diff --git a/packages/opencode/src/config/config.ts b/packages/opencode/src/config/config.ts
index 27ba4e186712..0194ddf1cf86 100644
--- a/packages/opencode/src/config/config.ts
+++ b/packages/opencode/src/config/config.ts
@@ -510,17 +510,31 @@ export namespace Config {
 
   /**
    * Extracts a canonical plugin name from a plugin specifier.
-   * - For file:// URLs: extracts filename without extension
+   * - For file:// URLs pointing into node_modules: extracts npm package name
+   * - For other file:// URLs: extracts filename without extension
    * - For npm packages: extracts package name without version
    *
    * @example
+   * getPluginName("file:///path/to/node_modules/oh-my-opencode/dist/index.js") // "oh-my-opencode"
+   * getPluginName("file:///path/to/node_modules/@scope/pkg/index.js") // "@scope/pkg"
    * getPluginName("file:///path/to/plugin/foo.js") // "foo"
    * getPluginName("oh-my-opencode@2.4.3") // "oh-my-opencode"
    * getPluginName("@scope/pkg@1.0.0") // "@scope/pkg"
    */
   export function getPluginName(plugin: string): string {
     if (plugin.startsWith("file://")) {
-      return path.parse(new URL(plugin).pathname).name
+      const parsed = new URL(plugin).pathname
+      const nm = parsed.lastIndexOf("/node_modules/")
+      if (nm !== -1) {
+        const after = parsed.substring(nm + "/node_modules/".length)
+        // scoped packages: @scope/pkg/dist/index.js → @scope/pkg
+        if (after.startsWith("@")) {
+          const parts = after.split("/")
+          return parts.slice(0, 2).join("/")
+        }
+        return after.split("/")[0]
+      }
+      return path.parse(parsed).name
     }
     const lastAt = plugin.lastIndexOf("@")
     if (lastAt > 0) {
diff --git a/packages/opencode/test/config/config.test.ts b/packages/opencode/test/config/config.test.ts
index baf209d86079..611a215a4887 100644
--- a/packages/opencode/test/config/config.test.ts
+++ b/packages/opencode/test/config/config.test.ts
@@ -1734,6 +1734,19 @@ describe("getPluginName", () => {
     expect(Config.getPluginName("file:///some/path/my-plugin.js")).toBe("my-plugin")
   })
 
+  test("extracts package name from file:// URL inside node_modules", () => {
+    expect(Config.getPluginName("file:///home/user/.config/opencode/node_modules/oh-my-opencode/dist/index.js")).toBe(
+      "oh-my-opencode",
+    )
+    expect(
+      Config.getPluginName("file:///home/user/.config/opencode/node_modules/opencode-openai-codex-auth/index.ts"),
+    ).toBe("opencode-openai-codex-auth")
+    expect(Config.getPluginName("file:///project/node_modules/@scope/plugin/dist/index.js")).toBe("@scope/plugin")
+    expect(Config.getPluginName("file:///project/node_modules/@different-ai/opencode-browser/index.js")).toBe(
+      "@different-ai/opencode-browser",
+    )
+  })
+
   test("extracts name from npm package with version", () => {
     expect(Config.getPluginName("oh-my-opencode@2.4.3")).toBe("oh-my-opencode")
     expect(Config.getPluginName("some-plugin@1.0.0")).toBe("some-plugin")
@@ -1781,6 +1794,18 @@ describe("deduplicatePlugins", () => {
     expect(result).toEqual(["a-plugin@1.0.0", "b-plugin@1.0.0", "c-plugin@1.0.0"])
   })
 
+  test("does not treat resolved node_modules index.js files as duplicates", () => {
+    const plugins = [
+      "file:///config/node_modules/oh-my-opencode/dist/index.js",
+      "file:///config/node_modules/opencode-openai-codex-auth/index.ts",
+      "file:///config/node_modules/@scope/plugin/dist/index.js",
+    ]
+
+    const result = Config.deduplicatePlugins(plugins)
+
+    expect(result.length).toBe(3)
+  })
+
   test("local plugin directory overrides global opencode.json plugin", async () => {
     await using tmp = await tmpdir({
       init: async (dir) => {