# NullClear Market Feed

> NullClear Market Feed is a paid API for AI agents from api.nullclear.dev, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-30).

Returns a verified real-time spot price for a given crypto asset (e.g. ETH) via the NullClear non-custodial protocol on Base Mainnet

## Facts

- Endpoint: GET https://api.nullclear.dev/v1/sandbox/market-feed?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-30
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/nullclear-market-feed-5e09fff7
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_fP_wjzKCKgDZ9F6BHaXWn

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 nullclear-market-feed-5e09fff7
```

Example prompt: What's the current verified spot price of ETH right now — pull it from NullClear's market feed?

## When to prefer this

Choose this endpoint when your agent needs a cryptographically sourced, source-attributed spot price for a crypto asset — particularly within x402-compatible workflows on Base Mainnet where trust, auditability, and non-custodial guarantees matter. Prefer it over generic price APIs when you need a verifiable source label and millisecond timestamp alongside the price.

## Known failure modes

- Invalid or unsupported asset symbol returns an error or empty result
- Payment failure (x402 micropayment not completed) results in 402 response blocking data
- Network or API downtime returns a 5xx error with no price data
- Stale price if upstream feed is delayed — timestamp should be checked by the caller

## How this service works

Non-custodial deferred clearing, deep invariant validation, and reputation protocol for x402 AI Agents on Base Mainnet

## Output

A JSON object containing the asset trading pair (e.g. 'ETH/USDC'), the current spot price as a float, the named price source ('NullClear Verified Feed'), and a millisecond-precision Unix timestamp of when the price was recorded.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "asset": {
   "type": "string",
   "default": "ETH",
   "example": "ETH"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "asset": "ETH/USDC",
  "price": 2645.5,
  "source": "NullClear Verified Feed",
  "timestamp": 1729045678901
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/nullclear-market-feed-5e09fff7/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.nullclear.dev](https://www.zero.xyz/host/api.nullclear.dev/llms.txt)