Postgres 9.4+ lets you use the write-ahead log and "replication slots" using which you can create streams of database changes that can be replayed to a client in the order they were made on the origin server [1]

EDIT: In case the question was which library did I use, I used BottledWater and it's worked great for me so far [2]

[1] https://www.postgresql.org/docs/9.4/static/logicaldecoding-e...

[2] https://github.com/confluentinc/bottledwater-pg