This reference uses mlb and the base path /v1/mlb. Expand the sidebar categories for games and live scores, identities and rosters, player profiles, lineups and box scores, batting, pitching and matchups, team statistics, first inning/NRFI, and pricing/history signals. Start with /games?date=YYYY-MM-DD, then use the returned canonical game ID for game detail, live state, lineup cards, box scores, matchup, play-by-play, and recap. Player profiles, game logs, comparisons, and team snapshots combine related reads for product workflows. MLB’s deeper statistics include batting/pitching splits, plate discipline, zone heatmaps, arsenals, pitch-type results, batter versus pitcher, bullpen, park factors, team pitching, and NRFI. Several deep-stat routes require an explicit season; check each endpoint’s parameters. Statcast-dependent metrics and advanced lineup blocks require source coverage. Missing values are unavailable, not zero. See the Baseball guide for metric units, split scopes, lineup-source flags, nested composite payloads, and differences from KBO/NPB. Historical and statistical reads require the stats entitlement. Current pricing and historical pricing have separate access requirements; see Odds, Props & Signals.