Build, Own, Scale.
Don't Rent.

The infrastructure map to power any regulated company that moves money — merchants, SaaS, fintechs, banks

When you outgrow Stripe or Adyen, you face a maze of 200+ providers across 21 layers. STACKS maps who does what, what it costs, and what you actually own. V33: fiat and crypto have merged — the schemes launched their own stablecoin, MiCA is enforced, GENIUS rules land July 18. New suppliers, agents and workflows every day. Built from 8+ years operating inside the stack—not from vendor decks.

WHO BUILDS ON THE STACK
Merchant
E-com · Retail
Platform
Marketplace · SaaS
Fintech
Neobank · Wallet
Enterprise
B2B · Treasury
↓ Relies On
21 BUILDING BLOCKS
0 3 4 6 7 9 10 11 12 13
Acquiring · Vault · Route · Stablecoin · Agentic · Credit · Insurance
↓ Managed By
ADMIN BLOCKS
📊 Data
Analytics · BI
⚙️ Ops
Refunds · Disputes
🔄 Recon
Settlement · Ledger
⚡ V33 — The Merge: Fiat × Crypto × Agents Is One Stack Now

The argument is over. Visa, Mastercard, Stripe, Coinbase and BlackRock launched a consortium stablecoin (OUSD, Jun 30). MiCA is enforced — 244 licensed CASPs survived, ~83% of the old register is gone. GENIUS final rules land Jul 18: stablecoin issuance becomes a chartered banking category. Google UCP won agent-commerce round one. 30+ MCP servers across every layer. One regulated stack — look for the 🤖 MCP badge.

30+ MCP servers live
~$1B Stripe buys Metronome — billing consolidates
UCP won round 1 — Shopify · Walmart · Stripe
140+ companies in the OUSD consortium
$320B stablecoin supply — record
Fiat × Crypto merged — 244 CASPs standing
📼 The Tape — what moved, and the read
DATED FACTS · NO VENDOR SPIN · UPDATED JUL 10
JUL 18GENIUS final rules land. Stablecoin issuance becomes a chartered banking category. → Stop asking which crypto company to trust; ask which of your banks will issue.
JUL 1MiCA grandfathering ends: 244 CASPs licensed, ~83% of the register gone. → Audit every crypto vendor for a license this week (L10.5).
JUN 30OUSD: Stripe, Visa, MC, Coinbase, BlackRock + 140 launch a consortium stablecoin. Circle −17%. → The neutral-issuer premium is dead; design every flow multi-issuer.
JUN 17Shopify makes UCP self-serve; Adyen ships a protocol translator. → The protocol war ends in translation — expose UCP first, translate the rest.
JUN 11Nuvei buys Payoneer ($2.75B). Acquiring + payouts, one counterparty. → Reprice your concentration risk; keep disburse multi-vendor.
JUNBilling consolidation completes: Stripe×Metronome (~$1B), Adyen×Orb ($335M), Salesforce×m3ter. → Your processor now meters your margins. Self-host (Lago) or accept it knowingly.
MAY 27SoFiUSD live to 15M retail users. First national-bank stablecoin at consumer scale. → The bank-issued wave is here; L10.1 is filling with charters, not startups.

What Are You Trying To Solve?

Pick your issue. We'll highlight the building blocks that matter.

💰
Improve Margins
Move from ~2.9% to IC++ (~1.2%)
L4 → L5 → L6
📊
Own Your Data
Raw auth codes, proprietary models
L3 → L5 → L8
🔐
Own Your Tokens
No PSP lock-in, portable PANs
L4 → L6
🏦
Own Financial Products
Cards, wallets, accounts, stablecoins
L7 → L10.1
📒
Own Your Ledger
Real-time balances, multi-currency, crypto
L7 → L10
🛡️
Own Your Compliance
MiCA enforced, GENIUS, DORA, PSD3
L3 → L10.5 → Backbone
📜
Get Licensed
Agent → EMI → PI → Bank
L3 → L5 → L7
🚀
New Rails Readiness
A2A, stablecoins, 24/7 settlement
L2 → L10.3
🤖
Sell to Agents
UCP/ACP endpoints, agent trust, KYA
L3.4 → L11.1 → L11.4
🔌
MCP Providers
30+ agent-ready APIs across the stack
L2 → L3 → L6 → L7 → L9 → L10
🧾
Monetize & Bill Right
Metering got bought: Stripe, Adyen, Salesforce
L0.1 → L8
⚠️
Survive Your Vendors
Parker, Synapse, Treezor — exit plans
L7 → L10.2 → L10.5
🔄
Show All Layers
Reset filter

