# Mavrin Prediction Market Batch Odds API

> Mavrin Prediction Market Batch Odds API is a paid API for AI agents from api.mavrin.app, paid per call via x402, $0.012/call, status unknown (last checked 2026-09-15).

Fetches real-time yes/no odds for up to 10 prediction market pairs from both Kalshi and Polymarket US in a single request

## Facts

- Endpoint: GET https://api.mavrin.app/api/v1/odds/batch
- Price: $0.012/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/mavrin-prediction-market-batch-odds-api-add77b86
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_0dN01zJujwMx6P1Cz36Fa

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 mavrin-prediction-market-batch-odds-api-add77b86
```

Example prompt: Pull the current Kalshi and Polymarket odds for these pair IDs: mlb-champ-2026-yankees and nba-finals-2026-celtics — and tell me the gap between them so I can see if there's an arbitrage opportunity.

## When to prefer this

Use this endpoint when you need odds from both Kalshi and Polymarket US simultaneously for multiple markets in one call, especially when comparing prices across exchanges or scanning for arbitrage gaps. Prefer this over single-market lookups when you have 2–10 markets to check at once, and over building your own scraper when you want normalized, cross-exchange data with hedge cost already calculated.

## Known failure modes

- Invalid or unknown pair_ids return empty results or errors — IDs must be found via the free /api/v1/markets/search endpoint first
- More than 10 pair_ids in a single request may be rejected
- Payment failure via x402 on Base blocks the request if wallet balance is insufficient
- Stale data flag may indicate odds are not fully current if the source exchanges are delayed
- Malformed comma-separated pair_ids string causes a 400-level validation error

## How this service works

Kalshi and Polymarket US research data for agents. Free market search and coverage, odds from 0.004 USDC, and x402 payments on Base.

## Output

Returns a JSON object with a timestamp (asOf), count of pairs returned, a staleness flag and staleness age in seconds, and an array of pairs each containing the pair_id, Kalshi yes_ask and no_ask prices, Polymarket US yes_ask and no_ask prices, the price gap between exchanges, and the hedge cost in USDC.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "pair_ids"
     ],
     "properties": {
      "pair_ids": {
       "type": "string",
       "description": "Comma-separated list of 1 to 10 unique tracked pair IDs; find IDs using the free /api/v1/markets/search endpoint"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "asOf": 1788826381,
  "count": 1,
  "pairs": [
   {
    "gap": 0.1,
    "kalshi": {
     "no_ask": 0.6,
     "yes_ask": 0.4
    },
    "pair_id": "mlb-champ-2026-yankees",
    "hedge_cost": 0.9,
    "polymarket_us": {
     "no_ask": 0.5,
     "yes_ask": 0.5
    }
   }
  ],
  "stale": false,
  "stalenessSeconds": 8
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/mavrin-prediction-market-batch-odds-api-add77b86/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.mavrin.app](https://www.zero.xyz/host/api.mavrin.app/llms.txt)