Journal and undo

Every confirmed write is recorded in a local journal, so that undo_operation can revert it later — even after the server restarted.

Where

Default file	$XDG_STATE_HOME/avenir-mcp/journal.jsonl, else ~/.local/state/avenir-mcp/journal.jsonl
Chosen file	AVENIR_MCP_JOURNAL
Permissions	created 0600: readable and writable by you only
Contents	identifiers only — no amount, no payee, no memo, no token

Format

JSON Lines, append-only. An applied operation is one line:

{"operation_id":"5f2c9a1e7b30","plan_id":"demo-budget","kind":"categorize","applied_at":"2026-09-25T09:12:04+00:00","moves":[{"transaction_id":"tx-048","from_category_id":null,"to_category_id":"cat-groceries"}],"details":{}}

Undoing it appends a marker; nothing is ever rewritten:

{"undone":"5f2c9a1e7b30"}

Field	Meaning
operation_id	12 random hexadecimal characters
plan_id	the budget changed
kind	categorize, budget, reconcile or create
applied_at	ISO 8601, UTC, to the second
moves	for categorize: each transaction’s category before and after
details	for the other kinds, what undoing needs (below)

kind	details
budget	month, category_id, from and to in milliunits
reconcile	account_id, reconciled_ids, adjustment_id (or null)
create	transaction_ids

Which operation undo picks

undo_operation without an id takes the most recent operation of the budget that is still in effect: not undone, and not itself an undo. With an id, that operation, if it is still in effect. Otherwise: “Nothing to undo: no operation of this budget is still in effect.”

What undo restores

kind	Undo	Checked first	If the check fails
categorize	each transaction back to its previous category	its category is still the one the operation set	that transaction is left alone and listed in conflicts
budget	the previous amount	the amount is still the one the operation set	nothing written; conflicts names the category
reconcile	reconciled transactions back to cleared; the adjustment deleted	each is still reconciled	those no longer reconciled are skipped
create	the created transactions deleted	each still exists	those already deleted are listed in conflicts

Undo is previewed and confirmed like any write. Undoing a categorize operation records the undo itself as an operation and marks both undone, so an undo cannot be undone.

Note

The journal is local: an operation made from another machine, or before the journal file was changed or deleted, cannot be undone from here. Deleting the file forgets the history and nothing else.