The Complete Payment Stack

Click any block to explore providers. From bundled PSPs to agentic commerce.

MATURE Production-ready GROWING Rapid adoption 2025 Major updates AT TABLE In protocol working groups
Surface Layer — The Bundled Starting Points
Core Stack — Build Your Own
L2
Accept
Payment methods
AllShow all
Local APMsiDEAL, BLIK, etc.
BNPLBuy Now Pay Later
A2A / Open BankingBank transfers
CryptoStablecoin accept
Coverage
local methods
L3
Risk, Identity & Compliance
Fraud, Auth, KYC, Disputes
AllShow all
FraudML + guarantee
IdentityAuth + verification
KYC / KYBOnboarding
DisputesChargebacks
AMLSanctions
Own Risk
or outsource
Sardine vs Forter in Agentic: Sardine = AI agents automate YOUR fraud ops (internal). Forter TACP = authenticate EXTERNAL AI shopping agents. Different problems, both L3.
L3.4
Agentic Trust & Security V26+
Trust the agent as a transacting entity
AllShow all
Agent TrustAuthentication
Agent SecurityBot discrimination
Agent Trust
new primitive
L7
Ledger, Accounts & Cards
Own the financial products
AllShow all
LedgerSource of truth
BaaS / AccountsIBANs, wallets
Card IssuingDebit, credit
Own Products
wallets, cards, data
L8
Data & Billing
Measure & monetize
AllShow all
Payment AnalyticsIntelligence, data
Usage BillingMetered, consumption
SubscriptionRecurring revenue
Intelligence
& monetization
Embedded Finance — Credit & Insurance
L12
Credit & Funding FIAT × CRYPTO
Lending, capital, treasury — now with on-chain credit
AllShow all
Lending-as-a-ServiceEmbed credit
Credit DecisioningUnderwriting
Funding SourceCapital providers
On-Chain CreditDeFi rails, regulated money
Credit Stack
invisible but complex
Credit Stack Pattern: Funding Source (who provides capital) → Decisioning (who underwrites) → Servicing (who manages loans). Each requires different suppliers. The 2026 twist: the funding source can now be a lending protocol — Coinbase fronts the UX, Morpho is the balance sheet. SocGen proved a regulated bank can do the same. On-chain credit isn't a crypto product anymore; it's a cheaper capital rail with programmable collateral.
L13
Embedded Insurance
Platform + Underwriter
AllShow all
PlatformDistribution/UX
UnderwriterRisk carrier
Coverage
always find both
Stablecoin Infrastructure — GENIUS Act + MiCA REGULATED 2026 FIAT × CRYPTO MERGED
L10.1
Stablecoin Issuance
GENIUS Act (US) + MiCA (EU)
AllShow all
Use ExistingUSDC, USDT, PYUSD
White-LabelIssue your own
Yield-BearingTokenized MMFs
Digital $
$320B supply
Who can use what: SoFiUSD + Bridge = fintechs/merchants can directly use or white-label. Stablecore = bank infrastructure only (plugs into Jack Henry, FIS cores). Merchants go through the bank, not direct API.
L10.3
On/Off-Ramp & Card Issuing
Fiat↔crypto + spend stablecoins
AllShow all
On/Off-RampFiat ↔ Crypto
Crypto Card IssuingStablecoin spend
Accept CryptoMerchant payments
Spend USDC
at 150M+ merchants
Rain = Marqeta for stablecoins: $1.95B unicorn. 200+ partners. Visa Principal Member, omni-chain settlement. Powers Western Union, Nuvei, KAST. The crypto card issuing infrastructure layer.
L10.5
Crypto Compliance & Licensing NEW V33
MiCA enforced · GENIUS live · Travel Rule mandatory
AllShow all
AnalyticsChain intelligence
Travel RuleCounterparty messaging
LicensingCASP, charters
License to Move
244 CASPs standing
Four different problems, four vendors: Chain analytics (who is behind the address) ≠ Travel Rule (mandatory counterparty messaging since Jul 1) ≠ Licensing (CASP / OCC charter / state MTL) ≠ Reserve attestation (GENIUS monthly reports). Every regulated company touching stablecoins needs all four. Most vendors sell one and market four.
Agentic Commerce Infrastructure — AI Payments SHIPPING Q1 2026
How Agent Commerce Actually Works
User Request
👤 Human
"Buy me Nike Air Max size 10"
LLM = The Agent
🤖 Agent
ChatGPT, Claude, Gemini
L11.1 Standards
📡 Protocol
ACP, UCP, AP2
Receives API call
🏪 Merchant
Shopify, Direct API
Processes payment
💳 PSP
