# Transaction Explainer

> Transaction Explainer is a paid API for AI agents from transaction-explainer.pdfextractapi.workers.dev, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-15).

Decodes an on-chain transaction hash and returns a plain-English explanation with token transfer detection

## Facts

- Endpoint: POST https://transaction-explainer.pdfextractapi.workers.dev/explain
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/transaction-explainer-d483ea96
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_0PnfHjAZBSNp0Job11wb9

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 transaction-explainer-d483ea96 -d '<json body>'
```

Example prompt: Can you explain what happened in this Ethereum transaction — 0x4a1b2c3d4e5f6789abcdef01234567890abcdef01234567890abcdef012345678 — in plain English, including any token transfers?

## When to prefer this

Use this endpoint when you need a human-readable summary of an on-chain transaction for non-technical users, auditing, or reporting purposes. It supports multiple EVM chains (Ethereum, Base, Polygon, Arbitrum, Optimism, BNB) and specializes in token transfer detection, making it ideal for wallets, block explorers, DeFi dashboards, or compliance tools that need to surface what a transaction actually did without requiring the caller to parse ABI data themselves.

## Known failure modes

- Invalid or malformed tx hash returns an error
- Transaction hash not found on the specified chain
- Unsupported chain key returns a validation error
- Network timeouts when fetching chain data
- Complex multi-call transactions may produce incomplete explanations

## How this service works

Decode an on-chain transaction and explain it in plain English, with token transfer detection.

## Output

A plain-English explanation of what the on-chain transaction did, including a description of the action performed, parties involved, and any token transfers detected (token names, amounts, sender/receiver addresses).

## 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",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "required": [
      "tx_hash"
     ],
     "properties": {
      "chain": {
       "type": "string",
       "description": "Optional chain key. Default 'ethereum'. One of: ethereum, base, polygon, arbitrum, optimism, bnb."
      },
      "tx_hash": {
       "type": "string",
       "description": "The 32-byte transaction hash, 0x-prefixed."
      }
     }
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "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/transaction-explainer-d483ea96/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from transaction-explainer.pdfextractapi.workers.dev](https://www.zero.xyz/host/transaction-explainer.pdfextractapi.workers.dev/llms.txt)