Information
- OpenAPI version:
3.1.0
Overview
Haddon 1
Section titled “Haddon 1”Haddon: an open-source double-entry ledger for AI agents. It comes with an optional web interface for people.
One database file is one entity; every path below /v1/entities/{entity_id} is resolved inside that
file, so an id that exists for another entity is simply not found here.
Amounts cross the wire as base-10 integer strings of micro-units (millionths), in both directions.
"amount_micros": "-12000000" is -12.00 of a two-decimal commodity. JSON numbers are refused.
Dates are inclusive from/to over one continuous journal. Either bound may be omitted (from means “from
the beginning”, to means “through the latest posting”), and any valid range is accepted; trial-balance and
balance-sheet take a point as_of instead. A range that merely ends in the future is fine; one that has not
begun is refused.
Pagination returns {items, next_cursor, snapshot_seq}. Cursors are opaque, signed and bind the entity,
the filters, the ordering and the snapshot; pass them back unchanged. Default 50 per page, maximum
200; events default 100, maximum 500. A cursor whose snapshot is gone is
409 cursor_expired with a resync link.
Writes require an Idempotency-Key. The same key with the same request replays the original status and body
with Idempotency-Replayed: true; the same key with a different request is 409 idempotency_conflict.
Authorisation records, it does not enforce. A credential is one opaque actor string scoped to explicit
entities; that string is written to created_by and is never parsed. Every write is applied on the caller’s own
authority and recorded with its actor and reason; there is no approval step.