# Blockchain Event Logs Query

> Blockchain Event Logs Query is a paid API for AI agents from biosfera.46-62-215-147.sslip.io, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-01).

Fetches recent on-chain event logs for a smart contract across Base, Ethereum, Arbitrum, Optimism, or Polygon, with optional event signature and block range filtering

## Facts

- Endpoint: GET https://biosfera.46-62-215-147.sslip.io/o/event-logs?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-01
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/blockchain-event-logs-query-03a946f4
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_qMGMsYcdlGZ3HCYUDS7sV

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 blockchain-event-logs-query-03a946f4
```

Example prompt: Can you pull the last 200 blocks of event logs for the USDC contract at 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 on Ethereum, filtered to Transfer events (topic0 0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef)?

## When to prefer this

Use this endpoint when you need raw on-chain event logs for a specific smart contract across major EVM chains without running your own node or indexer. It is ideal for lightweight event monitoring, debugging contract interactions, auditing recent token transfers, or triggering agent workflows based on on-chain activity — all within a 200-block sliding window. Prefer this over full indexing solutions when you only need a narrow recent block range and don't need historical data beyond 200 blocks.

## Known failure modes

- Block range exceeds 200 blocks — request rejected
- Invalid contract address format (must be 0x-prefixed 40-hex address)
- Invalid topic0 format (must be 0x-prefixed 64-hex hash)
- Unsupported chain value — must be one of base, ethereum, arbitrum, optimism, polygon
- No logs found in the specified range — returns empty list
- RPC node timeout or chain congestion causing delayed response
- Payment failure (x402) if USDC balance is insufficient

## How this service works

Use when you need recent event logs of a contract on Base, Ethereum, Arbitrum, Optimism or Polygon: filter by contract, optional topic0 (event signature hash) and a block range of at most 200 blocks (defaults to the last 10). Returns up to 200 logs with topics and data.

## Output

Returns up to 200 event log entries for the specified contract, each containing the block number, transaction hash, log index, topics array (including topic0 through topic3), and raw ABI-encoded data field, covering at most 200 blocks of history.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "chain",
      "address"
     ],
     "properties": {
      "chain": {
       "enum": [
        "base",
        "ethereum",
        "arbitrum",
        "optimism",
        "polygon"
       ],
       "type": "string"
      },
      "topic0": {
       "type": "string",
       "pattern": "^0x[0-9a-fA-F]{64}$"
      },
      "address": {
       "type": "string",
       "pattern": "^0x[0-9a-fA-F]{40}$"
      },
      "to_block": {
       "type": "integer",
       "minimum": 0
      },
      "from_block": {
       "type": "integer",
       "minimum": 0
      }
     },
     "additionalProperties": false
    }
   },
   "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/blockchain-event-logs-query-03a946f4/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from biosfera.46-62-215-147.sslip.io](https://www.zero.xyz/host/biosfera.46-62-215-147.sslip.io/llms.txt)