Cowrie Research

substreams-primary-sources-2026-05-09

4 min read

Substreams primary-source snapshot

Fetched: 2026-05-09 UTC

1) Official docs introduction

Source: https://docs.substreams.dev/

Selected excerpts from the docs:

Substreams is a powerful indexing technology

Extract data from several blockchains (Solana, Ethereum, Polygon, BNB…)

Apply custom transformations to the data.

Send the data to a place of your choice (for example, a Postgres database or a file).

Additional signals from this page:

  • The official docs define Substreams as a transformation-oriented indexing engine rather than primarily a hosted query API
  • The docs emphasize extraction, custom transformation, and arbitrary sinks, which is analytically useful for separating it from query-first indexing products
  • The package model is explicit enough to treat Substreams packages as reusable data primitives, not just one-off app code

2) Public README

Source: https://raw.githubusercontent.com/streamingfast/substreams/develop/README.md

Selected excerpts from the README:

Substreams is a powerful blockchain indexing technology, developed for The Graph Network.

Substreams enables developers to write Rust modules, composing data streams alongside the community, and provides extremely high performance indexing by virtue of parallelization, in a streaming-first fashion.

Substreams has all the benefits of StreamingFast Firehose, like low-cost caching and archiving of blockchain data, high throughput processing, and cursor-based reorgs handling.

Additional signals from this page:

  • The project explicitly situates itself inside The Graph ecosystem while remaining a standalone open-source stack
  • Rust modules and community-composable data streams are central to the product identity
  • Firehose dependency is not incidental; it is part of the project’s explanation of performance and reorg behavior

3) Firehose docs home

Source: https://firehose.streamingfast.io/

Selected excerpts from the docs:

Firehose is a blockchain data streaming technology developed by StreamingFast working with The Graph Foundation.

The product provides previously unseen capabilities and speeds for indexing such data using a files-based and streaming-first approach.

Additional signals from this page:

  • Firehose is presented as the underlying extraction and streaming substrate rather than merely a supporting service
  • The documentation is operator-oriented, which is useful for understanding where practical control and complexity live in the stack
  • The Firehose docs themselves point readers toward component-level architecture, reinforcing that this is infrastructure rather than only an SDK veneer

4) Firehose overview

Source: https://firehose.streamingfast.io/introduction/firehose-overview

Selected excerpts from the overview:

Firehose provides a files-based and streaming-first approach to processing blockchain data.

Firehose is responsible for extracting data from blockchain nodes in a highly efficient manner.

Substreams is another application in the suite that works with Firehose to execute massive operations on historical blockchain data, in an extremely parallelized manner.

Additional signals from this page:

  • StreamingFast frames the stack as a response to slow or brittle JSON-RPC extraction patterns
  • Firehose is positioned as a lower-layer single source of truth for downstream consumers and higher-level indexing products
  • The parallel historical-processing angle is one of the strongest reasons to catalog Substreams separately from ordinary hosted indexers

5) Firehose architecture components

Source: https://firehose.streamingfast.io/firehose/architecture/components

Selected excerpts from the architecture page:

The Firehose system is comprised of several key components that work together to provide your desired functionality.

Reader Node Merger Relayer Firehose Substreams

Additional signals from this page:

  • The architecture explicitly treats Substreams as a first-class component in the Firehose family
  • Reader, merger, and relayer roles make the system meaningfully different from a simple RPC-plus-indexer stack
  • This component view helps clarify where operational authority and performance assumptions sit in practice

Notes

  • This pass did not locate a classic whitepaper or litepaper from official sources.
  • The most useful primary materials were the official docs, Firehose docs, and public GitHub repository.
  • Substreams is worth cataloging because it sharpens the distinction between extraction/transformation infrastructure and query-serving/indexer products higher in the stack.
  • Performance claims such as speed improvements and ecosystem breadth should still be treated as vendor or project claims unless independently verified.

Graph View