# Biosfera ETH Call – Read-Only Smart Contract Call

> Biosfera ETH Call – Read-Only Smart Contract Call is a paid API for AI agents from biosfera.46-62-215-147.sslip.io, paid per call via x402, $0.0015/call, status unknown (last checked 2026-10-01).

Executes a read-only eth_call on a specified smart contract across Base, Ethereum, Arbitrum, Optimism, or Polygon, returning raw ABI-encoded return data without sending a transaction.

## Facts

- Endpoint: GET https://biosfera.46-62-215-147.sslip.io/o/eth-call?utm_source=zero.xyz
- Price: $0.0015/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-01
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/biosfera-eth-call-read-only-smart-contract-call-d0a30491
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_MBSdT7jgvRYS2pKegnnI6

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 biosfera-eth-call-read-only-smart-contract-call-d0a30491
```

Example prompt: Do a read-only eth_call on the Uniswap V3 factory contract at 0x1F98431c8aD98523631AE4a59f267346ea31F984 on Ethereum with calldata 0x1698ee82000000000000000000000000a0b86991c6218b36c1d19d4a2e9eb0ce3606eb480000000000000000000000006b175474e89094c44da98b954eedeac495271d0f0000000000000000000000000000000000000000000000000000000000000064 and give me the raw return data.

## When to prefer this

Use this endpoint when you need to call any arbitrary smart contract view or pure function with custom ABI-encoded calldata and get the raw return bytes — especially when no higher-level endpoint exists for the specific function you need. Prefer more specialized sibling endpoints (e.g. ERC-20 metadata, ERC-721 ownership, native balance) for common queries, as they handle encoding and decoding automatically. This endpoint is ideal for custom contracts, novel ABIs, or advanced DeFi protocol interactions across Base, Ethereum, Arbitrum, Optimism, or Polygon.

## Known failure modes

- Invalid contract address (not a valid 0x hex address) — request rejected
- Invalid or malformed calldata hex string — request rejected
- Contract does not exist at the given address on the specified chain — returns 0x or reverts
- Contract function reverts — may return an error or empty data
- Unsupported chain value — only base, ethereum, arbitrum, optimism, polygon accepted
- Network timeout or RPC outage for the target chain — transient error
- Calldata exceeds maximum length (1000 hex chars) — request rejected

## How this service works

Use when you need to simulate a read-only call to any contract on Base, Ethereum, Arbitrum, Optimism or Polygon: pass the target and the ABI-encoded calldata (hex), get the raw return data. No transaction is sent.

## Output

Returns the raw ABI-encoded hex bytes that the smart contract function returns, exactly as the EVM would produce them. The agent must decode this hex output using the expected return type ABI to interpret the result (e.g. uint256, address, tuple, etc.).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "chain",
      "to",
      "data"
     ],
     "properties": {
      "to": {
       "type": "string",
       "pattern": "^0x[0-9a-fA-F]{40}$"
      },
      "data": {
       "type": "string",
       "pattern": "^0x[0-9a-fA-F]{0,1000}$"
      },
      "chain": {
       "enum": [
        "base",
        "ethereum",
        "arbitrum",
        "optimism",
        "polygon"
       ],
       "type": "string"
      }
     },
     "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/biosfera-eth-call-read-only-smart-contract-call-d0a30491/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)