The analog library comes without the original parametric cell code. I know that there is some TCL code for Magic. Are there any additional resources that may help to recreate pcell code?

Only the DRC rules, which was all I used to write the Tcl parameterized cells for Magic. Also, we need to figure out if there is a way to submit an MPW project and run it all the way through Calibre checks at Google, which would allow you to create a "torture test" of devices inside a user project and get feedback about any DRC errors, without actually submitting the project for fabrication. I need to do something like this myself. (@jeffdi ---we should discuss this).

Tim, how did you ensure the devices your tcl code creates matches the spice models shipped in the PDK? Wouldn't it be a good idea if there was something like an open API for pcell? In the iPDK standard there is already something similar for an interface for callbacks using tcl. It defines a set of procs like [iPDK_getParameterValue W] to readout and set parameter { iPDK_setParameterValue L $lmax }. Why not extend it to draw the layout as well? That would result in a universally usable code for all tools. Maybe something like a: pcell_setLayer "MET1" pcell_box -100 -100 100 100 pcell_text "S" -100 -100 pcell_polygon .....

It's basically a given that the devices in the Tcl code will match the SPICE models, as the SPICE models are based only on the device width, length, and GDS layers. There are "RF"-approved layouts with controlled source/drain areas, etc., but these use the same SPICE models. In cases where there are SPICE models that are specific to a single device layout, e.g., the two PNP device layouts, I use the actual vendor GDS, not a Tcl-script-drawn device.