Real-time Crypto Pricing Data #

Looking for the old v1beta1 or v1beta2 endpoints?

The v1beta1 and v1beta2 endpoints were marked deprecated, and will be removed shortly. Please use the latest v1beta3 endpoints.

How is v1beta3 different from v1beta2?

Since Alpaca now executes your crypto orders in its own exchange, the v1beta3 crypto market data endpoints no longer distribute data from other providers, but from Alpaca itself.

The orderbooks and quotes are the actual orderbooks / top of orderbooks of the Alpaca exchange. The trades and the bars generated from them include all the trades executed on the Alpaca exchange. However, for better data quality and in order to provide historical data before the Alpaca exchange started, they are enriched by other providers as well.

Moreover, you may notice that the URL now includes a required path parameter: the crypto feed. So /v1beta1/crypto became /v1beta3/crypto/us. We’re planning to extend our offering with other feeds in the future, but for now, us is the only possible option there.

Crypto Data API provides websocket streaming for trades, quotes, orderbooks, minute bars and daily bars. This helps receive the most up to date market information that could help your trading strategy to act upon certain market movements.

Once a connection is established and you have successfully authenticated yourself you can subscribe to any event for a particular symbol or multiple symbols.

Subscription plans #

Both subscription plans provide the same source and level of crypto data, the only difference on real-time data is how many symbols (channels) you can listen to.

Free plan:

One concurrent connection is allowed.
Subscription is limited to 30 channels at a time for trades (trades) and quotes (quotes).
There is no limit for the number of channels with minute bars (bars).
Order book (orderbooks) subscription is limited to 10 symbols.

Unlimited plan:

One concurrent connection is allowed.
There is no limit for the number of channels at a time (trades,quotes, orderbooks and bars).

Advanced Websockets Tutorial

Checkout Advanced Live Websocket Crypto Data Streams in Python for some tips on handling live crypto data stream.

Common behavior #

URL #

To access real-time data use this URL:

wss://stream.data.alpaca.markets/v1beta3/crypto/us

Message format #

Every message you receive from the server will be in the format:

[{"T": "{message_type}", {contents}},...]

Control messages (i.e. where "T" is error, success or subscription) always arrive in arrays of size one to make their processing easier.

Data points however may arrive in arrays that have a length that is greater than one. This is to facilitate clients whose connection is not fast enough to handle data points sent one by one. Our server buffers the outgoing messages but slow clients may get disconnected if their buffer becomes full.

Encoding and compression #

Messages over the websocket are in encoded as clear text.

To reduce bandwidth requirements we have implemented compression as per RFC-7692. Our SDKs handle this for you so in most cases you won’t have to implement anything yourself.

Communication flow #

The communication can be thought of as two separate phases: establishment and receiving data.

Establishment #

To establish the connection first you will need to connect to our server using the URL above.

Upon successfully connecting, you will receive the welcome message:

[{"T":"success","msg":"connected"}]

Now you will need to authenticate yourself using your credentials by sending the following message:

{"action": "auth", "key": "{APCA-API-KEY-ID}", "secret": "{APCA-API-SECRET-KEY}"}

Please note that each account can have up to one concurrent websocket connection. Subsequent attempts to connect are rejected.

If you provided correct credentials you will receive another success message:

[{"T":"success","msg":"authenticated"}]

Receiving data #

Congratulations, you are ready to receive real-time crypto market data!

You can send one or more subscription messages (described below) and after confirmation you will receive the corresponding market data.

At any time you can subscribe to or unsubscribe from symbols. Please note that due to the internal buffering mentioned above for a short while you may receive data points for symbols you have recently unsubscribed from.

Client to server #

Authentication #

After connecting you will have to authenticate as described above.

{"action":"auth","key":"PK******************","secret":"***********************************"}

You can subscribe to trades, quotes, bars and orderbooks of a particular crypto pairs (or * for every pair with relevant limits still applicable). A subscribe message should contain what subscription you want to add to your current subscriptions in your session so you don’t have to send what you’re already subscribed to.

{"action":"subscribe","trades":["BTC/USD"],"quotes":["LTC/USD","ETH/USD"],"bars":["BCH/USD"]}

You can also omit either one of them (trades,quotes, bars or orderbooks) if you don’t want to subscribe to any pairs in that category but be sure to include at least one of the three.

Unsubscribe #

Much like subscribe you can also send an unsubscribe message that subtracts the list of subscriptions specified from your current set of subscriptions.

{"action":"unsubscribe","trades":["BTC/USD"],"quotes":["ETH/USD"],"bars":[], "orderbooks": []}

Server to client #

Control messages #

You may receive the following control messages during your session.

[{"T":"success","msg":"connected"}]

You have successfully connected to our server.

[{"T":"success","msg":"authenticated"}]

You have successfully authenticated.

