# Base Toolbox TX Explain

> Base Toolbox TX Explain is a paid API for AI agents from basetoolbox.cartonpliant.workers.dev, paid per call via x402, $0.1/call, status unknown (last checked 2026-09-15).

Decodes and explains a Base blockchain transaction before signing, identifying its kind (e.g. approve, swap) and recommended next step

## Facts

- Endpoint: POST https://basetoolbox.cartonpliant.workers.dev/v1/explain
- Price: $0.1/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/base-toolbox-tx-explain-bf6fbc26
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_3Sg60BA9Nyk2O8U1VEhH8

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-toolbox-tx-explain-bf6fbc26 -d '<json body>'
```

Example prompt: Before I sign this transaction, can you explain what it's doing — my wallet is showing a raw tx and I need to know if it's an approve, a swap, or something else on Base?

## When to prefer this

Use this endpoint when an AI agent or user needs to understand what a Base blockchain transaction will do before signing it — especially for Uniswap v3 swaps, ERC-20 approvals, or transfers where calldata is opaque. Prefer this over generic blockchain explorers when you need a structured, machine-readable classification with a recommended next action rather than a block explorer URL. Ideal for pre-signing safety checks in DeFi agent workflows on the Base network.

## Known failure modes

- Malformed or missing input/output transaction object returns an error
- Unrecognized transaction calldata may result in an unknown kind classification
- Payment of 0.10 USDC not received causes 402 Payment Required response
- Non-Base-network transactions may be misclassified or unsupported
- Empty or null transaction body returns a validation error

## How this service works

Base toolbox: before you sign on Base — Uniswap v3 preflight, leftover allowances, tx explain, transfer check. $0.10 USDC. Also $0.001 price/gas/ENS. GET /v1/constants free. No CoinGecko key.

## Output

Returns a JSON object with: ok (boolean success flag), kind (transaction classification such as 'approve', 'swap', 'transfer'), and next (recommended next action string like 'confirm_approve'), giving the agent a plain-language understanding of what the transaction will do on-chain.

## Request schema (JSON Schema)

```json
{
 "properties": {
  "input": {
   "type": "object"
  },
  "output": {
   "type": "object"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "kind": "approve",
  "next": "confirm_approve"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/base-toolbox-tx-explain-bf6fbc26/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from basetoolbox.cartonpliant.workers.dev](https://www.zero.xyz/host/basetoolbox.cartonpliant.workers.dev/llms.txt)