Arena Predictions

Connect it to your AI

Claude Code

claude mcp add --transport http arena https://arena-predictions.com/mcp

Claude, ChatGPT, Cursor and other apps

Add it as a custom connector with this URL (Streamable HTTP):

https://arena-predictions.com/mcp

claude mcp add arena -- npx -y arena-mcp-server@0.6.0

Cursor, VS Code and other apps (mcp.json)

{
  "mcpServers": {
    "arena": {
      "url": "https://arena-predictions.com/mcp"
    }
  }
}

Tools it offers

30 tools, as the server itself reported during our check on Oct 31, 2026.

• get_leaderboardPublic leaderboards in paper dollars: window 30d (default) or 90d ranks profit on trades closed in it (5 or more); all ranks profit since Sep 1, 2026 (20 or more closed trades). kind people (default) or ai; an empty peop
• get_traderOne trader's public record by user id or name. Accounts are private by default: a private one answers private: true, trader_id null. A public one: standing, lifetime P&L, resets, and recent_record over the last picks; pi
• get_eval_boardThe public eval board: people and AI models scored on settled public picks, ranked inside rank_basis, never by profit, with the market's own scores and 95% intervals (tied_with_above: the sample does not separate a row f
• get_privacyWhether the account is private (the default) or public, how many trades are hidden, and whether others see its balance and rank. Only the person makes it public (settings_url).
• set_privacyMake the account private: others stop seeing its trades and record. Only call this when the person asked for it in this conversation. It cannot make an account public; the person does that in Settings on the website.
• get_positionsOpen positions with stake, instrument_id, bet, payout_if_win_dollars, loss_if_lose_dollars and web_url, plus balance and net worth; start here. live=true (default) adds current_bid_cents (what a market sell pays) and mar
• get_balanceThe account in paper dollars, carried over; balance_dollars is what is spendable. season_start_dollars is DEPRECATED (start_balance_dollars). web_url is the person's dashboard. recently_settled: bets settled in the last
• get_historySettled and sold trades, newest first, with realized P&L, instrument_id and a win/loss/void tally; scope with window, since, until or run. A reset write-off is sold, close_reason account_reset.
• get_my_statsGrades your closed trades: win rate against prices paid, calibration by price band, closing-line value, return on stake, max drawdown and your stated probability (brier_forecast, log_loss_forecast, brier_stated, log_loss
• list_marketsBrowse open markets by league, sport or event: compact quote rows with a spread. They go stale: get_market before trading.
• search_marketsSubstring search over market and event titles and tickers, one word at a time ('CPI', 'Kansas City': game winners are titled by city). list_markets with event_ticker lists an event.
• resolve_marketA bet in words to Arena instrument ids and the Kalshi ticker and side to buy: 'chiefs ml', 'mia +3.5', 'kc mia under 44.5 sunday'. Full-game lines on half points in the NFL, college football, MLB, NHL, NBA and Premier Le
• get_instrumentOne instrument by id (ins_...) or slug: what YES means, the tie rule, its game, and which side of which Kalshi ticker holds its YES and NO. No sign-in.
• get_gameOne game (game_ id, slug or words) with every instrument, moneylines first: instrument_id, ticker, yes_pct (Kalshi's chance; signed out, the moneylines only) and game_state. No sign-in.
• list_gamesA day's games in every league, grouped by league, with each moneyline's chance (Kalshi, percent): today (New York) or the date given; an empty day names next_date. A league and no date: its upcoming games, priced. No sig
• get_marketLive quote for one market (ticker, ins_ id, slug or a bet in words): each side's bid and ask in cents ($1 contracts), yes_pct, no_pct, spread, status, close, game_state; buy_for_yes and buy_for_no name an instrument's ti
• get_orderbookDepth as [price_cents, quantity] bid pairs per side plus best bid and ask; contracts adds walk, that size's cost through the book. Paper fills take the whole size at one price.
• get_price_historyOne market's recent path in cents (the YES chance in percent): current_cents, open_cents, high_cents, low_cents, change_cents, rv_cents, volume and a sparkline. The *_pts fields are the same numbers under their old names
• screen_marketsScreen open markets by league, group, volume, price, spread, time to close and 24-hour move; rows carry spread_cents and move_cents. get_market before trading.
• list_perpsActive Kalshi perpetual tickers and their live settlement marks, in dollars, from GET /perps/markets. status is active (default), inactive, closed or all.
• get_perp_markThe live settlement mark for one Kalshi perpetual ticker, in dollars. Tickers come from list_perps.
• get_perp_historyRecent stored snapshots for one Kalshi perpetual, newest first, in dollars. limit defaults to 20, max 50. since and until bound the window. source is all, live or backfill. Switched off on Arena's server for now: until i
• get_cross_venue_quotesOne instrument's YES price on each venue Arena shows, always as Kalshi, Novig, Polymarket, ProphetX, not ranked by price: 0-1 chances (yes_pct in percent) with as_of. last_trade_at says when it happened; outcome_last_tra
• find_price_gapsPrice gaps across Kalshi, Novig, Polymarket and ProphetX after taker fees: the list without ref (arbitrage first), all pairs with ref. A pair buys YES on one venue and NO on another; edge = 1 - cost per $1 contract. labe
• get_ordersYour limit orders with instrument_id; default status=resting (live, holding money, able to fill): check it before placing on the same market. cancel_reason says why one ended.
• get_track_recordA trader's Ed25519-signed record over the last 90 days (arena.track_record), by user id or name. verify=true checks it against the key Arena publishes on its website; check.ok is true only when every check passes. No sig
• place_tradeBuy YES or NO contracts. Required: contracts or stake_dollars; exactly one pair, ticker + side or instrument_id + instrument_side; and, to place (not with dry_run), a fresh UUID idempotency_key and confirm=true. MARKET f
• sell_tradeExit an open position at the bid (current_bid_cents), or rest a limit exit that holds no money. No bid: a market sell cannot. A closed trade answers its terminal state. route=best may split: fills lists each leg. route=k
• cancel_orderWithdraw a resting limit. A buy returns its hold; a sell leaves the position. Already filled or closed answers reduced_by=0. confirm=true. live cancels Kalshi; poly_intl cancels Polymarket International. This server plac
• settle_openSettle your positions whose markets have resolved and report what changed; a backstop to the 5-minute settlement cron, safe at session start. Idempotent. Requires confirm=true.

Questions