Stripe, Adyen
Key insight: Agent sends structured API request. Agent triggers, doesn't navigate. No "checkout page" — just protocol calls.
🔧 MCP is the foundation layer. Anthropic created MCP → Linux Foundation (AAIF). 97M+ monthly SDK downloads. 10K+ active servers. All commerce protocols (ACP, UCP, AP2) build ON TOP of MCP. V33: 30+ payment companies ship MCP servers. Agents don't browse your checkout — they call your stack. Agent-readable AND agent-payable.
L11.1
Protocols & Standards
Rules for AI-initiated transactions
AllShow all
Open ProtocolsStripe ACP, Google AP2
Network ProtocolsVisa, Mastercard
Crypto-Nativex402, KYA
Standards
interoperability
Protocol War Update: ACP (OpenAI/Stripe) vs UCP (Google) vs ATXP (Circuit & Chisel). ChatGPT checkout LIVE with Etsy. Shopify backing all three. x402 at 100M+ payments. Production > announcements.
CROSS-STACK INDEX
🤖 MCP Server Catalog — 30+ Payment APIs, Agent-Ready
Not a layer. A map of every MCP server across the stack. Each entry lives on its home layer above — this is the index.
StripeL2
23 tools. PaymentIntents, refunds, subscriptions, search. LIVE
PayPalL2
Local + Remote. Payments, invoices, disputes, tracking. LIVE
GoCardlessL2 · A2A
Bank payments via natural language. SEPA, BACS, ACH. Feb '26. LIVE
FingerprintL3
Industry-first fraud MCP. Device intelligence for AI agents. Mar '26. LIVE
PagosDATA
Harmonized payments data via chat. Open-source. Feb '26 expansion. LIVE
PayabliL2 · EMBED
Forbes Fintech 50. Embedded payments for vertical SaaS. Agentic workflows. LIVE
AdyenL2
Agentic LLM integration. Google AP2 + UCP partner. PILOT
SquareL2
POS + invoicing. SMB agentic commerce. LIVE
ForterL3 · L3.4
MCP + TACP protocol. Real-time fraud for agents. LIVE
RiskifiedL3 · L3.4
AI Agent Approve (AWS Marketplace). Policy Builder. LIVE
Gr4vyL4
MCP per-tenant. AP2 partner. Checkout bridge. PILOT
VGSL6 · L3.4
Agentic Commerce Toolkit. Tokenized autofill. LIVE
MarqetaL7
Read+write. Virtual cards, spend controls, disputes. LIVE
LithicL7
Read-only. Txns, accounts, balances. Safety-first. LIVE
PlaidL8
Account mgmt, real-time balances, link tokens. LIVE
ChargebeeL8 · MOR
AgentKit MCP. Billing + subscription automation. LIVE
Modern TreasuryL9
ACH, wire, RTP, FedNow via natural language. LIVE
CircleL10.1
USDC ops, micropayments, wallets, x402 integration. LIVE
CoinbaseL10.2
Payments MCP + x402. Wallet, onramp, stablecoins. LIVE
FiptoL10.3
"Stablecoin Sandwich" — fiat in → settle → fiat out. ALPHA
VisaL11.2
visa/mcp + Acceptance Agent Toolkit. APAC + EU. PILOT
MastercardL11.2
Dev Agent Toolkit. Service discovery, API docs. LIVE
PaddleMOR
Subscriptions, pricing, invoices, revenue metrics. LIVE
BrexL7
Community-built. Card expenses, budget mgmt. Read-only.
XeroAdj.
Community-built. Accounting via MCP.
Alpic FRINFRA
First MCP-native cloud. Deploy in minutes. Top 10 SDK contributor.
StainlessINFRA
Generate MCP servers from your API. Powers OpenAI SDK.
SpeakeasyINFRA
OpenAPI → MCP server. Clients: Formance, Mistral.
AAIFGOV
Linux Foundation. MCP governance + goose (Block) + AGENTS.md.
This is not a layer. Every 🤖 badge on the stack above maps to an entry here. Sorted by home layer (L2 → L11.2 → MOR). Agent-readiness is a cross-cutting structural property, not a box you plug in at the end.
⚖️ Regulation Watch — Shapes Every Layer
🇺🇸 GENIUS Act
Stablecoin framework: reserves, audits, licensing. JPM & BofA signal issuance
Final rules due Jul 18 '26 — FDIC/OCC/Treasury NPRMs in
↳ L10.1, L10.2, L10.3
🇪🇺 MiCA
CASP licensing + Travel Rule enforced. 244 licensed, ~83% of register gone. EURC 41% of € market
✓ ENFORCED Jul 1, 2026
↳ L10.1, L10.2, L10.3, L10.4
🇪🇺 PSD3 / PSR
Open banking 2.0, fraud liability, API standards
Agreement Nov '25 → Compliance '27-28
↳ L2, L7, L8
🇺🇸 Nacha ACH
Same-day ACH limit raised to $10M. RTP expansion.
✓ Active Mar '26
↳ L9, L7
🇪🇺 CARF / DAC8
Crypto tax reporting, cross-border info exchange
✓ Active Jan 1, 2026
↳ L10.1, L10.2, L3

