# Base eth_getLogs – Contract Event Log Reader

> Base eth_getLogs – Contract Event Log Reader is a paid API for AI agents from api.arysphere.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-17).

Fetches filtered on-chain event logs from a Base smart contract by address, optional event signature topic, and optional block range.

## Facts

- Endpoint: GET https://api.arysphere.com/v1/ventures/x402_chain_reads_v1/base_eth_getlogs?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-17
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/base-eth-getlogs-contract-event-log-reader-d0176918
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_8BMS9BY2DDNco9qPtEi40

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-eth-getlogs-contract-event-log-reader-d0176918
```

Example prompt: Pull the last 20 blocks of Transfer event logs from the USDC contract on Base — the contract address is 0x833589fcd6edb6e08f4c7c32d4f71b54bda02913 and the Transfer topic is 0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef.

## When to prefer this

Use this endpoint when you need on-chain event log data from Base specifically — filtered by contract address and optionally by event signature — and only need the most recent N blocks (up to 100). It is purpose-built for Base and returns clean eth_getLogs results with block metadata. Prefer it over a generic RPC endpoint when you want a simple HTTP GET with optional topic filtering without managing a full node connection or RPC provider key. Not suitable for historical archive queries beyond 100 blocks or for other chains (see sibling Ethereum endpoint).

## Known failure modes

- Invalid contract address format (not 0x + 40 hex) returns validation error
- Invalid topic0 format (not 0x + 64 hex) returns validation error
- blocks parameter out of range (outside 1-100) returns error
- Contract address with no logs in range returns empty logs array
- Upstream Base node unavailability returns 5xx error
- Payment failure (402) if x402 micropayment header is missing or insufficient

## How this service works

ARYSPHERE sells AI-written verdicts on Base token contracts (a grade, a one-liner, a roast and the contract's facts) and Base/Ethereum chain reads, paid per call in USDC on Base over x402 v2. No account and no API key.

## Output

Returns a JSON object with ok status, chain identifier ('base'), method ('eth_getLogs'), and a result object containing an array of matching log entries. Each log includes address, topics array, data, blockNumber, blockHash, blockTimestamp, transactionHash, transactionIndex, logIndex, and a removed flag. Also returns count of matching logs, from_block, to_block, and a truncated flag indicating whether results were capped.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "blocks": {
       "type": "string",
       "description": "optional, last N blocks, 1-100 (default 10)"
      },
      "topic0": {
       "type": "string",
       "description": "optional event signature hash, 0x + 64 hex"
      },
      "address": {
       "type": "string",
       "pattern": "^0x[0-9a-fA-F]{40}$",
       "description": "contract, 0x + 40 hex"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "chain": "base",
  "method": "eth_getLogs",
  "result": {
   "logs": [
    {
     "data": "0x000000000000000000000000000000000000000000000000000000046059f24b",
     "topics": [
      "0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef",
      "0x000000000000000000000000b2cc224c1c9fee385f8ad6a55b4d94e92359dc59",
      ""
     ],
     "address": "0x833589fcd6edb6e08f4c7c32d4f71b54bda02913",
     "removed": false,
     "logIndex": "0x0",
     "blockHash": "0x070a9affe2a28d7cf48692cf3b39420a699e6e2c5549fcd351143931a329400f",
     "blockNumber": "0x31f549f",
     "blockTimestamp": "0x6ac90621",
     "transactionHash": "0xd6acc3445213c7bb13fafe113c818965d71567c3a8d0defdba730577e0f4c85d",
     "transactionIndex": "0x1"
    },
    {
     "data": "0x00000000000000000000000000000000000000000000000000000001b91d1bf1",
     "topics": [
      "0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef",
      "0x000000000000000000000000160d7e9d948b16c163332a277b393c288408eb12",
      ""
     ],
     "address": "0x833589fcd6edb6e08f4c7c32d4f71b54bda02913",
     "removed": false,
     "logIndex": "0x3",
     "blockHash": "0x070a9affe2a28d7cf48692cf3b39420a699e6e2c5549fcd351143931a329400f",
     "blockNumber": "0x31f549f",
     "blockTimestamp": "0x6ac90621",
     "transactionHash": "0x871c536d6987ca7ac859231108c11b5604874b55a50b9ed063bc55d1add86142",
     "transactionIndex": "0x3"
    },
    ""
   ],
   "count": 205,
   "to_block": 52384927,
   "truncated": true,
   "from_block": 52384927
  },
  "service": "x402_chain_reads_v1.base_eth_getlogs"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/base-eth-getlogs-contract-event-log-reader-d0176918/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.arysphere.com](https://www.zero.xyz/host/api.arysphere.com/llms.txt)