Polymarket: Auto-bet NBA Underdogs

Created by

B3 Team

Root

Search Nba

Filter Underdog Markets

Count Qualifying Markets

Check Any Qualifying

About

Scans Polymarket daily for cheap NBA underdog bets. Pulls up to 100 markets ranked by volume, checks liquidity and slippage, and places a bet on each market. Sends a recap to your notification channel after every bet

Quick Setup:

Import your wallet or use your B3OS Treasury Wallet
Pick the notification channel for trade recaps
Set the schedule - how often to scan (default: daily at 2:20 PM EDT)
Set the scope - search term picks the sport (default: NBA), tag picks the category (default: sports), limit caps markets per run (default: 100)
Set how markets get ranked (default: volume, which scans the most active markets first)
Set the amount - how much to bet per qualifying market (default: 1 USDC)
Test and publish!

Preview

Build Bet Summary

Action

Code:function transform(input) { if (!input || input.length === 0) return { betsPlaced: 0, lines: [], totalSpent: 0 }; const placed = []; for (const iter of input) { const item = iter['$item']; const slippageResult = iter.check_slippage && iter.check_slippage.output; const betResult = iter.place_bet; if (!betResult || betResult.status === 'skipped') continue; if (betResult.status !== 'success' && betResult.status !== 'filled' && betResult.status !== 'matched') continue; const price = betResult ? betResult.price : null; const impliedPct = price ? (price * 100).toFixed(1) : '?'; const potentialPayout = price && price > 0 ? (1 / price).toFixed(2) : '?'; const inputItem = iter.input.output const endDate = inputItem ? new Date(inputItem.endDate).toLocaleDateString('en-US', { month: 'short', day: 'numeric', year: 'numeric' }) : '?'; placed.push({ question: inputItem ? inputItem.question : 'Unknown', outcome: inputItem ? inputItem.outcome : 'Unknown', price: price ? price.toFixed(3) : '?', impliedPct: impliedPct, endDate: endDate, potentialPayout: potentialPayout, txHash: betResult.transactionHash || '' }); } return { betsPlaced: placed.length, lines: placed, totalSpent: placed.length }; }

Input:loop_markets:iterations

Input Type:{"items":{"type":"object"},"type":"array"}

Output Type:{"properties":{"betsPlaced":{"type":"number"},"lines":{"items":{"properties":{"endDate":{"type":"string"},"impliedPct":{"type":"string"},"outcome":{"type":"string"},"potentialPayout":{"type":"string"},"price":{"type":"string"},"question":{"type":"string"},"txHash":{"type":"string"}},"type":"object"},"type":"array"},"totalSpent":{"type":"number"}},"type":"object"}

check_any_qualifying

Action

Condition:{"$and":[{"{{get_qualifying_count.result.output}}":{"$gt":0}}]}

Calculate Order Slippage

Action

Code:function transform(input) { const asks = input.asks || []; if (asks.length === 0) return { ok: false, reason: 'no_asks', slippage: null, fillPrice: null }; const sortedAsks = asks.slice().sort((a, b) => a.price - b.price); const bestAsk = sortedAsks[0].price; const targetUSDC = 1.0; let remaining = targetUSDC; let totalShares = 0; let totalCost = 0; for (const level of sortedAsks) { if (remaining <= 0) break; const levelCost = level.price * level.size; const fillCost = Math.min(remaining, levelCost); const fillShares = fillCost / level.price; totalShares += fillShares; totalCost += fillCost; remaining -= fillCost; } if (remaining > 0.001) return { ok: false, reason: 'insufficient_liquidity', slippage: null, fillPrice: null }; const avgFillPrice = totalCost / totalShares; const slippage = (avgFillPrice - bestAsk) / bestAsk; if (slippage > 0.02) return { ok: false, reason: 'slippage_too_high', slippage: slippage, fillPrice: avgFillPrice }; return { ok: true, reason: 'ok', slippage: slippage, fillPrice: avgFillPrice }; }

