# Base Token Sell Check

> Base Token Sell Check is a paid API for AI agents from base-facts.yankii.fr, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-11).

Simulates a buy-then-immediate-sell of a Base token on its deepest WETH pool to detect honeypots, buy/sell taxes, and round-trip losses

## Facts

- Endpoint: POST https://base-facts.yankii.fr/v1/sellcheck?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-11
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/base-token-sell-check-fd21b651
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_yPfz7z5OMw5HR_T6fRFa1

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-token-sell-check-fd21b651 -d '<json body>'
```

Example prompt: Before I buy, can you run a sell simulation on token 0x4ed4E862860beD51a9570b96d89aF5E1B0Efefed on Base to check if it's a honeypot and what the buy and sell taxes are?

## When to prefer this

Use this endpoint when you need to determine if a Base chain token is safe to trade before committing real capital — specifically when you need buy/sell tax figures and honeypot detection via simulation rather than static code analysis. Prefer this over generic token scanners when you need numerical tax values (not just a pass/fail), and over the Base Token Verdict endpoint when you specifically want raw simulation data rather than a summarized risk score.

## Known failure modes

- Token address is invalid or not 0x-prefixed — returns validation error
- Token has no WETH liquidity pool on Uniswap v2/v3 or Aerodrome — simulation cannot proceed
- Network congestion or RPC failure may cause timeout
- Simulation is at one block and may not reflect current state — taxes or restrictions may have changed
- Token uses non-standard mechanics that bypass simulation detection — false negatives possible
- Malicious contract may behave differently in eth_call vs real transaction

## How this service works

Base honeypot and tax check for trading agents: simulates a small buy and an immediate sell of the token on its deepest WETH pool (Uniswap v2/v3, Aerodrome) inside eth_call, and returns buy tax, sell tax, round-trip loss and whether the sell reverted. $0.005. Simulation at one block, not a guarantee.

## Output

Returns buy tax percentage, sell tax percentage, total round-trip loss percentage, and a boolean indicating whether the sell transaction reverted — effectively classifying the token as a honeypot or flagging hidden taxes from a single-block eth_call simulation on the deepest WETH pool (Uniswap v2/v3 or Aerodrome).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "token": {
   "type": "string",
   "description": "Token contract address (0x-prefixed hex, 20 bytes)"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/base-token-sell-check-fd21b651/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from base-facts.yankii.fr](https://www.zero.xyz/host/base-facts.yankii.fr/llms.txt)