We present JWST NIRSpec Integral Field Unit (IFU) observations in the 1 ? 3.2 μm toward the low-mass protostar TMC1A. For the first time, a highly-collimated atomic jet is detected from TMC1A. We observe the dissociative jet shock and the reformation of molecules behind its wakes. Towards the protostar, we detected broad HI and He I emissions that can be explained by a combination of radiation from the protostellar accretion and disk wind. The 2 μm continuum dust emission, H I, He I, and O I all show emissions from the illuminated cavity wall by the radiation produced by the accretion and disk wind. These observations demonstrate the capability of JWST in improving our understanding of outflows and accretion in low-mass stars.