API reference

Markets: venue listings

The raw venue listings TPM tracks: a Kalshi event ticker or a Polymarket event. Use them to mirror one venue's catalog or to map venue ids to TPM events. For the cross-venue view, use events.

When to use it

Mirror the Kalshi or Polymarket catalog with TPM's normalised prices.
Find which TPM event a venue listing belongs to (event_slug).
Read a listing's settlement rules before comparing it with another venue.

New here? Read what a market and a contract are first.

GET/api/public/v1/marketsAPI key required

List venue markets

Largest by volume first. Add include=outcomes to get each market's outcomes and quotes.

Parameters

Name	In	Type	Required	Default	Description
venue	query	"kalshi" \| "polymarket"	No	—	Only this venue.
q	query	string	No	—	Search titles and venue ids.
event	query	string	No	—	Only markets grouped under this TPM event slug.
status	query	"active" \| "all"	No	active	Use `all` to include closed listings.
include	query	"outcomes"	No	—	`outcomes` adds each market's outcomes and quotes.
limit	query	integer	No	50	Rows per page, 1 to 200.
cursor	query	string	No	—	The `pagination.next_cursor` from the previous page. Keep the other filters the same. See pagination.

Request

curl -s 'https://api.thepredictionmarkets.com/api/public/v1/markets?venue=kalshi&q=nominee&limit=1' \
  -H 'X-API-Key: tpm_demo_key_authorized_2026'

Response

Example 200 response. Values are illustrative and change over time.

200 OK

{
  "data": [
    {
      "venue": "kalshi",
      "market_id": "KXPRESNOMD-28",
      "title": "Democratic Presidential Nominee 2028",
      "url": "https://kalshi.com/markets/kxpresnomd",
      "status": "active",
      "event_slug": "democratic-presidential-nominee-2028",
      "volume": 244696381.96,
      "liquidity": null,
      "end_date": "2028-11-07T00:00:00Z",
      "last_seen_at": "2026-10-21T08:24:28Z",
      "outcome_count": 41,
      "outcomes": null,
      "rules": null
    }
  ],
  "pagination": {
    "limit": 1,
    "has_more": true,
    "next_cursor": "eyJvIjoxfQ"
  }
}

Response fields

Field	Type	Description
venue	"kalshi" \| "polymarket"	Which exchange lists it.
market_id	string	The venue listing: a Kalshi event ticker (`KXPRESNOMD-28`) or a Polymarket event slug.
title	string \| null	Title as the venue shows it.
url	string \| null	Link to the listing on the venue.
status	string \| null	Venue status, e.g. `active`.
event_slug	string \| null	The TPM event this listing is grouped under. Use it with `/events/{slug}`.
volume	number \| null	Total traded volume in US dollars.
liquidity	number \| null	Order-book liquidity in US dollars, when the venue reports it.
end_date	string \| null	When trading is scheduled to close (UTC).
last_seen_at	string \| null	Last time TPM polled this listing from the venue.
outcome_count	integer	Number of outcomes (contracts) in the listing.
outcomes	Outcome[] \| null	Included on single-market requests and with `include=outcomes`. Same shape as in event detail.
rules	string \| null	Settlement rules text, on single-market requests.

Errors

HTTP	Code	When
400	validation.invalid_parameter	A filter has a bad value, e.g. `venue=robinhood`.
400	validation.invalid_cursor	The cursor is malformed or was made with other filters.
401	auth.missing_key	No `X-API-Key` header was sent.
401	auth.invalid_key	The key is wrong or was revoked.
429	rate_limit.per_second	Too many requests this second. Wait for `Retry-After`.

400 validation.invalid_parameter

{
  "error": {
    "code": "validation.invalid_parameter",
    "message": "venue: Input should be 'polymarket' or 'kalshi'",
    "request_id": "0f8969a6-0968-4d7c-9cbb-de379e8c19c4"
  }
}

All codes are listed on the errors page.

Try it

Runs a live request from your browser. Pre-filled with the shared demo key (5 requests per second for everyone); paste your own key for steadier results.

Request URLX-API-Keyvenuequeryqqueryeventquerystatusqueryincludequerylimitquerycursorquery

HTTP: —Time: —Rows: —Remaining this second: —Request: —

Press Send to run this request.

GET/api/public/v1/markets/{venue}/{market_id}API key required

Get one venue market

One listing with every outcome's quote and the settlement rules text. The sample is trimmed to one outcome.

Parameters

Name	In	Type	Required	Default	Description
venue	path	"kalshi" \| "polymarket"	Yes	—	The venue.
market_id	path	string	Yes	—	Kalshi event ticker or Polymarket event slug.

Request

curl -s 'https://api.thepredictionmarkets.com/api/public/v1/markets/kalshi/KXPRESNOMD-28' \
  -H 'X-API-Key: tpm_demo_key_authorized_2026'

Response

Example 200 response. Values are illustrative and change over time.

200 OK

{
  "data": {
    "venue": "kalshi",
    "market_id": "KXPRESNOMD-28",
    "title": "Democratic Presidential Nominee 2028",
    "url": "https://kalshi.com/markets/kxpresnomd",
    "status": "active",
    "event_slug": "democratic-presidential-nominee-2028",
    "volume": 244696381.96,
    "liquidity": null,
    "end_date": "2028-11-07T00:00:00Z",
    "last_seen_at": "2026-10-21T08:24:28Z",
    "outcome_count": 41,
    "outcomes": [
      {
        "id": "5c66f06e-dcac-44fa-93af-ba710d2a9ed2",
        "title": "Gavin Newsom",
        "contract_id": "KXPRESNOMD-28-GN",
        "status": "active",
        "volume": 11138438.36,
        "probability_change_24h": null,
        "quote": {
          "probability": 0.16,
          "best_bid": 0.16,
          "best_ask": 0.17,
          "spread": 0.01,
          "source": "live",
          "observed_at": "2026-10-21T08:38:56Z",
          "age_seconds": 3,
          "freshness": "live"
        },
        "stream": {
          "provider": "kalshi",
          "market_id": "KXPRESNOMD-28-GN",
          "outcome_id": "yes"
        },
        "match": {
          "group_id": "b5f0c3d2-6a1e-5f7b-9c2d-1e8a4f3b7d60",
          "key": "candidate:gnew",
          "state": "AUTO_MATCHED",
          "contract_compatibility": "unverified"
        }
      }
    ],
    "rules": "If the named person is the Democratic nominee for President in 2028, the market resolves to Yes."
  }
}

Errors

HTTP	Code	When
404	not_found.market	TPM has no market with this id on that venue.
401	auth.missing_key	No `X-API-Key` header was sent.
401	auth.invalid_key	The key is wrong or was revoked.
429	rate_limit.per_second	Too many requests this second. Wait for `Retry-After`.

404 not_found.market

{
  "error": {
    "code": "not_found.market",
    "message": "No kalshi market with id 'KXNOTREAL'.",
    "request_id": "0f8969a6-0968-4d7c-9cbb-de379e8c19c4"
  }
}

All codes are listed on the errors page.

Try it

Runs a live request from your browser. Pre-filled with the shared demo key (5 requests per second for everyone); paste your own key for steadier results.

Request URLX-API-Keyvenue*pathmarket_id*path

HTTP: —Time: —Rows: —Remaining this second: —Request: —

Press Send to run this request.

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When to use it

List venue markets

Parameters

Request

Response

Response fields

Errors

Try it

Get one venue market

Parameters

Request

Response

Errors

Try it

Related

Get your free API key