# Sentinel Token Safety — ERC-20 Tax & Transfer Restriction Scanner

> Sentinel Token Safety — ERC-20 Tax & Transfer Restriction Scanner is a paid API for AI agents from www.0816.cn, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-19).

Scans any ERC-20 token contract on Base for buy/sell taxes, transfer restrictions, cooldowns, blacklist/whitelist functions, and returns a trade-safety verdict to protect agents from fee-draining tokens.

## Facts

- Endpoint: GET https://www.0816.cn/v1/base/token-tax
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-19
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/sentinel-token-safety-erc-20-tax-transfer-restriction-scanner-0fa3d098
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ZUADqVpI_4zohHAx5lNvP

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 sentinel-token-safety-erc-20-tax-transfer-restriction-scanner-0fa3d098
```

Example prompt: Before you swap into this token at 0x4200000000000000000000000000000000000006 on Base, run a tax and transfer restriction check on it — I want to know the buy and sell tax, any cooldown rules, and whether it has blacklist functions, plus an overall trade-safety verdict.

## When to prefer this

Use this endpoint whenever an AI agent is about to swap, quote, or route a token on the Base network and needs to verify that the token won't drain value through hidden taxes or transfer restrictions. Prefer this over generic contract scanners when you specifically need buy/sell tax rates and transfer rule details — not just a generic rug score. Ideal as a mandatory pre-swap gate in automated trading agents, routing engines, or portfolio tools.

## Known failure modes

- Invalid or malformed contract address returns a 400 error
- Contract not deployed on Base returns a not-found or unsupported-chain error
- Non-ERC-20 contract address may return incomplete or null tax data
- Network or RPC timeout may cause a 503 or delayed response
- Unverified contracts may produce incomplete results if source code is unavailable

## How this service works

Token tax check and transfer restriction scan for any ERC-20 on Base (GET ?contract=0x… or POST body {contract}). Returns buy tax, sell tax, transfer limits, cooldown rules, blacklist/whitelist functions and a trade-safety verdict. Call before any agent swaps, quotes or routes a token, to avoid tokens that eat most of the trade in fees. $0.02 USDC

## Output

Returns structured data including the buy tax percentage, sell tax percentage, transfer limit rules, cooldown periods, presence of blacklist and/or whitelist functions, and an overall trade-safety verdict (pass/warn/fail or equivalent) for the queried ERC-20 token on Base.

## 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": [
      "contract"
     ],
     "properties": {
      "contract": {
       "type": "string",
       "description": "address (0x...) — also accepted in POST body"
      }
     }
    }
   },
   "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/sentinel-token-safety-erc-20-tax-transfer-restriction-scanner-0fa3d098/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from www.0816.cn](https://www.zero.xyz/host/www.0816.cn/llms.txt)