Another Portolan Catalogue, Published in Three Hours

Building Portolan: TriMet Mirror — Three hours from shapefiles to a live catalog

TriMet publishes eight geospatial datasets as plain files. Mirroring them into a Portolan catalog, with a custom-themed browser, took about three hours of work on a plane.

Here’s another example of how to publish a Portolan catalogue from existing data: Chris Holmes mirrored an existing catalogue of Shapefiles and published the Portolan version in just three hours, complete with custom styles and a customised Portolan browser. Unlike Bert Temme, who used the CLI, Chris used an early version of the Portolan agent skills in Claude.

The thing that strikes me most is how easy this is to do. I spent no more than 3 hours on the entire project, building both the catalog and the custom data browser. Most of it ran independently on the plane, and then I did some iterations on the results. I’d guess that doing the same project with the progress we’ve made in the last month would make it less than an hour of work to get to where I did. Yes, you need Claude or another capable agent, and it’s probably a few dollars worth of tokens if you’re paying API list rates. The agent is most of what makes this so easy, but it’s also the simplicity of the output - all the agent needs to do is format the files right, and then all the cool tooling ‘just works’.

Just three hours.