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Computer-aided dispatch in Argus has two audiences, and the API is split the same way.

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What Control does

Control owns the operational picture.
  • Calls come in and are recorded by hand. A call is converted into a new incident, attached to an existing one, or resolved with no incident.
  • Incidents are created, edited, closed and reopened.
  • Units are dispatched to incidents and released from them.
  • Control can also create and edit units, set any unit’s status, and change its crew.
Every Control endpoint requires cad.view. Each kind of change needs a second permission:

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What a crew does

A crew member manages their own presence, and nothing else.
  • Book on to start a unit, or join one that is already on duty.
  • Change status within what the unit’s situation allows.
  • Book off to leave.
  • Read their current unit, which includes the incident it has been sent to.
A crew cannot see other incidents, cannot assign itself to one, and cannot clear itself from one. Those are Control’s decisions. See Units and crew.

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How a dispatch reaches a crew

There is no push channel. A dispatch is a change of state that both sides read.
1

Control assigns

POST /api/cad/incidents/{id}/assign with the unit’s ID and version. The unit becomes ASSIGNED.
2

The crew sees it

The crew’s client polls GET /api/cad/me/unit. The unit now has status: "ASSIGNED" and incident filled in.
3

The crew responds

POST /api/cad/me/unit/status with EN_ROUTE, then ON_SCENE.
4

Control releases

POST /api/cad/incidents/{id}/remove, or the incident is closed. The unit returns to AVAILABLE.
Clients poll. The web application refreshes Control every ten seconds and the MDT every five.

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History

Every CAD change writes an event to an append-only history, together with an audit entry, in the same transaction as the change. GET /api/cad/events reads it, for one incident, one unit, or everything. Events are immutable: the database rejects updates and deletes. Nothing in CAD is deleted. Incidents are closed, units go off duty, and crew memberships end.

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What CAD does not do yet

  • It does not ingest calls from ER:LC. Calls are typed in.
  • It has no map, locations are free text, and it does not suggest the nearest unit.
  • It does not link incidents to PNC people or vehicles.
These are listed, with everything else that is missing, under API status.