← The evidence ledger
Evidence row 71436
Observed , by baseline/1.
- Kind
- listing
- About
- source_record x402_bazaar:https://base-facts.yankii.fr/v1/sellcheck
- Recorded
- Previous row
- None: the first of its kind about this subject
- Body SHA-256
- 5e3d1a8a0a7e1e68e714a42bea0c65cb1b1b45cf2f3d102df7fd9307189fea0c
- Leaf
- 0x01f9cacf2d4146e52d8d096105d554384d491f81aa9b1743a48c15cefbdf4e0a
What was observed
{
"endpoints": [
[
"x402",
"https://base-facts.yankii.fr/v1/sellcheck"
]
],
"name": "Base Token Sell Check",
"owner_address": "0x40661d56c2bf416c5946a8b21098eaf8d33459a2",
"raw": {
"accepts": [
{
"amount": "5000",
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": {
"name": "USD Coin",
"version": "2"
},
"maxTimeoutSeconds": 300,
"network": "eip155:8453",
"payTo": "0x40661D56c2Bf416c5946A8b21098eaF8D33459A2",
"scheme": "exact"
}
],
"description": "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. $0.005. Simulation at one block, not a guarantee.",
"extensions": {
"bazaar": {
"info": {
"input": {
"body": {
"token": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"
},
"bodyType": "json",
"method": "POST",
"type": "http"
},
"output": {
"example": {
"blockNumber": "52159737",
"disclaimer": "eth_call simulation at block 52159737: a small buy with WETH and an immediate sell on the token's deepest WETH pools. Not a guarantee: the token's code or owner can change, and some tokens treat addresses or sizes differently. Not financial advice.",
"flags": [
{
"fact": "Bought with 0.01 WETH and sold straight back on uniswap-v3 pool 0x6c561B446416E1A00E8E93E221854d6eA4171372 at block 52159737 (eth_call simulation): round-trip loss 0.6%, which includes a 0.30% pool fee paid twice and any token tax.",
"id": "sell_ok",
"severity": "info"
}
],
"name": "USD Coin",
"simulation": {
"amounts": {
"tokenReachedPool": null,
"tokenReceived": "26912247",
"tokenReleasedByPool": "26912247",
"tokenSent": "26912247",
"wethOut": "9940089592377343"
},
"attempts": [
{
"dex": "uniswap-v3",
"fee": 3000,
"ok": true,
"pool": "0x6c561B446416E1A00E8E93E221854d6eA4171372",
"wethIn": "10000000000000000"
}
],
"buyTaxPct": 0,
"dex": "uniswap-v3",
"fee": 3000,
"pool": "0x6c561B446416E1A00E8E93E221854d6eA4171372",
"roundTripLossPct": 0.6,
"sellTaxPct": null,
"status": "ok",
"wethIn": "10000000000000000"
},
"source": "base-mainnet-rpc",
"summary": "USDC: Simulated buy and sell on uniswap-v3: no transfer tax, round-trip loss 0.6%.",
"symbol": "USDC",
"token": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"
},
"type": "json"
}
},
"schema": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"properties": {
"token": {
"description": "Token contract address (0x-prefixed hex, 20 bytes)",
"type": "string"
}
},
"required": [
"token"
],
"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"
}
}
},
"lastUpdated": "2026-10-15T07:28:08.964Z",
"quality": {
"l30DaysTotalCalls": 4,
"l30DaysUniquePayers": 4,
"lastCalledAt": "2026-10-15T07:28:08.433Z"
},
"resource": "https://base-facts.yankii.fr/v1/sellcheck",
"serviceName": "Base Token Sell Check",
"tags": [
"base",
"token",
"honeypot",
"tax",
"sell"
],
"type": "http",
"x402Version": 2
},
"source": "x402_bazaar",
"summary": "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."
}What the leaf hashes
{"body":"5e3d1a8a0a7e1e68e714a42bea0c65cb1b1b45cf2f3d102df7fd9307189fea0c","id":71436,"kind":"listing","method":"baseline/1","observed_us":1793025482150824,"prev":null,"subject":"x402_bazaar:https://base-facts.yankii.fr/v1/sellcheck","subject_kind":"source_record"}Proof
Its day has not closed yet. A day closes ten minutes after midnight UTC; the proof appears here then.