Facts and dreaming

A page says what something is. A fact says what was true, and when. Each fact has a subject (a person, project, system or other entity), an attribute, a value, and dates. When a value changes, the brain does not overwrite it. It keeps the old fact with the dates it held and marks the newer one as current.

Reading facts

Each subject's timeline is in the Facts view of the wiki (wiki?view=facts). An agent can ask about a point in time: the brain_facts MCP tool takes an as_of date and returns the value then, with its earlier values.

Freshness

Each fact records when it was last confirmed: when it was written, and again whenever a later write repeats it. The Facts view shows current facts confirmed in the last 90 days, measured from the date you are viewing. Older ones are hidden unless you turn on Show stale. History always shows everything.

Facts are state, not events

A cost, an outage or an incident happened once; it is not a standing fact. When the brain writes facts, it refuses attributes that describe events, and it reuses an existing attribute when the same property changes, instead of inventing a new key for each issue or session.

Dreaming

Dreaming is the background pass that tidies one subject's facts. It reads every current fact of that subject and may:

• supersede an older fact with a newer one of the same attribute;
• end a fact at a date it stopped being true;
• retract an event or a duplicate;
• rename a fact to the ordinary attribute key.

A subject is due for a pass when it has at least 20 current facts and has never been tidied, when its last pass is seven or more days old, or when ten or more facts were added since. At most two passes run per cron tick, and each one counts against the same daily and monthly compile budget as a compile. When the budget is spent, the rest wait.

Nothing is deleted. A superseded, ended or retracted fact stays in the history with the date it stopped. Every decision is logged, whether or not it was applied, so you can see why a fact changed. The timeline shows when a subject was last dreamt about, and the facts a pass changed say so: "Ended while dreaming", "Superseded while dreaming", "Renamed while dreaming".

Reference

The fact format, the write rules and the dreaming queue are in the temporal facts reference.