tryx402 — the gateway behind tryx402.app

A safe, provider-agnostic wrapper over AgentCash / x402. Not limited to prospecting — it drives any endpoint, and adds what AgentCash itself lacks and we learned we need the hard way:

• hard budget caps — stop before overspending
• idempotency — never pay twice for the same call (the $0.83 double-charge lesson)
• cost ledger — USD spent, reconciled, grouped by origin / account
• multi-currency billing + margin — end users pay in THEIR currency (EUR, USD, GBP, JPY…), never touch the wallet

Two faces, one engine

Prospecting (../prospect_relay) is just one application on top of this core.

Embed it (for agents)

Python — one import:

from gateway import Gateway
gw = Gateway(max_budget_usd=1.0)               # safe by default
data = gw.call("https://stable-deepline.dev/api/email/validate",
               body={"email": "x@y.com"}, price=0.03)
print(gw.spent_usd)                            # 0.03

Terminal — one command (like agentcash), after pip install -e .:

gateway call https://stable-deepline.dev/api/email/validate \
  --body '{"email":"x@y.com"}' --price 0.03 --max-budget 0.10

MCP — the agent-native form (like AgentCash's own MCP, zero dependencies):

{
  "command": "python3",
  "args": ["-m", "gateway.mcp_server"],
  "env": { "GATEWAY_MAX_BUDGET_USD": "1.00" }
}

The agent gets four tools — gateway_search, gateway_discover, gateway_call (budget-capped, idempotent), gateway_spent — sharing one session-wide budget and cost ledger across every call.

Layout

gateway/
├── client.py    # SafeClient: any endpoint + budget + idempotency + timeout + ledger
├── ledger.py    # cost events, USD/EUR totals, by-origin / by-account
├── catalog.py   # search(intent) / discover(origin) over the AgentCash catalogue
├── accounts.py  # per-currency balances (integer minor units), margin, authorize/charge — Stripe stub
├── cli.py       # power-tool CLI (drives both faces)
└── tests/       # offline: budget, idempotency, EUR billing (no spend)

Use

Discover (free — no payment):

python3 -m gateway.cli search "find work email"
python3 -m gateway.cli discover https://stable-deepline.dev

Call any endpoint safely (spends USDC — budget-capped, idempotent):

python3 -m gateway.cli call https://stable-deepline.dev/api/email/validate \
  --body '{"email":"foo@bar.com"}' --price 0.03 --max-budget 0.10

Run it as a fiat gateway — the caller pays in their own currency, never sees the wallet:

python3 -m gateway.cli account create acme --currency GBP --margin 0.30
python3 -m gateway.cli account fund acme --amount 20            # 20 GBP — Stripe stub
python3 -m gateway.cli call https://stable-deepline.dev/api/email/validate \
  --body '{"email":"foo@bar.com"}' --price 0.03 --account acme
#  -> billed 0.04 GBP to acme (margin 30%, balance 19.96 GBP)

Provider cost stays in USD (the rail settles in USDC); each account is billed in its own currency via FxRates (a stub table today — wire a live FX feed in prod). Non-2-decimal currencies (JPY, KWD…) are handled.

What's real vs stubbed

• Real: the safe caller, budget cap, idempotency, cost ledger, multi-currency/margin math (integer minor units), catalogue search/discover.
• Stubbed: funding an account (fund_eur) stands in for the Stripe webhook. Wire real Stripe → call fund_eur on checkout.session.completed. Everything downstream already works.
• Deliberately off: auto-retry of paid calls (default max_retries=0) — retrying a possibly-paid call is what double-charged us; opt in only if the server honors the Idempotency-Key header.