npm · @piprail/mcp
$npx -y @piprail/mcp@0.10.0 PIPRAIL_PRIVATE_KEY · secret — Your wallet's private key/seed for the chosen chain. Optional: omit it to run read-only (discover/quote/register/budget/guide); set it to let the agent pay. Stays on your machine; the spend policy caps every payment.
PIPRAIL_CHAIN — Chain to pay on (default: base).
PIPRAIL_CHAINS — Pay across several chains (instead of PIPRAIL_CHAIN): a comma-separated list, e.g. base,polygon,solana. Give each its own PIPRAIL_<CHAIN>_KEY (+ optional PIPRAIL_<CHAIN>_RPC_URL). The agent pays whichever chain a 402 asks for — the first listed that can settle — under one shared budget.
PIPRAIL_MAX_AMOUNT — Max spend per single payment, in token units (default: 0.10).
PIPRAIL_MAX_TOTAL — Lifetime spend cap per token, in token units (default: 10.00).
PIPRAIL_MAX_TOTAL_DENOM — Cross-token GRAND TOTAL: one spend cap per denomination across every stablecoin and chain, e.g. USD:20.00,EUR:5.00. Not a price oracle — sums tokens of the same unit, each counted 1:1. Native coins are excluded.
PIPRAIL_MAX_PAYMENTS — Lifetime cap on the NUMBER of payments, across every chain + token (e.g. 100).
PIPRAIL_MAX_PAYMENTS_PER_WINDOW — Cap on the number of payments within PIPRAIL_WINDOW_SECONDS (a rolling rate limit; set PIPRAIL_WINDOW_SECONDS too).
PIPRAIL_WARN_AT_FRACTION — Emit an early-warning event when spend crosses this fraction of any cap, e.g. 0.8 (80%). Needs PIPRAIL_EVENT_LOG to be visible.
PIPRAIL_SPEND_LOG — Path to a local append-only spend log. When set, the budget (lifetime, grand total, counts) SURVIVES a restart — hydrated from this file. No backend; you own the file.
PIPRAIL_EVENT_LOG — Mirror payment events (settled / declined / budget-threshold) as one-line JSON to 'stderr' or a file path — the operator's notification stream. Default: off.
PIPRAIL_TOKENS — Comma-separated allowed token symbols, plus the alias 'native' for the chain's coin (default: USDC).
PIPRAIL_SCHEMES — Comma-separated payment schemes to settle (default: onchain-proof). Add 'exact' (onchain-proof,exact) to also pay standard x402 servers GASLESS on EVM + Solana (method auto-selected). Add 'upto' to also pay metered x402 servers on EVM (Permit2): sign a MAX, the server settles the actual <= max.