While you might be able to infer what a certain endpoint does based on context. For example: POST https://api.stripe.com/v1/charges https://api.stripe.com/v1/c

While you might be able to infer what a certain endpoint does based on context. For example: POST https://api.stripe.com/v1/charges https://api.stripe.com/v1/charges will create a CC charge POST https://api.lob.com/v1/letters https://api.lob.com/v1/letters will mail a letter There's no way you know what the parameters to each endpoint are without proper documentation. If the API has good validation you might be able to make a request work but you won't know the full extent of the APIs capabilities without documentation.