Call before buying, swapping into or accepting any Base ERC-20, to learn if you
Call before buying, swapping into or accepting any Base ERC-20, to learn if you can sell it back. $0.02, ~1-3 s, measured on-chain: honeypot test (simulated buy then sell via the deepest pool: sell ok? round-trip loss vs fees), per-pool transfer tax from real recent swap receipts, USD liquidity per pool (Uniswap v2/v3, Aerodrome, Slipstream), sell quotes, and an ok/caution/avoid verdict citing each fact. Errors: 400/503 JSON {error}, not charged.
Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.
Endpoint
GET https://tokencheck.402api.dev/v1/token-check
| Category | Market data |
|---|---|
| Provider host | tokencheck.402api.dev |
| Networks | eip155:8453 |
| Payment schemes | exact |
| Self-reported calls, 30 days | 2 from 1 payers (the provider's figure, not ours) |
Our checks, last 30 days
We never call tools that send, buy, move money or file anything, not even without paying.
Example input (from the provider)
{
"discoverable": true,
"method": "GET",
"queryParams": {
"token": "0x940181a94A35A4569E4529A3CDfB74e38FD98631"
},
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"discoverable": {
"const": true
},
"method": {
"enum": [
"GET"
],
"type": "string"
},
"queryParams": {
"properties": {
"token": {
"description": "ERC-20 token contract address on Base mainnet",
"pattern": "^0x[0-9a-fA-F]{40}$",
"type": "string"
}
},
"required": [
"token"
],
"type": "object"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"oneOf": [
{
"description": "HTTP 200: the token report",
"properties": {
"block": {
"type": "string"
},
"cached": {
"type": "boolean"
},
"ethUsd": {
"type": [
"number",
"null"
]
},
"measuredAt": {
"type": "string"
},
"notes": {
"items": {
"type": "string"
},
"type": "array"
},
"pools": {
"items": {
"description": "venue, pairedWith, feePct, liquidityUsd, transferTax, sellable",
"type": "object"
},
"type": "array"
},
"poolsOmitted": {
"type": "integer"
},
"reasons": {
"items": {
"type": "string"
},
"type": "array"
},
"sellSimulation": {
"description": "eth_simulateV1 buy-then-sell on the deepest pool: ok, roundTripLossPct, feesPct, error",
"type": [
"object",
"null"
]
},
"token": {
"type": "object"
},
"verdict": {
"enum": [
"ok",
"caution",
"avoid"
]
}
},
"required": [
"token",
"verdict",
"reasons",
"pools",
"measuredAt"
],
"type": "object"
},
{
"description": "Error body. HTTP 400 = bad or missing input; HTTP 503 = check failed or timed out (25 s). The payment is not settled on errors, so the caller is not charged.",
"example": {
"error": "query parameter `token` must be a 0x-prefixed 40-hex-digit Base token address"
},
"properties": {
"error": {
"description": "What went wrong, in plain words",
"type": "string"
}
},
"required": [
"error"
],
"type": "object"
}
],
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}