What Runs Your Stack

When you unbundle from Stripe/Adyen, you lose their dashboard. You need to rebuild three things.

📊
DATA
What really happened?
Decline codes Settlement IC breakdown Audit trails
Pagos — Payment intelligence
dbt — Transform payment data
Metabase — Open-source BI
Compliance (DORA, MiCA, PSD2)
Vanta — SOC2, DORA evidence
Drata — Continuous monitoring
⚙️
ADMIN
Let me manage it
Tokens Refunds Disputes Sub-merchants
Retool — Custom internal tools
Forest Admin — Back-office on data
Appsmith — Open-source tools
🔄
PROCESS
Automate it
Reconciliation Workflows Retries Dunning
Modern Treasury — Reconciliation
n8n — Workflow automation
Temporal — Durable execution
Compliance Workflow Pattern
Trigger Analyze Human Review Execute
Architecture Principle: Dual-Database
🏦
Banking Ledger
Regulatory source of truth. Immutable. Auditable.
Held by license holder
Sync
💾
App Database
Feature layer you control. Product logic, user data.
Owned by fintech
💡
Why this matters: Back-office tools (Forest Admin, Retool) operate on your App Database — not the Banking Ledger. You can't "fix" regulated data directly. This is why reconciliation matters, why Formance exists, and why BaaS isn't just "renting accounts."
The pattern: As you go deeper in the stack, operational complexity increases. Admin blocks become essential — not optional.

Find Your Profile

Your business model determines which building blocks matter most.

