# Blockchain Transaction Explainer

> Blockchain Transaction Explainer is a paid API for AI agents from store.agentexchange.work, paid per call via x402, $0.002/call, status unknown (last checked 2026-09-14).

Decodes and explains an on-chain transaction hash into a human-readable summary with action type, asset changes, and method details

## Facts

- Endpoint: GET https://store.agentexchange.work/chain/tx-explain
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/blockchain-transaction-explainer-c5e12c95
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Fssa8FcLPMtg0DU48Hrox

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-transaction-explainer-c5e12c95
```

Example prompt: Can you explain what this Base transaction did: 0x4f3a2b1c9e8d7f6a5b4c3d2e1f0a9b8c7d6e5f4a3b2c1d0e9f8a7b6c5d4e3f2a1 — I want to know the action, any asset changes, and the fee paid.

## When to prefer this

Use this endpoint when you need to decode and explain a specific EVM transaction hash into human-readable form across Base, Ethereum, Optimism, Arbitrum, Polygon, or Gnosis — especially when you want structured asset change data without setting up an API key or subscription. Ideal for AI agents that receive a tx hash and need to explain it to a user or route on its contents.

## Known failure modes

- Invalid or malformed transaction hash returns an error
- Transaction hash not found on specified chain
- Unsupported chain identifier returns 402 or 400 error
- Unrecognized contract method may return partial decode with limited action label
- Network timeout on RPC node lookup

## How this service works

Decode any transaction by hash into plain English: what happened (swap/transfer/approval/mint/call), the actors, and the full asset changes (every native+token in/out with symbol, amount, direction), plus status, fee and method. For wallet UX, accounting, risk and trading agents. Base, Ethereum, Optimism, Arbitrum, Polygon, Gnosis via Blockscout.

## Output

A JSON object with the transaction hash, chain, decoded action label (e.g. 'swap'), contract method name, success/failure status, ETH fee, a plain-English summary sentence, and an array of asset changes each showing symbol, amount, and in/out direction.

## 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": [
      "hash"
     ],
     "properties": {
      "hash": {
       "type": "string"
      },
      "chain": {
       "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/blockchain-transaction-explainer-c5e12c95/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from store.agentexchange.work](https://www.zero.xyz/host/store.agentexchange.work/llms.txt)