How to use
- Copy the installation command and review the source package before installing it in your own agent environment.
- Check the source document for required tools, credentials and supported hosts.
- Describe your input and desired deliverable; review the output against the source material.
npx skills add https://github.com/nousresearch/hermes-agent --skill polymarketBefore you start
- Installation does not include a model subscription, API allowance or permission to access your files.
- Repository stars and installation counts describe activity, not an independent quality or security test.
Original skill document
Rendered from the source repository. Headings, examples, code, tables, links, and referenced images are preserved.
Polymarket — Prediction Market Data
Query prediction market data from Polymarket using their public REST APIs. All endpoints are read-only and require zero authentication.
See references/api-endpoints.md for the full endpoint reference with curl examples.
When to Use
- User asks about prediction markets, betting odds, or event probabilities
- User wants to know "what are the odds of X happening?"
- User asks about Polymarket specifically
- User wants market prices, orderbook data, or price history
- User asks to monitor or track prediction market movements
Key Concepts
- Events contain one or more Markets (1:many relationship)
- Markets are binary outcomes with Yes/No prices between 0.00 and 1.00
- Prices ARE probabilities: price 0.65 means the market thinks 65% likely
outcomePricesfield: JSON-encoded array like["0.80", "0.20"]clobTokenIdsfield: JSON-encoded array of two token IDs [Yes, No] for price/book queriesconditionIdfield: hex string used for price history queries- Volume is in USDC (US dollars)
Three Public APIs
- Gamma API at
gamma-api.polymarket.com— Discovery, search, browsing - CLOB API at
clob.polymarket.com— Real-time prices, orderbooks, history - Data API at
data-api.polymarket.com— Trades, open interest
Typical Workflow
When a user asks about prediction market odds:
- Search using the Gamma API public-search endpoint with their query
- Parse the response — extract events and their nested markets
- Present market question, current prices as percentages, and volume
- Deep dive if asked — use clobTokenIds for orderbook, conditionId for history
Presenting Results
Format prices as percentages for readability:
- outcomePrices
["0.652", "0.348"]becomes "Yes: 65.2%, No: 34.8%" - Always show the market question and probability
- Include volume when available
Example: "Will X happen?" — 65.2% Yes ($1.2M volume)
Parsing Double-Encoded Fields
The Gamma API returns outcomePrices, outcomes, and clobTokenIds as JSON strings inside JSON responses (double-encoded). When processing with Python, parse them with json.loads(market['outcomePrices']) to get the actual array.
Rate Limits
Generous — unlikely to hit for normal usage:
- Gamma: 4,000 requests per 10 seconds (general)
- CLOB: 9,000 requests per 10 seconds (general)
- Data: 1,000 requests per 10 seconds (general)
Limitations
- This skill is read-only — it does not support placing trades
- Trading requires wallet-based crypto authentication (EIP-712 signatures)
- Some new markets may have empty price history
- Geographic restrictions apply to trading but read-only data is globally accessible
