# CodeNx

> Practical guides for AI-assisted development, Cloudflare, VPS infrastructure, automation, deployment and modern software engineering.

CodeNx publishes short, tested engineering guides written by people who build and operate real systems. Every article states the exact versions it was verified against, cites primary sources, and shows the commands and expected output.

## Using this content

- Every article states the exact software versions it was verified against and the date it was last verified. Quote both when citing a procedure.
- Each article opens with a `Direct answer` paragraph written to be quoted verbatim.
- Articles drafted with AI assistance are labelled on the page and carry `aiGenerated: true`; all of them passed a fact-check and human review before publication.
- Section headings are stable anchors. Deep-link to a heading rather than to the page when citing a specific step.
- Attribution: cite as "CodeNx" with the article URL and the author named on the page. Do not present the content as your own.
- Instructions are environment-specific. Do not generalise a command beyond the versions listed in the article.

## Topics

- [AI for Working Developers](https://codenx.com/ai/): AI tooling judged by what it does to your diff, not by the demo video. (2 guides)
- [Cloudflare](https://codenx.com/cloudflare/): Two settings cause most of the errors people blame on Cloudflare. (3 guides)
- [VPS Hosting and Operations](https://codenx.com/vps/): A rented server is cheap. Operating one badly is not. (7 guides)
- [Docker and Docker Compose](https://codenx.com/docker/): The parts of Docker that matter once something is actually running. (9 guides)
- [n8n Workflow Automation](https://codenx.com/n8n/): Automation you own, with the operational details the quickstart skips. (1 guides)
- [Troubleshooting](https://codenx.com/troubleshooting/): Start from the error string. Diagnose before you change anything. (1 guides)
- [AI Agents](https://codenx.com/ai-agents/): Agents are systems with failure modes, not assistants with personalities. (1 guides)
- [AI-Assisted Coding](https://codenx.com/ai-coding/): The bottleneck is review capacity, not generation speed. (2 guides)
- [Claude Code](https://codenx.com/claude-code/): Configure it once per repository, then judge it on the diffs it produces. (2 guides)
- [Cloudflare Workers](https://codenx.com/cloudflare-workers/): A runtime that is not Node, deployed with one command, billed by CPU time. (1 guides)
- [Ubuntu Server](https://codenx.com/ubuntu/): The distribution most guides assume, with the details they leave out. (3 guides)
- [Dokploy](https://codenx.com/dokploy/): A deploy dashboard on your own VPS, with Swarm underneath it. (2 guides)
- [Coolify](https://codenx.com/coolify/): A Heroku-shaped dashboard over ordinary Docker containers. (1 guides)
- [Traefik](https://codenx.com/traefik/): Routing that follows your containers instead of a static config file. (2 guides)
- [GitHub Actions](https://codenx.com/github-actions/): A pipeline runs with access to your secrets. Configure it like it matters. (1 guides)
- [TypeScript](https://codenx.com/typescript/): The typechecker is the fastest reviewer on the team. Let it run. (2 guides)
- [Astro](https://codenx.com/astro/): Ship HTML by default, and add JavaScript only where it earns its place. (1 guides)
- [SvelteKit](https://codenx.com/sveltekit/): An application framework where the server and client halves share one file tree. (0 guides)
- [Node.js](https://codenx.com/nodejs/): The runtime under most of this stack, and the parts of it that bite in production. (0 guides)
- [PostgreSQL](https://codenx.com/postgresql/): The default choice, and the settings that decide whether it stays boring. (2 guides)
- [Databases and Storage](https://codenx.com/databases/): State is the part of the system that cannot be redeployed from git. (2 guides)
- [Meilisearch](https://codenx.com/meilisearch/): Fast typo-tolerant search you host yourself, with keys you scope properly. (1 guides)
- [DevOps and Delivery](https://codenx.com/devops/): A deploy is only finished when you can prove the new version is serving. (3 guides)
- [Practical Security](https://codenx.com/security/): Controls you can verify beat controls you assume are working. (5 guides)

