# Casino Odds API > Casino game maths as an API, computed locally and deterministically — exact house edge, expected value and return-to-player, never a simulation. The roulette endpoint takes a wheel variant (European single-zero or American double-zero) and a bet type (straight, split, street, corner, six-line, column, dozen, red/black, odd/even, high/low, or the American basket) and returns the win probability, the payout, the expected value per unit staked and the house edge — the famous 2.70 % on every European bet, 5.26 % on American (7.89 % on the basket), and 1.35 % when the European la-partage rule is applied to even-money bets. The craps endpoint gives the exact 36-outcome dice maths for the pass line (1.41 %), don't pass (1.36 %, with its 12-push), the field (2.78 % when 12 pays 3:1) and any seven (16.67 %). The bet endpoint is fully generic: give any win probability and payout and it returns the expected value, house edge, return-to-player and the standard deviation of a unit bet — perfect for keno, slots, scratch cards or a custom wager. Everything is computed locally and deterministically, so it is instant and private. Ideal for gaming-analytics, responsible-gambling, casino-education and odds-comparison app developers, advantage-play and bankroll tools, and probability teaching. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 compute endpoints. This is the game-odds maths; for Texas Hold'em hand equity use a poker API and for converting betting prices use an odds API. ## Authentication All requests require your oanor API key in the `x-oanor-key` header. Get one at https://www.oanor.com/developer/keys. ```bash curl -H "x-oanor-key: oanor_live_…" "https://api.oanor.com/casino-api/..." ``` ## Pricing - **Free** (Free) — 4,450 calls/Mo, 2 req/s - **Starter** ($4/Mo) — 47,000 calls/Mo, 6 req/s - **Pro** ($12/Mo) — 228,000 calls/Mo, 15 req/s - **Mega** ($39/Mo) — 1,270,000 calls/Mo, 40 req/s ## Endpoints ### Casino #### `GET /v1/bet` — Generic expected value **Parameters:** - `win_probability` (query, required, string) — Win probability (0–1 or %) Example: `0.1` - `payout` (query, required, string) — Payout to-1 Example: `5` - `push_probability` (query, optional, string) — Push/tie probability **Example:** ```bash curl -H "x-oanor-key: $KEY" \ "https://api.oanor.com/casino-api/v1/bet?win_probability=0.1&payout=5" ``` **Response:** ```json { "data": { "note": "EV per unit staked = p_win·payout − p_lose. House edge = −EV; RTP = 1 + EV. Works for keno, slots or any custom bet.", "inputs": { "payout_to_1": 5, "win_probability": 0.1, "push_probability": 0 }, "rtp_percent": 60, "lose_probability": 0.9, "house_edge_percent": 40, "standard_deviation": 1.8, "expected_value_per_unit": -0.4 }, "meta": { "timestamp": "2026-06-05T19:50:09.117Z", "request_id": "7ea4a501-ddc4-4a3c-84d3-1599ac77c328" }, "status": "ok", "message": "Generic EV", "success": true } ``` #### `GET /v1/craps` — Craps house edge **Parameters:** - `bet` (query, optional, string) — passline, dontpass, field, anyseven Example: `passline` - `twelve_pays` (query, optional, string) — Field 12 payout (3 or 2) Example: `3` **Example:** ```bash curl -H "x-oanor-key: $KEY" \ "https://api.oanor.com/casino-api/v1/craps?bet=passline&twelve_pays=3" ``` **Response:** ```json { "data": { "note": "Exact 36-outcome dice maths. Pass line 1.41%, don't pass 1.36%, field (12 pays 3:1) 2.78%, any seven 16.67% house edge.", "inputs": { "bet": "pass line" }, "payout_to_1": 1, "win_probability": 0.492929, "lose_probability": 0.507071, "push_probability": 0, "house_edge_percent": 1.4141, "expected_value_per_unit": -0.014141 }, "meta": { "timestamp": "2026-06-05T19:50:09.282Z", "request_id": "70b3674f-aa82-4bfa-bfb9-4ac9158104b7" }, "status": "ok", "message": "Craps edge", "success": true } ``` #### `GET /v1/roulette` — Roulette house edge **Parameters:** - `variant` (query, optional, string) — european or american (default european) Example: `american` - `bet` (query, optional, string) — straight, red, dozen, basket, … Example: `straight` - `la_partage` (query, optional, string) — European even-money half-back rule Example: `true` **Example:** ```bash curl -H "x-oanor-key: $KEY" \ "https://api.oanor.com/casino-api/v1/roulette?variant=american&bet=straight&la_partage=true" ``` **Response:** ```json { "data": { "note": "EV per unit = p·payout − (1−p); house edge = −EV. European single-zero is 2.70% on every bet; American double-zero is 5.26% (7.89% on the basket). La partage halves the even-money edge to 1.35%.", "inputs": { "bet": "straight", "variant": "american" }, "pockets": 38, "payout_to_1": 35, "rtp_percent": 94.7368, "numbers_covered": 1, "win_probability": 0.026316, "house_edge_percent": 5.2632, "expected_value_per_unit": -0.052632, "win_probability_percent": 2.6316 }, "meta": { "timestamp": "2026-06-05T19:50:09.402Z", "request_id": "8a2269fc-5db1-4209-a1ff-6caa8b002288" }, "status": "ok", "message": "Roulette edge", "success": true } ``` ### Meta #### `GET /v1/meta` — Spec **Example:** ```bash curl -H "x-oanor-key: $KEY" \ "https://api.oanor.com/casino-api/v1/meta" ``` **Response:** ```json { "data": { "notes": "Closed-form probability — no simulation. For Texas Hold'em equity use a poker API; for converting betting prices use an odds API.", "service": "casino-api", "endpoints": { "GET /v1/bet": "Generic EV, house edge, RTP and standard deviation from win probability and payout.", "GET /v1/meta": "This document.", "GET /v1/craps": "Exact house edge for pass line, don't pass, field and any seven.", "GET /v1/roulette": "House edge and EV for any roulette bet (European or American, la partage optional)." }, "description": "Casino game maths: house edge, expected value and RTP for roulette, craps and any custom bet — exact, not simulated." }, "meta": { "timestamp": "2026-06-05T19:50:09.503Z", "request_id": "1a189a88-71ec-4c85-9578-18b26347e62d" }, "status": "ok", "message": "Meta", "success": true } ``` --- Marketplace page: https://www.oanor.com/api/casino-api OpenAPI spec: https://www.oanor.com/api/casino-api/openapi.json