> ## Documentation Index > Fetch the complete documentation index at: https://docs.sx.bet/llms.txt > Use this file to discover all available pages before exploring further. # Glossary > Definitions of key terms used across the SX Bet API and developer docs. ### API Key A credential required for posting orders, cancelling orders, and accessing real-time WebSocket updates. Generated from your account at [sx.bet](https://sx.bet). Passed as an `X-Api-Key` HTTP header for REST calls, and used to obtain a connection token for WebSocket subscriptions. See [API Key](/api-reference/api-key). ### apiExpiry A Unix timestamp (in seconds) specifying when an order expires from the API's perspective. After this time, the order is removed from the orderbook. Distinct from the on-chain `expiry` field, which is deprecated and must always be `2209006800`. ### Base token The ERC-20 token used to denominate a bet. On SX Bet, the primary base token is USDC (6 decimals). Referenced by contract address in API calls. See [References](/api-reference/references). ### Bet group A categorical grouping of related market types (e.g., `"game-lines"`, `"outright-winner"`, `"set-betting"`). Returned in market objects from the API. ### Betting delay A short waiting period between when a fill is submitted and when the exchange matches it against the orderbook. Protects makers from toxic flow during in-play betting. See [Betting Delays](/developers/betting-delays). ### Capital efficiency (CE) A system that recognizes hedged exposure across opposing outcomes within a market group and releases escrowed funds early. Driven by the maximum-loss (MXL) algorithm. See [Capital Efficiency](/developers/capital-efficiency). ### Cash out The ability to exit a position early by selling it back. Mutually exclusive with CE refunds within the same market group. ### Chain ID A numeric identifier for a blockchain network. SX mainnet is `4162`, SX testnet (Toronto) is `79479957`. ### Checksum format A way of writing Ethereum addresses with mixed uppercase and lowercase letters (EIP-55) to catch typos. All addresses in the SX Bet API must use checksum format. ### Diming Posting odds in tiny increments to gain an unfair edge over existing orders. The [odds ladder](/developers/odds-rounding) prevents this by enforcing minimum step sizes. ### EIP-712 An Ethereum standard for signing structured typed data. Used by SX Bet to sign fill payloads and cancel requests. See [EIP-712 Signing](/api-reference/eip712-signing). ### Escrow A smart contract that holds both sides' funds while a bet is active. Automatically pays out the winner after settlement. ### Exchange model SX Bet's peer-to-peer model where users trade directly with each other rather than against a house or sportsbook. See [The Exchange Model](/developers/exchange-model). ### Executor The SX Bet exchange contract address that executes matched orders on-chain. Retrieved from [`GET /metadata`](/api-reference/get-metadata) and required in every maker order. ### Exposure The total amount of capital at risk across your open orders. Calculated as the sum of `totalBetSize - fillAmount` for all active orders. Must stay under your wallet balance. ### fillAmount The portion of a maker order that has already been matched by takers. The remaining fillable amount is `totalBetSize - fillAmount`. ### fillSalt A random 32-byte value that uniquely identifies a fill submission. Must match between the EIP-712 signature and the API request body. ### Fixture An individual sporting event (game, match, race, etc.) that betting markets are created for. Each fixture has a status indicating its current state. See [Fixture Statuses](/api-reference/fixture-statuses). ### Heartbeat A safety mechanism that automatically cancels all your open orders if your service stops sending periodic heartbeat requests within a configured timeout. See [Heartbeat](/api-reference/heartbeat). ### Implied probability Odds expressed as a probability between 0% and 100%. The native odds format on SX Bet. Stored as a fixed-point integer with 20 decimal places (e.g., 52.5% = `52500000000000000000`). ### isMakerBettingOutcomeOne A boolean field on orders indicating which outcome the maker is backing. `true` = outcome one, `false` = outcome two. The taker always takes the opposite side. ### Maker A user who posts an order to the orderbook, specifying an outcome, stake, and odds. Makers wait for takers to fill their orders. Makers