done callback, the first argument passed will be an error object. If error is null, your request was successful and there were no errors. However, if your request failed, the error object will not be null, and will be of type FirstRally.Error, which extends from the native Error object. An example error object (converted to json) looks like this:

{ [FirstRally.Error: Invalid password.]
  statusCode: 417,
  message: 'Invalid password.',
  original: [ { message: 'Invalid password' } ],
  name: 'FirstRally.Error' }

Note that this error object contains a few extra attributes you can use for processing the response. These are:

• statusCode: Integer, the HTTP error code for the response. This will be 400 or above.
• message: String, a English-formatted message you can use for printing, or understanding the error message. This is a single string containing all individual error messages.
• original: Array, an array of separate error messages originally sent by the server. The server can respond with more than one message (though most often won’t), and so you have access to the distinct error responses, if needed.

Conversions

First Rally provides currency conversions to and from every currency we track, including both fiat and cryptocurrencies. Often conversions are the average trading value of a trading pair across all exchanges, where the currencies are traded directly (e.g., USD -> BTC). However, some conversions like NAUT -> TOP are indirect, where the calculation follows NAUT -> BTC -> LTC -> TOP. We call these “conversion chains”. Though conversions with longer conversion chains may not provide practical value in the trading process due to exchange fees, and may not be precise due to extra calculations, we feel these conversions are useful to achieve an approximate value when moving from one currency to another.

current([from, to,] done) : Does Not Require Authentication

Get the conversions for the specified currency/currencies.

• from: String, optional: the first currency code you’d like conversions for.
• to: String, optional; the second currency code for calculating the conversion.

Both the from parameter and the to parameter are optional parameters. When only from is passed, you’ll receive an object in the done callback that contains all the currencies from can convert to, as well as the conversion ratios. When to is passed, you’ll receive a single conversion from the from currency to the to currency.

If neither from nor to is passed, you’ll receive an object with all conversions, showing conversion ratios from every currency we track to every other currency we track. Note that this is a large response (in megabytes), and you’ll likely want to stream it. See the Historical Data section above for an example.

An example conversion response from USD to BTC looks like this:

{
  "result": {
    "conversion": 0.0036177106543686,
    "chain": "usd/btc"
  },
  "timestamp": 1425577229972
}

This response states that 1 USD is equal to 0.0036177106543686 BTC at the time of the conversion. The timestamp parameter specifies when this conversion was calculated, and the chain result shows how we calculated it. Chains with only two currencies represent a conversion that is directly traded across one or more exchanges.

Note that you can alternate the currencies passed to Conversion.current() for the opposite conversion ratio. In this case, we’re converting from BTC to usd, meaning that 1 BTC is worth x USD at the time of conversion:

{
  "result": {
    "conversion": 277.24704786142854,
    "chain": "btc/usd"
  },
  "timestamp": 1425579028873
}

User

balance(done)

Get the current available balance on your account. The done callback will be passed an object like the following:

{
  balance: 947.50
}

update_profile(profile, done)

Update your user's profile. Profile should be an object with the following keys:

• first_name: String, the first name of your user.
• last_name: String, the last name of your user.
• email: String, the email of
• password: String, your user's current password. You cannot use this method to update your password, see change_password However, your password is required for security reasons.

change_password(new_password, current_password, done)

Change the password for your user. Parameters are:

• new_password: String, the new password for your user.
• current_password: String, the current password of your user, required for security reasons.

login(email, password, done)

Log in as the user specified by the email and password. This will set a cookie that, if passed with all other requests, can be used instead of api key authentication.

• email: String, the registered email for your user.
• password: String, your user's password.

Notification

create(stream_id, price, direction, done)

Create a new notification for your user across the specified stream_id and the given price.

• stream_id: String. Stream ids are in the form exchange/first_currency/second_currency, and they specify the exchange and the currencies being traded. A stream_id of coinbase_exchange/usd/btc, for instance, will denote the value of Bitcoin in U.S. Dollars on Coinbase Exchange.
• price: Float, the value that, when crossed in the direction specified by direction, will cause the notification to be sent. Note that this price is the same currency as first_currency.
• direction: String, one of above, below, crosses, default crosses. If above, the notification will be sent when the price of the specified stream goes above the value listed in price. If below, the notification will be sent if the price has gone below price. If crosses, the notification will be sent regardless of direction.

Returns: JSON object representing the notification created, including id.

delete(notification_id, done)

Delete the notification specified by notification_id.

• notification_id: Integer, the id of the notification to delete.

DataStream

list(done) : Does Not Require Authentication

List all data streams. Takes no parameters.

Output is similar to the following. Notice that the top-most keys are the exchange ids, whose objects contain a label and a streams object that lists the streams. The keys within each exchange’s streams object are the stream ids (used by the real-time data and historical data APIs), and the values are an object containing data about the stream.

{
  "bitx": {
    "label": "BitX",
    "streams": {
      "bitx/zar/btc": {
        "primary_currency_code": "ZAR",
        "secondary_currency_code": "BTC"
      }
    }
  },
  "cryptsy": {
    "label": "Cryptsy",
    "streams": {
      "cryptsy/btc/42": {
        "primary_currency_name": "BitCoin",
        "primary_currency_code": "BTC",
        "secondary_currency_name": "42Coin",
        "secondary_currency_code": "42"
      },
      "cryptsy/btc/ac": {
        "primary_currency_name": "BitCoin",
        "primary_currency_code": "BTC",
        "secondary_currency_name": "AsiaCoin",
        "secondary_currency_code": "AC"
      },
      # All of the Cryptsy streams...
    }
  },
  # All the other exchanges...
}

All streams will contain a primary_currency_code -- often called the “base currency” -- and a secondary_currency_code, which is the currency being traded. Some streams, like Cryptsy, have other information provided by the exchange, but that information is not guaranteed across all exchanges and streams.

subscribe(stream_id, callbacks)

Subscribe to a data stream.

