Open Cap Table Format

The Open Cap Table Format (OCF ) is a JSON-based open-source standard for storing and sharing cap table data.

TAP vendors the schemas as a git submodule at ocf/, from transfer-agent-protocol/tap-ocf . The pin in this repo is commit 6d8c9322 (ocf_version 1.2.1-alpha+main). We validate offchain records against those files.

TAP is a stock-centric subset of OCF. Convertibles, warrants, vesting v2, consolidation, and stakeholder change events have no onchain TAP surface. Mongo also stores TAP-only fields (tx_hash, is_onchain_synced, deployed_to, deployed_by) that are not OCF.

• ocf
  • schema
    • enums
    • files
    • objects
    • primitives
    • types

OCF Terminology

The Open Cap Format uses specific terminology:

• Stakeholder: An equity holder on the cap table (shareholder). Can be an individual (person) or institution (company/fund).
• Issuer: The company whose cap table is being tracked.
• Security: A specific equity position (shares, options, warrants, convertibles).
• Transaction: Events that modify the cap table (issuances, transfers, cancellations, etc.).

Note that “stakeholder” in OCF context is more specific than the general business term—it refers only to equity holders, not all parties with interest in the company.

TAP still uses OCF’s singular current_relationship onchain and in the product UI. The schema also has current_relationships (array); TAP does not persist that field yet.

How TAP Uses OCF Offchain

OCF defines the JSON shapes TAP uses for offchain records. The API routes on this site use those shapes for issuers, stakeholders, stock classes, transactions, and supporting records.

Use the Cap Table API guides for the routes you can call today. Generated schema docs live under ocf/docs/schema_markdown.

Our Database

TAP stores OCF-shaped records in a database layer . Models are under server/db/objects; reads and writes go through server/db/operations.

• server
  • db
    • config
    • objects
    • operations