diff --git a/workbench-ui/src/app/trace/practiceEvidenceEndpoint.test.ts b/workbench-ui/src/app/trace/practiceEvidenceEndpoint.test.ts
new file mode 100644
index 00000000..81b7887a
--- /dev/null
+++ b/workbench-ui/src/app/trace/practiceEvidenceEndpoint.test.ts
@@ -0,0 +1,38 @@
+import { describe, expect, it, vi } from "vitest";
+import type { PracticeEvidence } from "../../types/practiceEvidence";
+import {
+  fetchTracePracticeWith,
+  tracePracticePath,
+  tracePracticeReproducer,
+} from "./practiceEvidenceEndpoint";
+
+const evidence: PracticeEvidence = {
+  schema_version: "practice_evidence_v1",
+  turn_id: 7,
+  status: "missing_evidence",
+  missing_reason: "sealed practice evidence was not persisted for this turn",
+  record_kind: null,
+  practice_disposition: null,
+  chain: [],
+  sealed_trace: null,
+  trace_refusal: null,
+  diagnostic_only: true,
+  serving_allowed: false,
+  mutation_allowed: false,
+  replay_execution_allowed: false,
+  replay_executed_by_workbench: false,
+};
+
+describe("practice evidence endpoint helpers", () => {
+  it("builds encoded trace practice paths", () => {
+    expect(tracePracticePath(7)).toBe("/trace/7/practice");
+    expect(tracePracticeReproducer(7)).toBe("curl /trace/7/practice");
+  });
+
+  it("fetches practice evidence through an injected fetcher", async () => {
+    const fetcher = vi.fn(<T,>(_path: string): Promise<T> => Promise.resolve(evidence as T));
+
+    await expect(fetchTracePracticeWith(7, fetcher)).resolves.toBe(evidence);
+    expect(fetcher).toHaveBeenCalledWith("/trace/7/practice");
+  });
+});