Yes, these agreements occur in the pre-incarnation planning phase of existence, as well as during the sleep state, where these agreements are also created, altered, or even rescinded. 

Every entity possesses free will, which is an attribute of consciousness. Because of this freedom of will, choices involving other souls in a specific lifetime must be agreed upon, so there is an initial planning and agreement phase that sets up the initial conditions of the experience—like a script for a movie.

There exists an infinite number of variables and probabilities in each lifetime, even in a 3D or 4D spacetime reality such as this one. If an entity elects to choose another vector of possibilities, agreements with all parties involved are constructed during the dream state (this dream state houses an ongoing modification of agreements).

Since linear time is a collectively agreed-upon belief, these agreements are constructed by predicting what will happen according to the flow of time at every Delta-T. 

Delta-T is a unit of measurement for time sequences, with each Delta-T understood as being 10 to the -44 seconds. Linear time is magnified, and equations are constructed to determine the degree of probability that an event will happen or not happen. The highest probability is assumed, and then the agreements are constructed.

Usually, there is a give-and-take relationship in these agreements. Soul B agrees to participate in an experience with Soul A, and then Soul A agrees to participate in an experience with Soul B, and so on. All these agreements occur in what could be termed “now-time jurisdiction,” with probability clouds being the subject of analysis.