add endpoints to readme

README.md

@@ -1,6 +1,19 @@
-# Ethereum Blobs Monorepo
+# Ethereum Blobs
 This repository contains several components:
 - `proto` - Blobs protobuf definitions
 - `substreams` - Substreams modules to stream blobs data from substreams-enabled Consensus Layer Firehose
 - `subgraph` - Substreams-based Subgraph that uses substreams module
 - `api-service` - REST API service to access to blobs via substreams sink that can be used as a drop-in replacement for Consensus Layer clients' blob_sidecar API
+
+## Substreams
+For source of block data, you need to have access to consensus layer substreams-enabled firehose endpoint for your chain, powered by [Beacon Firehose](https://github.com/pinax-network/firehose-beacon).
+
+You can either run your own stack (hard) or use endpoints provided by [Pinax](https://pinax.network/) (easy).
+
+Currently, the following chains are supported:
+- Ethereum: `eth-cl.substreams.pinax.network:443`
+- Holesky: `holesky-cl.substreams.pinax.network:443`
+- Sepolia: `sepolia-cl.substreams.pinax.network:443`
+- Goerli: `goerli-cl.substreams.pinax.network:443`
+- Gnosis: `gnosis-cl.substreams.pinax.network:443`
+- Chiado: `chiado-cl.substreams.pinax.network:443`