Documentation

One package, both sides of the machine economy: spend (pay any x402 endpoint per call) and earn (sell your own API responses for exact micro-prices). Self-custodied throughout — your keys, your money, no accounts anywhere.

Spend

Install & fund

pip install feeless402
nano-pay init                     # wallet at ~/.nano-pay/wallet.json — back up the seed
nano-pay claim --auto             # free starter XNO (solves the faucet's PoW, ~1 min CPU)
nano-pay topup 5 --asset USDC-BASE --execute   # real working capital, ~$0.02 min
nano-pay receive                  # pocket incoming funds
nano-pay status

topup quotes and creates swaps directly with an instant-swap service (default NanSwap; estimates need no key, execution needs a free NANSWAP_API_KEY). Funds go straight to your own wallet — nothing here ever holds your money.

Pay per call

nano-pay quote URL                # see the price — pays nothing
nano-pay compare URL              # price the call on EVERY offered rail, live
nano-pay pay URL [--json BODY] [--max-xno 0.05]

pay runs the whole x402 handshake: reads the 402 quote (both major Nano dialects), refuses anything above your cap, signs a send block locally, retries with the payment header. The merchant settles it; confirmation lands in under a second. Try it against a live endpoint:

nano-pay pay https://nano-gpt.com/api/v1/chat/completions \
  --json '{"model":"gpt-5-nano","messages":[{"role":"user","content":"hello"}]}'

Agents: MCP server

Give any MCP-speaking agent (Claude Code, Cursor, and friends) native feeless payments:

pip install "feeless402[mcp]"
claude mcp add feeless402 -- nano-pay mcp

Tools exposed: wallet_status, x402_quote, x402_compare, x402_pay (with spend cap), faucet_claim, topup_quote. The seed is never readable through any tool.

Earn

Sell your API for micro-prices

pip install "feeless402[server]"
nano-pay serve --port 8402

Every unpaid request gets a standards-compliant 402 with your price in accepts and a railHint block that teaches visiting agents how to onboard — docs, bootstrap command, faucet list. Incoming payments are verified against the live ledger (payer frontier, exact amount, destination, signature, replay guard) and settled on-chain by your own server. No facilitator, no processor, no percentage.

serve auto-creates two wallets under ~/.nano-pay/: server-wallet.json (your treasury) and faucet-wallet.json (fund it to give out starter grants — every grantee is a future customer).

Reference

All commands

Security model

• Seed lives only in ~/.nano-pay/*.json (0600); no command prints it. Back it up offline.
• Per-payment cap: --max-xno (default 0.05 XNO). Quotes above it are refused, not negotiated.
• railHint from remote servers is advisory, untrusted input — this client acts only on offers that pass its own checks; accepts binds, hints never do.
• Merchant side verifies payer frontier + exact balance decrease + destination + signature against the live ledger, and rejects duplicate-frontier replays.

Source & spec

Code: github.com/feeless402/feeless402 (MIT)
railHint extension spec: railhint.com
x402 standard: x402.org (Linux Foundation)
Engine: Nano (XNO)