I created a custom mapper using cookiecutter and copying the code in meltano_map_transformer with a custom PluginMapper implementation. Debugging the code works great and I have the expected output showing up. Now I'm trying to add it to our project, and I'm wondering how to correctly do that. Here is the relevant part in my meltano.yml, which was added when I ran

meltano add --custom mapper column_mapper

mappers:
  - name: column-mapper
    namespace: column_mapper
    pip_url: -e map/column-mapper
    executable: column-mapper

And my project structure attached. When I run

meltano run tap-mssql column-mapper target-snowflake --state-id-suffix dbo-test

, I get the following error:

Environment 'default' is active
Found unexpected mapper plugin name.  plugin_name=column-mapper
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block violates set requirements: Expected unique mappings name not the mapper plugin name: column-mapper.

What am I doing wrong here?

Mappers are a bit weird https://docs.meltano.com/guide/mappers/#example-1 Take a look at this meltano.yml example and I think you'll see it, there's a

mappings

key you're missing

Just realized I cut off the top of the project directory screenshot. Here's the full one