GraphQL

@rhi-zone/fractal-graphql-api-projector projects a Node tree into a GraphQL surface — SDL, resolver dispatch, subscriptions, and a typed client — deriving query/mutation naming and argument shapes from the tree's own structure and tags.

What it does

projectGraphQL walks the tree once: readOnly-tagged leaves (and read-like naming) become Query fields, everything else becomes Mutation fields; nested branches become namespace object types (camelCase-joined field names); a fallback becomes an argument on every field beneath it. Field-level type SDL is delegated to type-ir's toGraphQL/toGraphQLType (see Type-IR: wire formats) rather than re-implemented here. toSDL/toSchema render the assembled result to SDL text or an executable graphql-js schema.

Basic usage

import { api, op } from "@rhi-zone/fractal-api-tree"
import { toSDL, createHttpGraphQLServer } from "@rhi-zone/fractal-graphql-api-projector"

const tree = api({
  books: api({
    get: op((input: { id: string }) => ({ id: input.id, title: "Dune" }), { tags: { readOnly: true } }),
    add: op((input: { title: string }) => ({ id: "2", title: input.title })),
  }),
})

console.log(toSDL(tree))
// type Query { books: BooksQuery }
// type BooksQuery { get(id: String!): Book }
// type Mutation { booksAdd(title: String!): Book }

const handler = createHttpGraphQLServer(tree, { path: "/graphql" })
// (req: Request) => Promise<Response> — POST {query, variables?} or GET ?query=...

Resolver map (bring your own server)

import { createResolver } from "@rhi-zone/fractal-graphql-api-projector"

const resolvers = createResolver(tree) // dispatches onto the tree's own handlers

Typed client

import { createGraphQLClient } from "@rhi-zone/fractal-graphql-api-projector"

const client = createGraphQLClient(tree, { transport })
await client.books.get({ id: "1" })

Builds the query document (buildDocument) and selection set from the same field/type projection the server uses, so client and server never drift.

Subscriptions & codegen

import { createWsHandler, handleBunWebSocket } from "@rhi-zone/fractal-graphql-api-projector/ws" // stream leaves as GraphQL subscriptions
import { generateGraphQLClient } from "@rhi-zone/fractal-graphql-api-projector"                    // emit a standalone typed client module

Key exports

Export	Description
projectGraphQL(node, opts?)	Core walk — Node → ProjectGraphQLResult (fields, dispatch, named types)
toSDL(node, opts?) / toSchema(projection)	SDL text / executable graphql-js schema
createResolver(tree, opts?)	Resolver map dispatching onto tree handlers
createGraphQLServer(tree, opts?) / createHttpGraphQLServer(tree, opts?)	Server object / fetch-compatible HTTP handler
createWsHandler/handleBunWebSocket	Subscription transport wiring
createGraphQLClient(tree, opts?)	Typed client over a supplied GraphQLTransport
generateGraphQLClient(tree, opts?)	Codegen a standalone client module
graphqlErrors(mapping)	Error-to-GraphQL-error mapping