[federation] add utility to fetch managed federation supergraph

.gitignore

@@ -75,3 +75,5 @@ package-lock.json
 website/public/_redirects
 website/public/sitemap.xml
 website/src/pages/docs/api/
+
+.mise.toml

packages/federation/src/gateway.ts

@@ -22,6 +22,7 @@ import {
  inspect,
 } from '@graphql-tools/utils';
 import { SubgraphBaseSDL } from './subgraph.js';
+import { getStitchedSchemaFromSupergraphSdl } from './supergraph.js';
 import {
  filterInternalFieldsAndTypes,
  getArgsFromKeysForFederation,
@@ -232,3 +233,75 @@ export const federationSubschemaTransformer: SubschemaConfigTransform =
  },
  };
  };
+
+export async function getStitchedSchemaFromManagedFederation(options: {
+ graphRef: string;
+ apiKey: string;
+ upLink?: string;
+ lastSeenId?: string;
+ abortSignal?: AbortSignal;
+}) {
+ const { upLink = 'https://gateway.apollo.dev/graphql', abortSignal, ...variables } = options;
+
+ const response = await fetch(upLink, {
+ method: 'POST',
+ signal: abortSignal,
+ headers: {
+ 'Content-Type': 'application/json',
+ },
+ body: JSON.stringify({
+ query: /* GraphQL */ `
+ query ($apiKey: String!, $graphRef: String!, $lastSeenId: ID) {
+ routerConfig(ref: $graphRef, apiKey: $apiKey, ifAfterId: $lastSeenId) {
+ __typename
+ ... on FetchError {
+ code
+ message
+ }
+ ... on RouterConfigResult {
+ id
+ supergraphSDL
+ minDelaySeconds
+ }
+ }
+ }
+ `,
+ variables,
+ }),
+ });
+
+ if (!response.ok) {
+ throw new Error(
+ `Failed to fetch supergraph SDL from managed federation up link '${upLink}': [${response.status} ${response.statusText}] ${await response.text()}`,
+ );
+ }
+
+ try {
+ const { data, errors }: ExecutionResult = await response.json();
+
+ if (errors) {
+ throw new Error(
+ `Failed to fetch supergraph SDL from managed federation up link '${upLink}': ${errors.map(({ message }) => '\n' + message).join('')}`,
+ );
+ }
+
+ if (data.routerConfig.__typename === 'FetchError') {
+ const { code, message } = data.routerConfig;
+ throw new Error(
+ `Failed to fetch supergraph SDL from managed federation up link '${upLink}': [${code}] ${message}`,
+ );
+ }
+
+ const { supergraphSDL, id, minDelaySeconds } = data.routerConfig;
+
+ return {
+ schema: getStitchedSchemaFromSupergraphSdl(supergraphSDL),
+ id,
+ minDelaySeconds,
+ };
+ } catch (err) {
+ throw new Error(
+ `Failed to parse response from managed federation up link '${upLink}': ${await response.text()}`,
+ );
+ }
+}

packages/federation/src/supergraph.ts

@@ -1067,6 +1067,8 @@ export function getSubschemasFromSupergraphSdl({
  return subschemaMap;
 }
 
+export function getStichedSchemaFromManageFederation() {}
+
 export function getStitchedSchemaFromSupergraphSdl(opts: GetSubschemasFromSupergraphSdlOpts) {
  const subschemaMap = getSubschemasFromSupergraphSdl(opts);
  const supergraphSchema = stitchSchemas({