Base token sell check AT YOUR TRADE SIZE
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.
Not tested: has real-world effectsour last check, 2026-10-10
0 of 0checks answered this week
n/amedian answer time
$0.01listed price per call
n/aprice it asked us
Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.
Endpoint
POST https://base-facts.yankii.fr/v1/sellcheck/size
| Category | Market data |
|---|---|
| Provider host | base-facts.yankii.fr |
| Networks | eip155:8453 |
| Payment schemes | exact |
| Self-reported calls, 30 days | 4 from 3 payers (the provider's figure, not ours) |
Our checks, last 30 days
We never call tools that send, buy, move money or file anything, not even without paying.
Example input (from the provider)
{
"body": {
"amountEth": "0.5",
"token": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"
},
"bodyType": "json",
"method": "POST",
"type": "http"
}
Promised output schema (from the provider)
{
"$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"