ProvenPaid

provenpaid-mcp

Give your agent a pre-payment check for paid x402 endpoints. Evidence before you pay.

ProvenPaid checks an x402 endpoint before your agent relies on it: is its payment challenge valid, and do real wallets actually pay it on-chain, come back, and how concentrated are payments? This MCP server exposes that check as a tool. The first 10 checks are free, with no wallet and no setup. After that it pays automatically, about $0.01 in USDC on Base per check, from a wallet you control.

Use it once before relying on an unfamiliar endpoint, not before every call.

Tools

Tool	Cost	What it does
check_x402_endpoint(url)	first 10 free, then about $0.01	Validates the endpoint's x402 challenge and reports public on-chain evidence for its receiving address: distinct payers, repeat-payer share, payer concentration, coverage.
provenpaid_methodology()	free	How each signal is computed, what is not verified, and when a check is charged.
provenpaid_status()	free	Free checks left, paying wallet address, network, price cap and paid checks left today.

You are not charged when the URL is invalid or unsafe, is not an x402 endpoint, or offers no payment option in USDC on Base. Results are evidence, not a verdict: ProvenPaid does not verify service quality or that an endpoint controls its receiving address.

Install

Requires Python 3.11+. With uv:

uvx provenpaid-mcp

or pip install provenpaid-mcp.

Try it free (no wallet)

{
  "mcpServers": {
    "provenpaid": { "command": "uvx", "args": ["provenpaid-mcp"] }
  }
}

On first run it creates a local identity key (~/.provenpaid-mcp/identity.key, owner-only). The key holds no funds; it only lets ProvenPaid count your 10 free checks. Only checks that return evidence count.

Keep going after the free checks

Add a dedicated, low-balance wallet:

{
  "mcpServers": {
    "provenpaid": {
      "command": "uvx",
      "args": ["provenpaid-mcp"],
      "env": {
        "PROVENPAID_WALLET_PRIVATE_KEY": "0x...",
        "PROVENPAID_DAILY_LIMIT": "20"
      }
    }
  }
}

Wallet safety

• Use a dedicated wallet holding only a few dollars of USDC on Base. Never use a wallet with meaningful funds.
• The key stays on your machine, in memory only. It is never logged, returned by a tool, or sent anywhere; only signed payment authorizations leave the process.
• No ETH is needed: the payment facilitator pays network fees.

Guardrails enforced before anything is signed:

Setting	Default	Meaning
PROVENPAID_MAX_PRICE_USD	0.01	Refuse any check priced above this (hard ceiling 0.10).
PROVENPAID_DAILY_LIMIT	20	Maximum paid checks per UTC day, persisted across restarts.
PROVENPAID_NETWORK	eip155:8453	Pay only on this network, only in its USDC. eip155:84532 for Base Sepolia testing.
PROVENPAID_API_URL	https://api.provenpaid.com	Must be https.
PROVENPAID_STATE_DIR	~/.provenpaid-mcp	Where the daily counter is kept.

How it works

The server calls GET https://api.provenpaid.com/v1/check?url=.... The API answers HTTP 402 with x402 payment requirements; the official x402 SDK signs a single-use USDC authorization within the guardrails above and retries. Settlement happens only when the check delivers evidence. Methodology: https://api.provenpaid.com/methodology

License

MIT