Input:get_orderbook.result

Input Type:{"properties":{"asks":{"items":{"properties":{"price":{"type":"number"},"size":{"type":"number"}},"type":"object"},"type":"array"},"bestAsk":{"type":"number"}},"type":"object"}

Output Type:{"properties":{"fillPrice":{"type":"number"},"ok":{"type":"boolean"},"reason":{"type":"string"},"slippage":{"type":"number"}},"type":"object"}

Check Slippage Gate

Action

Condition:{"$and":[{"{{check_slippage.result.output.ok}}":{"$eq":true}}]}

Filter Underdog Markets

Action

Code:function transform(input) { if (!input || input.length === 0) return []; const now = Date.now(); const twentyFourHours = 24 * 60 * 60 * 1000; const qualifying = []; for (const market of input) { if (!market.active || market.closed) continue; const endMs = new Date(market.endDate).getTime(); if (isNaN(endMs) || endMs - now < twentyFourHours) continue; const candidates = []; for (let i = 0; i < market.outcomes.length; i++) { const price = parseFloat(market.outcomePrices[i]); if (!isNaN(price) && price < 0.20) { candidates.push({ question: market.question, slug: market.slug, endDate: market.endDate, outcome: market.outcomes[i], price: price, tokenId: market.tokenIds[i] }); } } if (candidates.length === 0) continue; candidates.sort((a, b) => a.price - b.price); qualifying.push(candidates[0]); } return qualifying; }

Input:search_nba:markets

Input Type:{"items":{"properties":{"active":{"type":"boolean"},"closed":{"type":"boolean"},"conditionId":{"type":"string"},"endDate":{"type":"string"},"id":{"type":"string"},"liquidity":{"type":"number"},"outcomePrices":{"items":{"type":"string"},"type":"array"},"outcomes":{"items":{"type":"string"},"type":"array"},"question":{"type":"string"},"slug":{"type":"string"},"tokenIds":{"items":{"type":"string"},"type":"array"},"volume":{"type":"number"}},"type":"object"},"type":"array"}

Output Type:{"items":{"properties":{"endDate":{"type":"string"},"outcome":{"type":"string"},"price":{"type":"number"},"question":{"type":"string"},"slug":{"type":"string"},"tokenId":{"type":"string"}},"type":"object"},"type":"array"}

format_bet_lines

Action

Format build_summary.result.output.lines using a template

Get Market Orderbook

Action

Token Id:Item: tokenId

Count Qualifying Markets

Action

Code:function transform(input) { return Array.isArray(input) ? input.length : 0; }

Input:Filter Underdog Markets:output

Input Type:{"items":{"type":"object"},"type":"array"}

Output Type:{"type":"number"}

Pass Market Item

Action

Code:function transform(input) { return input }

Input:Current Item

Timeout:5000

loop_markets

Action

Array:Filter Underdog Markets:output

notify_no_bets

Message configured

🏀 *NBA Underdog Bet Scanner* — No qualifying markets found today. No open NBA markets had any outcome priced below $0.20 with more than 24h until resolution.

notify_summary

Message configured

🏀 *NBA Underdog Bets Placed* — {{build_summary.result.output.betsPlaced}} bet(s) | ${{build_summary.result.output.totalSpent}} total spent {{format_bet_lines.result.formatted}} _All bets: ${{$props.polymarket_place_bet_fixedamount}} FAK market order on Polymarket. Outcomes priced <20% implied probability, >24h to resolution, <2% slippage._

place_bet

Action

Mode:manual

Order Type:FAK

Outcome:Item: outcome

Price Mode:market

Side:BUY

Token Id:Item: tokenId

Amount:Prop: polymarket_place_bet_fixedamount

root

Action

Schedule:

search_nba

Action

Include Closed:false

Include Inactive:false

Limit:Prop: polymarket_search_markets_limit

Order By:Prop: polymarket_search_markets_orderby

Query:Prop: polymarket_search_markets_query

Tag:Prop: polymarket_search_markets_tag

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