> ## Documentation Index
> Fetch the complete documentation index at: https://docs.oddspapi.io/llms.txt
> Use this file to discover all available pages before exploring further.
# Parlays & SGP - Building a Betslip
> A workflow guide for multi-leg betting on OddsPapi: choosing between the parlay and SGP endpoints, keeping a live slip priced, comparing bookmakers, and degrading gracefully when a leg suspends.
[Parlays & SGP](/api-reference/parlays) is the field-by-field reference for the
two multi-leg endpoints. This guide is the other half: **how to wire them into a
betslip that stays correct while a user is still building it.**
***
## Which endpoint
The choice is made by the legs, not by preference.
Use `GET /fixtures/odds/sgp`. The bookmaker prices it, so `price` reflects
the real correlation between the legs — "over 2.5 goals" and "home win" are
not independent events, and a naive product would overprice the slip.
Use `GET /fixtures/odds/parlay`. Legs are independent, so the price is the
product of the decimal odds, computed locally and instantly.
`/sgp` rejects it — all legs must share one fixture. Either split the slip
or price the whole thing with `/parlay` and accept the uncorrelated number.
The two answers for the same two legs, side by side:
```json theme={null}
"parlay": {
"bet365": {
"id1400003160574217:bet365:141:0,id1400003160574217:bet365:146:0": {
"bookmaker": "bet365",
"active": true,
"price": 7.98,
"singlesPrice": 7.98,
"changedAt": 1766667441097
}
}
}
```
```json theme={null}
"sgp": {
"bet365": {
"id1400003160574217:bet365:141:0,id1400003160574217:bet365:146:0": {
"bookmaker": "bet365",
"active": true,
"price": 6.5,
"singlesPrice": 7.98,
"changedAt": 1766667441097,
"betslip": "https://www.bet365.com/dl/sportsbookredirect?bs=..."
}
}
}
```
Same legs, same `parlayId`, two different prices. `singlesPrice` is the naive
product in both; on `/sgp` the gap down to `price` is the correlation margin.
Showing both numbers is what makes an SGP legible to a user.
***
## Comparing bookmakers
Legs are grouped **by bookmaker**, and `parlayId` is built the same way on both
endpoints (sorted, deduped `oddsIds` joined by `,`). Two consequences you can
build on:
* Request the same selection at several books in one call and you get every
book's price for that slip side by side, under the same `parlayId`.
* A `/parlay` result and an `/sgp` result for an identical selection are
directly comparable — same key, different pricing model.
A book that cannot price the slip is simply absent from the section. Absence is
not an error; see below.
***
## Keeping a live slip priced
A betslip is a long-lived object and prices move under it.
* **Re-price on every leg change.** `parlayId` changes the moment the selection
changes, so cached prices are keyed correctly for free.
* **Re-price on a clock, not on every tick.** Both endpoints are capped at
**10 requests/second**. Poll a live slip on a fixed interval rather than
chasing every odds update — an `/sgp` call can round-trip the bookmaker, so
it is the slower of the two even where the budget is the same.
* **Cap at 20 legs.** Both endpoints reject more.
Do not fan a language sweep or a bookmaker sweep out in parallel against
`/parlay`. Ten requests per second is per key, and the endpoint answers
quickly enough that a burst trips the limit before you notice — the symptom
looks like empty parlay sections, not like a rate-limit error.
***
## Degrading gracefully
Three different things can make a slip unpriceable, and a good UI distinguishes
them:
| What happened | How you see it | What to tell the user |
| ------------------------ | ----------------------------------------------------------------------- | -------------------------------------------- |
| A leg was never found | the `oddsId` appears in `missingOddsIds` | the selection is invalid — drop it |
| A leg is temporarily off | the leg is present but inactive, with `meta.inactiveReason` | suspended — the slip returns when it reopens |
| The book could not quote | the bookmaker is absent from `sgp`, and `missingOddsIds` is **not** set | try another book |
That third row is the one that surprises people: every leg was found on our
side, but the bookmaker's own pricing service could not resolve the parlay. The
section is empty and nothing is reported as missing, because nothing *was*
missing. Read [suspended vs missing
legs](/api-reference/parlays#suspended-vs-missing-legs) for the full
`inactiveReason` list.
The `odds` section is never filtered for you — inactive legs come back
included, deliberately, so you can render a suspended leg in place instead of
having it vanish from the slip.
***
## Periods and legs
Legs from different periods of the same fixture combine normally — a `fulltime`
1X2 and a `p1` totals line are two legs like any other. If you are building
market groupings to select from, read [Periods per sport](/guides/periods)
first: whether a sport even offers `fulltime` depends on its structure, and
assuming it does is the most common source of empty market buckets.
***
## Related
Every field, error and `inactiveReason`.
Authoritative per-endpoint budgets.
Which periods exist where, and why.
The full pipeline this slip sits inside.