Base Token Facts
Base token checks for agents: simulated buy and sell, taxes, honeypots. Pay per call in USDC (x402).
Runs on your machine from its package; the steps are below.
What it does
- Reads
- Writes
- High impact
Not assessed yet.
What it costs
FreeOdel charges nothing per call. The publisher may charge for its own service.
Runs locally over stdio
This server isn't hosted — your MCP client launches it from a package registry. Use one of the commands below, or drop the config into your client (e.g. Claude Desktop).
Run
npx -y base-facts-mcp
MCP client config
{
"mcpServers": {
"base-token-facts": {
"command": "npx",
"args": [
"-y",
"base-facts-mcp"
]
}
}
}base-facts-mcp
An MCP server for AI agents that trade or move money on Base. Each tool calls Base Token Facts and pays for the call itself in USDC over x402, from a small wallet you control. Every answer is read at one block and says which.
| Tool | Price | Answers |
|---|---|---|
base_token_verdict | $0.01 | Before buying a token: risk level, score and flags (proxy, mint, pause, blacklist, owner, DEX liquidity), each with its on-chain fact |
base_token_sellcheck | $0.005 | Honeypot and tax check: simulates a small buy and immediate sell on the deepest pool, returns buy/sell tax, round-trip loss |
base_token_sellcheck_size | $0.01 | The same check at your trade size (amountEth, 0.001 to 10 ETH): tax, round-trip loss, buy price impact and a depth warning when the size is larger than the pool can absorb |
base_token_facts | $0.005 | ERC20 metadata, owner, proxy and implementation, admin selectors in the bytecode |
base_wallet_snapshot | $0.002 | ETH and USDC balances, nonce, contract or not |
base_gas | $0.001 | Base fee, priority fee, gas price |
base_tx_summary | $0.003 | Status, fee and decoded ERC20 transfers of a transaction |
basename_resolve | $0.002 | name.base.eth to address, or address to its verified primary Basename |
base_facts_budget | free | What this session has spent |
Facts and heuristics, not financial advice. API docs and live revenue counter: https://base-facts.yankii.fr and https://base-facts.yankii.fr/stats
Setup
- Make a dedicated wallet and put a little USDC on it, on the Base network (1 USDC pays for 100 verdicts). No ETH is needed: the x402 facilitator pays the gas. Never use your main wallet.
- Add the server to your MCP client, for example
claude_desktop_config.json:
{
"mcpServers": {
"base-facts": {
"command": "npx",
"args": ["-y", "base-facts-mcp"],
"env": {
"X402_PAYER_FILE": "/path/to/payer.json",
"MAX_PRICE_USD": "0.02",
"SESSION_BUDGET_USD": "1"
}
}
}
}
payer.json is { "privateKey": "0x..." }; X402_PRIVATE_KEY works too. Without either, the server
uses ~/.base-facts-mcp/payer.json when it exists.
Every setting also exists as an option, for hosts that pass only command and args (Preste):
--payer-file <path>, --max-price <usd>, --budget <usd>, --api <url>. See
integrations/preste/ for the Preste config and skill.
Spending safety
MAX_PRICE_USD(default 0.02): the client refuses to sign any single payment above it.SESSION_BUDGET_USD(default 1): once reached, the client stops signing until restarted.- Only USDC on Base (
eip155:8453) is ever signed. - A refused or failed call (4xx/5xx) cancels the settlement: you are not charged, and the tool says
charged: falsewith the reason (for example not enough USDC). - Paid calls run one at a time so the budget count stays exact.
Development
npm test drives the server over stdio like a real client, with empty wallets: no USDC is spent.