{"slug":"base-facts-yankii-fr-v1-sellcheck-size-9c13c7","title":"Base token sell check AT YOUR TRADE SIZE","host":"base-facts.yankii.fr","method":"POST","resource":"https://base-facts.yankii.fr/v1/sellcheck/size","category":"market","description":"Base token sell check AT YOUR TRADE SIZE: simulates a buy of amountEth (0.001 to 10 ETH) and an immediate sell inside eth_call (no trade is sent) and reports the buy tax, the sell tax and the round-trip loss including price impact. Uniswap v2, v3, v4 (ETH, WETH, ZORA, USDC quotes) and Aerodrome. Mea","price_listed":0.01,"price_asked":null,"state":"effects","state_label":"Not tested: has real-world effects","checks_7d":0,"answered_7d":0,"latency_ms_median":null,"reported_calls_30d":4,"reported_payers_30d":3,"networks":["eip155:8453"],"badge":"unverified","paid_checks_7d":0,"paid_ok_7d":0,"example_input":{"body":{"amountEth":"0.5","token":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"},"bodyType":"json","method":"POST","type":"http"},"output_schema":{"$schema":"https://json-schema.org/draft/2020-12/schema","properties":{"input":{"additionalProperties":false,"properties":{"body":{"properties":{"amountEth":{"description":"Trade size in ETH as a decimal string, from 0.001 to 10 (example: \"0.5\")","type":"string"},"token":{"description":"Token contract address (0x-prefixed hex, 20 bytes)","type":"string"}},"required":["token","amountEth"],"type":"object"},"bodyType":{"enum":["json","form-data","text"],"type":"string"},"method":{"enum":["POST"],"type":"string"},"type":{"const":"http","type":"string"}},"required":["type","method","bodyType","body"],"type":"object"},"output":{"properties":{"example":{"properties":{"blockNumber":{"type":"string"},"disclaimer":{"type":"string"},"flags":{"items":{"properties":{"fact":{"description":"The on-chain observation behind the flag","type":"string"},"id":{"enum":["not_erc20","upgradeable_proxy","owner_not_renounced","can_mint","can_pause","can_blacklist","no_liquidity","thin_liquidity","deep_liquidity","v4_liquidity_unmeasured","v4_pool_empty","sell_ok","buy_tax","sell_tax","high_round_trip_loss","sell_reverted","buy_reverted","not_simulated"],"type":"string"},"severity":{"enum":["info","warn","high"],"type":"string"}},"type":"object"},"type":"array"},"name":{"type":["string","null"]},"simulation":{"description":"eth_call buy-and-sell simulation at the verdict's block; null when the address is not an ERC20","properties":{"amounts":{"properties":{"tokenReachedPool":{"type":["string","null"]},"tokenReceived":{"type":"string"},"tokenReleasedByPool":{"type":"string"},"tokenSent":{"type":"string"},"wethOut":{"type":"string"}},"type":"object"},"attempts":{"items":{"properties":{"dex":{"type":"string"},"fee":{"type":["integer","null"]},"leg":{"enum":["buy","sell","unknown"],"type":"string"},"ok":{"type":"boolean"},"pool":{"type":"string"},"revertReason":{"type":"string"},"wethIn":{"type":"string"}},"type":"object"},"type":"array"},"buyTaxPct":{"type":["number","null"]},"dex":{"enum":["uniswap-v2","uniswap-v3","aerodrome-volatile","uniswap-v4"],"type":"string"},"fee":{"description":"Uniswap fee in hundredths of a basis point (500 = 0.05%)","type":["integer","null"]},"hooks":{"type":"string"},"pool":{"type":"string"},"reason":{"description":"Why the simulation was not run (status not_simulated)","type":"string"},"roundTripLossPct":{"description":"WETH lost buying and selling straight back, pool fees included","type":"number"},"sellTaxPct":{"description":"null on Uniswap v3 (not measurable)","type":["number","null"]},"status":{"enum":["ok","sell_reverted","buy_reverted","not_simulated"],"type":"string"},"wethIn":{"description":"WETH wei used for the simulated buy","type":"string"}},"type":["object","null"]},"source":{"type":"string"},"summary":{"type":"string"},"symbol":{"type":["string","null"]},"token":{"type":"string"}},"type":"object"},"type":{"type":"string"}},"required":["type"],"type":"object"}},"required":["input"],"type":"object"},"history":[],"description_full":"Base token sell check AT YOUR TRADE SIZE: simulates a buy of amountEth (0.001 to 10 ETH) and an immediate sell inside eth_call (no trade is sent) and reports the buy tax, the sell tax and the round-trip loss including price impact. Uniswap v2, v3, v4 (ETH, WETH, ZORA, USDC quotes) and Aerodrome. Measured at one block, not a guarantee, not financial advice.","last_updated":"2026-10-09T09:28:53.067Z","schemes":["exact"]}