# Plainchain Price Feed – Spot Prices for Crypto Symbols

> Plainchain Price Feed – Spot Prices for Crypto Symbols is a paid API for AI agents from plainchain.appin60.com, paid per call via x402, $0.001042/call, status unknown (last checked 2026-10-14).

Returns current USD spot prices for one or more cryptocurrency symbols (e.g. ETH, BTC, SOL) sourced from Coinbase, paid per-call via x402 USDC on Base.

## Facts

- Endpoint: GET https://plainchain.appin60.com/v1/price?utm_source=zero.xyz
- Price: $0.001042/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/plainchain-price-feed-spot-prices-for-crypto-symbols-cb2c1726
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_H2Fl-04rnKE8_7PBZ0ytz

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 plainchain-price-feed-spot-prices-for-crypto-symbols-cb2c1726
```

Example prompt: What are the current USD spot prices for ETH, BTC, and SOL right now? Use the Plainchain price feed to look them up.

## When to prefer this

Choose this endpoint when you need real-time USD spot prices for major cryptocurrencies (ETH, BTC, SOL, etc.) sourced from Coinbase, without an API key, paying only per call in USDC via x402 on Base. It is ideal for AI agents that need lightweight, pay-as-you-go price lookups without committing to a subscription or managing API credentials.

## Known failure modes

- Missing or invalid 'symbols' query parameter returns an error
- Unrecognized ticker symbol may return null or omit that symbol from results
- Payment failure via x402 (insufficient USDC balance) results in 402 Payment Required
- Network or upstream Coinbase data unavailability may cause 503 or stale data
- Malformed symbol list (wrong delimiter) may return partial or empty results

## How this service works

Gas, balances, token data, address type, approvals, transaction decoding, x402 receipt verification and verifiable randomness on Base, Arbitrum, Ethereum and Optimism. No API key: pay $0.001-$0.01 per call in USDC on Base via x402.

## Output

A JSON object containing a timestamp (ISO 8601), a map of requested symbols to their current USD spot prices (e.g. {"ETH": 2527.22, "BTC": 111845.5}), the data source ('Coinbase spot'), and the currency ('USD').

## 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"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "symbols"
     ],
     "properties": {
      "symbols": {
       "type": "string",
       "description": "comma-separated symbols, e.g. ETH,BTC,SOL"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "at": "2026-10-13T08:40:00.000Z",
  "prices": {
   "BTC": 111845.5,
   "ETH": 2527.22
  },
  "source": "Coinbase spot",
  "currency": "USD"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/plainchain-price-feed-spot-prices-for-crypto-symbols-cb2c1726/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from plainchain.appin60.com](https://www.zero.xyz/host/plainchain.appin60.com/llms.txt)