Open Transaction Layer | OTL

Open protocol stack for coordinating onchain transactions

Blockchain infrastructure is built. The coordination layer for secure, compliant transactions isn't. Until now, every institution has built it alone.

[10] Partners
[500m] Wallets reached
5 Active tracks
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Why a Shared Standard

Every institution builds its own coordination layer. Each new counterparty type, jurisdiction, use case requires a bilateral integration or a different vendor. The result is parallel systems for transaction rails, PII exchange, and reconciliation - across chains and wallet types. Engineering and operational costs compound.

Yet coverage gaps persist. Networks don't interoperate: travel rule completion remains low, transfers still go to unknown addresses. Institutions can only reach the counterparties they integrated; non-custodial wallets and agents are in a compliance deadlock. As for those within reach, manual input and inconsistent wallet experience push conversion down. Even when all else checks out, transfers carry residual risk: no integrity guarantee means tampering can go undetected.

OTL builds shared standards to close these gaps - so every participant can operate on one interoperable foundation, instead of rebuilding the same layer independently.

The Stack

The four base layers - identity, messaging, transport, session - are modular and interoperable. They can be combined into end-to-end applications (the fifth layer): merchant checkout, B2B settlement, agentic payments... With pre-transaction coordination, compliance and security built in. Each layer is independently adoptable so existing integrations keep operating.

SPECIFICATION  → EXPLORER  →
Builds on existing standards
W3C VCs · LEI · ISO 20022 · IVMS101 · x402 · ISO 18245 · RFC 9901 · RFC 7595 · DTI · CAIP-19 · EIP-1193 · DIDComm · MPP · OID4VCI
What it provides
[ ✓ ]
Network of verified identities
Every address, payment, settlement message is cryptographically authenticated and tied to a DID.
[ ≡ ]
One stack, many applications
Modular, composable standards to build interoperable flows across blockchains and transport mechanisms.
[ ⊕ ]
End-to-end security
Tamper-evident messages, app-layer encryption for PII. Every exchange produces an auditable record.
[ ○ ]
Decentralized trust
Anyone can join, no central gatekeeper. Each institution decides who it connects to.
[ ∀ ]
One standard, any participant
Custodial accounts, non-custodial wallets, and agents are all first-class participants.
[ ⊙ ]
Critical mass from day one
Leading financial institutions, infrastructure providers, and blockchain foundations are in.
Who It's For
Financial Institutions
Exchanges · Banks · Fintechs · Broker-dealers · Asset managers
Solve coverage gaps for compliant transactions and improve conversion rates. Pay from [your brand] anywhere. Provide all-in-one connections to OTC desks, liquidity providers…
Payment Providers
PSPs · Payment processors
Increase payments acceptance from verified wallets of any type - without sacrificing compliance or security. Tamper-proof payment flows from start to finish.
Infrastructure & Middleware
Wallet providers · Agent platforms · DeFi protocols
Expand your reach by building on industry standards. Ensure your systems are compliant and universally accepted.
Blockchain Foundations
L1 foundations · L2 foundations
Attract more institutional capital and regulated customers, with native support for identity and coordination.
The Initiative

Open Transaction Layer is a technical initiative, operating as an industry alliance. Collaboration starts from the problems we want to solve, not theoretical frameworks. Founding members gain a shared voice to engage regulators and advocate for concrete technical implementations.

The core deliverable is protocol libraries: open-source, interoperable, and designed to be agent-friendly. Work is organized in tracks, spanning multiple layers of the stack. Each track produces reference specifications and defines how existing standards interoperate.

OTL tracks ├── Immediate tracks │ ├── Identity & authentication │ │ ├── DID │ │ ├── Credentials │ │ └── Wallet attribution │ ├── Payment messaging │ │ ├── Deposit │ │ ├── Payout │ │ ├── DvP │ │ └── Swaps │ ├── Compliance messaging │ │ ├── Verification of payee │ │ ├── PII rails - custodial │ │ └── PII rails - non-custodial │ ├── Account connectivity │ │ ├── Exchange account linking │ │ └── Non-custodial wallet linking │ └── Agentic │ ├── KYA & policy │ └── Agentic payments └── Next tracks ├── Onchain identity ├── Onchain privacy └── Cross-custody clearing messaging
How to participate
Become a founding partner. Shape specifications before they exist. Protocols will reflect your constraints and implementation preferences. You can actively contribute to select tracks, driving the reference implementation conversation and code for that domain.
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