🏪
Marketplace / B2B SaaS Platform
Multi-seller splits, escrow, seller payouts
When should I own my ledger?
Full-Stack PSP
Stripe Connect
<€10M GMV
Regulated Platform
Lemonway, Mangopay
Standard splits
BaaS + Own Logic
Formance + Swan
€50M+ GMV
Full Build
Formance + EMI
Split IS product
Product → Supplier Linkage
Seller Payouts Formance Swan Wise
Critical Layers
L3 KYCL7 LedgerL9 SplitsL9 Payouts
PayFac / Embedded Payments
Embed payments, own merchant relationship
How deep do I go?
PSP Wrapper
Stripe Connect
Fast, their compliance
Orchestrate + Vault
ProcessOut + VGS
Multi-PSP, own tokens
Sponsor Model
BPCE + Duna
Own compliance
Full PayFac
Own license
€500M+ volume
Product → Supplier Linkage
Sub-Merchant Onboard Persona KYC Sponsor Bank Visa/MC
Critical Layers
L3 KYCL5 SponsorL6 VaultL7 Ledger
🏬
Omnichannel Retail
Unify online + POS, one customer view
How do I unify online and in-store?
Single PSP
Adyen Unified
Simplicity
POS Abstraction
Nepting + PSP
Multi-acquirer POS
Unified Vault
VGS + Nepting
Single token
Direct Acquiring
Silverflow + VGS
€100M+, IC++
Critical Layers
L1 POSL4 OrchestrationL6 VaultL5 Direct
🏦
Fintech / Neobank
Issue cards, generate accounts
BaaS wrapper or build the bank?
Full BaaS
Swan, Unit
Fast, their license
BaaS + Ledger
Formance + Swan
Custom logic
Core Banking
Mambu + EMI
Full products
Full Build
Mambu + License
You ARE the bank
Product → Supplier Linkage
Card Issuing Marqeta Visa Bank Sponsor
Critical Layers
L3 KYCL7 LedgerL7 BaaSL7 Cards
🌍
Global Payouts
Pay creators, suppliers, 100+ countries
Traditional rails or crypto?
Traditional FX
Wise, Airwallex
Established corridors
Mass Payout
Payoneer, Tipalti
High volume
Emerging
Thunes, Nium
Africa, LatAm
Stablecoin
Bridge, Lightspark
24/7, zero FX
Critical Layers
L3 IdentityL9 FXL10.3 SettlementL11.2 Agent Wallets
🔗
Crypto Player
Exchanges, wallets, DeFi going compliant
How do I bridge to fiat?
Crypto-Native
DFNS, Fireblocks
Custody only
Fiat Ramp
MoonPay, Sardine
User fiat entry
BaaS
Swan + Chainalysis
Fiat accounts
Full Banking
Mambu + Cards
Crypto bank
Critical Layers
L2 Fiat rampL3 SardineL7 BaaSL10.2 Custody

How Leading Companies Actually Built It

Real stacks, mapped layer by layer. Public sources only — filings, IR pages, press releases.

