# Base Toolbox Send Check

> Base Toolbox Send Check 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).

Pre-flight validation check for token transfers on Base before signing, verifying safety and readiness of ERC-20 or native sends

## Facts

- Endpoint: POST https://basetoolbox.cartonpliant.workers.dev/v1/send-check
- 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-send-check-c60eacc4
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_GMFzc0Ea7n4pybgHJWnR5

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-send-check-c60eacc4 -d '<json body>'
```

Example prompt: Before I send 50 USDC from my Base wallet 0xAbC...123 to 0xDeF...456, run a preflight send check to make sure the transfer is valid and tell me what to do next.

## When to prefer this

Use this endpoint when an AI agent or user wants to validate a token transfer on Base before signing or broadcasting — especially useful for ERC-20 sends where allowance and balance pre-checks prevent failed transactions. Prefer over generic blockchain RPC calls when you want a human-readable next-action recommendation alongside the safety check.

## Known failure modes

- Invalid or missing wallet addresses returns validation error
- Insufficient balance or allowance detected returns ok: false with reason
- Unsupported token type returns error or unknown kind
- Network connectivity issues to Base RPC return service error
- Malformed input object returns 400-level 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 indicating whether the transfer is valid (ok: true/false), the kind of transfer detected (e.g. 'erc20' or native), and a recommended next action (e.g. 'confirm_send'). May include warnings about insufficient balance, allowance issues, or other pre-flight problems.

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "kind": "erc20",
  "next": "confirm_send"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/base-toolbox-send-check-c60eacc4/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)