• stream_id: String. Stream ids are in the form exchange/first_currency/second_currency, and they specify the exchange and the currencies being traded. A stream_id of coinbase_exchange/usd/btc, for instance, will denote the value of Bitcoin in U.S. Dollars on Coinbase Exchange.
• callbacks: Object, an object that contains callback functions for specific events. Currently, two events/functions are supported: message, subscribe. The message function will be called every time new data has arrived from the stream; the subscribe function will be called when the subscription is successful.

Example use of this function:

FirstRally.DataStream.subscribe "coinbase/usd/btc", 
  message: (message) ->
    console.log "Message received on #{message.identifier}, sent at #{new Date(message.date)}. Price = #{message.value}"
  subscribe: () ->
    console.log "Successfully subscribed to coinbase/usd/btc!"

unsubscribe(stream_id)

Unsubscribe from messages on a specific stream. This will prevent listening for new price events across the stream, and you’ll need to re-subscribe to that stream to begin receiving messages again.

• stream_id: String. Stream ids are in the form exchange/first_currency/second_currency, and they specify the exchange and the currencies being traded. A stream_id of coinbase_exchange/usd/btc, for instance, will denote the value of Bitcoin in U.S. Dollars on Coinbase Exchange.

DataBatch

quote(stream_id, start_date, end_date, done)

Before creating a batch request, you must first request a quote from our servers. This is a necessary security step to ensure you know exactly how much credit will be deducted from your account when the batch request is processed. The parameters are:

• stream_id: String. Stream ids are in the form exchange/first_currency/second_currency, and they specify the exchange and the currencies being traded. A stream_id of coinbase_exchange/usd/btc, for instance, will denote the value of Bitcoin in U.S. Dollars on Coinbase Exchange.
• start_date: Date, the date specifying the lower bound of data to be included in the resultant batch file.
• end_date: Date, the date specifying the upper bound of data to be included in the resultant batch file.

The done callback will receive a quote object like the following. You will need to pass this object into DataBatch.create() in order to create the requested data batch.

create(quote, done)

Request a set of historical data. This logs your request in our system only. Once we process your request, a batch file will be available for download. There is only one parameter:

• quote: Object, a quote object returned from DataBatch.quote(). This quote will contain the data batch information you provided to DataBatch.quote() to describe the resultant data file. It will also be signed by our servers as being a valid quote. When sent to DataBatch.create(), we’ll then queue your request for processing, and deduct the quoted price from your account once the batch file has finished processing.

The done callback will be passed an object representing the data batch you just created, which includes its id for checking its processing status at a later date. The object will look something like this:

{ 
  id: 27,
  user_id: 2,
  job_id: 1478,
  stream_id: 'coinbase/usd/btc',
  start_date: '2015-03-04T06:07:17.000Z',
  end_date: '2015-03-05T06:07:17.000Z',
  created_at: '2015-03-05T06:07:17.000Z',
  updated_at: '2015-03-05T06:07:17.000Z',
  deleted_at: null
}

See DataBatch.status() for further information about checking the status of your batch request.

status(data_batch_id, done)

Check on the status of a data batch. This takes a single argument:

• data_batch_id: Integer, the id of the data batch.

The done callback will be passed the same object as DataBatch.create(), except that if the data batch has been successfully processed, batch_file information will be included. If the batch has not yet been processed, no batch_file information will be returned. Example:

{ 
  id: 27,
  user_id: 2,
  job_id: 1478,
  stream_id: 'coinbase/usd/btc',
  start_date: '2015-03-04T06:07:17.000Z',
  end_date: '2015-03-05T06:07:17.000Z',
  created_at: '2015-03-05T06:07:17.000Z',
  updated_at: '2015-03-05T06:07:17.000Z',
  deleted_at: null,
  batch_file: { 
    id: 24, 
    file_name: 'coinbase_usd_btc_1425535637000.json.gz' 
  } 
}

BatchFile

download(batch_file_id, done)

Download the batch file specified by batch_file_id.

• batch_file_id: Integer, the id of the batch file to download.

This method is slightly different from the other methods in that it returns large amounts of data, so you’ll want to stream the response. See Historical Data above for an example.

Subscription

Manage your Real-Time Data subscription.

quote(frequency, done)

Get a quote for your Real-Time Data subscription, on a daily, weekly or monthly basis. This will return a quote object with an amount that will be deducted from your account on the frequency specified.

• frequency: String, one of daily, weekly, or monthly. The period in which we will deduct funds from your account to sustain your subscription.

This method will return an error response if you already have a Real-Time data subscription at any frequency.

create(quote, done)

Start the actual subscription. You must first pass in a quote object from Subscription.quote().

• quote: Object, quote object returned from Subscription.quote()

Building

First, install dependencies:

npm install

To build javascript for distribution, run:

grunt

Contributing

Please help contribute to this API. To contribute, submit a pull request with your changes, making sure to include distribution builds as described above.

Author and Other Contributors

@tcoulter - original author.

License

MIT