> ## Documentation Index > Fetch the complete documentation index at: https://docs.cloud.coinbase.com/llms.txt > Use this file to discover all available pages before exploring further. # Prime FIX 5.0 Messages > The FIX 5.0 specification can be used for and derivatives on Coinbase Prime. This specification is currently in **beta** and requires account enablement. Features and definitions are subject to change. In the tables below, the **Req** column indicates whether a field is required: `Y` = Required, `N` = Optional, `C` = Conditional on another field. `↳` denotes a field within a repeating group.
## Session Management Messages ### (A) Logon Initiates FIX session connection between client and server.

**Standard Header Fields** | Tag | Name | FIX Type | Req | Description | | :-- | :----------- | :----------- | :-- | :--------------------------- | | 8 | BeginString | String | Y | `FIX.5.0` | | 9 | BodyLength | Int | Y | Message body length in bytes | | 35 | MsgType | String | Y | `A` = Logon | | 49 | SenderCompID | String | Y | Sender's unique identifier | | 56 | TargetCompID | String | Y | Target's unique identifier | | 34 | MsgSeqNum | Int | Y | Message sequence number | | 52 | SendingTime | UTCTimestamp | Y | Time of message transmission | **Logon Message Fields** | Tag | Name | FIX Type | Req | Description | | :--- | :--------------- | :------- | :-- | :---------------------------------------------- | | 96 | RawData | text | Y | Signature | | 98 | EncryptMethod | Int | Y | `0` = None | | 108 | HeartBtInt | Int | Y | Heartbeat interval in seconds (recommended: 30) | | 141 | ResetSeqNumFlag | Boolean | N | `Y` = Reset sequence numbers to 1 | | 553 | Username | String | Y | Client username for authentication | | 554 | Password | String | Y | Client password for authentication | | 1137 | DefaultApplVerID | String | Y | `9` = FIX50SP2 = FIX 5.0 Service Pack 2 | ### (5) Logout Terminates FIX session gracefully. | Tag | Name | FIX Type | Req | Description | | :-- | :--- | :------- | :-- | :------------------------------------- | | 58 | Text | String | N | Logout reason or informational message | ### (0) Heartbeat Maintains session connectivity and confirms system responsiveness. | Tag | Name | FIX Type | Req | Description | | :-- | :-------- | :------- | :-- | :-------------------------------------------------------------------------------------- | | 112 | TestReqID | String | C | Required if responding to TestRequest. Echo the TestReqID from the TestRequest message. | ### (1) TestRequest Validates session responsiveness when no messages received within HeartBtInt period. | Tag | Name | FIX Type | Req | Description | | :-- | :-------- | :------- | :-- | :---------------------------------------------------------- | | 112 | TestReqID | String | Y | Unique identifier that must be echoed in Heartbeat response | ### (3) Reject Indicates session-level rejection of a received message. | Tag | Name | FIX Type | Req | Description | | :-- | :------------------ | :------- | :-- | :---------------------------------------------------------------------------------------------------------------------------------------------- | | 45 | RefSeqNum | Int | Y | MsgSeqNum of rejected message | | 371 | RefTagID | Int | C | Tag number of the field with error | | 372 | RefMsgType | String | C | MsgType of rejected message | | 373 | SessionRejectReason | Int | C | `0` = Invalid tag number
`1` = Required tag missing
`2` = Tag not defined
`5` = Value incorrect
`6` = Incorrect data format | | 58 | Text | String | N | Human-readable description of rejection | ### (2) ResendRequest Requests retransmission of messages when gap detected in sequence numbers. | Tag | Name | FIX Type | Req | Description | | :-- | :--------- | :------- | :-- | :------------------------------------------------------------------ | | 7 | BeginSeqNo | Int | Y | Starting sequence number for resend range | | 16 | EndSeqNo | Int | Y | Ending sequence number (`0` = resend all messages after BeginSeqNo) | ### (4) SequenceReset Resets message sequence numbers or fills sequence gaps. | Tag | Name | FIX Type | Req | Description | | :-- | :---------- | :------- | :-- | :--------------------------------------------------------------------- | | 