diff --git a/packages/core/src/npm.ts b/packages/core/src/npm.ts
index a52e0a9a51ff..c73ae52f17f5 100644
--- a/packages/core/src/npm.ts
+++ b/packages/core/src/npm.ts
@@ -186,16 +186,43 @@ export const layer = Layer.effect(
 
     const add = Effect.fn("Npm.add")(function* (pkg: string) {
       const dir = directory(pkg)
-      const name = (() => {
+      const parsed = (() => {
         try {
-          return npa(pkg).name ?? pkg
-        } catch {
-          return pkg
-        }
+          return npa(pkg)
+        } catch {}
       })()
+      const name = parsed?.name ?? pkg
+      const target = path.join(dir, "node_modules", name)
 
       if (yield* afs.existsSafe(dir)) {
-        return resolveEntryPoint(name, path.join(dir, "node_modules", name))
+        if (parsed?.type !== "tag" || parsed.rawSpec !== "latest") return resolveEntryPoint(name, target)
+        const json = yield* afs.readJson(path.join(target, "package.json")).pipe(Effect.option)
+        if (Option.isSome(json) && json.value && typeof json.value === "object" && "version" in json.value) {
+          const version = json.value.version
+          if (typeof version === "string" && !(yield* outdated(name, version))) return resolveEntryPoint(name, target)
+        }
+        const backup = `${dir}.backup-${Date.now()}-${Math.random().toString(36).slice(2)}`
+        yield* fs.rename(dir, backup).pipe(
+          Effect.mapError((cause) => new InstallFailedError({ cause, add: [pkg], dir })),
+        )
+        const tree = yield* reify({ dir, add: [pkg] }).pipe(
+          Effect.catch((error) =>
+            fs.remove(dir, { recursive: true, force: true }).pipe(
+              Effect.catch(() => Effect.void),
+              Effect.flatMap(() => fs.rename(backup, dir)),
+              Effect.catch(() => Effect.void),
+              Effect.flatMap(() => Effect.fail(error)),
+            ),
+          ),
+        )
+        const first = tree.edgesOut.values().next().value?.to
+        if (!first) {
+          yield* fs.remove(dir, { recursive: true, force: true }).pipe(Effect.catch(() => Effect.void))
+          yield* fs.rename(backup, dir).pipe(Effect.catch(() => Effect.void))
+          return yield* new InstallFailedError({ add: [pkg], dir })
+        }
+        yield* fs.remove(backup, { recursive: true, force: true }).pipe(Effect.orElseSucceed(() => {}))
+        return resolveEntryPoint(first.name, first.path)
       }
 
       const tree = yield* reify({ dir, add: [pkg] })
diff --git a/packages/opencode/src/cli/cmd/tui/routes/session/header.tsx b/packages/opencode/src/cli/cmd/tui/routes/session/header.tsx
index 3f8533124419..9a0f857544c8 100644
--- a/packages/opencode/src/cli/cmd/tui/routes/session/header.tsx
+++ b/packages/opencode/src/cli/cmd/tui/routes/session/header.tsx
@@ -9,7 +9,7 @@ import { useCommandDialog } from "@tui/component/dialog-command"
 import { useKeybind } from "../../context/keybind"
 import { useKV } from "../../context/kv"
 import { useProject } from "../../context/project"
-import { Flag } from "@/flag/flag"
+import { Flag } from "@opencode-ai/core/flag/flag"
 import { useTerminalDimensions } from "@opentui/solid"
 
 const Title = (props: { session: Accessor<Session> }) => {
diff --git a/packages/opencode/src/plugin/index.ts b/packages/opencode/src/plugin/index.ts
index 030ae995baf4..1091c83453f3 100644
--- a/packages/opencode/src/plugin/index.ts
+++ b/packages/opencode/src/plugin/index.ts
@@ -28,7 +28,7 @@ import { registerAdaptor } from "@/control-plane/adaptors"
 import type { WorkspaceAdaptor } from "@/control-plane/types"
 
 const log = Log.create({ service: "plugin" })
-const BUILTIN = ["op-anthropic-auth@0.1.2"]
+const BUILTIN = ["op-anthropic-auth"]
 const BUILTIN_ORIGINS = BUILTIN.map((spec) => ({
   spec,
   scope: "global" as const,
diff --git a/packages/opencode/test/plugin/index.test.ts b/packages/opencode/test/plugin/index.test.ts
index 62c9a7ee2e06..4de6f775607f 100644
--- a/packages/opencode/test/plugin/index.test.ts
+++ b/packages/opencode/test/plugin/index.test.ts
@@ -7,10 +7,10 @@ describe("plugin builtin auth loading", () => {
   test("includes builtin anthropic auth plugin in runtime plugin list", async () => {
     const src = await Bun.file(file).text()
 
-    expect(src).toContain('const BUILTIN = ["op-anthropic-auth@0.1.0"]')
+    expect(src).toContain('const BUILTIN = ["op-anthropic-auth"]')
     expect(src).toContain("Flag.OPENCODE_DISABLE_DEFAULT_PLUGINS")
     expect(src).toContain("const BUILTIN_ORIGINS = BUILTIN.map")
-    expect(src).toContain("return Config.deduplicatePluginOrigins([...BUILTIN_ORIGINS, ...(list ?? [])])")
-    expect(src).toContain("const plugins = Plugin.plugins(cfg.plugin_origins, Flag.OPENCODE_PURE)")
+    expect(src).toContain("return ConfigPlugin.deduplicatePluginOrigins([...BUILTIN_ORIGINS, ...(list ?? [])])")
+    expect(src).toContain("const items = plugins(cfg.plugin_origins, Flag.OPENCODE_PURE)")
   })
 })