# Apiosk Gateway: Signed Spot Price (Market Price Attestation)

> Apiosk Gateway: Signed Spot Price (Market Price Attestation) is a paid API for AI agents from gateway.apiosk.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-15).

Returns a JWS-HS256 signed spot price for a cryptocurrency token in a specified quote currency (default USD), sourced from CoinGecko, serving as a verifiable provenance receipt.

## Facts

- Endpoint: POST https://gateway.apiosk.com/attestations/market-price
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/apiosk-gateway-signed-spot-price-market-price-attestation-78157f9b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_YCvdho4xCNJCYZGILT_sk

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 apiosk-gateway-signed-spot-price-market-price-attestation-78157f9b -d '<json body>'
```

Example prompt: What's the current spot price of Bitcoin in USD? I need a signed attestation receipt I can verify later.

## When to prefer this

Choose this endpoint when you need not just a cryptocurrency spot price but also a cryptographic provenance receipt (JWS-HS256) that proves the price origin and can be verified later. Ideal for AI agents that must maintain an auditable trail of price data used in decisions, on-chain transactions, or financial reporting. Prefer over raw CoinGecko calls when tamper-evidence and verifiability are required.

## Known failure modes

- Unknown or unsupported token identifier returns an error or empty price
- CoinGecko API unavailability causes downstream failure
- Invalid quote currency parameter causes a 400-level error
- Network timeout or rate limiting on the CoinGecko source
- Malformed request body results in a validation error

## How this service works

Return a signed spot price for a token in a quote currency (default USD) from a public keyless source (CoinGecko). The JWS-HS256 envelope is a provenance receipt an agent keeps for every few-cent call, verifiable via /verify.

## Output

A JWS-HS256 signed envelope containing the spot price of the requested token in the specified quote currency (defaulting to USD), sourced from CoinGecko. The envelope acts as a provenance receipt that can be verified later via the /verify endpoint, including price, token identifier, quote currency, and timestamp.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/apiosk-gateway-signed-spot-price-market-price-attestation-78157f9b/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from gateway.apiosk.com](https://www.zero.xyz/host/gateway.apiosk.com/llms.txt)