feat: initial implementation of backlinks extension

README.md

@@ -0,0 +1,26 @@
+# Obsidian Local REST API — Backlinks Extension
+
+This is an extension for the [Obsidian Local REST API](https://github.com/coddingtonbear/obsidian-local-rest-api) plugin. It adds a new endpoint to retrieve backlinks for a specific note.
+
+## Features
+- **GET `/extensions/backlinks/{filepath}`**: Returns all notes that link to the specified file.
+
+## Installation
+1. Install the [Obsidian Local REST API](https://github.com/coddingtonbear/obsidian-local-rest-api) plugin.
+2. Download the `main.js` and `manifest.json` from the `/dist` folder of this repository.
+3. Create a folder named `obsidian-local-rest-api-backlinks` in your vault's `.obsidian/plugins/` directory.
+4. Place `main.js` and `manifest.json` into that folder.
+5. Restart Obsidian or reload plugins.
+6. Enable the plugin in **Settings > Community Plugins**.
+
+## Usage Example
+```bash
+curl -k -H "Authorization: Bearer YOUR_API_KEY" \
+  "https://127.0.0.1:PORT/extensions/backlinks/MyNote.md"
+```
+
+## Development
+```bash
+npm install
+npm run build
+```

manifest.json

@@ -0,0 +1,9 @@
+{
+  "id": "obsidian-local-rest-api-backlinks",
+  "name": "Local REST API — Backlinks Extension",
+  "version": "1.0.0",
+  "minAppVersion": "1.0.0",
+  "description": "Adds a /extensions/backlinks/ route to Obsidian Local REST API to retrieve backlinks for a specific note.",
+  "author": "Hermes",
+  "isDesktopOnly": false
+}

package.json

@@ -0,0 +1,18 @@
+{
+  "name": "obsidian-local-rest-api-backlinks",
+  "version": "1.0.0",
+  "description": "Obsidian Local REST API Backlinks Extension",
+  "main": "main.js",
+  "types": "main.d.ts",
+  "dependencies": {
+    "obsidian": "npm:obsidian@^1.0.0",
+    "obsidian-local-rest-api": "npm:obsidian-local-rest-api@^2.5.0"
+  },
+  "devDependencies": {
+    "typescript": "^5.0.0",
+    "esbuild": "^0.19.0"
+  },
+  "scripts": {
+    "build": "esbuild src/main.ts --bundle --outfile=dist/main.js --external:obsidian --platform=node --target=es2020"
+  }
+}

src/main.ts

@@ -0,0 +1,77 @@
+import { Plugin, TFile, normalizePath } from "obsidian";
+import {
+  LocalRestApiPublicApi,
+  Route,
+  Request,
+  Response,
+} from "obsidian-local-rest-api";
+
+interface LinkMetadata {
+  displayText: string;
+  link: string;
+  original: string;
+  position: { start: unknown; end: unknown };
+}
+
+interface BacklinksData {
+  data: Record<string, LinkMetadata[]>;
+}
+
+export default class BacklinksExtension extends Plugin {
+  async onload() {
+    console.log("Loading Local REST API Backlinks Extension...");
+    
+    const api = (this.app as any).plugins.plugins[
+      "obsidian-local-rest-api"
+    ]?.api as LocalRestApiPublicApi | undefined;
+
+    if (!api) {
+      console.error("Local REST API plugin not found. Please ensure it is installed and enabled.");
+      return;
+    }
+
+    const routes: Route[] = [
+      {
+        path: "/extensions/backlinks/{*}",
+        method: "get",
+        handler: async (req: Request, res: Response) => {
+          const filePath = req.params["*"] ?? "";
+          const path = normalizePath(filePath);
+
+          const file = this.app.vault.getAbstractFileByPath(path);
+          if (!file) {
+            return res.status(404).json({
+              errorCode: 40,
+              message: `File not found at path: ${filePath}`,
+            });
+          }
+          if (!(file instanceof TFile)) {
+            return res.status(400).json({
+              errorCode: 405,
+              message: `Path is a folder, not a file: ${path}`,
+            });
+          }
+
+          const backlinks: BacklinksData =
+            (this.app as any).metadataCache.getBacklinksForFile(file);
+
+          const result: Record<string, LinkMetadata[]> = {};
+          if (backlinks && backlinks.data) {
+            for (const [sourcePath, links] of Object.entries(backlinks.data)) {
+              result[sourcePath] = links;
+            }
+          }
+
+          return res.json({
+            file: path,
+            backlinks: result,
+            count: Object.keys(result).length,
+          });
+        },
+      },
+    ];
+
+    api.registerRoutes(routes);
+    console.log("Backlinks route registered: GET /extensions/backlinks/{*}");
+  }
+}