SubstreamsJS


TypeScript library for consuming Substreams suitable for web browsers, Node.js and alternative runtimes.

``typescript
import { createGrpcTransport } from "@bufbuild/connect-node";
import {
createAuthInterceptor,
createRegistry,
createRequest,
fetchSubstream,
isEmptyMessage,
streamBlocks,
unpackMapOutput,
} from "@substreams/core";

const SUBSTREAM = "https://github.com/streamingfast/substreams-uniswap-v3/releases/download/v0.2.7/substreams.spkg";
const MODULE = "map_pools_created";

const substream = await fetchSubstream(SUBSTREAM);
const registry = createRegistry(substream);
const transport = createGrpcTransport({
baseUrl: "https://mainnet.eth.streamingfast.io",
httpVersion: "2",
interceptors: [createAuthInterceptor("")],
jsonOptions: {
typeRegistry: registry,
},
});

const request = createRequest({
substreamPackage: substream,
outputModule: MODULE,
productionMode: true,
startBlockNum: 17250000n,
stopBlockNum: "+10000",
});

for await (const response of streamBlocks(transport, request)) {
const output = unpackMapOutput(response.response, registry);
if (output !== undefined && !isEmptyMessage(output)) {
console.dir(output.toJson({ typeRegistry: registry }));
}
}
`

Installation

> Note
> This library is pure ESM and no longer provides CommonJS (CJS) exports. If your project uses CommonJS, you will have to convert to ESM or use the dynamic import() function. Please don't open issues for questions regarding CommonJS / ESM.

`bash


Using pnpm

pnpm add @substreams/core

Using yarn

yarn add @substreams/core

Using npm

npm install @substreams/core
`

Packages

- @substreams/core:
Provides all core functionality for interacting with substreams packages and consuming substream modules. (source code).
- @substreams/manifest:
Parses and validates substreams.yaml manifests and bundles them into substream packages. (source code).
- @substreams/mermaid:
Generates mermaid graph visualizations of substream module graphs. (source code).
- @substreams/react:
Lightweight utilities for building React based user interfaces on top of substreams. (source code).
- @substreams/proxy:
Proxy server for adding connect protocol compatibility for substreams requests. This will be deprecated once the substreams service adds connect` compatibility. (source code).

Authors

- @fubhy (fubhy.eth, Twitter)

License

MIT License