<p>I am writing a script to get SNP positions from dbSNP by using NCBI E-Utils. When I use esearch and efetch to retrieve the positions, I can only access positions from the newest genome build. Since I want to use GRCh37, this causes problem. I was wondering if you knew of a way of asking for a specific assembly in E-Utils.</p>

dbSNP does not support searches for older assembly coordinates.

Depending on exactly what you are trying to do, you can probably use lift-over or <a href="https://www.ncbi.nlm.nih.gov/genome/tools/remap">remap</a> to first convert your coordinates.