📂 Real Stack #01 — Klarna
100% PUBLIC SOURCES
BNPL → Bank → Card Issuer → Stablecoin Issuer. The whole map in one company.
L2 · ACCEPT
BNPL at checkout — RENTS distribution
119M consumers. Apple Pay in-store since '26 — distribution via someone else's wallet.
L7 · CARDS — RENTS from Marqeta
Klarna pays Marqeta to run its cards
Card processing outsourced since 2018, 6 countries. Visa Flexible Credential puts debit + pay-later on one card. Klarna's name, Marqeta's infrastructure.
L5/L7 · LICENSE — OWNS
Klarna IS a bank (Klarna Bank AB)
Full Swedish banking license: customer deposits fund the BNPL loans at bank-grade cost of capital. This is what most fintechs rent from a sponsor — Klarna owns it.
L10.1 · STABLECOIN — RENTS infra
KlarnaUSD via Bridge Open Issuance
First bank-issued token on Tempo. Issuance infra rented from Stripe's Bridge. (Klarna PR, Nov '25.)
L10.4 · RAIL — RENTS
Tempo blockchain (Stripe/Paradigm)
Cross-border + everyday payments target. Mainnet live Mar '26.
L12 · CREDIT — OWNS
The credit book: 119M consumers
Twenty years of underwriting + repayment data — the moat. Publicly scored since the IPO: Q1'26 revenue $1.01B (+44%), first operating profit $68M.
The operator read — follow who pays whom: Klarna PAYS Marqeta to process cards, PAYS Bridge to mint KlarnaUSD, PAYS Tempo for the rail, and reaches shoppers through Apple's wallet. It pays nobody for the two things that matter: the banking license (deposits fund the loans cheaply) and the credit history of 119M consumers. Rent the commodity, own what compounds. Most fintechs invert this — sponsor-bank license rented, commodity tech built in-house — and wonder where their margin went.
📂 Real Stack #02 — Shopify
100% PUBLIC SOURCES — 10-Q, Q1'26 CALL
The inverse of Klarna: owns zero licenses, rents the entire regulated layer — and prints money anyway.
L0/L5 · PROCESSING — RENTS from Stripe
Shopify Payments runs on Stripe rails
The world's largest PayFac program, outsourced since 2013. Q1'26 GPV: $67B (+41%), 67% of GMV. Stripe carries the acquiring, Shopify keeps the merchant.
L1 · CHECKOUT — OWNS
Shop Pay — the conversion moat
$35B processed in Q1 (+59%), 70%+ growth abroad. The buyer wallet and accelerated checkout are the product other merchants can only envy.
L2 · BNPL — RENTS from Affirm
Shop Pay Installments = Affirm's balance sheet
Affirm carries the credit risk and the capital; Shopify keeps the checkout surface and the data exhaust.
L0.1 · CROSS-BORDER — RENTS from Global-e
Managed Markets: MOR outsourced
Duties, taxes, seller-of-record liability — Global-e carries it, Shopify sells it as a feature.
L11 · AGENTIC — OWNS
UCP co-author; self-serve since Jun 17
Any agent can now sell Shopify inventory through a public endpoint. Owning the catalog API = owning agentic distribution. AI-driven orders up 13x in Q1.
L8/L12 · DATA — OWNS
The merchant graph funds Shopify Capital
Payments + inventory + buyer data across millions of merchants. It underwrites Capital's cash advances — credit without a banking license.
The operator read — the mirror image: Klarna owns the balance sheet and rents the funnel; Shopify owns the funnel and rents the balance sheet. Stripe, Affirm and Global-e carry every license and every dollar of liability — Shopify keeps checkout, the buyer wallet, the merchant graph, and now the agentic endpoint. Two opposite answers to rent-vs-own, both work. What doesn't work is the middle: renting the funnel AND the license while building commodity tech. Check which quadrant you're in.
Klarna
↑ Mapped above — full public-source breakdown
Shopify
↑ Mapped above — $101B GMV last quarter alone
Toast
Vertical SaaS → Full Stack
Revolut
Neobank Multi-License

Nicolas & Friends

Operators, not consultants. We've built the stacks, not just advised on them.

Curator
Nicolas Devillard
8 years scaling a European PSP from early stage to €100M+ revenue. Grew the team from 15 to 400+. Saw every layer decision firsthand—what worked, what didn't, what we'd do differently.
CRO @ PayPlug (BPCE) €100M+ Revenue Now in NYC
Connect →
Contributors
Friends of the Stack
Payment architects, fintech founders, merchant CTOs, and infrastructure nerds who've lived the build-vs-buy decisions. This isn't theory—it's pattern recognition from the trenches.
Merchants PSP Veterans Fintech Founders Advisory Firms
Philosophy
Challenge the Status Quo
Most payment content is vendor marketing. We're here to show what actually works—from real infrastructure, real trade-offs, real failures. No sponsored content. No affiliate links.
No BS Operator POV Open Source Intel

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Stack reviews, infrastructure audits, build-vs-buy decisions. If you're making a call on your payment infrastructure, let's talk.