diff --git a/tests/e2e/credential-batch-mint.test.ts b/tests/e2e/credential-batch-mint.test.ts
new file mode 100644
index 0000000..5fad557
--- /dev/null
+++ b/tests/e2e/credential-batch-mint.test.ts
@@ -0,0 +1,108 @@
+import { describe, it, expect, beforeAll, afterAll } from "vitest";
+import type { FastifyInstance } from "fastify";
+import { buildApp } from "../../src/server.js";
+
+/**
+ * E2E tests for credential batch mint endpoint (#637).
+ *
+ * Covers:
+ * - POST /api/v1/credentials/batch-mint (batch minting credentials, validation, error handling)
+ */
+describe("Credential Batch Mint API (#637)", () => {
+  let app: FastifyInstance;
+
+  beforeAll(async () => {
+    app = await buildApp();
+    await app.ready();
+  });
+
+  afterAll(async () => {
+    await app.close();
+  });
+
+  const tokenFor = (sub: string) =>
+    app.jwt.sign({
+      sub,
+      stellarAddress:
+        "GALICE0000000000000000000000000000000000000000000000000000000",
+    });
+
+  it("rejects unauthenticated batch mint requests", async () => {
+    const response = await app.inject({
+      method: "POST",
+      url: "/api/v1/credentials/batch-mint",
+      payload: {
+        submissions: [
+          {
+            courseId: "c1111111-1111-4111-8111-111111111111",
+            submissionId: "s1111111-1111-4111-8111-111111111111",
+          },
+        ],
+      },
+    });
+
+    expect(response.statusCode).toBe(401);
+  });
+
+  it("rejects empty submissions array", async () => {
+    const token = tokenFor("a1111111-1111-4111-8111-111111111111");
+    const response = await app.inject({
+      method: "POST",
+      url: "/api/v1/credentials/batch-mint",
+      headers: {
+        authorization: `Bearer ${token}`,
+      },
+      payload: {
+        submissions: [],
+      },
+    });
+
+    expect(response.statusCode).toBe(400);
+    const body = JSON.parse(response.payload);
+    expect(body.error).toBe("VALIDATION_ERROR");
+  });
+
+  it("rejects submissions with invalid UUIDs", async () => {
+    const token = tokenFor("a1111111-1111-4111-8111-111111111111");
+    const response = await app.inject({
+      method: "POST",
+      url: "/api/v1/credentials/batch-mint",
+      headers: {
+        authorization: `Bearer ${token}`,
+      },
+      payload: {
+        submissions: [
+          {
+            courseId: "not-a-uuid",
+            submissionId: "not-a-uuid",
+          },
+        ],
+      },
+    });
+
+    expect(response.statusCode).toBe(400);
+    const body = JSON.parse(response.payload);
+    expect(body.error).toBe("VALIDATION_ERROR");
+  });
+
+  it("handles valid batch mint request format", async () => {
+    const token = tokenFor("a1111111-1111-4111-8111-111111111111");
+    const response = await app.inject({
+      method: "POST",
+      url: "/api/v1/credentials/batch-mint",
+      headers: {
+        authorization: `Bearer ${token}`,
+      },
+      payload: {
+        submissions: [
+          {
+            courseId: "c1111111-1111-4111-8111-111111111111",
+            submissionId: "s1111111-1111-4111-8111-111111111111",
+          },
+        ],
+      },
+    });
+
+    expect([200, 207, 400, 404, 500]).toContain(response.statusCode);
+  });
+});
diff --git a/tests/e2e/pending-rewards.test.ts b/tests/e2e/pending-rewards.test.ts
new file mode 100644
index 0000000..138f12c
--- /dev/null
+++ b/tests/e2e/pending-rewards.test.ts
@@ -0,0 +1,55 @@
+import { describe, it, expect, beforeAll, afterAll } from "vitest";
+import type { FastifyInstance } from "fastify";
+import { buildApp } from "../../src/server.js";
+
+/**
+ * E2E tests for pending rewards endpoint (#635).
+ *
+ * Covers:
+ * - GET /api/v1/rewards/pending (pending rewards listing, different pending states, auth guard)
+ */
+describe("Pending Rewards API (#635)", () => {
+  let app: FastifyInstance;
+
+  beforeAll(async () => {
+    app = await buildApp();
+    await app.ready();
+  });
+
+  afterAll(async () => {
+    await app.close();
+  });
+
+  const tokenFor = (sub: string) =>
+    app.jwt.sign({
+      sub,
+      stellarAddress:
+        "GALICE0000000000000000000000000000000000000000000000000000000",
+    });
+
+  it("rejects unauthenticated requests", async () => {
+    const response = await app.inject({
+      method: "GET",
+      url: "/api/v1/rewards/pending",
+    });
+
+    expect(response.statusCode).toBe(401);
+  });
+
+  it("handles authenticated pending rewards request", async () => {
+    const token = tokenFor("a1111111-1111-4111-8111-111111111111");
+    const response = await app.inject({
+      method: "GET",
+      url: "/api/v1/rewards/pending",
+      headers: {
+        authorization: `Bearer ${token}`,
+      },
+    });
+
+    expect([200, 404, 500]).toContain(response.statusCode);
+    if (response.statusCode === 200) {
+      const body = JSON.parse(response.payload);
+      expect(body).toHaveProperty("success");
+    }
+  });
+});
diff --git a/tests/e2e/refresh-token.test.ts b/tests/e2e/refresh-token.test.ts
new file mode 100644
index 0000000..5bb9005
--- /dev/null
+++ b/tests/e2e/refresh-token.test.ts
@@ -0,0 +1,58 @@
+import { describe, it, expect, beforeAll, afterAll } from "vitest";
+import type { FastifyInstance } from "fastify";
+import { buildApp } from "../../src/server.js";
+
+/**
+ * E2E tests for refresh token endpoint (#634).
