# Polymarket Markets Lookup via Gamma API

> Polymarket Markets Lookup via Gamma API is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-30).

Fetches Polymarket prediction markets with outcomes, prices, decimal odds, volume, liquidity, and end date via the public Gamma API

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/polymarket-markets?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-30
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/polymarket-markets-lookup-via-gamma-api-8b6c27cf
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_GLdh19tuwhgkQHl9xD1HH

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability polymarket-markets-lookup-via-gamma-api-8b6c27cf -d '<json body>'
```

Example prompt: Pull up the top 5 active Polymarket markets tagged 'bitcoin' — I want to see the current prices, odds, volume, and end dates for each.

## When to prefer this

Use this endpoint when an agent needs structured Polymarket prediction market data including odds, prices, volume, and liquidity without building direct Gamma API integration. Ideal for agents that need filtered market lists by topic tag or keyword search. Prefer this over direct Gamma API calls when x402 micropayment-based access is already in use and the sandbox endpoint has been validated first.

## Known failure modes

- Invalid or unknown tag slug returns empty results or error
- Limit exceeds maximum of 20 returns validation error
- Search text under 2 characters or containing special characters (#, &, ?) is rejected
- Gamma API unavailable causes upstream timeout or error response
- Payment of exactly $0.005 USDC on Base required; underpayment returns 402
- Conflicting active/closed flags may return empty result sets

## How this service works

Call when an agent needs Polymarket markets from the public Gamma API, with outcomes, prices, decimal odds, volume, liquidity, and end date. Optional search, tag, limit, active, and closed. Send JSON {"tag":"bitcoin","limit":1,"active":true,"closed":false}. Exact $0.005 USDC on Base. Try unpaid POST /v1/sandbox/polymarket-markets first.

## Output

Returns a list of Polymarket markets matching the filters, each with market name, possible outcomes, current prices, decimal odds, total trading volume, liquidity, and end date as provided by the Gamma API.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "tag": {
   "type": "string",
   "pattern": "^[A-Za-z0-9-]{1,40}$",
   "examples": [
    "bitcoin"
   ],
   "description": "Polymarket tag slug or numeric tag id. Example: bitcoin. Resolved through gamma-api.polymarket.com. Omit it for no tag filter."
  },
  "limit": {
   "type": "integer",
   "default": 10,
   "maximum": 20,
   "minimum": 1,
   "examples": [
    1
   ],
   "description": "How many markets to return. Example: 1. Default 10. At most 20. Ordered by volume when Gamma provides it."
  },
  "active": {
   "type": "boolean",
   "default": true,
   "examples": [
    true
   ],
   "description": "When true, keep markets Gamma marks active. Example: true. Omit it for the default, which is active markets only."
  },
  "closed": {
   "type": "boolean",
   "default": false,
   "examples": [
    false
   ],
   "description": "When true, keep markets Gamma marks closed. Example: false. Omit it to leave closed markets out."
  },
  "search": {
   "type": "string",
   "pattern": "^[^#&?]{2,80}$",
   "maxLength": 80,
   "minLength": 2,
   "description": "Search text for the public Gamma API. Example: bitcoin. Omit it to list markets without a text query."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/polymarket-markets-lookup-via-gamma-api-8b6c27cf/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agentshelf.syntexa.ch](https://www.zero.xyz/host/agentshelf.syntexa.ch/llms.txt)