123 | GapFillFlag | Boolean | C | `Y` = Gap fill mode (messages 34 through NewSeqNo-1 have been skipped) | | 36 | NewSeqNo | Int | Y | New sequence number for next message | *** ## Order Entry Messages All messages in this section must include the Standard Header fields. See [(A) Logon](#a-logon) for the full field list. ### (D) NewOrderSingle Request to submit new single-legged order. | Tag | Name | FIX Type | Req | Description | | :--- | :-------------------- | :----------- | :-- | :------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | | 1 | Account | String(16) | Y | Trading account identifier | | 11 | ClOrdID | String(36) | Y | Unique client order identifier. Must be unique across all orders. | | 38 | OrderQty | Int(9) | Y | Order quantity (positive integer) | | 152 | CashOrderQty | Int(9) | Y | Order quantity (in quote units) | | 40 | OrdType | Char(1) | Y | `1` = Market
`2` = Limit
`4` = Stop Limit | | 44 | Price | Price(20) | C | Limit price. Required for Limit and Stop Limit orders. | | 54 | Side | Char(1) | Y | `1` = Buy, `2` = Sell | | 55 | Symbol | String(24) | Y | Instrument symbol (e.g., BTC-27FEB26-CDE, ETH-USD). | | 167 | SecurityType | String(6) | Y | `FUT` = Futures | | 59 | TimeInForce | Char(1) | N | `1` = Good Till Cancel (GTC)
`6` = Good Till Date (GTD)
`3` = Immediate or Cancel (IOC)
`4` = Fill or Kill (FOK) | | 60 | TransactTime | UTCTimestamp | Y | Order submission time (YYYYMMDD-HH:MM:SS.sss in UTC) | | 18 | ExecInst | Char | N | `A` = Post only | | 99 | StopPx | Price(20) | C | Stop trigger price. Required for Stop and Stop Limit orders. | | 126 | ExpireTime | UTCTimestamp | C | Expiration time. Required when TimeInForce = `6` (GTD). | | 168 | EffectiveTime | UTCTimestamp | C | Start time of an order (required for TWAP/VWAP orders) | | 1138 | DisplayQty | Qty | N | Display quantity for iceberg orders. Only available when OrdType `2` = Limit or `4` = Stop Limit. | | 528 | OrderCapacity | Char(1) | N | `A` = Agency, `P` = Principal | | 847 | TargetStrategy | | N | Requires ExpireTime and EffectiveTime for TWAP/VWAP orders. `1001` = TWAP | | 1028 | ManualOrderIndicator | Boolean | Y | `Y` = Manual order entry, `N` = Automated/algorithmic | | 1031 | CustOrderHandlingInst | String | Y | `W` = Desk
`Y` = Electronic (default)
`C` = Vendor provided platform billed by executing broker
`G` = Sponsored access via exchange API
`H` = Premium algorithmic trading provided by executing broker
`D` = Other | ### (F) OrderCancelRequest Request to cancel submitted single or multi-leg order. | Tag | Name | FIX Type | Req | Description | | :--- | :------------------- | :----------- | :-- | :--------------------------------------------------------------- | | 1 | Account | String(16) | Y | Account identifier | | 11 | ClOrdID | String(36) | Y | New unique client order identifier for this cancel request | | 37 | OrderID | String(17) | Y | Exchange-assigned order ID to be canceled (from ExecutionReport) | | 41 | OrigClOrdID | String(36) | N | ClOrdID of the order being canceled | | 54 | Side | Char(1) | Y | Original order side (`1` = Buy, `2` = Sell) | | 55 | Symbol | String(24) | Y | Instrument symbol | | 167 | SecurityType | String(6) | Y | `FUT` | | 60 | TransactTime | UTCTimestamp | Y | Cancel request submission time | | 1028 | ManualOrderIndicator | Boolean | Y | `Y` = Manual, `N` = Automated | ### (H) OrderStatusRequest Queries current status of an order. | Tag | Name | FIX Type | Req | Description | | :-- | :----------- | :--------- | :-- | :--------------------------------- | | 1 | Account | String(16) | N | Account identifier | | 11 | ClOrdID | String(36) | Y | Client order identifier | | 37 | OrderID | String(17) | C | Exchange order ID (if known) | | 54 | Side | Char(1) | Y | Order side (`1` = Buy, `2` = Sell) | | 55 | Symbol | String(24) | Y | Instrument symbol | | 167 | SecurityType | String(6) | Y | `FUT` | ### (8) ExecutionReport Reports order status changes, fills, rejections, and other execution events. | Tag | Name | FIX Type | Req | Description | | :--- | :----------------- | :----------- | :-- | :---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | 1 | Account | String(16) | Y | Account identifier | | 11 | ClOrdID | String(36) | Y | Client order identifier from request message | | 13 | CommType | String | Y | `3` = Absolute | | 12 | Commission | Amt | Y | The Coinbase commission incurred for this fill in quote currency | | 17 | ExecID | String | Y | Unique execution identifier assigned by exchange. Returns `0` when sent in with OrderStatusRequest | | 30 | LastMkt | String | Y | Venue of execution for last fill | | 37 | OrderID | String(17) | Y | Exchange-assigned order identifier | | 41 | OrigClOrdID | String(36) | C | Original ClOrdID when responding to cancel/replace requests | | 150 | ExecType | Char | Y | `A` = Pending New
