diff --git a/packages/kilo-vscode/tests/unit/i18n-shim.test.ts b/packages/kilo-vscode/tests/unit/i18n-shim.test.ts
new file mode 100644
index 00000000000..ce586428cc3
--- /dev/null
+++ b/packages/kilo-vscode/tests/unit/i18n-shim.test.ts
@@ -0,0 +1,65 @@
+import { describe, it, expect } from "bun:test"
+import { t } from "../../src/services/autocomplete/shims/i18n"
+
+describe("t()", () => {
+  it("returns translated string for known key", () => {
+    const result = t("kilocode:autocomplete.statusBar.enabled")
+    expect(typeof result).toBe("string")
+    expect(result.length).toBeGreaterThan(0)
+    expect(result).not.toBe("kilocode:autocomplete.statusBar.enabled")
+  })
+
+  it("returns the key itself for unknown key", () => {
+    expect(t("nonexistent.key.that.does.not.exist")).toBe("nonexistent.key.that.does.not.exist")
+  })
+
+  it("returns empty string for empty key", () => {
+    expect(t("")).toBe("")
+  })
+
+  it("interpolates a single variable", () => {
+    const result = t("kilocode:autocomplete.statusBar.tooltip.noUsableProvider", {
+      providers: "OpenAI, Anthropic",
+    })
+    expect(result).toContain("OpenAI, Anthropic")
+    expect(result).not.toContain("{{providers}}")
+  })
+
+  it("interpolates multiple variables", () => {
+    const result = t("kilocode:autocomplete.statusBar.tooltip.completionSummary", {
+      count: "5",
+      startTime: "10:00",
+      endTime: "11:00",
+      cost: "$0.05",
+    })
+    expect(result).toContain("5")
+    expect(result).toContain("10:00")
+    expect(result).toContain("11:00")
+    expect(result).toContain("$0.05")
+    expect(result).not.toContain("{{")
+  })
+
+  it("interpolates numeric variable as string", () => {
+    const result = t("kilocode:autocomplete.statusBar.tooltip.noUsableProvider", {
+      providers: 42 as unknown as string,
+    })
+    expect(result).toContain("42")
+  })
+
+  it("leaves unreferenced vars intact in template", () => {
+    const key = "kilocode:autocomplete.statusBar.tooltip.noUsableProvider"
+    const result = t(key, { unrelated: "value" })
+    expect(result).toContain("{{providers}}")
+  })
+
+  it("returns the raw key when called without vars on a template key", () => {
+    const result = t("kilocode:autocomplete.statusBar.tooltip.noUsableProvider")
+    expect(result).toContain("{{providers}}")
+  })
+
+  it("handles empty vars object (no interpolation)", () => {
+    const result = t("kilocode:autocomplete.statusBar.enabled", {})
+    expect(typeof result).toBe("string")
+    expect(result).not.toContain("{{")
+  })
+})