Constraints

Constraint	Detail
One FIX connection per Dealer	Dealers require a dedicated connection to enable Professional (Tiered) pricing.
Shared connection for Customers	An introducing broker may share one connection across multiple customers. Regular prices only; all customers see all levels.
Accounts	Orders may be tagged with an account code. Orders from the same party with different account codes will match and execute — useful for clearing brokers hosting multiple customers.

Constraint	Detail
Security identifier	ISIN (12 characters), CUSIP (9 characters), or FIGI. All formats require a valid check digit.
Prices are firm	OpenYield is authorized to execute at the price specified (or better).
Price range enforcement	All prices must be within a reasonable range of top-of-market or third-party live pricing. Too-wide or fat-finger prices are rejected.
Prices are clean	Prices are expressed as a percentage of face value, excluding accrued interest.
Tiered pricing	Dealers may set a Regular price (visible to all) and a Professional (Tiered) price (visible to other Dealers only). Customers see and set Regular prices only. OpenYield can automate tiered price generation via formula or fixed level.
All-to-all market	All orders may match across all Subscribers and Subscriber Accounts. All Subscribers have access to all available liquidity.
Pre-trade anonymous	OpenYield does not disclose the party behind an order. For bilateral trades, MPID and clearing house are shared post-trade only.

Constraint	Detail
Unit	Bonds (1 `bond` = $1,000 face value) or notional.
Minimum & increment	1 bond ($1,000 face). Municipal Bond and Agency Bond denominations apply where relevant.
Fills	OpenYield is authorized to fill up to the full Order or Quote quantity.
Quantity limits	Per-order, asset group, and gross/long/short exposure limits are set per subscriber. Orders exceeding limits are rejected. OpenYield can signal when limits are approaching; once breached, further orders in that asset group are rejected until approved.

Order kinds: Limit or Market.

Order formats: Quote (fixed income style), Order (fixed income style).

Limit Orders and Quotes

Require a price. Orders without a price are rejected; Quotes without a price are treated as cancellations.
Default TIF is GTC (Good Till Cancel = Good for Day on OpenYield). May also use IoC, FoK, or AoN.
Crossing orders are matched and executed at the crossed level.
Price/Time Order. Layered FIFO at each price level — earlier orders fill first.
Updates may only change quantity, price, and (for Limit Orders) order ID. Side, security, time in force and account cannot be changed.
If an update is rejected, OpenYield cancels the original order to maintain order book confidence.
Quote IDs are stable for the lifetime of the quote.
Order IDs must be unique per message. Replace and cancel messages must reference the active Order ID.

Market Orders

RFO

Indicative request: summons liquidity into an empty order book.
Tradeable request: traditional RFQ seeking quotes for a quantity at an undisclosed price.
RFO Quotes must come from algorithms — the collection window is too short for manual responses.
Traditional RFQ is available to subscribers with automated algorithmic systems.

Commission: Added in cash settlement for Intermediated trades. Not included as a separate field for Bilateral trades.

On connection, OpenYield will:

Send a full market data snapshot on the MD feed, followed by streaming incremental updates.
Replay any missing trade messages on the TR and DC feeds (same-day reconnections only).

On disconnection, OpenYield will:

Pause filling active orders. Fills matched before disconnection are detected are queued for delivery on reconnect.
Cancel all subscriber orders and quotes on the book.

At end of day, OpenYield cancels all live orders.

State transition	FIX message sent
Closed → Pre-Open	Pre-Open: includes scheduled Open and Close times for the day.
Pre-Open → Open	Open: includes scheduled Close time for the day.
Open → Closed	Close: state change notification.
Halt	Halt: trading suspended notification.
Halt → Resume	Closed message followed by Pre-Open message with new reopening time.

OpenYield rejects: