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Open banking routing and electronic invoicing — live across 30 countries. Routing · invoicing · 30 countries See coverage
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AI

Usage-based AI billing —
without forcing every customer onto cards.

AI platforms bill credits, seats, and metered inference. Cards add interchange on low-margin API businesses and fail on enterprise bank-transfer preferences. StixBNK unifies API collections and invoicing payment links on open banking rails — sandbox first, KYB for live keys, settlement in fiat or USDC on T+5.

Talk to sales Get API keys
API + links Same stack for checkout and invoices
Webhooks Normalised events per collection
Sandbox Test keys before KYB completion
T+5 Payout in fiat or USDC

The problem

Why ai merchants leave card rails.

01

Interchange erodes API margins

A $29 credit pack with 2.9% card pricing loses $0.84 to interchange before compute costs. At 50,000 packs/month, that is $42k/month in scheme fees on low-ARPU transactions.

02

Enterprise buyers blocked from cards

Fortune 500 procurement policies forbid AI spend on corporate cards. Finance wants bank transfer with PO numbers — your self-serve checkout only accepts Visa.

03

Two integrations for checkout vs. billing

Engineering maintains one PSP for in-app credit top-ups and another for monthly usage invoices. Duplicate webhook schemas double reconciliation work.

Payment flow

How StixBNK handles ai checkout

  1. 01

    Sandbox integration

    Ship against test keys while KYB runs. Same API for credit top-ups and invoice links — one webhook schema from day one.

  2. 02

    Collection with workspace reference

    Billing system POSTs amount, currency, and workspace ID (e.g. WS-8842). Reference appears in payer's bank app for enterprise audit trails.

  3. 03

    Payer completes bank SCA

    Hosted checkout or emailed payment link — payer selects bank, authorises via PSD2 or ACH. No card number in your infrastructure.

  4. 04

    Credits or invoice marked paid

    Webhook triggers credit ledger update or closes invoice in your billing system. Metered usage continues uninterrupted for enterprise accounts.

  5. 05

    T+5 settlement

    Platform receives payout in fiat or USDC on T+5. Finance exports one reconciliation line per collection with workspace ref intact.

Self-serve credits

Developer top-up — $500 inference credits

An AI code-assistant sells credit packs from $29 to $500. Indie developers prefer bank debit; card interchange on $29 packs makes unit economics tight.

  1. Developer selects $500 pack in billing settings; collection WS-DEV-9912 for $500.
  2. Pay by bank → selects Revolut Business; SCA in app with workspace ref visible.
  3. Webhook authorised → 500 credits added in 8 seconds; API keys stay active.
  4. No PAN stored; PCI scope stays minimal on developer-facing billing pages.

Outcome: Credit top-up completion improves for EU/UK developers. Interchange savings reinvested into compute bounties instead of scheme fees.

Enterprise usage invoice

Monthly bill — $47,200 with payment link

An enterprise LLM platform bills a Fortune 500 client for December metered usage. AP requires bank transfer with PO-2026-AI-441 on the remittance.

  1. Billing system generates invoice INV-AI-1225 for $47,200 with embedded pay link.
  2. Client AP opens link, selects corporate bank, authorises ACH with PO ref in banking portal.
  3. Webhook confirms → invoice closed, usage caps lifted for January.
  4. Same routing layer as self-serve checkout — one integration, one webhook contract.

Outcome: Enterprise DSO drops from 28 days to 3 days on bank-first accounts. Engineering maintains one payment integration for PLG and sales-led revenue.

Stack

Products ai teams run on

01

Open banking routing

Credit top-ups and in-app checkout — REST API, sandbox keys, and market-aware routing for global AI teams.
02

Invoicing & payment links

Metered usage invoices with hosted pay links — enterprise AP pays from business bank with structured references.
03

Data enrichment

Enrich payment events with payer bank metadata for billing analytics and enterprise reconciliation exports.

FAQ

Common questions from ai operators

Can we test before KYB is complete?

Yes. Sandbox keys let you run checkout and invoice flows end-to-end with simulators. Live routing activates after KYB approval — same API contract throughout.

One webhook schema for credits and invoices?

Exactly. Whether the payer started from API checkout or an emailed invoice link, status events share the same normalised schema — one reconciliation pipeline.

Do enterprise clients accept Pay by bank?

Many prefer it. Finance teams want bank debit with PO references for audit — A2A gives them a one-click path instead of manual wire instructions.

Wire open banking into your AI billing stack.

Get API keys