mcp

PipRail

Budget-bound x402 payment wallet for AI agents — pays HTTP 402 URLs, capped locally. No backend.

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Package Details

@piprail/mcp

0.9.0•https://www.npmjs.com/package/@piprail/mcp

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Environment Variables

PIPRAIL_PRIVATE_KEY(str)

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(str)

Chain to pay on (default: base).

PIPRAIL_CHAINS(str)

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(str)

Max spend per single payment, in token units (default: 0.10).

PIPRAIL_MAX_TOTAL(str)

Lifetime spend cap per token, in token units (default: 10.00).

PIPRAIL_MAX_TOTAL_DENOM(str)

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(str)

Lifetime cap on the NUMBER of payments, across every chain + token (e.g. 100).

PIPRAIL_MAX_PAYMENTS_PER_WINDOW(str)

Cap on the number of payments within PIPRAIL_WINDOW_SECONDS (a rolling rate limit; set PIPRAIL_WINDOW_SECONDS too).

PIPRAIL_WARN_AT_FRACTION(str)

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(str)

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(str)

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(str)

Comma-separated allowed token symbols, plus the alias 'native' for the chain's coin (default: USDC).

PIPRAIL_SCHEMES(str)

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.