# Raxol Payments

Agent payment protocols for Elixir. Autonomous agents that can pay for things: x402/MPP auto-pay, Xochi cross-chain intents, stealth addresses, ZKSAR attestation, Xochi Mandate delegation, spending controls.

## Install

```elixir
{:raxol_payments, "~> 0.1"}
```

## Features

- **Protocol behaviour**: five pluggable payment protocols (x402, MPP, Xochi, Permit2, Riddler). Riddler is deprecated and delegates to Xochi.
- **Wallet behaviour**: `Wallets.Env` (env var, refuses to load in production without opt-in) and `Wallets.Op` (1Password via GenServer, key cached and signed with locally)
- **AutoPay**: Req response step handling HTTP 402 transparently
- **Xochi**: cross-chain intent settlement (quote -> sign -> execute -> poll)
- **Permit2**: `PermitWitnessTransferFrom` signing for Riddler `/order` origin pulls (most ERC-20 tokens; x402 covers USDC via ERC-3009)
- **Stealth**: ERC-5564/ERC-6538 stealth addresses (~300 LOC, secp256k1)
- **ZKSAR**: zero-knowledge attestation verification (6 proof types)
- **TrustScore**: diminishing-returns trust aggregation (0-100)
- **PrivacyTier**: Glass Cube model (6 tiers, attestation-gated)
- **Router**: auto-select protocol based on chain, privacy, trust score
- **SpendingPolicy + Ledger**: per-request/session/lifetime spending limits
- **PXE Bridge**: Aztec Private eXecution Environment client (JSON-RPC 2.0)
- **Mandate**: Xochi delegation envelopes (per-request EIP-712 auth, agent inherits Member's tier). Verified byte-for-byte against viem's `hashTypedData`. See `Raxol.Payments.Mandate`, `Mandate.Store`, `Req.Mandate` plugin, and the `payment_create_mandate` / `payment_list_mandates` / `payment_revoke_mandate` agent actions.

## Quick Start

```elixir
alias Raxol.Payments.{Router, Req.AgentPlugin}

# Router auto-selects protocol
Router.select(cross_chain: true)  # => :xochi
Router.select(privacy: :stealth)  # => :xochi
Router.select()                   # => :x402

# Wire auto-pay into agent HTTP backend
plugin = AgentPlugin.auto_pay(
  wallet: Raxol.Payments.Wallets.Env,
  ledger: ledger_pid,
  policy: SpendingPolicy.dev(),
  agent_id: :my_agent
)
```

## Examples

A guided path from an offline rehearsal to a real on-chain settlement lives in
[`examples/`](examples/README.md): `preflight.exs` (local echo server, no funds)
-> `crosschain_stealth_payment.exs` (in-process Xochi sim, no funds) ->
`run_live_xochi_gate.sh` (live cross-chain settlement, real funds). Start with
the README there.

## Relay (Tron) gasless pull

The Relay rail (`Raxol.Payments.Relay`, `actions/payments/execute_relay_transfer`)
has two EVM->Tron funding paths: **gasless (A)** -- sign the quote's `gasless`
typed-data block, the signature rides on `/relay/execute`, no broadcast -- and
**broadcast (B)** -- an on-chain transfer to the `deposit_address`.

Path A is delivered on the Riddler side (axol-io/Riddler#120, PR #160):
`POST /relay/quote` returns a Permit2 `gasless` block for EVM->Tron when the solver
runs with `RELAY_GASLESS_PULL_ENABLED=true`. The client already signs it and plumbs
the signature, so no raxol change is needed -- the `execute_relay_transfer`
moduledoc "Pending Riddler support ... #120" note can be cleared. Caveats:

- Permit2 only (USDC + other ERC-20s); ERC-3009 is deferred (axol-io/Riddler#159).
- Riddler's `/relay/*` surface is still production-gated, so the flag stays off
  until that unblocks; path B (broadcast) remains the working route meanwhile.

## Architecture

- `Raxol.Payments.Protocol`: behaviour for payment protocol detection + signing
- `Raxol.Payments.Wallet`: behaviour for key management
- `Raxol.Payments.Router`: protocol selection + settlement routing
- `Raxol.Payments.PrivacyTier`: trust score to tier mapping
- `Raxol.Payments.Zksar`: attestation proof verification
- `Raxol.Payments.Xochi.Stealth`: ERC-5564/6538 implementation
- `Raxol.Payments.Mandate`: Xochi delegation envelope (EIP-712-signed, per-request)
- `Raxol.Payments.Mandate.Store`: singleton ETS + optional DETS holder for envelopes
- `Raxol.Payments.Req.Mandate`: Req plugin attaching `X-Xochi-Delegation` on outbound Xochi calls

See [Agentic Commerce docs](../../docs/features/AGENTIC_COMMERCE.md) for the full design.