Memories

A memory is one JSON file, .dd/memories/<id>.json, committed with the project. The authoritative definition is src/memory/schema.js.

{
  "schema_version": 8,
  "id": "6f1c…",
  "project_id": "my-app",
  "topic": "testing/store-handle",
  "kind": "trap",
  "status": "active",
  "title": "Close stores in t.after",
  "body": "A test that opens a store must close it in t.after: a failing assertion otherwise leaves the handle open and node --test never ends.",
  "not_derivable": "Only a hung CI run shows it; no test or comment says so.",
  "triggers": [{ "on": ["edit", "write"], "paths": ["tests/**/*.test.js"], "symbols": ["createStore"] }],
  "evidence": [{ "type": "file", "path": "tests/store.test.js", "sha256": "…", "summary": "The test that hung" }],
  "origin": "model_initiated",
  "replaces": null,
  "revisit_when": [],
  "review": { "migrated": false, "issues": [] },
  "created": "2026-10-13T12:00:00.000Z",
  "updated": "2026-10-13T12:00:00.000Z"
}

Kinds

Kind	For	Delivered as
`trap`	Something that breaks, and how to avoid it	`[TRAP]`
`decision`	A project choice, with why	`[DECISION]`
`failed_approach`	Something tried and abandoned	`[ABANDONED]`
`procedure`	Steps to follow for a recurring task	`[PROCEDURE]`
`fact`	A fact about the project or its environment the code does not show	`[FACT]`

Fields

Field	Meaning
`topic`	`area/subject` path; at most one live memory per topic
`title`, `body`	What the agent reads: title up to 200 characters, body up to 1,500
`not_derivable`	Why an agent reading the code, tests and docs would not work this out (up to 300 characters); required for a live memory
`triggers`	When DD delivers it (below)
`check`	An optional rule DD checks the agent’s changes against (below)
`evidence`	`file` (a repository path DD hashes), `observation`, `correction` or `note`, each with a summary
`origin`	`model_initiated` (the agent decided) or `user_explicit` (a person asked or edited it)
`replaces`	The live memory a candidate revises; accepting it supersedes that one
`revisit_when`	Conditions under which the memory should be reviewed again

Triggers

A trigger clause names the events it applies to in on: prompt, read, edit, write, search or run. At least one more field narrows it:

paths: globs of repository files the event touches (*, **, ? and {a,b} alternatives);
symbols: identifiers the edited or written text contains;
commands: words of a command the agent runs;
keywords: words or phrases of the prompt or tool call;
not, not_paths: phrases or globs that cancel the clause.

A memory fires when any of its clauses matches. deltadictum health and the review UI report triggers that can never fire (a glob with no file, a symbol absent from the code) and globs so broad they match much of the repository.

Checks

A check states a rule DD verifies itself:

Field	Meaning
`on`	`edit`, `write` or `run`
`paths`	The files it applies to (edit and write)
`if_content`, `unless_content`	A violation when the changed file matches the first and not the second
`if_command`, `unless_command`	The same over a command
`when`	`turn` (the default for files: once, at the end of the turn), `edit` or `run`
`say`	What the agent is told, up to 200 characters
`examples`	`violates` and `passes` samples, required: a check whose examples fail is left out

DD reports only violations the change introduced, at most twice per file per epoch (a session until its next compaction or /clear), and never runs code.

Statuses

Status	Delivered
`candidate`	No: waits for review
`active`	Yes
`contested`	Yes, marked `[DISPUTED]`
`superseded`	No: a revision replaced it
`archived`	No: retired, merged or archived by a person; restorable

A memory converted from v1 carries review.migrated: true and stays live without not_derivable until a person supplies it in the review UI.