Errors #

You may receive an error during your session. You can differentiate between them using the list below.

 [{"T":"error","code":400,"msg":"invalid syntax"}]

The message you sent to the server did not follow the specification

 [{"T":"error","code":401,"msg":"not authenticated"}]

You have attempted to subscribe or unsubscribe before authentication.

[{"T":"error","code":402,"msg":"auth failed"}]

You have provided invalid authentication credentials.

[{"T":"error","code":403,"msg":"already authenticated"}]

You have already successfully authenticated during your current session.

[{"T":"error","code":404,"msg":"auth timeout"}]

You failed to successfully authenticate after connecting. You have a few seconds to authenticate after connecting.

[{"T":"error","code":405,"msg":"symbol limit exceeded"}]

The symbol subscription request you sent would put you over the limit set by your subscription package. If this happens your symbol subscriptions are the same as they were before you sent the request that failed.

[{"T":"error","code":406,"msg":"connection limit exceeded"}]

You already have an ongoing authenticated session.

[{"T":"error","code":407,"msg":"slow client"}]

You may receive this if you are too slow to process the messages sent by the server. Please note that this is not guaranteed to arrive before you are disconnected to avoid keeping slow connections active forever.

[{"T":"error","code":500,"msg":"internal error"}

An unexpected error occurred on our end. Please let us know if this happens.

Subscription confirmation #

After subscribing or unsubscribing you will receive a message that describes your current list of subscriptions.

[{"T":"subscription","trades":["BTC/USD"],"quotes":["ETH/BTC"],"bars":[], "orderbooks": ["UNI/USDT"]}]

You will always receive your entire list of subscriptions, as illustrated by the sample communication excerpt below:

> {"action": "subscribe", "trades": ["BTC/USD"], "quotes": ["BTC/USD", "LTC/USD"], "bars": ["*"], "orderbooks": ["ETH/BTC"]}
< [{"T":"subscription","trades":["BTC/USD"],"quotes":["BTC/USD","LTC/USD"],"orderbooks":["ETH/BTC"],"bars":["*"],"updatedBars":[],"dailyBars":[]}]
< [{"T":"t","S":"BTC/USD","p":26711.38,"s":0.00672,"t":"2023-03-17T12:32:12.116Z","i":6403852,"tks":"S"}]
< [{"T":"t","S":"BTC/USD","p":26711.38,"s":0.00427,"t":"2023-03-17T12:32:12.12Z","i":6403853,"tks":"S"}]
< [{"T":"t","S":"BTC/USD","p":26711.38,"s":0.01328,"t":"2023-03-17T12:32:12.121Z","i":6403854,"tks":"S"}]
< [{"T":"q","S":"BTC/USD","bp":26677.1564929,"bs":0.52365586,"ap":26730.8798,"as":0.25825915,"t":"2023-03-17T12:32:12.713306656Z"}]
> {"action": "unsubscribe", "bars": ["*"]}
> [{"T":"subscription","trades":["BTC/USD"],"quotes":["BTC/USD","LTC/USD"],"orderbooks":["ETH/BTC"],"bars":[],"updatedBars":[],"dailyBars":[]}]

Example #

$ wscat -c wss://stream.data.alpaca.markets/v1beta3/crypto/us
connected (press CTRL+C to quit)
< [{"T":"success","msg":"connected"}]
> {"action": "auth", "key": "**\***", "secret": "**\***"}
< [{"T":"success","msg":"authenticated"}]
> {"action": "subscribe", "bars": ["BTC/USD"]}
< [{"T":"subscription","trades":[],"quotes":[],"orderbooks":[],"bars":["BTC/USD"],"updatedBars":[],"dailyBars":[]}]
< [{"T":"b","S":"BTC/USD","o":26675.04,"h":26695.36,"l":26668.79,"c":26688.7,"v":3.227759152,"t":"2023-03-17T12:28:00Z","n":93,"vw":26679.5912436798}]
< [{"T":"b","S":"BTC/USD","o":26687.9,"h":26692.91,"l":26628.55,"c":26651.39,"v":11.568622108,"t":"2023-03-17T12:29:00Z","n":197,"vw":26651.7679765663}]

Disclosures

Brokerage services are provided by Alpaca Securities, member FINRA/SIPC, a wholly-owned subsidiary of AlpacaDB, Inc.

Technology and services are offered by AlpacaDB, Inc.

Brokerage services are provided to customers who can write automated investment code and self-direct their own investments. Alpaca brokerage services are only provided to customers who agree to electronically sign agreements and agree to receive messages, confirmations, and statements electronically. Is Alpaca right for me?

This is not an offer, solicitation of an offer, or advice to buy or sell securities or cryptocurrencies, or open a brokerage account or cryptocurrency account in any jurisdiction where Alpaca Securities or Alpaca Crypto respectively, are not registered or licensed, as applicable.