`0` = New
`4` = Canceled
`8` = Rejected
`C` = Expired
`F` = Trade (partial or full fill)
`3` = Done for Day
`L` = Stop Triggered | | 39 | OrdStatus | Char | Y | `A` = Pending New
`0` = New
`I` = Order Status
`1` = Partially filled
`2` = Filled
`4` = Canceled
`8` = Rejected
`C` = Expired
`6` = Pending Cancel
`E` = Pending Replace | | 54 | Side | Char(1) | Y | `1` = Buy, `2` = Sell | | 55 | Symbol | String(24) | Y | Instrument symbol | | 167 | SecurityType | String(6) | Y | `FUT` | | 38 | OrderQty | Int(9) | Y | Original order quantity | | 40 | OrdType | Char(1) | Y | `1` = Market
`2` = Limit
`3` = Stop
`4` = Stop Limit | | 44 | Price | Price(20) | C | Limit price (if applicable) | | 99 | StopPx | Price(20) | C | Stop trigger price (if applicable) | | 59 | TimeInForce | Char(1) | N | `1` = GTC
`6` = GTD
`3` = IOC
`4` = FOK | | 60 | TransactTime | UTCTimestamp | Y | Transaction time (YYYYMMDD-HH:MM:SS.ssssss) | | 14 | CumQty | Qty | Y | Cumulative quantity filled | | 151 | LeavesQty | Qty | Y | Quantity remaining open (OrderQty - CumQty) | | 152 | CashOrderQty | Qty | Y | Quantity remaining in quote currency | | 32 | LastQty | Qty | C | Quantity filled in this execution (required when ExecType = `F`) | | 31 | LastPx | Price(20) | C | Execution price (required when ExecType = `F`) | | 6 | AvgPx | Price(20) | Y | Average fill price across all executions | | 136 | NoMiscFees | | C | Number of MiscFees (repeating group) | | ↳137 | MiscFeeAmt | Amt | C | Misc fee value | | ↳138 | MiscFeeCurr | String | C | Currency of misc fees in quote currency | | ↳139 | MiscFeeType | String | C | `1` = Regulatory Fee
`7` = Client Fee
`4` = Venue Fee
`3` = Trading Desk Fee
`14` = Financing Fee
`31` = Clearing Fee | | 103 | OrdRejReason | Int | C | Required when ExecType = `8` (Rejected):
`1` = Unknown symbol
`2` = Exchange closed
`3` = Order exceeds limit
`4` = Too late to enter
`5` = Unknown order
`6` = Duplicate order
`8` = Stale order
`18` = Invalid price increment
`99` = Other (see Text) | | 58 | Text | String | N | Rejection reason or other informational message | | 168 | EffectiveTime | UTCTimestamp | C | Start time of an order (required for TWAP/VWAP) | | 126 | ExpireTime | UTCTimestamp | C | Expiration time (when TimeInForce = GTD) | | 1138 | DisplayQty | Qty | C | Display quantity for iceberg orders. Only available when OrdType `2` = Limit or `4` = Stop Limit | | 528 | OrderCapacity | Char(1) | N | `A` = Agency, `P` = Principal | | 1057 | AggressorIndicator | Boolean | N | `Y` = Aggressor, `N` = Passive (for trade reporting) | *** ## Appendix A: Code Sets ### OrdType (40) | Value | Description | | :---- | :---------- | | 1 | Market | | 2 | Limit | | 3 | Stop | | 4 | Stop Limit | ### Side (54) | Value | Description | | :---- | :---------- | | 1 | Buy | | 2 | Sell | ### SecurityType (167) | Value | Description | | :---- | :---------- | | FUT | Futures | ### TimeInForce (59) | Value | Description | | :---- | :------------------------ | | 1 | Good Till Cancel (GTC) | | 3 | Immediate or Cancel (IOC) | | 4 | Fill or Kill (FOK) | | 6 | Good Till Date (GTD) | ### ExecType (150) | Value | Description | | :---- | :--------------------------- | | 0 | New | | 3 | Done for Day | | 4 | Canceled | | 5 | Replace | | 8 | Rejected | | A | Pending New | | C | Expired | | F | Trade (partial or full fill) | | I | Order Status | | L | Stop Triggered | ### OrdStatus (39) | Value | Description | | :---- | :--------------- | | 0 | New | | 1 | Partially filled | | 2 | Filled | | 4 | Canceled | | 6 | Pending Cancel | | 8 | Rejected | | A | Pending New | | C | Expired | | E | Pending Replace |