# Base Mainnet JSON-RPC Gateway (x402 Pay-per-call)

> Base Mainnet JSON-RPC Gateway (x402 Pay-per-call) is a paid API for AI agents from kr-x402-mvp.kgy5612.workers.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-31).

Provides pay-per-call Base mainnet Ethereum JSON-RPC access via x402 micropayments, supporting read and broadcast methods with no API key or account required.

## Facts

- Endpoint: GET https://kr-x402-mvp.kgy5612.workers.dev/crypto/base-rpc?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-31
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/base-mainnet-json-rpc-gateway-x402-pay-per-call-6629c55b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Uj5bR8R_g7xjL9fiB66Og

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 base-mainnet-json-rpc-gateway-x402-pay-per-call-6629c55b
```

Example prompt: What is the current ETH balance of 0xe4be4d0bd82d8e68203deff81f79ede0529f2617 on Base mainnet? Use eth_getBalance with 'latest' as the block parameter.

## When to prefer this

Choose this endpoint when your agent needs direct Base mainnet JSON-RPC access without managing API keys or subscriptions, especially for low-frequency or ad-hoc onchain reads that benefit from pay-per-call micropayment pricing at $0.002 per call. It is ideal for autonomous agents that pay with USDC on Base via x402 protocol. Prefer batching up to 10 calls in one POST request for cost efficiency at $0.002 vs $0.005 per call at competing x402 RPC gateways.

## Known failure modes

- Invalid JSON-RPC method returns error response with code and message
- Malformed params array causes parse error or invalid params error
- Payment failure (x402) if USDC payment not provided or insufficient
- Rate limits or upstream dRPC unavailability causing timeout
- Contract call reverts return execution revert error in JSON-RPC response
- Invalid Ethereum address format returns invalid argument error

## How this service works

Pay-per-call Base mainnet JSON-RPC, no API key, no account: GET ?method=eth_call&params=[...] (params = URL-encoded JSON array) or POST a standard JSON-RPC body. POST a batch of up to 10 calls for ONE $0.002 payment (vs $0.005 per call at other x402 RPC gateways). Read + broadcast methods: eth_blockNumber, eth_chainId, eth_call, eth_estimateGas, eth_getBalance, eth_getTransactionCount, eth_getCode, eth_getStorageAt, eth_getTransactionByHash, eth_getTransactionReceipt, eth_getBlockByNumber,...

## Output

A JSON-RPC 2.0 response object containing the method result (e.g. hex-encoded balance, block number, call return data), along with chain metadata including chain name 'base', chain_id 8453, upstream URL, and latency in milliseconds.

## 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",
     "properties": {
      "method": {
       "type": "string",
       "examples": [
        "eth_blockNumber",
        "eth_getBalance",
        "eth_call"
       ],
       "description": "JSON-RPC method (default eth_blockNumber)"
      },
      "params": {
       "type": "string",
       "examples": [
        "[]",
        "[\"0xe4be4d0bd82d8e68203deff81f79ede0529f2617\",\"latest\"]"
       ],
       "description": "URL-encoded JSON array of params (default [])"
      }
     },
     "additionalProperties": false
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "id": 1,
  "chain": "base",
  "result": "0x32c8f1a",
  "jsonrpc": "2.0",
  "chain_id": 8453,
  "upstream": "https://base.drpc.org",
  "latency_ms": 84
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/base-mainnet-json-rpc-gateway-x402-pay-per-call-6629c55b/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from kr-x402-mvp.kgy5612.workers.dev](https://www.zero.xyz/host/kr-x402-mvp.kgy5612.workers.dev/llms.txt)