Choose an odds format - TheRundown API

Use the optional odds_format query parameter on V1 and V2 REST GET endpoints to choose how sportsbook prices are returned. It also applies to GET /api/v2/public/odds/{sportID} and RapidAPI REST mirrors. The public snapshot contents and delay remain unchanged. WebSocket messages remain unchanged. If you omit odds_format or set it to american, the response stays byte-for-byte unchanged in its existing American format. Set the value once, in lowercase:

Value	Example for an American price of `-110`	Example for `+150`	Output type
`american`	`-110`	`150`	Existing response type; default
`decimal`	`1.909091`	`2.5`	Preserves whether the source field is a number or numeric string
`fractional`	`10/11`	`3/2`	Reduced ratio string
`probability`	`0.52381`	`0.4`	Implied, not de-vigged, probability from 0 to 1; preserves whether the source field is a number or numeric string

Decimal and probability values are rounded to six decimal places with trailing zeroes removed. For extreme valid prices, probability output uses additional precision when needed so the value does not round to 0 or 1. Fractional output is reduced to its exact ratio.

Request a format

cURL

if [ -z "${API_KEY:-}" ]; then
  echo "Set API_KEY" >&2
  exit 1
fi

curl --fail-with-body --compressed \
  -H "X-TheRundown-Key: ${API_KEY}" \
  "https://therundown.io/api/v2/sports/4/events/2026-11-13?market_ids=1,2,3&odds_format=decimal"

The parameter works the same way on V1 responses:

cURL

curl --fail-with-body --compressed \
  -H "X-TheRundown-Key: ${API_KEY}" \
  "https://therundown.io/api/v1/events/EVENT_ID?odds_format=fractional"

A successful non-American JSON response includes the X-Odds-Format response header with the selected format.

What changes

The API converts supported price fields, including price, fair_price, adjusted_price, previous_price, V1 moneyline/spread/total prices, hedge prices, promotion prices, and compact chart-history prices. A numeric source value stays numeric for decimal and probability output; a numeric string stays a string. Fractional prices are strings in either case. The API leaves line values, IDs, probabilities already present in the response, liquidity values, and other non-price fields unchanged. Explicit unit fields such as american_odds and decimal_odds are unchanged. Delta fields such as price_delta and *_money_delta remain in American-point difference units; they are not recalculated into another odds format. Values that are not convertible American prices stay unchanged. This includes null, nonnumeric sentinels, off-board placeholders such as 0 and 0.0001, and numeric values whose absolute value is below 100. Empty, repeated, or unsupported odds_format values return HTTP 400. Supported values are american, decimal, fractional, and probability. The selected representation changes only returned odds; it does not change the requested markets, lines, event scope, or snapshot delay.