You need to create/edit the configuration file config.json in the same folder as your bootstrap file. Please see this example.

Main Entries

db.<mydb>.<prop>: put your database info here. <mydb> is the name of CouchDB database you want to stream to Elasticsearch. Put as many databases as you want here, Nesu will stream all the way.

default.<prop>: serve as default properties. Will be used if none are provided in db.<mydb>.<prop>section.


bulkLimit: max. number of documents in a bulk operation. Optional, defaults to 1000 documents

idleTimeout: how long to wait for a new changes to arrive. In seconds, optional, default to 2 seconds. If you put 0 in it, it’ll use continuous stream provided by nano.db.follow instead of regular polling (nano.db.changes)

cdb.url: the url of your CouchDB server endpoint. Optional, defaults to http://localhost:5984 name of CouchDB database if different from the db’s key name. Optional, defaults to the db’s key

es.url: the url of your Elasticsearch endpoint. Optional, defaults to http://localhost:9200 name of Elasticsearch index if different from the db’s key name. Optional, defaults to the db’s key

es.typeField: document’s key name to be used as Elasticsearch’s type field. Optional, defaults to doc.


You have the ability to transform each document to something new before written to Elasticsearch easily.

All you need to do is just create a new js file inside the transformer folder with the exact name as its corresponding database. E.g. if your database name is mydb, than your transformer file will be mydb.js

And use the following code fragment as your starting point:

module.exports = function(doc, callback) {

Last Sequence

Everytime a bulk of documents is written to Elasticsearch, its last sequence is saved in a file named after the database name, inside last_seq folder.

To reset the sequence from the very beginning, just delete the file. To start from an exact known sequence, just override its content. And to start from the actual one, put ‘now’ (without the quotes) in it

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