Polymarket

Polymarket

Purpose

• Use this skill to pull live prediction market data for research and forecasting workflows.
• Polymarket is useful for probability-oriented views of current events, elections, macro themes, and sports or policy questions.
• Treat the market price as a crowd-implied probability signal, not ground truth.

API Surface

• Base reference: https://clob.polymarket.com/
• Public market discovery is commonly accessed through the gamma API.
• Start with active markets and then filter by topic or keyword.

Request Discipline and Rate Limits

• Send a timeout on every request and fail fast instead of hanging a long-running research pass.
• Start with at most 1 request per second when iterating on the gamma API and slow down further if responses get unstable.
• Back off and retry once on 429 or transient 5xx responses with a short sleep before the second request.
• Cache raw JSON snapshots by timestamp when polling the same topic so you do not hit the API repeatedly for the same view.
• Keep limit small during discovery, then widen only after you confirm the endpoint shape and the filter logic you need.
• Record the exact URL you used in notes or logs so later analysis can reproduce the same market slice.

Fetch Active Markets

curl "https://gamma-api.polymarket.com/markets?active=true&limit=20"

• This returns a JSON list of market objects.
• Use small limits during exploration and larger limits when building a topic watcher.

Important Market Fields

• question
• outcomes
• outcomePrices
• volume

These are usually enough for first-pass research.

Additional Fields to Inspect

• Inspect slug when you need a stable human-readable identifier for later lookups or reporting.
• Inspect endDate or other settlement timing fields when the timing of resolution matters more than the headline probability.
• Inspect liquidity when present to separate tradeable markets from thin markets that move on little size.
• Inspect active and closed to keep live monitoring separate from post-resolution analysis.
• Inspect category, tags, or related event metadata when you need to group markets into a watcher by theme.
• Inspect conditionId or token identifiers when you need to correlate market data across downstream systems.

Interpret the Data

• question is the market prompt.
• outcomes lists the named outcomes, often Yes and No.
• outcomePrices represents the current market-implied probabilities.
• volume helps indicate liquidity and how much weight to assign the price signal.

Probability Interpretation

• Interpret a price like 0.65 as roughly a 65 percent implied chance.
• Lower-liquidity markets may be noisier.
• High probability is not certainty.
• Large probability moves over time can matter more than a single point estimate.

Python Example

import requests

url = "https://gamma-api.polymarket.com/markets?active=true&limit=20"
markets = requests.get(url, timeout=20).json()

for market in markets:
    question = market.get("question")
    prices = market.get("outcomePrices")
    print(question, prices)

• This is the minimum useful fetch loop.
• Add defensive parsing because API field presence can vary.