# Base Pre-Trade Sellability Check

> Base Pre-Trade Sellability Check is a paid API for AI agents from api.x402risk.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-02).

Simulates a buy, transfer, and sell of a Base ERC-20 token on live chain state to detect honeypots, hidden taxes, and sell restrictions before a real trade.

## Facts

- Endpoint: POST https://api.x402risk.com/v1/pretrade-check?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/base-pre-trade-sellability-check-d96307af
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_efECYJ14cYcEgWR2xBopt

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-pre-trade-sellability-check-d96307af -d '<json body>'
```

Example prompt: Before I buy this Base token at 0x532f27101965dd16442E59d40670FaF5eBB142E4, run a honeypot simulation with a $100 hypothetical trade on auto router and tell me the buy/sell tax, whether I can actually sell it afterward, and any risk flags.

## When to prefer this

Use this endpoint when you need a fast, live-state simulation of whether a Base ERC-20 token can be bought and sold without restrictions, specifically to detect honeypots, hidden taxes, and sell locks before committing real funds. Prefer this over static contract analysis when you want dynamic execution-based evidence rather than bytecode heuristics. Choose this over generic token risk checks when the specific concern is trade executability and tax measurement on Uniswap v2/v3 or Aerodrome on Base chain.

## Known failure modes

- Invalid token address format returns 400 error with no charge
- Token has no supported liquidity pool — verdict returns unknown
- Simulation reverts with a revert_reason string explaining why sell failed
- Token owner changes rules between simulation and real trade — results may not reflect live conditions
- Unsupported router specified for the available pools returns error or falls back to auto
- Token with extremely low liquidity may return inaccurate tax measurements

## How this service works

Pre-trade sellability / honeypot check for Base tokens: simulates a buy, a wallet transfer and a sell of a Base ERC-20 on live Base state (Uniswap v2/v3 or Aerodrome; nothing is signed or spent). Returns buy/sell/transfer success, measured tax %, revert reason and a simulation-driven verdict (ok/caution/avoid/unknown); owner/holder flags go in risk_flags. $0.02 USDC. Invalid input is not charged. Informational, not financial advice.

## Output

Returns a JSON object with buy_ok, sell_ok, transfer_ok boolean flags, buy/sell/transfer tax percentages, a simulation verdict (ok/caution/avoid/unknown), revert_reason if any step failed, risk_flags array (e.g. active owner, blacklist function), pool address used, gas estimates for each step, block number of simulation, and a disclaimer. Also includes chain, router route, and schema version.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "token": {
   "type": "string",
   "pattern": "^0x[0-9a-fA-F]{40}$",
   "description": "Base (chain 8453) ERC-20 token contract address"
  },
  "router": {
   "enum": [
    "auto",
    "uniswap_v2",
    "uniswap_v3",
    "aerodrome"
   ],
   "type": "string",
   "default": "auto",
   "description": "Restrict the simulated pool type; auto = deepest supported WETH/USDC pool"
  },
  "amount_usd": {
   "type": "number",
   "default": 100,
   "maximum": 10000,
   "minimum": 1,
   "description": "Hypothetical trade size in USD (capped to 5% of the pool's quote reserve)"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "gas": {
   "buy": 150000,
   "sell": 133537,
   "transfer": 40000
  },
  "pool": "0xBA3F945812a83471d709BCe9C3CA699A19FB46f7",
  "chain": "base",
  "route": "uniswap_v3:fee_10000 WETH",
  "token": "0x532f27101965dd16442E59d40670FaF5eBB142E4",
  "buy_ok": true,
  "cached": false,
  "status": "ok",
  "product": "pretrade-check",
  "reasons": [
   "buy, transfer and sell simulated successfully with < 1% tax"
  ],
  "sell_ok": true,
  "verdict": "ok",
  "chain_id": 8453,
  "disclaimer": "Informational, not financial advice. Simulation of a hypothetical buy/transfer/sell against public Base state at the stated block; it is not a guarantee that a real trade will succeed or be taxed the same way (token owners can change rules at any time). Heuristic flags can be wrong; do your own research.",
  "risk_flags": [
   {
    "flag": "HAS_ACTIVE_OWNER",
    "note": "contract has an active (non-renounced) owner"
   }
  ],
  "buy_tax_pct": 0,
  "transfer_ok": true,
  "block_number": 35000000,
  "sell_tax_pct": 0,
  "revert_reason": null,
  "schema_version": "1.0",
  "transfer_tax_pct": 0,
  "token_check_risk_level": "low"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/base-pre-trade-sellability-check-d96307af/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.x402risk.com](https://www.zero.xyz/host/api.x402risk.com/llms.txt)