Express Showcase | CrossConnection

CrossConnection Docs

Interactive package documentation

Express Showcase

Gateway-style and telemetry-aware integration patterns for Node services.

Gateway Route Example

1import express from "express";
2import { createCrossConnection } from "cross-connection";
3
4const app = express();
5app.use(express.json());
6
7const upstream = createCrossConnection({
8  baseURL: "https://api.example.com",
9  retry: { retries: 2, baseDelayMs: 90, maxDelayMs: 900 },
10  security: {
11    allowHosts: ["api.example.com"],
12    blockPrivateIPs: true,
13    blockLocalhost: true,
14  },
15});
16
17app.get("/gateway/health", async (_req, res) => {
18  const response = await upstream.get("/health");
19  res.status(response.status).json(response.data);
20});

Telemetry Hooks

1const client = createCrossConnection({
2  telemetry: {
3    onRetry: (event) => logger.warn({ event }, "retrying upstream call"),
4    onComplete: (event) => logger.info({ event }, "upstream complete"),
5  },
6});

Protect upstream calls with SSRF and allowlist controls near your edge routes.
Use telemetry hooks for retry visibility in logs and tracing systems.
Apply consistent retry behavior for flaky third-party dependencies.