---
title: "Ontology Ledger"
description: "Read and append workspace ledger records. Records contain subjects, designators, observations, and claims with verification states and valid-time intervals. Read a subject at a record time and a valid time. Export records as NDJSON or STIX 2.1. Use a workspace-bound key with `ledger:read` or `ledger:write`. x402 is not supported."
canonical: https://y2.dev/docs/api/reference/ontology-ledger/
---

Endpoint Reference

# Ontology Ledger

Read and append workspace ledger records. Records contain subjects, designators, observations, and claims with verification states and valid-time intervals. Read a subject at a record time and a valid time. Export records as NDJSON or STIX 2.1. Use a workspace-bound key with \`ledger:read\` or \`ledger:write\`. x402 is not supported.

[GET /api/v2/ledger/subjects](https://y2.dev/docs/api/reference/ontology-ledger/listLedgerSubjectsV2): List ledger subjects

[POST /api/v2/ledger/subjects](https://y2.dev/docs/api/reference/ontology-ledger/openLedgerSubjectV2): Open a ledger subject

[GET /api/v2/ledger/subjects/{subjectId}](https://y2.dev/docs/api/reference/ontology-ledger/getLedgerSubjectV2): Fold a ledger subject

[GET /api/v2/ledger/subjects/{subjectId}/stix](https://y2.dev/docs/api/reference/ontology-ledger/getLedgerSubjectStixV2): Export a ledger subject as STIX 2.1

[GET /api/v2/ledger/records](https://y2.dev/docs/api/reference/ontology-ledger/listLedgerRecordsV2): Export sealed ledger lines

[POST /api/v2/ledger/records](https://y2.dev/docs/api/reference/ontology-ledger/appendLedgerRecordV2): Append a ledger record

[GET /api/v2/ledger/verify](https://y2.dev/docs/api/reference/ontology-ledger/verifyLedgerV2): Verify the ledger seal