What are the odds on this question across venues?

Q: What are the odds on this question across venues?

subtract the timestamps before you compare the prices get the matched prediction market pairs with surf on monid, passing active_only true so the endpoint does the open-on-both filter server-side rather than you doing it by hand. if you want a particular question rather than a browse, the search endpoint takes a q keyword over the question text and the ticker what arrives: twenty cross-venue pairs, every one at confidence 100 and match type exact, across culture, sports, politics and economics, each carrying both venues' identifiers the flag that is never false: one venue reported its market active on all twenty rows while the other reported sixteen of them finalized, on both runs, so that one flag on its own keeps everything and the venue name changes case: the source field comes back capitalised while every request enum is lowercase, so a naive equality filter matches nothing the volumes are different units: one side reports dollars and the other reports contracts, in the same position of the same object; dividing one by the other means nothing there IS a keyword search, and this page said there was not: the search endpoint declares a q field described as searching the question text or the ticker, and it works: a plain phrase returned five matching markets and the status filter is a parameter, not a chore: an active-only flag is declared and does the job server-side in the same call, returning twenty rows open on both sides; an earlier version of this page told readers to filter it by hand the unit trap is documented, not hidden: the two volume fields are named for their units and the daily endpoint's own summary says so, so this is a field you must read rather than a trap that catches you

Prediction Markets APIs

The same question on two venues

Say this to your agent

>get the matched prediction market pairs with surf on monid, passing active_only true so the endpoint does the open-on-both filter server-side rather than you doing it by hand. if you want a particular question rather than a browse, the search endpoint takes a q keyword over the question text and the ticker

What the agent runsdone

surf /prediction-market/matching/pairs$0.024

surf /prediction-market/matching/daily · not run$0.024

surf /search/prediction-market$0.024

surf /prediction-market/correlations$0.024

What came backone matched question · 2026-09-25

Do the two venues agree the market is openof 20 matched pairs

one venue says active20 of 20

the other says finalized16 of 20

genuinely open on both4 of 20

what arrivestwenty cross-venue pairs, every one at confidence 100 and match type exact, across culture, sports, politics and economics, each carrying both venues' identifiers

the flag that is never falseone venue reported its market active on all twenty rows while the other reported sixteen of them finalized, on both runs, so that one flag on its own keeps everything

and the venue name changes casethe source field comes back capitalised while every request enum is lowercase, so a naive equality filter matches nothing

the volumes are different unitsone side reports dollars and the other reports contracts, in the same position of the same object; dividing one by the other means nothing

there IS a keyword search, and this page said there was notthe search endpoint declares a q field described as searching the question text or the ticker, and it works: a plain phrase returned five matching markets

and the status filter is a parameter, not a chorean active-only flag is declared and does the job server-side in the same call, returning twenty rows open on both sides; an earlier version of this page told readers to filter it by hand

the unit trap is documented, not hiddenthe two volume fields are named for their units and the daily endpoint's own summary says so, so this is a field you must read rather than a trap that catches you

$0.02420 pairs, one call

Check the timestamps before the prices

Say this to your agent

>price this matched question on both venues with surf on monid using interval latest, then subtract the two timestamps and tell me how far apart the quotes are before you tell me the prices

What the agent runsdone

surf /prediction-market/kalshi/prices$0.024

surf /prediction-market/polymarket/prices$0.024

surf /prediction-market/polymarket/price-ohlc · not run$0.024

What came backone matched question · 2026-09-25

Two quotes, both returned as latestdays between the two quotes

this pair, the gap156.9 days

a second pair, same group37.5 days

what it looks likeone venue quotes Yes at 0.001 and the other at 0.005, which reads as a 5x disagreement between two markets on one question

what it isthe two quotes are 156.9 days apart, both returned under interval latest and neither marked stale. A second question in the same event group came out 37.5 days apart and 1.25x, so the gap is a property of the pair rather than of the venues: measure it on yours

and quote the gap, not the agesthe two timestamps are fixed, so the ages grow by a day every day while the gap between them does not move

the only tellsubtracting the timestamps. Nothing else in either response distinguishes a current quote from a five-month-old one

the quotes are fineboth sides sum to exactly 1.000 on both venues, so each is internally coherent; they are simply not contemporaneous, and comparing them is the error

$0.048two quotes, one question

How the two venues compare overall

Say this to your agent

>get the prediction market analytics with surf on monid and compare the two venues on the last day where both series have a point. do not take the last row: their series end on different days

