# SperaxOS Contract Explorer - Decode Transaction

> SperaxOS Contract Explorer - Decode Transaction is a paid API for AI agents from chat.sperax.io, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-12).

Decodes a blockchain transaction hash into human-readable function calls, parameters, and event logs using AI-powered DeFi intelligence

## Facts

- Endpoint: POST https://chat.sperax.io/api/x402/tools/contract-explorer/decodeTransaction?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/speraxos-contract-explorer-decode-transaction-f7ab0d39
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_TBtGLUNVyQtz9WWDKiDcY

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 speraxos-contract-explorer-decode-transaction-f7ab0d39 -d '<json body>'
```

Example prompt: Decode this Base transaction for me — 0x4a3f8b2c1d9e7a6f5b4c3d2e1f0a9b8c7d6e5f4a3b2c1d0e9f8a7b6c5d4e3f2 — and tell me what contract function was called and with what parameters.

## When to prefer this

Choose this endpoint when you need to decode a specific on-chain transaction into human-readable form across major EVM chains (Ethereum, Base, Arbitrum, Polygon, Optimism, Avalanche, BSC). It is ideal for DeFi agents auditing wallet activity, debugging smart contract interactions, or explaining transaction behavior to end users. Prefer this over generic block explorers when you need programmatic, AI-interpreted output rather than raw data.

## Known failure modes

- Invalid or malformed transaction hash returns an error
- Transaction hash not found on the specified chain
- Unsupported chain name causes a validation error
- Unverified or non-standard contract ABI may result in partial or failed decoding
- Network timeout if the chain RPC is slow or unavailable
- Payment failure via x402 protocol blocks the request

## How this service works

AI-powered DeFi intelligence APIs payable via the x402 HTTP payment protocol. No API key required — pay per request with USDC on Base. Identity-only (SIWX) endpoints are free for wallets with an agentcash identity.

## Output

Returns a decoded breakdown of the blockchain transaction including the contract method name, decoded input parameters with their types and values, and any emitted event logs — presented in human-readable form rather than raw hex calldata.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "chain": {
   "type": "string",
   "description": "Chain name: ethereum, arbitrum, polygon, base, optimism, avalanche, bsc. Defaults to ethereum."
  },
  "txHash": {
   "type": "string",
   "description": "Transaction hash (0x…)"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/speraxos-contract-explorer-decode-transaction-f7ab0d39/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from chat.sperax.io](https://www.zero.xyz/host/chat.sperax.io/llms.txt)