Get started

Quickstart

Three steps: get a key, check the API is up, then find an event and read its prices on every venue. Five minutes, no SDK needed.

1. Get an API key

Sign in and open API keys.
Click Generate Key. Every account gets one free key.
Copy the key and keep it on your server, for example in an environment variable called TPM_API_KEY.

Just looking?

Use the demo key tpm_demo_key_authorized_2026. Everyone shares it, it is limited to 5 requests per second, and it cannot open the WebSocket. Details in authentication.

2. Check the API is up

/status needs no key and does not count against your quota.

Request

curl -s 'https://api.thepredictionmarkets.com/api/public/v1/status'

3. Find an event and read its prices

An event is one real-world question, like who will be the Democratic nominee in 2028. Search with /events, take a slug, then call /events/{slug}.

Full script

export TPM_API_KEY=tpm_demo_key_authorized_2026   # replace with your own key

# 1. Is the API up? (no key needed)
curl -s https://api.thepredictionmarkets.com/api/public/v1/status

# 2. Find an event
curl -s 'https://api.thepredictionmarkets.com/api/public/v1/events?q=nominee&limit=3' \
  -H "X-API-Key: $TPM_API_KEY"

# 3. Read every venue's prices for it
curl -s https://api.thepredictionmarkets.com/api/public/v1/events/democratic-presidential-nominee-2028 \
  -H "X-API-Key: $TPM_API_KEY"

The Python script prints something like this (prices change all the time):

Output

Democratic Presidential Nominee 2028 ['kalshi', 'polymarket']
kalshi      Jon Ossoff                   0.16  (live)
kalshi      Gavin Newsom                 0.16  (live)
kalshi      Alexandria Ocasio-Cortez     0.14  (live)
polymarket  Alexandria Ocasio-Cortez     0.1645  (fresh)
polymarket  Gavin Newsom                 0.1635  (fresh)
polymarket  Jon Ossoff                   0.1475  (fresh)

How to read the response

markets has one entry per venue listing. Here: Kalshi KXPRESNOMD-28 and the Polymarket event of the same name.
Each market has outcomes. Each outcome has a quote whose probability is a price from 0 to 1. 0.16 means the market gives that answer a 16% chance.
quote.freshness tells you how current the price is. live and fresh are safe to show; treat stale with care. See freshness.
Outcomes with the same match.group_id are the same answer on different venues. spreads lists the gap between venues for each matched outcome.

Next steps

Build with TPM

Get your free API key

One key gives you Kalshi and Polymarket events, prices with freshness, price history, cross-venue gaps and the live quotes WebSocket.

Get a free API key Read the quickstart