# Polkadot Bid-Ask Spread Check

> Polkadot Bid-Ask Spread Check is a paid API for AI agents from market.datapackvibe.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-02).

Calculates the latest absolute and percentage bid-ask spread for Polkadot (DOT-USD) using Coinbase Exchange public market data.

## Facts

- Endpoint: POST https://market.datapackvibe.com/x402/demand-market-polkadot-spread-check?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/polkadot-bid-ask-spread-check-ebd7fd7c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_dnvsDJebiPqJqwUMCETbB

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 polkadot-bid-ask-spread-check-ebd7fd7c -d '<json body>'
```

Example prompt: What's the current bid-ask spread for Polkadot on Coinbase — give me both the absolute dollar spread and the percentage spread for DOT-USD.

## When to prefer this

Choose this endpoint when you specifically need real-time bid-ask spread data for Polkadot (DOT) denominated in USD from Coinbase Exchange. It is ideal for pre-trade analysis, liquidity checks, and slippage estimation when trading DOT. Prefer this over general price endpoints when the spread width (not just price) is the key metric.

## Known failure modes

- Invalid product ID returns an error — only valid Coinbase USD product IDs are accepted
- Coinbase API unavailability may cause stale or missing data
- Market closed or illiquid conditions may result in unusual spread values
- Malformed request body may return a validation error

## How this service works

Polkadot Bid-ask spread check: Calculate the latest absolute and percentage bid-ask spread. Coinbase Exchange public USD market data; not investment advice.

## Output

Returns the current best bid price, best ask price, absolute spread (ask minus bid in USD), and percentage spread (spread relative to mid-price) for the DOT-USD pair sourced from Coinbase Exchange public market data.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "product": {
   "type": "string",
   "default": "DOT-USD",
   "description": "Coinbase USD product ID; defaults to DOT-USD."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/polkadot-bid-ask-spread-check-ebd7fd7c/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from market.datapackvibe.com](https://www.zero.xyz/host/market.datapackvibe.com/llms.txt)