Security · x402 · early usage

Base token verdict for trading agents: risk level, score and flags (proxy, mint, pause,…

Base token verdict for trading agents: risk level, score and flags (proxy, mint, pause, blacklist, owner, DEX liquidity on Uniswap v2/v3 and Aerodrome), each with the on-chain fact behind it. Facts and heuristics, not financial advice.

by base-facts.yankii.fr · discovered, not yet claimed by its owner · updated 2026-10-04

30d calls1

30d payers1

MethodPOST

Outputjson

Mirrored from Coinbase's public x402 Bazaar. The description is the provider's own text and has not been reviewed here; the payment requirements are copied as published.

What it does

Tags: base · token · verdict · risk · defi · bazaar

Call contract

Method: POST
Input: json
Output: json
Last paid call: 2026-10-04

Input example from Bazaar metadata

{
  "token": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"
}

Output example

{
  "blockNumber": "52136127",
  "disclaimer": "On-chain facts and heuristics read at block 52136127. Spot reserves can move within one block. Not financial advice.",
  "flags": [
    {
      "fact": "ZeppelinOS proxy: its code can be replaced; current implementation 0x2Ce6311ddAE708829bc0784C967b7d77D19FD779",
      "id": "upgradeable_proxy",
      "severity": "warn"
    },
    {
      "fact": "owner() returns 0x3ABd6f64A422225E61E435baE41db12096106df7",
      "id": "owner_not_renounced",
      "severity": "warn"
    },
    {
      "fact": "mint(address,uint256) selector found in the implementation bytecode (heuristic)",
      "id": "can_mint",
      "severity": "warn"
    },
    {
      "fact": "pause() selector found in the implementation bytecode (heuristic)",
      "id": "can_pause",
      "severity": "warn"
    },
    {
      "fact": "a blacklist selector was found in the implementation bytecode (heuristic)",
      "id": "can_blacklist",
      "severity": "high"
    },
    {
      "fact": "WETH/USDC-side reserves in Uniswap v2/v3 and Aerodrome pools: $96,907,720 (at least $1,000,000)",
      "id": "deep_liquidity",
      "severity": "info"
    }
  ],
  "level": "high",
  "liquidity": {
    "pools": [
      {
        "dex": "uniswap-v3",
        "fee": 3000,
        "pool": "0x6c561B446416E1A00E8E93E221854d6eA4171372",
        "quote": "WETH",
        "quoteReserve": "32055779596978119535815",
        "quoteReserveUsd": "86078494.19",
        "tokenReserve": "76522772029843"
      },
      {
        "dex": "uniswap-v3",
        "fee": 500,
        "pool": "0xd0b53D9277642d899DF5C87A3966A349A798F224",
        "quote": "WETH",
        "quoteReserve": "1983500656279964419661",
        "quoteReserveUsd": "5326239.19",
        "tokenReserve": "4598355794854"
      }
    ],
    "quoteLiquidityUsd": "96907719.96",
    "scope": "WETH and USDC pairs on Uniswap v2, Uniswap v3 (4 fee tiers) and Aerodrome (volatile and stable)",
    "wethPriceUsd": "2685.27"
  },
  "name": "USD Coin",
  "riskScore": 83,
  "source": "base-mainnet-rpc",
  "summary": "USDC: High-severity: can_blacklist. Warnings: upgradeable_proxy, owner_not_renounced, can_mint, can_pause. $96,907,720 of WETH/USDC-side liquidity in 7 pool(s).",
  "symbol": "USDC",
  "token": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"
}

Use with an agent

Discover. Agents find this listing with GET https://bazaar.saylorinnovations.com/discovery/search?query=…, the MCP tool search_resources, or /discovery/resources.
Inspect. Fetch /resources/35736.json for the price and payment options.
Pay. Call GET https://base-facts.yankii.fr/v1/verdict. The provider answers 402 with its payment requirements. An x402 client signs one of the options below and retries with PAYMENT-SIGNATURE.
Execute. The provider returns 200 with the data. Agent Bazaar is not in the request path and never sees your payment.

For humans

You don't need an account or an API key; you need a wallet holding a small amount of USDC on Base, and an x402-capable client (see the examples below). Call the endpoint unpaid first to see exactly what it asks for.

