Graffy

Graffy is a live query library for the browser and Node.js. Graffy-powered servers fulfill each query with its initial result followed by a stream of relevant incremental updates. This is different (and better!) than GraphQL subscriptions, PouchDB sync, etc.

npm install @graffy/core

Graffy supports complex, expressive live queries - with multiple levels of resource expansion and pagination - based on a novel application of set theory and CRDTs.

Client-side example

import Graffy from '@graffy/core';
import GraffyClient from '@graffy/client';

const store = new Graffy();
store.use(new GraffyClient('/api'));

const query = {
  posts: [{ last: 10 }, { // Pagination parameters
    title: true,
    author: { name: true }
  }]
};

for await (const state of store.watch(query)) {
  // Iterates each time relevant data changes on the server.
  console.log(state);
}

Why Graffy?

Graffy provides live queries, which give clients a real-time view of the data they need. Graffy supports complex queries with nested graph traversals and pagination, while exposing a simple and intuitive API for building clients and servers.

Graffy was inspired by (and borrows from) Facebook's GraphQL and Netflix's Falcor. Compared to GraphQL, Graffy offers a more familiar data model, true live queries and more efficient caching. Compared to Falcor, it provides cursor-based pagination and real-time subscriptions.

Unlike GraphQL resolvers and Falcor data providers, Graffy providers can be composed like Express/Koa middleware. This allows authentication, validation, custom caches and resource limiting to be implemented in a straightforward manner.

Graffy providers can also perform efficient bulk reads from underlying data stores (for example by constructing optimized SQL queries). This is particularly hard to do with GraphQL (see dataloader) and Falcor.

Documentation

Modules

The graffy metapackage exports a constructor for a Graffy store in its default configuration.

All the Graffy packages are published under the @graffy scope on NPM.

Module	Description
core	Module management
fill	Fulfil queries from many providers
client	EventStream/HTTP client
server	EventStream/HTTP server
cache	In-memory cache
common	Shared utilities
react	React container and hooks API
stream	Utility for making AsyncIterables
testing	Testing and debugging utilities
graphql	Translate GraphQL to Graffy
schema	⌛ Validation, introspection API
viewer	⌛ Schema introspection client
auth	⌛ Authentication and authorization
limit	⌛ Resource consumption accounting
mysql	⌛ Data source connector
postgres	⌛ Data source connector

⌛ = On the roadmap.

Capabilities