Standardized representation
Structured data aligned with the Open Cap Table Format (OCF), so transfers, restrictions, and reconciliation stay consistent across implementations and compatible with industry cap table workflows.
Book-entry equity · Onchain settlement
Equity that settles onchain, with compliance built in
The Open Cap Table Protocol (OCP) extends the Open Cap Table Format (OCF) onchain: issuer equity as programmable book-entry on distributed infrastructure. Fast settlement, tamper-evident audit trails, and rule-based controls aligned with securities obligations, for private and public issuers, without inventing a new cap table data model.
Development sponsors
What is the Open Cap Table Protocol
OCP implements the OCF data model onchain: ownership and transfers are recorded with enforceable restrictions, clear provenance, and automation that cuts operational friction for issuers, transfer agents, broker-dealers, and investors, whether the stock is privately held or publicly traded. The standard is designed for institutional use: controls you can audit, settlement you can reconcile, and policy you can enforce in code.
Open Cap Table Protocol whitepaper
Settlement efficiency
Near-instant settlement with a tamper-evident audit trail and the controls regulators and operators require.
Institutional controls
Permissioned visibility, role-based access, and policy hooks so sensitive ownership data stays with authorized parties.
Regulatory alignment
Design for transfer restrictions, transfer agent obligations, and market-integrity conditions, implemented as verifiable rules rather than ad hoc spreadsheets.
Open Cap Table Format
The onchain implementation of the Open Cap Table Format
OCF mark from the Open Cap Table Format project.
The Open Cap Table Format (OCF) is the open source capitalization data standard developed and maintained by the Open Cap Table Coalition , a nonprofit trade organization whose members include leading U.S. securities law firms and major equity platform providers. OCF is the JSON-based model the industry uses to structure and exchange cap table data with interoperability and portability in mind.
The Open Cap Table Protocol is the onchain extension of that same standard. It is not a parallel format. When you use OCP, onchain equity records align with the cap table data model that top firms already promote, so your book of record stays compatible with counsel, transfer agents, and the broader ecosystem.
Adoption
Who uses OCP today?
Fairmint is an SEC-registered transfer agent running issuer book-entry on the Open Cap Table Protocol in production. The same open standard is available to other transfer agents and operators who want interoperable, onchain book-entry alongside their existing controls.
Transfer agent
SEC-registered transfer agent. OCP in production for issuers.
“Cap tables are the foundation of every company’s equity structure. Moving them onchain isn’t just about efficiency. It’s about making equity programmable.”
Transfer agent planning to add onchain book-entry on OCP? Contact the team to align on integration and controls. Get in touch
History
The future was sketched in 1969. OCP completes it onchain.
Long before today’s digital rails, U.S. markets hit a breaking point: by the late 1960s, trading volume had overwhelmed the settlement of physical stock certificates, fueling widespread fails and stress on broker-dealers. Regulators and exchanges went looking for models that would stop moving paper and instead settle ownership as book entry tied to the issuer’s official register.
In 1969, the American Stock Exchange commissioned what became known as the Rockwell Study, a sweeping look at how clearance and settlement could work in a modern securities industry. To cut certificate traffic, Rockwell proposed individual transfer agent depositories (TADs): a design pairing a national clearing system with a decentralized network of individual transfer agent depositories, with each transfer agent maintaining the issuer’s register in electronic form and settling by debiting and crediting securities accounts on that register instead of delivering physical certificates.
At the time, the Commission noted, that model remained “a theoretical proposal that had not been implemented in any market.” In practice, listed U.S. equity largely converged on central depository and multilateral clearing that immobilized certificates and netted settlement, while transfer agents maintained the issuer’s official securityholder records in the book-entry chain. Outside that rail, private and other issuers still depended on the same register and transfer-agent concepts, but the capitalization record often fractured across spreadsheets, PDFs, and vendor silos. The idea of a networked, transfer-agent-centered book never went away. What it needed was infrastructure that could make multi-party, compliant electronic book entry practical at scale, alongside portable capitalization data that counsel and operators can exchange. That foundation is what programmable networks and open standards provide today.
Liquidity got centralized rails. The issuer’s book often did not.
The Rockwell-era diagnosis was blunt: markets were drowning in paper and segmentation. Trillions of private markets depend on issuer-controlled issuance, transfer restrictions, and transfer-agent obligations that do not disappear just because a secondary venue or a bank portal goes live. Liquidity can move quickly; the authoritative capitalization record still has to satisfy issuers, counsel, and regulators.
Today, secondaries, continuation vehicles, and bank-led platforms show that access to liquidity is infrastructure-driven, but the bottleneck remains the cap table, the issuer’s book of record. You can stand up electronic order matching or secondary markets; if the official book stays fragmented, manual, or off the same rails as your compliance story, you have not upgraded the system securities law cares about.
Programmable networks are what make the transfer-agent vision practical again: compliance by automation, a shared source of truth, and settlement with controls that match transfer-agent obligations. Portable capitalization data (the kind the industry is already standardizing offchain) is the natural complement when that record moves onchain. The operative question stops being only “public or private?” and becomes whether ownership is on an interoperable, auditable, programmable system of record.
That is the through-line to the Open Cap Table Protocol: an open layer for transfer-agent-grade book-entry on distributed infrastructure, where settlement, restrictions, and the issuer’s record can move at the speed today’s markets demand, without trading away the controls regulators expect.
For partners
Integrate OCP into your products
Transfer agents, cap table software vendors, banks, and other market participants use the same open interfaces to connect their systems to OCP. Below you will find production-ready tooling by network (runtime), plus documentation and source so your engineering team can wire issuance, transfers, and reconciliation into your existing stack.
- Canton Network available
ocp-canton-sdk
TypeScript library for product teams connecting to OCP on Canton: model issuance, transfers, and book-entry reconciliation with network-level guarantees your stack can rely on.
Language: TypeScript
More runtimes and partner tools will be listed here as they ship. If you are scoping an integration, need a security or compliance review, or want to add a new runtime, contact the team .
Talks & resources
Talks on OCP, Rockwell-era history, and why the authoritative cap table is the system to upgrade, with Fairmint leadership at EthCC and Digital Asset Summit NYC.
Technical · EthCC 2025
Intro to the Open Cap Table Protocol
Thibauld Favre (CTO, Fairmint)
What OCP is, how it models ownership as interoperable data, and why a shared standard matters for issuers, investors, and regulators, including chain choice and deployment.
Markets · DAS NYC 2026
The Blurring Lines of Private & Public Markets
Joris Delanoue (CEO, Fairmint), Digital Asset Summit, New York
From the Rockwell report through today’s markets: why centralized clearing won for public liquidity while cap tables often lagged, and how programmable infrastructure closes the gap.