# Base Tx Explain

> Base Tx Explain is a paid API for AI agents from api.arysphere.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-24).

Decodes a Base chain transaction by hash, returning status, transfers, swaps, approvals, USD values, and a one-line summary.

## Facts

- Endpoint: POST https://api.arysphere.com/v1/ventures/x402_eth_reads_v1/base_tx_explain?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-24
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/base-tx-explain-7d3c8e03
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_qzDYTzZ-X603AhxmKeQrM

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 base-tx-explain-7d3c8e03 -d '<json body>'
```

Example prompt: Can you decode this Base transaction for me and tell me what happened — what tokens moved, if there was a swap, and what the fee was in USD? The hash is 0x7250ea109382c1c23d3209c766f8a04ca749c17cf9f2ebc2963ac19b56e9966c.

## When to prefer this

Use this endpoint when you need a complete, human-readable breakdown of a single Base chain transaction — including decoded token transfers, swap events, approvals, and USD valuations — without running your own RPC node or writing ABI decoding logic. It is deterministic (no AI model involved in decoding) and caches mined transactions for fast repeat lookups. Prefer it over raw RPC calls when you need USD context via Chainlink or want approval/swap detection out of the box. Use it specifically for Base mainnet; sibling endpoints cover Ethereum mainnet.

## Known failure modes

- Transaction hash not found returns status not_found
- Malformed or non-0x-prefixed hash causes a 400 bad request
- Transaction still pending may return limited data without receipt logs
- Token USD price unavailable for obscure tokens (usd field may be null)
- RPC backend timeout or node unavailability causes 5xx errors
- Log truncation for very high log-count transactions (truncated: true)

## How this service works

ARYSPHERE sells AI-written verdicts on Base and Ethereum token contracts (a grade, a one-liner, a roast and the contract's facts) and Base/Ethereum chain reads, paid per call in USDC on Base, Polygon, and Arbitrum over x402 v2. No account and no API key.

## Output

A JSON object containing: transaction status (pending, confirmed, reverted, or not_found), block number, from/to addresses, ETH and USD value (via Chainlink ETH/USD), fee in ETH and USD, decoded log events (ERC-20/ERC-721 transfers with symbol, amount, USD price; approvals with unlimited flag; WETH wraps; DEX swap events with pool and protocol), a one-line plain-English summary, and metadata like RPC call count, cache status, and whether logs were truncated.

## 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",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "hash": {
       "type": "string",
       "description": "transaction hash, 0x + 64 hex"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "chain": "base",
  "cached": false,
  "method": "explain",
  "result": {
   "to": "0x8ea5ad2a58c1dae75394b1e8636e6518eb6dac50",
   "from": "0x2c2e035d20cd6da1664a7cf0eaf98e3647607304",
   "hash": "0x7250ea109382c1c23d3209c766f8a04ca749c17cf9f2ebc2963ac19b56e9966c",
   "block": 52718625,
   "swaps": [
    {
     "dex": "uniswap_v3_shape",
     "pool": "0x0abe41c8aaa9282429e06ebed48be36298981d94"
    }
   ],
   "wraps": [],
   "status": "confirmed",
   "eth_usd": 2430.46003758,
   "fee_eth": "0.000003059537476466",
   "fee_usd": 0.0074,
   "summary": "Confirmed in block 52718625; moved 4194.908918312848701351 RECALL, 164.78 USDC; 1 swap(s); 1 approval(s); fee $0.0074.",
   "approvals": [
    {
     "owner": "0x8ea5ad2a58c1dae75394b1e8636e6518eb6dac50",
     "token": "0x833589fcd6edb6e08f4c7c32d4f71b54bda02913",
     "amount": "164.78",
     "symbol": "USDC",
     "spender": "0x698cb2b6dd822994581fea6ea4fc755d1363a92f",
     "unlimited": false
    }
   ],
   "rpc_calls": 5,
   "transfers": [
    {
     "to": "0x8ea5ad2a58c1dae75394b1e8636e6518eb6dac50",
     "usd": 162.62,
     "from": "0x0abe41c8aaa9282429e06ebed48be36298981d94",
     "token": "0x1f16e03c1a5908818f47f6ee7bb16690b40d0671",
     "amount": "4194.908918312848701351",
     "symbol": "RECALL",
     "usd_basis": "uniswap v3 deepest-pool spot"
    },
    {
     "to": "0x0abe41c8aaa9282429e06ebed48be36298981d94",
     "usd": 164.78,
     "from": "0x8ea5ad2a58c1dae75394b1e8636e6518eb6dac50",
     "token": "0x833589fcd6edb6e08f4c7c32d4f71b54bda02913",
     "amount": "164.78",
     "symbol": "USDC",
     "usd_basis": "dollar stablecoin"
    }
   ],
   "truncated": false,
   "value_eth": "0",
   "value_usd": 0,
   "logs_total": 5,
   "other_logs": 1,
   "nft_transfers": [],
   "eth_usd_source": "chainlink ETH/USD 0x71041dddad3595f9ced3dccfbe3d1f4b0a16bb70",
   "method_selector": "0x708909ad",
   "contract_created": null
  },
  "service": "x402_eth_reads_v1.base_tx_explain"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/base-tx-explain-7d3c8e03/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.arysphere.com](https://www.zero.xyz/host/api.arysphere.com/llms.txt)