A unique feature of gravity is its ability to control the information
accessible to any specific observer. We quantify the notion of cosmic
information ('CosmIn') for an eternal observer in the universe. Demanding the
finiteness of CosmIn requires the universe to have a late-time accelerated
expansion. Combining the introduction of CosmIn with generic features of the
quantum structure of spacetime (e.g., the holographic principle), we present a
holistic model for cosmology. We show that (i) the numerical value of the
cosmological constant, as well as (ii) the amplitude of the primordial, scale
invariant, perturbation spectrum can be determined in terms of a single free
parameter, which specifies the energy scale at which the universe makes a
transition from a pre-geometric phase to the classical phase. For a specific
value of the parameter, we obtain the correct results for both (i) and (ii).
This formalism also shows that the quantum gravitational information content of
spacetime can be tested using precision cosmology.