Hi, I have an application in c++/qt (https://gitorious.org/micropos). Direct connection with PostgreSQL is a big security hole, so I'm trying to redesign my architecture. I want to add an application server between PostgreSQL and client/admin and I want to write that application in Haskell. The core concept of my new architecture is a custom protocol. With that, it would be possible with little effort to create web and mobile clients, possibly using different technologies. Totally custom protocol would be interesting, but writing a parser for c ++ _and_ python _and_ java (and haskell of course) will be too much for me at the moment. XML-RPC looks too heavy, so I ended up with JSON-RPC ('id' attribute is ommited): * authentication example: | > { method: "auth-login", params: { name: <name>, passwd: <passwd> } } | < { result: <status-object> } | > { method: "auth-logout", params: null } | < { result: <status-object> } * uploading/downloading binary data/files example: | > { method: "fs-upload", params: <binary-data> } | { result: <status-object> } | > { method: "fs-download", params: <binary-data-id> } | < { result: <status-object> } * low level generic database methods: | > { method: "db-create", params: { type: <type>, object: <object> } } | < { result: <status-object> } | > { method: "db-update", params: { type: <type>, object: <object> } } | < { result: <status-object> } | > { method: "db-delete", params: { type: <type>, id: <id> } } | < { result: <status-object> } | > { method: "db-list", params: | { type: <type>, | filter-by: [ <predicate-objects> ], | order-by: [ <ordering-objects> ] } } | < { result: [ <ids> ] } | > { method: "db-show", params: | { type: <type>, | ids: [ <ids> ], | fields: [ <fields-options-objects> ] } } | < { result: [ <objects> ] } | > { method: "db-list-show", params: | { type: <type>, | filter-by: [ <predicate-objects> ], | order-by: [ <ordering-objects> ], | fields: [ <fields-options-objects> ] } } | < { result: [ <objects> ] } * low level generic relations: | > { method: "db-insert", params: | { group-type: <type>, | group-id: <id>, | member-type: <type>, | members: [ <ids> ] } } | < { result: <status-object> } | > { method: "db-remove", params: | { group-type: <type>, | group-id: <id>, | member-type: <type>, | members: [ <ids> ] } } | < { result: <status-object> } Example usage (this should add a record in 'client' table): | > { method: "db-create", params: | { type: client, | object:{ name:"John Doe", address: "...", ... } } } | < { result: <status-object> } This 'parsing engine' should be generated from some kind of 'routes description' like in django, rails or yesod. For example something like this: | auth-login (user-name :: String) (user-password :: String) | auth-logout | auth-lock | auth-unlock (user-name :: String) (user-code :: String) | fs-upload (binary-data :: BinaryData) | fs-download (binary-data-id :: BinaryDataId) | db-create (type :: String) (object :: a) | db-update (type :: String) (object :: a) | db-delete (type :: String) (id :: String) The user should supply all data definitions and conversion functions to guarantee type corectness in case of a match, for example: class FromJson a where fromJson :: String -> Maybe a data Client = Client { name :: String, address :: String, ... } instance FromJason Client where fromJson = ... This looks very generic. Am I reinventing the wheel? Which package should I use for this task? msgpack-rpc looks interesting. Other packages have very low download rate. Or maybe there is some kind of generic appliaction server (but I'm looking for tcp/ip level, no http)? Any hints are very welcome. Thanks, Emanuel