railgate — payment gate settlement rails (P21)

By TextForAgents LLC · Support: support@textforagents.com · Product page: https://textforagents.com/products/payment-gate-settlement-rails/

A pre-signing payment policy gate for agents that settles on more than one rail. One unmodified policy core (budgets, counterparty allowlists, velocity, intent, replay protection — every decision receipted, every refusal structured) drives swappable settlement adapters behind one interface:

• EVM / x402 — EIP-3009 exact scheme authorizations via a facilitator.
• XRPL — Payments whose replay window closes at validation by protocol sequence consumption; LastLedgerSequence is only the expiry ceiling.

A rail oracle picks the rail at decide time against your standing rail declaration (pinned / cheapest / fastest finality / minimum replay exposure, with fee and finality caps). Rail choice is a policy decision and is receipted with the payment. If the settled fee disagrees with the quote that justified the choice, the outcome is flagged QUOTE_MISMATCH.

Operator-side only. Settlement runs through your signer and your funds. This package never custodies funds or keys, and v1 has no hosted or multi-tenant mode. The adapters shipped here are test doubles encoding each rail's published settlement semantics; railgate.live adds a read-only live-testnet path (ServerInfo / AccountInfo) — it never signs or submits.

Install

pip install railgate-1.0.0-py3-none-any.whl   # or from the sdist

Dependencies: x402[evm] (>=2.25,<3, Apache-2.0) and xrpl-py — both are ordinary PyPI dependencies; no third-party code is vendored into this wheel. The vendored EXP-001 policy core is included (policy_gate/) and is byte-identical to the proven originals — verify after install:

cd $(python -c "import policy_gate,os;print(os.path.dirname(policy_gate.__file__))") && sha256sum -c MANIFEST.sha256

Quickstart

import time
from policy_gate import PaymentPolicy, PolicyGate
from railgate import RailGate, RailDeclaration
from railgate.adapters import EvmX402Adapter, XrplTestnetAdapter

clock = time.time
adapters = {}
for cls in (EvmX402Adapter, XrplTestnetAdapter):
    a = cls(clock); adapters[a.rail] = a

policy = PaymentPolicy.from_dict({
    "per_call_cap_atomic": 1_000_000, "session_budget_atomic": 5_000_000,
    "daily_budget_atomic": 20_000_000, "per_counterparty_cap_atomic": 10_000_000,
    "allowed_networks": [a.network for a in adapters.values()],
    "allowed_assets": [a.asset for a in adapters.values()],
    "counterparty_allowlist": [a.pay_to for a in adapters.values()],
    "max_payments_per_window": 30, "window_seconds": 60,
    "replay_window_seconds": 300, "intent_required": True, "asset_decimals": 6,
})
gate = RailGate(PolicyGate(policy, "/tmp/spend.db", clock=clock), adapters)
gate.declare_intent("buy weather data")
out = gate.pay(amount_atomic=100_000,
               resource_url="https://api.example.test/weather",
               declaration=RailDeclaration(mode="cheapest"))
print(out.status, out.rail, out.receipt)   # settled xrpl-testnet {...}

# Live testnet read (read-only; no submission, no funds):
from railgate import xrpl_server_info
print(xrpl_server_info())

Pricing

The adapter package is free (distribution). The hosted policy + rails service is $2 per agent / month flat — no percentage of payment volume, ever; rail fees (e.g. XRPL ~$0.0002/tx) pass through at cost. First month free for the first 10 agents, once per operator. See the product page.

License

MIT for this package's own code (see LICENSE). The x402 dependency is Apache-2.0 — see THIRD-PARTY-NOTICES.md.