# Obol BTC/USD Spot Price with Cross-Exchange Divergence Check

> Obol BTC/USD Spot Price with Cross-Exchange Divergence Check is a paid API for AI agents from obol-x402.fly.dev, paid per call via x402, $0.01/call, status down (last checked 2026-09-15).

Returns the current Bitcoin BTC/USD spot price sourced from Coinbase and Kraken, with a divergence flag if the two exchanges disagree significantly.

## Facts

- Endpoint: GET https://obol-x402.fly.dev/v1/price/BTC
- Price: $0.01/call
- Payment: x402
- Status: down
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/obol-btc-usd-spot-price-with-cross-exchange-divergence-check-fcba2828
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_HIuD9iZyVogULul5csPkI

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 obol-btc-usd-spot-price-with-cross-exchange-divergence-check-fcba2828
```

Example prompt: What's the current Bitcoin price in USD? Check both Coinbase and Kraken and let me know if there's any divergence between them.

## When to prefer this

Use this endpoint when you need a real-time BTC/USD spot price with built-in cross-exchange validation — ideal when accuracy and manipulation resistance matter, since it checks both Coinbase and Kraken and flags divergence. Prefer over single-source price feeds when you want confidence that the price is consistent across major venues.

## Known failure modes

- One or both exchange APIs (Coinbase or Kraken) are unavailable, resulting in partial data or an error response
- Network timeout reaching obol-x402.fly.dev
- Payment not processed (x402 payment required, returns 402 if unpaid)
- Price data is stale if upstream exchange feeds lag
- Unexpected schema change from upstream exchanges causing parse failure

## How this service works

Bitcoin BTC USD spot price Coinbase Kraken cross-check with divergence flag. Single-asset BTC/USD for AI agents. Cryptographically signed (Ed25519) — every response is independently verifiable via /.well-known/obol-pubkey.

## Output

Returns a JSON object with the BTC/USD spot price (likely a consensus or averaged value), individual prices from Coinbase and Kraken, and a boolean divergence flag indicating whether the two exchanges show a meaningful price difference. May include a timestamp.

## 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",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {}
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/obol-btc-usd-spot-price-with-cross-exchange-divergence-check-fcba2828/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from obol-x402.fly.dev](https://www.zero.xyz/host/obol-x402.fly.dev/llms.txt)