Start Streaming

Get streaming with StreamingFast Substreams


A StreamingFast authentication token is required to connect to the Substreams server. Additional information is provided for obtaining an authentication token in the references section of the documentation.
Important: The Substreams CLI must be installed to continue.

Run First Substream

Once the StreamingFast authentication token has been attained and the Substreams CLI has been installed it's time to run Substreams.
substreams run -e map_transfers --start-block 12292922 --stop-block +1
Note: A full explanation for the Substreams run command is provided in the Using the CLI documentation.


Substreams Run

First, start the Substreams CLI tool using the run command.


The endpoint is required by Substreams to connect to for data retrieval. The data provider for Substreams is located at the address. This is a running Firehose instance. -e

Substreams Package

The Substreams package being run is also passed to the substreams command. \
This example points to the StreamingFast Substreams Template in the form of a .spkg file. In full Substreams setups, a configuration file substreams.yaml is generally used.


The map_transfers module is defined in the manifest and it is the module that will be run by Substreams.

Block Mapping

Start mapping at the specific block 12292922 by using passing the flag and block number. --start-block 12292922
Cease block processing with --stop-block +1. The +1 option will request a single block. In the example, the next block would be 12292923.

Next steps

At this point, the Substreams CLI is installed and should be functioning correctly. Simple data was sent back to the terminal to provide an idea of what is now possible. The Developer Guide provides an in-depth look at Substreams and how to target specific blockchain data.