Add page backlink helper method

packages/nclient/readme.md

@@ -29,6 +29,19 @@ const collectionViewId = 'ab639a5a-853e-45e1-9ef7-133b486c0acf'
 const collectionData = await api.getCollectionData(collectionId, collectionViewId)
 ```
 
+### Fetch backlinks
+
+Backlinks require an auth token.
+
+```ts
+const backlinks = await api.getBacklinks({
+  block: { id: 'page-id', spaceId: 'space-id' }
+})
+
+// or simply pass the page id
+const pageBacklinks = await api.getPageBacklinks('page-id')
+```
+
 ### Fetch a database's content
 
 You can pass a database ID to the `getPage` method. The response is an object which contains several important properties:

packages/nclient/src/notion-api.test.ts

@@ -59,6 +59,12 @@ test(`Backlink`, { timeout: 10000, concurrent: true }, async () => {
   expect(backlinks.backlinks.length > 0)
 })
 
+test(`Page Backlink`, { timeout: 10000, concurrent: true }, async () => {
+  const api = new NotionAPI({ authToken: process.env.NOTION_TOKEN })
+  const backlinks = await api.getPageBacklinks('441d5ce2-b781-46d0-9354-54042b4f06d9')
+  expect(backlinks.backlinks.length > 0)
+})
+
 test(`Get block`, { timeout: 10000, concurrent: true }, async () => {
   const id = '3f9e0d86-c643-4672-aa0c-78d63fa80598'
   const api = new NotionAPI()

packages/nclient/src/notion-api.ts

@@ -574,6 +574,23 @@ export class NotionAPI {
     })
   }
 
+  /**
+   * Fetch backlinks for a page by automatically resolving its space id.
+   * Requires an authToken since backlinks are a private API.
+   *
+   * @param pageId page id or url
+   * @param fetchOption additional fetch options
+   */
+  public async getPageBacklinks(pageId: string, fetchOption?: FetchOption) {
+    const id = parsePageId(pageId)
+    const res = await this.getBlocks([id], fetchOption)
+    const block = res.recordMap.block[id]?.value
+    if (!block) throw new Error(`Block not found "${uuidToId(id)}"`)
+    const spaceId = block.space_id
+
+    return this.getBacklinks({ block: { id, spaceId } }, fetchOption)
+  }
+
   public async fetch<T>({
     endpoint,
     body,