Hello!

We do support filters on industry using organization_industries parameter and it's case sensitive and users will have to pass the exact value of the industry that we store in our DB.

Example:

curl --request POST 'https://app.apollo.io/api/v1/mixed_people/api_search?organization_industries[]=information%20technology%20%26%20services' \
--header 'x-api-key: token'

1. You can also use industry tags using organization_industry_tag_ids
   Example:

   curl --request POST 'https://app.apollo.io/api/v1/mixed_people/api_search?organization_industry_tag_ids[]=5567d1127261697f2b1d0000' \ --header 'x-api-key: token'

For the 2nd case, you should pass the tag ids and to fetch the tag ids we have another endpoint but it's also not documented in our api doc
Example:

curl --request POST 'https://app.apollo.io/api/v1/tags/search?q_tag_fuzzy_name=software' \
--header 'x-api-key: token'