The exchange lay odds API that carries liquidity, not just prices

Aggregating back prices is table stakes — dozens of APIs do it. The lay side is different: it means carrying exchange markets as well as bookmakers, keeping both fresh on the same cycle, and pairing each back price to the current lay price for the same selection. That last step is the hard one, which is why most providers either omit exchanges entirely or list them as just more odds columns.

For a matched-betting tool or an arbitrage scanner, that omission isn't a smaller dataset — it's a missing product. Every calculation those products perform needs both sides of the pair. The field-by-field shape of a matched pair, lay price and liquidity included, is in the public API docs; most teams have a first call returning it within an afternoon.

An exchange price is an offer, not a quote — it only exists up to the amount other users have put behind it. A lay at 2.14 with almost nothing available is not a price your user can place a real stake against; showing it as if it were produces matches that fail at the exchange. Any lay feed that omits liquidity is reporting nominal prices, and downstream products built on them break in exactly this way.

So every lay price in the OddsRelay feed carries its available liquidity alongside the odds. Your product can filter thin markets out, rank matches by how much stake they genuinely support, or surface the figure to users directly. The exchanges and books behind those pairs are listed on the live coverage dashboard — the coverage claim is checkable, not asserted.

There is a real difference between "we also cover exchanges" and matched output. In this feed, each of the 60+ UK bookmaker back prices — bet365 included — arrives already paired to the current exchange lay price for the same selection, with a rating and qualifying loss computed. That pairing is the processing layer the matched-betting feed is built on, and it's the same structure an arbitrage scanner reads to find back-high, lay-low gaps.

The lay side flows through all seven feed types — standard, each-way, extra-place, BOG, dutching, 2up and price-boost — so wherever your product needs a pair, the pair is there. One schema, both sides, no second integration to reconcile.

Betfair carries the deepest UK liquidity; Smarkets and Matchbook price many of the same markets, often at lower commission, which can make them the better lay for a given match. Integrating each directly means three APIs, three data shapes and three sets of quirks to maintain. In this feed all three arrive in one normalised schema, and the pairing logic picks across them.

If Betfair is your reference point, the Betfair Exchange coverage entry shows how it appears in the feed, and we've written up why lay liquidity matters for the fuller argument on thin markets and failed matches.

Exchange prices move faster than bookmaker prices, so freshness matters twice over here: pre-match markets poll on roughly a three-second cycle, monitored, with a published status. The feed already powers a leading UK matched-betting platform — a product whose entire output depends on the lay side being current and honest. If you'd rather test than read, a free trial key delivers the real matched pairs, liquidity included, into your own product this week.