pay 0% fees on SX Bet. ### Market A specific betting proposition on a fixture, defined by its sport, league, fixture, market type, and line. Identified by its `marketHash`. ### Market group A collection of related markets for a single fixture (e.g., all markets for one game). Used for calculating maximum loss and CE refunds. ### marketHash A unique keccak256 hash identifying a specific market. The primary key used in API calls to reference markets. ### Market type The category of bet — moneyline (1), spread (2), total/over-under (3), Asian handicap, etc. See [Market Types](/api-reference/market-types). ### Maximum loss (MXL) The worst-case net loss across all open positions within a market group. The CE algorithm calculates this to determine when escrow funds can be released. ### Moneyline A market type where you predict which team or player will win outright, with no point spread. Market type ID `1`. ### Odds ladder The set of valid odds values you can post orders at. Currently enforced at 0.125% intervals to prevent diming. See [Odds Rounding](/developers/odds-rounding). ### oddsSlippage An integer (0–100) representing the percentage tolerance on `desiredOdds` when filling. Applied to the weighted average odds across all matched orders. See [Slippage](/developers/slippage). ### Orderbook The collection of all active, unfilled maker orders for a given market. Fully transparent — all users can see all orders. See [The Orderbook](/developers/orderbook). ### orderHash A unique identifier for a specific maker order, computed from the order fields. Returned when an order is successfully posted. ### Outcome One of two bettable sides in a market. Outcome one is typically the first team/option listed, outcome two is the second. Some markets also have a void outcome (e.g., draw). ### Parlay A multi-leg bet combining multiple markets. All legs must win for the parlay to pay out. SX Bet applies a 5% fee on parlay profits. See [Parlays](/developers/parlays). ### Partial fill When a taker fills only a portion of a maker's available stake. The remaining unfilled portion stays on the orderbook for other takers. ### percentageOdds The odds for a maker order expressed as the maker's implied probability multiplied by 10^20. For example, 52.5% implied = `"52500000000000000000"`. The taker receives the complementary odds on the opposite outcome. ### RFQ (Request for Quote) The system used for parlay betting. When a bettor requests a parlay, makers receive the request via WebSocket and have 3 seconds to post orders. See [Parlays](/developers/parlays). ### Salt A random number included in an order to differentiate otherwise identical orders. Ensures each order produces a unique hash. ### Settlement The process of determining the outcome of a market after the event concludes and distributing funds to winners. Handled by the on-chain ReporterService contract. ### solidityKeccak256 A hashing function used to compute maker order hashes. Takes ABI-encoded order fields and produces a bytes32 hash that the maker signs. ### Spread A market type where you predict whether a team will win by more or less than a specified point margin (the "line"). Market type ID `2`. ### sportXeventId A string identifier for sporting events within SX Bet's system. Used to group markets by fixture and for event-level cancellations. ### stakeWei The taker's bet amount in base token units (Ethereum format). For USDC with 6 decimals, `"50000000"` = 50 USDC. See [Unit Conversion](/api-reference/unit-conversion). ### SX Network The blockchain that SX Bet runs on. Mainnet chain ID `4162`. ### Taker A user who fills an existing order from the orderbook. Takers get immediate execution at the posted price. Takers pay 0% fees on single bets, 5% on parlay profits. ### TokenTransferProxy A smart contract that must be approved (via ERC-20 `approve`) before you can place bets. It transfers tokens on your behalf when orders are matched. See [Approve Token Spending](/api-reference/post-approve). ### Total (Over/Under) A market type where you predict whether a combined score or statistic will be over or under a specified line. Market type ID `3`. ### totalBetSize The maximum amount of tokens a maker puts at risk if the order is fully filled. Expressed in base token units (e.g., `"100000000"` = 100 USDC). ### Vig (vigorish) The commission or house edge charged by a sportsbook. SX Bet charges 0% vig — odds are set entirely by makers and takers.