Instant payments.
Open to every bank.
Open-Pai is a production-grade SCT Instant payment engine any bank can download, audit, and run. TIPS and SIC IP ready. No license fees. No black boxes.
Built different
Correct by construction, not by luck.
Legacy payment engines fight race conditions with locks and hope. Open-Pai eliminates them with a single-writer state machine — every event for a payment is processed strictly in order.
Race-free engine
One explicit finite state machine, ordered per payment. Timeout vs. confirmation races are impossible by design.
CSM-agnostic
TIPS and SIX SIC IP behind one adapter interface. Adding a new rail is one adapter, zero core changes.
Event-sourced ledger
Every payment is a replayable, hash-chained event log. Your regulator-grade audit trail comes built in.
ISO 20022 native
pacs.008, pacs.002, camt.056, pacs.004 and friends — scheme-compliant message handling out of the box.
Trust, verified
Your keys. Your ledger. Our code — fully auditable.
Open-Pai can never move money on its own. Signing keys stay in your HSM, every build is reproducible, and independent reconciliation against the CSM catches any divergence within one cycle.
Bank holds the keys
CSM signing certificates never touch our code. Only your HSM can authorize a payment message.
Reproducible builds
Signed releases with SLSA provenance and SBOM. Verify your binary matches the audited source.
Independent audits
Recurring third-party security reviews with published reports, plus per-scheme certification.
Open governance
Neutral foundation, multiple maintainers, signed commits. No single party can subvert a release.
How it works
From API call to settled funds in seconds.
Receive
REST or pain.001 in, validated and screened in <1s
Reserve
Funds earmarked, pacs.008 signed by your HSM
Settle
Cleared via TIPS or SIC IP in central-bank money
Confirm
Posted, notified, and reconciled — fully auditable
Quickstart
Running in minutes, not months.
# Pull and start Open-Pai with the CSM simulator $ git clone https://github.com/open-pai/open-pai $ cd open-pai && docker compose up # Send your first instant payment $ curl -X POST localhost:8080/v1/payments \ -H "Idempotency-Key: demo-001" \ -d '{"debtor":"CH93...","creditor":"DE89...","amount":"42.00"}' → status: SETTLED · 1.8s · UETR eb6305c9-1f3f-4b12
Contact us
The code is free. The expertise is here.
Every bank gets the full source code, forever. When you want help going live — integration, certification, operations — our team offers hands-on implementation consultation.
- Full source code, no strings
Download, audit, and self-host Open-Pai under Apache 2.0. Consultation is optional — the code never is.
- Implementation consultation
Core banking integration, HSM and key setup, CSM connectivity, and go-live planning with engineers who built the engine.
- Bare-minimum pricing
Consultation is priced at cost — just enough to sustain the project. Our goal is banks going live, not billable hours.
- Scheme certification support
Guidance through TIPS and SIC IP test campaigns, EPC scheme adherence, and regulator conversations.
- Operations & SLA support
24/7 support contracts, hardening reviews, and upgrade management for teams that want a partner on call.
Payments infrastructure should belong to everyone.
Join the banks, engineers, and regulators building the open standard for instant payments.