Parago is an unofficial go client for the paraswap api. See it as the javascript sdk but for go.
The client has the following calls
NewConfiguation : creates a new configuration for the client
GetTokens : get all the tokens on the network of the client
GetToken : returns a token object for a given symbol on the network of the client
GetRate : gets the rate for a given pair
BuildParameters : builds the transaction parameters
Pull requests welcome.