Substreams Support for Avalanche C-Chain

3 min readJan 18, 2024


StreamingFast has kicked off 2024 with a bang — a new chain has Firehose and Substreams support! Developed for The Graph, The RPC Poller has allowed the StreamingFast team to easily integrate the Avalanche C-Chain, the first of many chains to be supported throughout 2024!

About Avalanche
At the time of writing, Avalanche is one of the largest alternatives to Ethereum.

It boasts:

  • 8th largest blockchain network by Total Value Locked (TVL)
  • 6th largest count of tracked dapps (as reported by DappRadar)
  • Nearly 100,000 Unique Active Wallets
  • 8th highest amount of value transacted weekly through dapps

This all points to a vibrant developer and user community, looking for better tooling to provide first-class user experiences.

Like many other L1 and L2 solutions, Avalanche was created with scalability in mind. Avalanche introduces the concept of subnets. You can think of a subnet as an independent blockchain depending on a parent blockchain (i.e. a sub-blockchain). Anyone can create a subnet and help the Avalanche network to scale horizontally.

Among all the subnets of the Avalanche network, there is a special one called the Primary Network, which runs three independent blockchains: The Platform Chain (P-Chain), the Contract Chain (C-Chain), and The Exchange Chain (X-Chain).

Source: Avalanche Documentation

Every Avalanche blockchain serves a different purpose. With Substreams, you will currently be able to retrieve indexed data from the Contract chain (C-chain). The Avalanche C-Chain is an implementation of the EVM and is used to deploy Solidity smart contracts. You can get more information within the Avalanche documentation.

Remember that chains indexed using the RPC Poller software will provide Base Blocks. You can get more information about Base Blocks in this article.

Getting Started with Avalanche Substreams
Avalanche is an EMV-compatible chain, so getting started is super easy! You can use the StreamingFast-provided endpoint (, which you can also find in the Substreams documentation.

substreams gui \ \
map_block_full \
-e \
- start-block 33323 - stop-block +100

If this is your first time building with Substreams, simply create an authentication key in the StreamingFast portal to get started on Avalanche. Also check out the StreamingFast Discord and The Graph Discord, which are great support tools for any questions you may have along the way.




StreamingFast is a protocol infrastructure company that provides a massively scalable architecture for streaming blockchain data.