WIP Python Interface for querying via substreams

1. Install the package:

pip3 install substreams

2. Generate a StreamingFast API Token

   • Can do so via this link
   • Be sure to save the Token as an env var

   export SUBSTREAMS_API_TOKEN="<MY_CUSTON_SPI_TOKEN>"
   

3. Retrieve the relevant .spkg file

   • Can retrieve officially released .spkg files from the instructions here
     • Alternatively, can refer to the official StreamingFast README or generate a Messari .spkg from these build instructions

First import the Substream object and pass in the path to your .spkg file

from substreams import Substream

sb = Substream("substreams-uniswap-v2-v0.1.0.spkg")

If you already have the sf/substreams repo generated (as per step #3 in these instructions), then the library will import from those files. Otherwise, the files will be generated dynamically.

In order to poll the substream, you will need to call the poll() function on the Substream object. poll() requires that you specify a list of output modules, you can inspect what modules are available by calling supported_output_modules

# View available modules on .spkg
print(sb.output_modules)

# Poll the module and return a list of SubstreamOutput objects in the order of teh specified modules
result = sb.poll(["store_swap_events"], start_block=10000835, end_block=10000835+20000)

The result here is a SubstreamOutput object, you can access both the data and snapshots dataframes by doing:

# These will return pandas DataFrames
swap_events_result = results[0]
data_df = swap_events_result.data
snapshots_df = swap_events_result.snapshots