MCP tool-list token cost
What an MCP server's tool list costs in every model request: tokens, dollars per 1,000 requests and the heaviest tools, against 18,204 packages HISTOR observes.
You paste: a server address or a tools/list
Open the check →Paste it. Get a diagnosis.
Five browser checks for MCP tool lists and x402 payments. No account or wallet is required. Four checks also have x402 endpoints that accept USDC on Base.
x402 payment check
Why a USDC transferWithAuthorization reverts: the signer, the token domain, the window and the seller's terms — and the domain a failing signature was really made for.
You paste: an X-PAYMENT header
Open the check →MCP rug-pull diff
Two tools/list results of one server — the one you approved and today's. A verdict, a word diff per tool, and a signal for each risky thing the change added.
You paste: two tools/list results
Open the check →MCP tool scan (WARDEN)
One tools/list. WARDEN, the open-source MCP firewall, checks every name, description, schema and annotation for prompt injection, exfiltration and credential theft.
You paste: a tools/list result
Open the check →MCP server history (HISTOR)
A server's address or registry name. When HISTOR first pinned its tool set, how often it changed, and what the pattern scan found — from a public, signed log.
You paste: a server address
Open the check →Checked by someone else
vet402 is an independent service that pays x402 sellers and publishes what each paid call returned. Its current record for the paid routes of this site:
Find public sensors near a point
ATLAS nearby sensors API · x402 · $0.03 per call
How the checks work
Rules and cryptography
Checks use explicit rules, published observations or signature verification, depending on the input.
Signed
The x402 and diff answers carry an Ed25519 signature of our HESTIA runtime; HISTOR signs its own.
Optional x402 access
Four of these checks are available over x402 with per-call pricing.