---
title: "Cross-Platform Daily Comparison (Polymarket <> Kalshi)"
method: GET
path: "/gateway/v1/prediction-market/matching/daily"
tags: ["Prediction Market"]
---

# Cross-Platform Daily Comparison (Polymarket <> Kalshi)

`GET /gateway/v1/prediction-market/matching/daily`

## Request

- Base URL: `https://api.asksurf.ai`
- URL: `https://api.asksurf.ai/gateway/v1/prediction-market/matching/daily`
- Auth: HTTP bearer

Returns daily volume and open interest comparison for a specific Polymarket <> Kalshi matched pair.

Both `polymarket_condition_id` and `kalshi_market_ticker` are required. Use `matching-market-pairs` to discover matched pairs first.

**Volume units:** Polymarket = USD, Kalshi = contracts.

## Query parameters

- `polymarket_condition_id` string, required: Polymarket condition ID
- `kalshi_market_ticker` string, required: Kalshi market ticker
- `time_range` '1d' | '7d' | '30d' | '90d' | '180d' | '1y' | 'all': Window of daily data to return: `1d`, `7d`, `30d`, `90d`, `180d`, `1y`, or `all`. Bucket size is fixed at 1 day — this endpoint uses `time_range` only and does NOT accept `interval`.
- `limit` integer: Maximum rows
- `offset` integer: Pagination offset

## Response `200`

OK

- DataResponseMatchedMarketDailyItem
  - `$schema` string, uri: A URL to the JSON Schema for this object.
  - `data` MatchedMarketDailyItem[], nullable, required
    - `kalshi_oi_contracts` number, double, required: Kalshi open interest (contracts)
    - `kalshi_volume_contracts` number, double, required: Kalshi daily volume (contracts)
    - `polymarket_oi_usd` number, double, required: Polymarket open interest (USD)
    - `polymarket_volume_usd` number, double, required: Polymarket daily volume (USD)
    - `timestamp` integer, required: Unix timestamp (midnight UTC)
  - `meta` OffsetMeta, required
    - `cached` boolean, required: Whether this response was served from cache
    - `credits_used` integer, required: Credits deducted for this request
    - `empty_reason` string: Hint explaining why the data array is empty, when applicable
    - `has_more` boolean: Whether more items may exist beyond this response. For offset-paged endpoints, continue with a larger offset. For time-series endpoints without offset/cursor controls, true means the requested time range hit an upstream cap; narrow from/to to continue. Omitted when exhaustion cannot be proven.
    - `limit` integer, required: Maximum number of items returned in this response
    - `offset` integer, required: Number of items skipped (pagination offset)
    - `total` integer: Total number of matching items (before pagination). Omitted when total is unknown.
    - `watermark` integer: Warehouse watermark (Unix seconds) this response was computed at, on warehouse-backed endpoints (e.g. Hyperliquid /trades/aggregate) — rows up to this time come from the warehouse, newer rows from the live tail. Omitted elsewhere.

## Other responses

- `default`: Error

---

[API](https://skmtc.dev/asksurf/apis/asksurf-public-rest-api.md) - [All operations](https://skmtc.dev/asksurf/apis/asksurf-public-rest-api/llms.txt) - [OpenAPI document](https://skmtc.dev/asksurf/apis/asksurf-public-rest-api/revisions/91774fdd5302?raw)