FIX (Financial Information eXchange) is a standard protocol which can be used to enter orders, submit cancel requests, and receive fills. Users of the FIX API will typically have existing software using FIX for order management. Users who are not familiar with FIX should first consider using the REST API.

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FIX API Endpoint URL

tcp+ssl://fix.prime.coinbase.com:4198

Connectivity

Before logging onto a FIX session, clients must establish a secure connection to the FIX gateway (fix.prime.coinbase.com:4198). If your FIX implementation does not support establishing a TCP SSL connection natively, you will need to setup a local proxy such as stunnel to establish a secure connection to the FIX gateway. See the SSL Tunnels section for more details and examples.

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Sessions are forcibly logged out every day between 5pm ET and 5:05pm ET for a maintenance window. All users are required to restart their sessions during this time and reset sequence numbers to 0.

Rate Limiting

During the beta period, requests are limited to 50 calls per second.

Messages

The baseline specification for this API is FIX 4.2. We've made note below the places in which the FIX API for Coinbase Prime extends (or clarifies) the FIX spec. For example, there are custom tags in with a four-digit number range, as allowed by the standard, which are unique to Prime.

A standard header must be present at the start of every message in both directions. You should configure your sessions to use the service account ID associated with the API key as your SenderCompID and the string "COIN" as the TargetCompID. This is typically accomplished via your FIX client's configuration file.

Logon (A)

// create a new Logon message
var logon = new Msgs.Logon();
logon.SendingTime = new Date();
logon.passphrase = '...';

var presign = [
 logon.SendingTime,
 logon.MsgType,
 session.outgoing_seq_num,
 apiKey,
 session.target_comp_id,
 passphrase
].join('');

// add the presign string to the RawData field of the Logon message
logon.RawData = sign(presign, secret);

// send the logon message to the server
session.send(logon);

function sign(what, secret) {
 var key = Buffer(secret, 'base64');
 var hmac = crypto.createHmac('sha256', key);
 return hmac.update(what).digest('base64');
}

Sent by the client to initiate a session, and by the server as an acknowledgement. Only one session may exist per API key; sending a Logon message within an established session, or while the first session is still running, results in an error.

The Logon message sent by the client must be signed for security. The prehash string is the following fields joined by the empty string:

{timestamp}, "A", seqNum, apiKey, targetComp, passphrase.

There is no trailing separator. The RawData field should be a base64 encoding of the HMAC signature.

A single API key must not be used in multiple connections at the same time. To establish multiple FIX connections, please generate a new API key for each one. All messages must have a SendingTime value within 5 seconds of server time in UTC or they will be rejected.

New Order Single (D)

Sent by the client to enter an order. Each profile can place a maximum of 500 open orders on a product. Once reached, the profile will not be able to place any new orders until the total number of open orders is below 500.

Note that not every tag is required for every order; the requiredness for individual tags is dependent on the target strategy used. See the table below for more information.

TargetStrategy Values

OrderType Values

TimeInForce Values

Order Cancel Request (F)

Sent by the client to cancel an order.

Order Status Request (H)

->
   MsgType=H
   OrderID=3f8b09f2-3b25-4bf3-90be-330f7d68aee3

<-
   MsgType=8
   ClOrdID=3dce15be-3ad8-4cc9-85b6-55ec34c49069
   OrderID=3f8b09f2-3b25-4bf3-90be-330f7d68aee3
   Symbol=GNT-USDC
   CumQty=0.00000000
   Side=1
   Price=0.01000000
   ExecID=ece88c19-4aaa-404f-a525-2977f26664e7
   ExecTransType=3
   OrderQty=1.00000000
   OrdStatus=0
   OrdType=2
   SenderCompID=Coinbase
   SendingTime=20200710-14:48:23.577
   TargetCompID=1e709a798e12f5a1a92e88852087d2g6
   TransactTime=20200710-14:47:11.379
   Commission=12
   ExecType=I

   Note: the Tags in this example have been replaced with Name for readability

Sent by the client to obtain information about pending and completed orders.

Response

The response to an Order Status Request is an ExecutionReport with ExecType=I.
The ExecutionReport will contain the ClOrdID if the value is supplied.
If the order cannot be found, the ExecutionReport will have OrderID=0.

Execution Report (8)

Sent by the server when an order is accepted, rejected, filled, or canceled. Also sent when the user sends an OrderStatusRequest.

ExecType Values

Order Cancel Reject (9)

Sent by the server when an Order Cancel Request cannot be satisfied, e.g. because the order is already canceled or completely filled.

OrdStatus Values

CxlRejResponseTo Values

Reject (3)

Sent by either side upon receipt of a message which cannot be processed, e.g. due to missing fields or an unsupported message type.

SSL Tunnels

fix.prime.coinbase.com:4198 only accepts TCP connections secured by SSL. If your FIX client library cannot establish an SSL connection natively, you will need to run a local proxy that will establish a secure connection and allow unencrypted local connections.