  We present the survey design, implementation, and outlook for COSMOS-Web, a
255 hour treasury program conducted by the James Webb Space Telescope in its
first cycle of observations. COSMOS-Web is a contiguous 0.54 deg$^2$ NIRCam
imaging survey in four filters (F115W, F150W, F277W, and F444W) that will reach
5$\sigma$ point source depths ranging $\sim$27.5-28.2 magnitudes. In parallel,
we will obtain 0.19 deg$^2$ of MIRI imaging in one filter (F770W) reaching
5$\sigma$ point source depths of $\sim$25.3-26.0 magnitudes. COSMOS-Web will
build on the rich heritage of multiwavelength observations and data products
available in the COSMOS field. The design of COSMOS-Web is motivated by three
primary science goals: (1) to discover thousands of galaxies in the Epoch of
Reionization ($6<z<11$) and map reionization's spatial distribution,
environments, and drivers on scales sufficiently large to mitigate cosmic
variance, (2) to identify hundreds of rare quiescent galaxies at $z>4$ and
place constraints on the formation of the Universe's most massive galaxies
($M_\star>10^{10}$\,M$_\odot$), and (3) directly measure the evolution of the
stellar mass to halo mass relation using weak gravitational lensing out to
$z\sim2.5$ and measure its variance with galaxies' star formation histories and
morphologies. In addition, we anticipate COSMOS-Web's legacy value to reach far
beyond these scientific goals, touching many other areas of astrophysics, such
as the identification of the first direct collapse black hole candidates,
ultracool sub-dwarf stars in the Galactic halo, and possibly the identification
of $z>10$ pair-instability supernovae. In this paper we provide an overview of
the survey's key measurements, specifications, goals, and prospects for new
discovery.
