# Polymarket

> Query Polymarket prediction market data — search markets, get prices, orderbooks, and price history. Read-only via public REST APIs, no API key needed.

- **Type:** Skill
- **Install:** `agentstack add skill-martin-hausleitner-martins-awesome-skills-polymarket`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [Martin-Hausleitner](https://agentstack.voostack.com/s/martin-hausleitner)
- **Installs:** 0
- **Category:** [Productivity](https://agentstack.voostack.com/c/productivity)
- **Latest version:** 0.1.0
- **License:** MIT
- **Upstream author:** [Martin-Hausleitner](https://github.com/Martin-Hausleitner)
- **Source:** https://github.com/Martin-Hausleitner/martins-awesome-skills/tree/main/skills/research/polymarket

## Install

```sh
agentstack add skill-martin-hausleitner-martins-awesome-skills-polymarket
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# 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
- `outcomePrices` field: JSON-encoded array like `["0.80", "0.20"]`
- `clobTokenIds` field: JSON-encoded array of two token IDs [Yes, No] for price/book queries
- `conditionId` field: hex string used for price history queries
- Volume is in USDC (US dollars)

## Three Public APIs

1. **Gamma API** at `gamma-api.polymarket.com` — Discovery, search, browsing
2. **CLOB API** at `clob.polymarket.com` — Real-time prices, orderbooks, history
3. **Data API** at `data-api.polymarket.com` — Trades, open interest

## Typical Workflow

When a user asks about prediction market odds:

1. **Search** using the Gamma API public-search endpoint with their query
2. **Parse** the response — extract events and their nested markets
3. **Present** market question, current prices as percentages, and volume
4. **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

## Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [Martin-Hausleitner](https://github.com/Martin-Hausleitner)
- **Source:** [Martin-Hausleitner/martins-awesome-skills](https://github.com/Martin-Hausleitner/martins-awesome-skills)
- **License:** MIT

Install and usage instructions live in the source repository linked above.

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** yes
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** no
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/skill-martin-hausleitner-martins-awesome-skills-polymarket
- Seller: https://agentstack.voostack.com/s/martin-hausleitner
- Browse the marketplace: https://agentstack.voostack.com/browse

---
Listed on AgentStack — the marketplace for AI agent skills and MCP servers. Every listing is security-reviewed. Creators keep 70%.