# EVM Transaction Explainer

> EVM Transaction Explainer is a paid API for AI agents from tools-agent-x402-production.up.railway.app, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-15).

Decodes and explains any EVM blockchain transaction in human-readable language across 11 supported chains

## Facts

- Endpoint: GET https://tools-agent-x402-production.up.railway.app/tx-explainer
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/evm-transaction-explainer-5413f31d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_xPZa4YeINo8NXlRsqgUDQ

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 evm-transaction-explainer-5413f31d
```

Example prompt: Can you explain what happened in this Base transaction — 0x4a3f1c2d9e8b7a0f5c6d2e1b9f3a4c7d8e2f1b0a3c5d6e7f8a9b0c1d2e3f4a5b — give me a detailed breakdown?

## When to prefer this

Use this endpoint when you need a plain-English explanation of what an EVM transaction did — especially for swaps, transfers, approvals, or DeFi interactions across Base, Ethereum, Arbitrum, Optimism, Avalanche, Polygon, Mantle, Monad, Plasma, BSC, or Hyperliquid. Ideal when a user pastes a transaction hash and wants to understand it without reading raw calldata or logs.

## Known failure modes

- Invalid or malformed transaction hash (not 0x-prefixed or not 64 hex chars) returns an error
- Transaction hash does not exist on the specified chain
- Unsupported chain specified outside the 11 supported networks
- Network timeout or RPC node unavailability for the target chain
- Payment failure — insufficient USDC balance for the $0.01 per-call fee

## How this service works

Decode and explain any EVM blockchain transaction across 11 chains (Base, Ethereum, Arbitrum, Optimism, Avalanche, Polygon, Mantle, Monad, Plasma, BSC, Hyperliquid). Get a human-readable summary of swaps, transfers, approvals, DeFi interactions, and more.

## Output

Returns a JSON object containing the transaction hash, the chain it occurred on, a human-readable summary of what the transaction did (e.g. swap, transfer, approval, DeFi interaction), and a link to the blockchain explorer for that transaction.

## Example request

```json
{
 "input": {
  "type": "http",
  "method": "POST",
  "queryParams": {
   "chain": "ethereum",
   "txHash": "0x5c504ed432cb51138bcf09aa5e8a410dd4a1e204ef84bfed1be16dfba1b22060",
   "outputLevel": "summary"
  }
 }
}
```

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "txHash"
     ],
     "properties": {
      "chain": {
       "enum": [
        "base",
        "ethereum",
        "arbitrum",
        "optimism",
        "avalanche",
        "polygon",
        "mantle",
        "monad",
        "plasma",
        "bsc",
        "hyperliquid"
       ],
       "type": "string",
       "description": "Blockchain network (default: base). 11 EVM chains supported."
      },
      "txHash": {
       "type": "string",
       "pattern": "^0x[a-fA-F0-9]{64}$",
       "description": "Transaction hash (0x-prefixed, 64 hex characters)"
      },
      "outputLevel": {
       "enum": [
        "summary",
        "detailed"
       ],
       "type": "string",
       "description": "'summary' = one-liner, 'detailed' = full breakdown"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "required": [
      "status"
     ],
     "properties": {
      "chain": {
       "type": "string",
       "description": "Blockchain name"
      },
      "error": {
       "type": "string",
       "description": "Error message if failed"
      },
      "status": {
       "enum": [
        "success",
        "failed"
       ],
       "type": "string"
      },
      "txHash": {
       "type": "string",
       "description": "Transaction hash"
      },
      "details": {
       "type": "object",
       "description": "Structured decode — from, to, value, method, selector, signature, pattern, events (always included; interpretation prose only when outputLevel=detailed)"
      },
      "summary": {
       "type": "string",
       "description": "Human-readable transaction summary"
      },
      "explorerUrl": {
       "type": "string",
       "description": "Link to block explorer"
      }
     }
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/evm-transaction-explainer-5413f31d/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from tools-agent-x402-production.up.railway.app](https://www.zero.xyz/host/tools-agent-x402-production.up.railway.app/llms.txt)