# Sentinel Token Safety

> Sentinel Token Safety is a paid API for AI agents from www.0816.cn, paid per call via x402, $0.1/call, status unknown (last checked 2026-09-18).

Returns a single ALLOW/WARN/BLOCK safety verdict for any ERC-20 token contract on Base before a buy, swap, or approval

## Facts

- Endpoint: GET https://www.0816.cn/v1/base/token-safety
- Price: $0.1/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-18
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/sentinel-token-safety-68decb42
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_g22e6OT6PyjJx5sf04iQm

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-68decb42
```

Example prompt: Before we swap into 0x4ed4E862860beD51a9570b96d89aF5E1B0Efefed on Base, run a Sentinel token safety check on that contract address and tell me whether to proceed, review, or abort — and show me the verdict reason and any tax or honeypot flags.

## When to prefer this

Use this endpoint when your agent is about to execute any ERC-20 buy, swap, or approval on the Base network and needs a single authoritative go/no-go decision aggregating honeypot, tax, transfer restriction, and proxy risk signals. Prefer it over individual honeypot checkers or tax scanners when you want one consolidated verdict with an actionable branch (PROCEED/REVIEW/ABORT) rather than assembling multiple raw signals yourself. Especially valuable for autonomous trading agents, DeFi bots, or wallet UIs that need a fast pre-trade safety gate.

## Known failure modes

- Invalid or malformed contract address returns an error response
- Contract address not found on Base network returns unknown/unverifiable verdict
- Network or provider timeout may delay or fail the safety check
- Non-ERC-20 contracts (e.g. NFTs, proxy-only) may return incomplete check coverage
- Rate limiting or payment failure (x402) blocks the request

## How this service works

Token safety pre-flight — one verdict before your agent buys, swaps or approves any ERC-20 on Base (GET ?contract=0x… or POST body {contract}). Call it right before the trade and branch on `verdict`: ALLOW / WARN / BLOCK, with `action`: PROCEED / REVIEW / ABORT and a one-line `reason`. Aggregates honeypot and scam-token detection, buy tax and sell tax, transfer restrictions, hidden mint and owner privileges, and EIP-1967 proxy upgrade risk into a single decision. `checks` carries the raw fields for audit. $0.10 USDC

## Output

A JSON object containing: `verdict` (ALLOW, WARN, or BLOCK), `action` (PROCEED, REVIEW, or ABORT), and `reason` (a one-line human-readable explanation). Also includes a `checks` object with raw audit fields covering honeypot detection, buy/sell tax percentages, transfer restrictions, hidden mint flags, owner privilege flags, and EIP-1967 proxy upgrade risk indicators.

## 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-68decb42/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)