What the agent runsdone

surf /prediction-market/analytics$0.024

surf /prediction-market/kalshi/volumes · not run$0.024

surf /prediction-market/polymarket/volumes · not run$0.024

surf /prediction-market/polymarket/open-interest · not run$0.024

What came backone matched question · 2026-09-25

The last day both series coverone venue against the other

daily volume30.2x one way

market count1.87x the other

open interest1.50x the other

the series do not line upone venue's data runs ten to thirteen days further than the other's inside the same array, with nothing marking either as the end of its series, so the naive last row is a zero

and the multiple reverses by categoryplatform-wide the daily volume gap was 30.2x one way; on a single category it ran 2.5x the OTHER way. A platform-wide ratio is not a fact about the question you are pricing

and the other directionthe smaller-volume venue carried more open interest and more markets, which held on both runs, though which venue that is depends on the slice

read the array order tooone analytics array is oldest-first and another in the same aisle is newest-first, and neither says so

so which is biggerdepends entirely on the measure, which is why the page reports all three rather than picking one

$0.02430 days, both venues

The window that returns nothing

Say this to your agent

>when you price a market with surf on monid, pass interval latest explicitly. the default is a thirty-day window, so any market whose last activity falls outside it returns an empty array and bills in full: that is most dormant markets and it is not an error you can see from the status

What the agent runsdone

surf /prediction-market/polymarket/prices$0.024

surf /prediction-market/kalshi/orderbooks$0.024

surf /prediction-market/kalshi/prices$0.024

What came backone matched question · 2026-09-25

Eight billed callsUS dollars

returned rows$0.120

returned nothing$0.072

the window is the problem, not the default as suchthe default is a thirty-day range, so it answers for a market that traded inside it and returns an empty array for one that did not. On a second question it came back empty for a market last active 176 days ago and returned rows for one last active 20 days ago, in the same run

which is why latest is the safe instructionasking for latest removes the window from the question entirely, and on every id that came back empty under the default it returned a row

and the order book tooan order-book call on the exact ticker that had just priced correctly returned no snapshots and a count of zero, billed in full

what that is worth$0.072 of a $0.192 run, which is 37.5% of the spend on responses with nothing in them

none of them erroredall three were 200s, which is why the check has to be on the row count rather than on the status

$0.072what the empties cost

The identifier that changes its name

Say this to your agent

>when you take an identifier from the matching endpoint into a price call, rename it: the matching response calls it market_ticker and the price endpoint expects ticker. a wrong field NAME fails for free, but the right name carrying the other venue's identifier returns an empty 200 and bills in full, so check the value as well as the key

What the agent runsdone

surf /prediction-market/matching/pairs$0.024

surf /prediction-market/kalshi/prices$0.024

surf /search/prediction-market$0.024

What came backone matched question · 2026-09-25

the renamethe matching endpoint hands you market_ticker and the Kalshi price endpoint wants ticker; passing the field you were given fails validation

the workflow the description points at does workthe price endpoint tells you to discover tickers with a q keyword on the search endpoint, the search endpoint declares q, and that route works. An earlier version of this page reported a contradiction here that does not exist

a wrong field NAME costs nothingit is refused before a run exists, so the round trip is the whole price

a wrong field VALUE does notthe right field name carrying an identifier from the other venue returned a 200 with an empty array and billed in full, which is exactly the mistake this sentence is about

$0.00the 422s are free

Before you build a scanner

Say this to your agent

>before you design a scanner, get the analytics momentum summary with surf on monid and tell me what share of active markets carry any classification at all. then price the same scan on the other prediction-market provider on monid: it is roughly two and a half times cheaper per call and covers more venues, so the provider choice decides the budget before the call count does

What the agent runsdone

surf /prediction-market/analytics$0.024

surf /prediction-market/polymarket/smart-money · not run$0.024

surf /prediction-market/polymarket/leaderboard · not run$0.024

surf /market/fear-greed · not run$0.012

What came backone matched question · 2026-09-25

How much of the surface carries a signalof 3,646,753 active markets

neutral3,630,597

confirming, either way13,758

diverging, either way2,398

the share16,156 markets out of 3,646,753 carry any momentum classification, which is 0.44% of the surface; a second run put it at 0.41%, so it is a fraction of one percent rather than a fixed figure

what that means for a scana design that assumes most markets carry a reading is designing for 0.44% of them; the neutral bucket is the answer almost everywhere

there IS a cheaper rung, and this page said there was nota second provider runs a parallel prediction-market aisle at about $0.00935 a call, roughly two and a half times cheaper, and its market search covers five venues against this one's two. This provider's own options and futures endpoints are $0.012 rather than $0.024, so even inside it the price is not flat

what one pair costs to watchthree calls a day is $2.16 for thirty days here and about $0.84 on the cheaper provider, which is the difference a scanner is actually built on

$0.0243.6 million markets classified

Prediction Markets

How-to guide

Set up Monid.

Pick what you need. Say it in one sentence.

The same question on two venues

Check the timestamps before the prices

How the two venues compare overall

The window that returns nothing

The identifier that changes its name

Before you build a scanner

Read more

LLM gateway or MCP gateway

Bing Search API retired: the alternatives

When the site will not let you in