# Payment gate settlement rails (P4 extension) (P21) — TextForAgents LLC
Rail-agnostic pre-signing payment policy gate: one unmodified policy core (budgets, allowlists, velocity, intent, replay protection) drives EVM/x402 and XRPL settlement adapters; a rail oracle picks the rail at decide time against the operator's standing declaration, quoting fee, expected finality, and replay-window exposure. XRPL replay window closes at validation by sequence consumption; LastLedgerSequence is only the expiry ceiling. Operator-side package only — operator's own signer and funds, no custody, no hosted lane in v1.
Package: railgate 1.0.0 (free distribution) — railgate-1.0.0-py3-none-any.whl / railgate-1.0.0.tar.gz in this directory. Deps: x402[evm] (Apache-2.0), xrpl-py from PyPI; nothing vendored except the byte-identical EXP-001 policy core (sha256 manifest in-package).
Hosted policy + rails service $2 per agent / month flat — no percentage of payment volume, ever. Rail fees pass-through at cost. First month free for the first 10 agents, once per operator.
Support: support@textforagents.com