Pricing & payment

Price: $0.01 / request
Protocol: x402 v2
Auth: No account or API key. Pay per request.
Networks: Base
Demand: 1 calls · 1 unique payers in 30d (public x402 Bazaar data)

x402 payment requirements

Scheme	Network	Asset	Amount	Pay to	Timeout
exact	Base eip155:8453	USDC	$0.01	0x40661D56c2Bf416c5946A8b21098eaF8D33459A2	300s

accepts[] (raw JSON)

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0x40661D56c2Bf416c5946A8b21098eaF8D33459A2",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "10000",
    "amountUsd": 0.01,
    "maxTimeoutSeconds": 300
  }
]

Schemas

Output schema (JSON Schema)

{
  "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"
                ],
                "type": "string"
              },
              "severity": {
                "enum": [
                  "info",
                  "warn",
                  "high"
                ],
                "type": "string"
              }
            },
            "type": "object"
          },
          "type": "array"
        },
        "level": {
          "enum": [
            "low",
            "medium",
            "high"
          ],
          "type": "string"
        },
        "liquidity": {
          "properties": {
            "pools": {
              "items": {
                "properties": {
                  "dex": {
                    "type": "string"
                  },
                  "fee": {
                    "type": [
                      "integer",
                      "null"
                    ]
                  },
                  "pool": {
                    "type": "string"
                  },
                  "quote": {
                    "enum": [
                      "WETH",
                      "USDC"
                    ],
                    "type": "string"
                  },
                  "quoteReserve": {
                    "type": "string"
                  },
                  "quoteReserveUsd": {
                    "type": "string"
                  },
                  "tokenReserve": {
                    "type": [
                      "string",
                      "null"
                    ]
                  }
                },
                "type": "object"
              },
              "type": "array"
            },
            "quoteLiquidityUsd": {
              "type": "string"
            },
            "scope": {
              "type": "string"
            },
            "wethPriceUsd": {
              "type": "string"
            }
          },
          "type": [
            "object",
            "null"
          ]
        },
        "name": {
          "type": [
            "string",
            "null"
          ]
        },
        "riskScore": {
          "maximum": 100,
          "minimum": 0,
          "type": "integer"
        },
        "source": {
          "type": "string"
        },
        "summary": {
          "type": "string"
        },
        "symbol": {
          "type": [
            "string",
            "null"
          ]
        },
        "token": {
          "type": "string"
        }
      },
      "type": "object"
    },
    "type": {
      "type": "string"
    }
  },
  "required": [
    "type"
  ],
  "type": "object"
}

Example shape — generated from the schema, not a captured live response

{
  "example": {
    "blockNumber": "string",
    "disclaimer": "string",
    "flags": [
      {
        "fact": "string",
        "id": "not_erc20",
        "severity": "info"
      }
    ],
    "level": "low",
    "liquidity": {
      "pools": [
        {
          "dex": "string",
          "fee": 0,
          "pool": "string",
          "quote": "WETH",
          "quoteReserve": "string",
          "quoteReserveUsd": "string",
          "tokenReserve": "string"
        }
      ],
      "quoteLiquidityUsd": "string",
      "scope": "string",
      "wethPriceUsd": "string"
    },
    "name": "string",
    "riskScore": 0,
    "source": "string",
    "summary": "string",
    "symbol": "string",
    "token": "string"
  },
  "type": "string"
}

Examples

curl

curl "https://base-facts.yankii.fr/v1/verdict"
# -> 402 Payment Required, accepts[] lists how to pay
# retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid

JavaScript

const res = await fetch("https://base-facts.yankii.fr/v1/verdict");
if (res.status === 402) {
  const { accepts } = await res.json();
  // pay one of accepts[] via an x402 client, then retry with the payment header
}

Python

import httpx
res = httpx.get("https://base-facts.yankii.fr/v1/verdict")
if res.status_code == 402:
    accepts = res.json()["accepts"]
    # pay one of accepts[] via an x402 client, then retry with the payment header

Details

Provider: base-facts.yankii.fr
Endpoint: https://base-facts.yankii.fr/v1/verdict
Machine-readable: /resources/35736.json