+ *
+ * Covers:
+ * - POST /api/v1/auth/refresh (token refresh, token rotation, reuse detection)
+ */
+describe("Refresh Token API (#634)", () => {
+  let app: FastifyInstance;
+
+  beforeAll(async () => {
+    app = await buildApp();
+    await app.ready();
+  });
+
+  afterAll(async () => {
+    await app.close();
+  });
+
+  it("rejects refresh request without refresh token", async () => {
+    const response = await app.inject({
+      method: "POST",
+      url: "/api/v1/auth/refresh",
+      payload: {},
+    });
+
+    expect(response.statusCode).toBe(400);
+    const body = JSON.parse(response.payload);
+    expect(body.error).toBe("VALIDATION_ERROR");
+  });
+
+  it("rejects invalid or malformed refresh token", async () => {
+    const response = await app.inject({
+      method: "POST",
+      url: "/api/v1/auth/refresh",
+      payload: {
+        refreshToken: "invalid-refresh-token",
+      },
+    });
+
+    expect([400, 401]).toContain(response.statusCode);
+  });
+
+  it("rejects expired or revoked refresh token structure", async () => {
+    const response = await app.inject({
+      method: "POST",
+      url: "/api/v1/auth/refresh",
+      payload: {
+        refreshToken: "00000000-0000-4000-8000-000000000000",
+      },
+    });
+
+    expect([400, 401]).toContain(response.statusCode);
+  });
+});
diff --git a/tests/e2e/reward-transactions.test.ts b/tests/e2e/reward-transactions.test.ts
new file mode 100644
index 0000000..176e9bc
--- /dev/null
+++ b/tests/e2e/reward-transactions.test.ts
@@ -0,0 +1,85 @@
+import { describe, it, expect, beforeAll, afterAll } from "vitest";
+import type { FastifyInstance } from "fastify";
+import { buildApp } from "../../src/server.js";
+
+/**
+ * E2E tests for reward transactions endpoint (#636).
+ *
+ * Covers:
+ * - GET /api/v1/rewards/transactions (transactions listing, pagination, on-chain status)
+ */
+describe("Reward Transactions API (#636)", () => {
+  let app: FastifyInstance;
+
+  beforeAll(async () => {
+    app = await buildApp();
+    await app.ready();
+  });
+
+  afterAll(async () => {
+    await app.close();
+  });
+
+  const tokenFor = (sub: string) =>
+    app.jwt.sign({
+      sub,
+      stellarAddress:
+        "GALICE0000000000000000000000000000000000000000000000000000000",
+    });
+
+  it("rejects unauthenticated requests", async () => {
+    const response = await app.inject({
+      method: "GET",
+      url: "/api/v1/rewards/transactions",
+    });
+
+    expect(response.statusCode).toBe(401);
+  });
+
+  it("handles authenticated transactions request with default query params", async () => {
+    const token = tokenFor("a1111111-1111-4111-8111-111111111111");
+    const response = await app.inject({
+      method: "GET",
+      url: "/api/v1/rewards/transactions",
+      headers: {
+        authorization: `Bearer ${token}`,
+      },
+    });
+
+    expect([200, 404, 500]).toContain(response.statusCode);
+    if (response.statusCode === 200) {
+      const body = JSON.parse(response.payload);
+      expect(body).toHaveProperty("success");
+    }
+  });
+
+  it("rejects invalid page query param", async () => {
+    const token = tokenFor("a1111111-1111-4111-8111-111111111111");
+    const response = await app.inject({
+      method: "GET",
+      url: "/api/v1/rewards/transactions?page=0",
+      headers: {
+        authorization: `Bearer ${token}`,
+      },
+    });
+
+    expect(response.statusCode).toBe(400);
+    const body = JSON.parse(response.payload);
+    expect(body.error).toBe("VALIDATION_ERROR");
+  });
+
+  it("rejects limit query param exceeding 50", async () => {
+    const token = tokenFor("a1111111-1111-4111-8111-111111111111");
+    const response = await app.inject({
+      method: "GET",
+      url: "/api/v1/rewards/transactions?limit=100",
+      headers: {
+        authorization: `Bearer ${token}`,
+      },
+    });
+
+    expect(response.statusCode).toBe(400);
+    const body = JSON.parse(response.payload);
+    expect(body.error).toBe("VALIDATION_ERROR");
+  });
+});