The Postman API at https://api.getpostman.com reads and edits your Postman workspaces, collections, and environments.
Generate a key under Settings → API keys and send it as the X-Api-Key header. In the examples it's written {{POSTMAN_API_KEY}}.
Full reference: https://learning.postman.com/docs/developer/postman-api/intro-api/
curl https://api.getpostman.com/me \
-H "X-Api-Key: {{POSTMAN_API_KEY}}"
curl https://api.getpostman.com/collections \
-H "X-Api-Key: {{POSTMAN_API_KEY}}"
curl https://api.getpostman.com/workspaces \
-H "X-Api-Key: {{POSTMAN_API_KEY}}"