Technology
APIs, mappers and an orchestration fabric that let applications talk to more than one ledger — and to systems that are not ledgers at all. Fusion, PayScript, Flow Applications, MCP agents, x402, Hyperledger Fabric and Oracle sit on top of that sentence, not beside a new chain.
Layer
Overledger does not mint a native L1. It maps requests onto the settlement domains it is connected to. If a flow needs Ethereum, Hyperledger Fabric, Corda, Besu, or a bank core, the gateway routes — it does not replace. The ACM DLT paper and Riley’s research note put this in a taxonomy: among interoperability options, the API gateway category is the one Quant ships.
How to use it · Use it when an institution already has many ledgers and does not want a twelfth.
Connectors
Alex Chiriac’s public bio lists connectors under the Overledger umbrella including Hyperledger Fabric, Corda, Polkadot and the XRP Ledger. Murex MX.3 is the named capital-markets integration: one connector, many ledgers, inside a system 60,000 people already use. Oracle Blockchain Platform (Fabric, with Besu in the family) is the named cloud DLT that Overledger orchestrates across.
How to use it · Use Fabric or Besu as the permissioned execution domain; use Overledger when that domain must talk to another domain or to a core.
Sources & further research
Linux Foundation
Three LF surfaces touch this stack. Fabric is an execution domain Overledger maps onto — and the DLT under Oracle Blockchain Platform Digital Assets Edition. Cacti (Belchior is a maintainer) is LF’s enterprise interoperability project, cousin to SATP, not a Quant SKU. Riley’s 2021 Hyperledger webinar is how Quant explained the gateway category to that community. Do not confuse Fabric (a ledger) with Overledger (a gateway to ledgers).
How to use it · Procurement language: Fabric (or Besu) for the permissioned record; Cacti/SATP for open protocol shape; Overledger for the commercial gateway OS.
Fusion
Quant’s Fusion is published as a multi-ledger rollup — a ‘Layer 2.5’ — connecting dozens of networks in one execution environment. A 2026 Japanese patent, Quant says, protects the multi-DLT token method behind it. Fusion apps are the shippable unit; Flow Applications are the workflows that run on Overledger and can be called from Fusion, from a browser, or from an agent.
How to use it · Use Fusion when a token or workflow must be the same object on more than one ledger, without the application becoming a custom bridge shop.
Sources & further research
Programmability
PayScript is Quant’s published programming layer for programmable money — named in the GBTD stack. Flow Applications (Riley, May 2026) package Overledger connectivity as reusable workflows. Every Flow Application auto-exposes MCP tool definitions: natural-language hints, risk classifications, idempotency flags. The same steps a human runs in Quant Connect can be run by Claude Desktop, Cursor, or a headless agent. MCP itself is an open protocol (modelcontextprotocol.io), not a Quant product.
How to use it · Use Flow + MCP when an AI agent must execute a bank-grade workflow rather than a one-off script. Use PayScript when the money itself must carry the conditions.
Protocol
Secure Asset Transfer Protocol is standardised at the IETF. Quant contributes authors (Hargreaves, Chiriac) and a co-chair (Facer). Belchior and Hardjono (MIT) also author the drafts. The 2020 individual draft was called ODAP — Open Digital Asset Protocol — same gateway-to-gateway shape. Treat SATP as a protocol: Stage-0 verification, Stage-1 initiation, Stage-2 lock-assertion, Stage-3 2PC commit. Overledger can implement a SATP-shaped gateway; that still does not make SATP a SKU.
How to use it · Use SATP language in procurement when two regulated gateways must transfer an asset with a standard state machine. Read the architecture draft before the core; read ODAP if you want the 2020 wording.
Internet payments
x402 revives HTTP 402 so machines can pay machines. Coinbase contributed the protocol; the x402 Foundation is hosted by the Linux Foundation (operational launch July 2026). Quant is listed among general members. Quant’s own note says Fusion is x402-ready out of the box, with the strategic claim that agent payments should settle in tokenised bank money, not only in unregulated tokens. That is how a 1997 status code meets GBTD.
How to use it · Use x402 when an agent needs to pay an API. Use Fusion + tokenised deposits when that payment must be regulated commercial-bank money.
Cloud DLT
Oracle Blockchain Platform Digital Assets Edition (February 2025) is built on Hyperledger Fabric. Oracle’s blog names Overledger as the orchestration layer for XA/2PC cross-ledger workflows and quotes the BIS ‘singleness of money’ problem. How the stack actually sits: Oracle for the operations plane a bank already trusts; Fabric as the permissioned ledger of record; Overledger when that ledger must settle, escrow or swap with another domain.
How to use it · Do not buy ‘Oracle’ and ‘Overledger’ as substitutes. They stack.
Sources & further research
Did you know
Technology
Did you know Overledger is not a twelfth blockchain?
The 2018 whitepaper’s whole point is single-ledger dependency. Overledger maps a request onto Ethereum, Hyperledger Fabric, Corda, a bank core, or all of them. If the future of money is many ledgers and many rails, the scarce resource is a gateway OS, not another validator set.
Read the whitepaper →Technology
Did you know Oracle’s digital-asset platform sits on Hyperledger Fabric?
Oracle Blockchain Platform Digital Assets Edition (Feb 2025) is Fabric-based, with Besu also in the family. Oracle’s own blog names Quant Overledger as the orchestration layer for cross-ledger, two-phase workflows — the ‘singleness of money’ problem the BIS talks about. Linux Foundation software underneath, Quant gateway across.
Oracle’s blog →Technology
Did you know GBTD names PayScript next to Overledger?
UK Finance’s live tokenised-sterling-deposit pilot selected Quant to provide the programmable-money infrastructure: Overledger as the gateway OS, PayScript as the language the banks’ tokens can be programmed in. The product claim is orchestration of commercial-bank money — not issuance of a digital pound.
GBTD programme →Technology
Did you know Fusion Layer 2.5 is Quant’s x402-ready claim?
The x402 Foundation, hosted at the Linux Foundation, revives HTTP 402 so software can pay software. Quant’s published claim is that Fusion Layer 2.5 is ready from day one, and that the missing piece is settling those agent payments in tokenised bank money rather than only in unregulated tokens. A claim, not a live CBDC.
x402 note →