Welcome to enviPath
Your Options:
See all Packages: https://envipath.org/package
See all Pathways sorted by Packages: https://envipath.org/pathway
See all Reactions sorted by Packages: https://envipath.org/reaction
See all Rules sorted by Packages: https://envipath.org/rule
See all Compounds sorted by Packages: https://envipath.org/compound
See all User: https://envipath.org/user
See all Groups: https://envipath.org/group
To predict a SMILES to the default package, make a POST on the URI https://envipath.org/pathway with the parameter: 
(required) smilesinput
(optional) maxNodes
(optional) maxDepth
Every Ressource has a text/plain and text/html representation. So these Accept-Types are accepted on every ressource. Furthermore, there are special accept types on other ressources.