The Paper Trading API is offered by AlpacaDB, Inc. and does not require real money or permit a user to transact in real securities in the market. Providing use of the Paper Trading API is not an offer or solicitation to buy or sell securities, securities derivative or futures products of any kind, or any type of trading or investment advice, recommendation or strategy, given or in any manner endorsed by AlpacaDB, Inc. or any AlpacaDB, Inc. affiliate and the information made available through the Paper Trading API is not an offer or solicitation of any kind in any jurisdiction where AlpacaDB, Inc. or any AlpacaDB, Inc. affiliate (collectively, "Alpaca") is not authorized to do business.

You should know that the use or granting of any third party access to your account information or place transactions in your account at your direction is solely at your risk. Alpaca does not warrant against loss of use or any direct, indirect or consequential damages or losses to you caused by your assent, expressed or implied, to a third party accessing your account or information, including access provided through any other third party apps, systems, or sites.

Market prices, data and other information available through Alpaca are not warranted as to completeness or accuracy and are subject to change without notice. System response and account access times may vary due to a variety of factors, including trading volumes, market conditions, system performance, and other factors. A more complete description of the impact these factors may have can be found in our risks of automated trading systems section.

All investments involve risk and the past performance of a security, or financial product does not guarantee future results or returns. Keep in mind that while diversification may help spread risk it does not assure a profit, or protect against loss, in a down market. There is always the potential of losing money when you invest in securities, or other financial products. Investors should consider their investment objectives and risks carefully before investing.

There are risks unique to automated trading algorithms that you should know about and plan for. You should setup a method or system of continuous monitoring or alerting to let you know if there is a mechanical failure, such as connectivity issues, power loss, a computer crash, or system quirk. You should also monitor for instances where your automated trading system experiences anomalies that could result in errant, missing, or duplicated orders. A more complete description of these and other risks can be found in our FAQ section.

Conditional orders may have increased risk as a result of their reliance on trigger processing, market data, and other internal and external systems. Such orders are not sent to the market until specified conditions are met. During that time, issues such as system outages with downstream technologies or third parties may occur. Conditional orders triggering near the market close may fail to execute that day. Furthermore, our executing partner may impose controls on conditional orders to limit erroneous trades triggering downstream orders. Alpaca Securities may not always be made aware of such changes to external controls immediately, which may lead to some conditional orders not being executed. As such, it is important to monitor conditional orders for reasonability. Conditional orders are “Not Held” orders whose execution instructions are on a best efforts basis upon being triggered. Furthermore, conditional orders may be subject to the increased risks of stop orders and market orders outlined above. Given the increased potential risk of using conditional orders, the client agrees that Alpaca Securities cannot be held responsible for losses, damages, or missed opportunity costs associated with market data problems, systems issues, and user error, among other factors. By using conditional orders the client understands and accepts the risks outlined above. Alpaca Securities encourages leveraging the use of Paper accounts to become more comfortable with the intricacies associated with these orders.

ETFs can entail risks similar to direct stock ownership, including market, sector, or industry risks. Some ETFs may involve international risk, currency risk, commodity risk, and interest rate risk. Trading prices may not reflect the net asset value of the underlying securities.

All accounts are opened as limited purpose margin accounts. You should know that margin trading involves interest charges and risks, including the potential to lose more than deposited or the need to deposit additional collateral in a falling market. Before using margin, customers must determine whether this type of trading strategy is right for them given their specific investment objectives, experience, risk tolerance, and financial situation. For more information please see Alpaca's Margin Disclosure Statement and Margin Agreement. These disclosures contain information on Alpaca Securities's lending policies, interest charges, and the risks associated with margin accounts.

Commission-Free trading means that there are no commission charges for Alpaca Securities self-directed individual brokerage accounts that trade U.S. listed securities through an API. Relevant regulatory fees may apply.

Commission free trading is available for Alpaca's retail customers. Alpaca reserves the right to charge additional fees if it is determined that orders flow is non-retail in nature.

Cryptocurrency is highly speculative in nature, involves a high degree of risks, such as volatile market price swings, market manipulation, flash crashes, and cybersecurity risks. Cryptocurrency is not regulated or is lightly regulated in most countries. Cryptocurrency trading can lead to large, immediate and permanent loss of financial value. You should have appropriate knowledge and experience before engaging in cryptocurrency trading. For additional information please click here.

Cryptocurrency services are made available by Alpaca Crypto, a FinCEN registered money services business (NMLS # 2160858), and a wholly-owned subsidiary of AlpacaDB, Inc. Alpaca Crypto is not a member of SIPC or FINRA. Cryptocurrencies are not stocks and your cryptocurrency investments are not protected by either FDIC or SIPC. Please see the Disclosure Library for more information.