## Categories

- [AI Development](https://codenx.com/categories/ai-development/): Using AI models and AI-assisted tooling inside real codebases: Claude Code, Codex, Cursor, prompt engineering and Model Context Protocol.
- [AI Agents](https://codenx.com/categories/ai-agents/): Designing, running and supervising autonomous agent workflows, tool use, evaluation and guardrails.
- [Cloudflare](https://codenx.com/categories/cloudflare/): Workers, Pages, R2, DNS, tunnels, caching and edge security on the Cloudflare platform.
- [VPS and Linux](https://codenx.com/categories/vps-linux/): Provisioning, hardening and operating Ubuntu servers: users, firewalls, SSH, systemd and day-two administration.
- [Docker and Deployment](https://codenx.com/categories/docker-deployment/): Containers, Compose, registries and self-hosted deployment platforms such as Dokploy, Coolify and Traefik.
- [n8n Automation](https://codenx.com/categories/n8n-automation/): Self-hosting n8n and building dependable automation workflows that integrate real business systems.
- [Modern Web Development](https://codenx.com/categories/modern-web/): TypeScript, Astro, SvelteKit, Hono and Node.js patterns for building fast, maintainable web applications.
- [Databases and Search](https://codenx.com/categories/databases-search/): PostgreSQL, Redis and Meilisearch in production: schema design, backups, indexing and query performance.
- [DevOps](https://codenx.com/categories/devops/): GitHub Actions, deployment pipelines, infrastructure automation and release engineering.
- [Security](https://codenx.com/categories/security/): Practical hardening for servers, containers, secrets and the software supply chain.
- [Performance](https://codenx.com/categories/performance/): Measuring and improving latency, throughput, Core Web Vitals and resource use in production systems.
- [Troubleshooting](https://codenx.com/categories/troubleshooting/): Reproducible fixes for concrete production failures, with the diagnosis that leads to them.

## Key guides

- [How to Use Claude Code on an Existing TypeScript Project](https://codenx.com/claude-code/claude-code-existing-typescript-project/): Install Claude Code with `npm install -g @anthropic-ai/claude-code`, run `claude` in the repo root, and use `/init` to generate a CLAUDE.md. Then edit that file so it describes your real build, test and lint commands, add a `.claude/settings.json` with an explicit permission allow list, and wire a PostToolUse hook that runs your typechecker after every edit. No migration or restructuring of the repo is needed.
- [How to Secure a VPS That Runs Docker Containers](https://codenx.com/vps/secure-vps-running-docker/): Harden SSH to key-only authentication, enable a default-deny UFW policy, then stop Docker from publishing container ports past that firewall — bind published ports to `127.0.0.1` and add an explicit DROP rule at the top of the `DOCKER-USER` iptables chain. UFW alone does not protect published container ports, because Docker writes its own DNAT rules that are evaluated before UFW's.
- [How to Deploy n8n on an Ubuntu VPS with Docker](https://codenx.com/n8n/deploy-n8n-vps-docker/): Run n8n on a VPS with a three-service Docker Compose stack: n8n itself, PostgreSQL for storage, and Caddy in front for automatic HTTPS. Point an A record at the server, set `N8N_ENCRYPTION_KEY` and `WEBHOOK_URL` before the first start, keep port 5678 unpublished so only Caddy can reach n8n, and back up both the Postgres database and the encryption key.

## All published guides

- [How to Run PostgreSQL Securely on a VPS](https://codenx.com/postgresql/postgresql-secure-vps/): Keep the listener off the public internet, get pg_hba.conf right, require TLS for remote connections, and give the application a role that cannot drop your tables — on PostgreSQL 17 and Ubuntu 24.04. (deployment-guide, advanced, verified 2026-07-23)
- [How to Build a GitHub Actions Deployment Pipeline](https://codenx.com/github-actions/github-actions-deployment-pipeline/): Test, build a container image, push it to GHCR and deploy it to a VPS over SSH — with the concurrency guard, environment approval and token scoping that keep the pipeline from becoming the weak point. (tutorial, intermediate, verified 2026-07-16)
- [How to Run Meilisearch in Production with Docker](https://codenx.com/meilisearch/meilisearch-production-setup/): A Meilisearch deployment that survives a real workload — master key handling, scoped API keys, the index settings you must set before loading data, snapshots, and what its memory usage actually means. (deployment-guide, intermediate, verified 2026-07-15)
- [An AI Coding Agent Workflow That Keeps Diffs Reviewable](https://codenx.com/ai-agents/ai-coding-agent-workflow/): A working loop for running a coding agent on a real codebase — task scoping, branch isolation, tests as the contract, and the review discipline that stops unreviewed code reaching main. (workflow-guide, intermediate, verified 2026-07-10)
- [How to Use Claude Code on an Existing TypeScript Project](https://codenx.com/claude-code/claude-code-existing-typescript-project/): Add Claude Code to a TypeScript repo you already have: a CLAUDE.md that matches your real build, permission rules that block dangerous commands, and a typecheck loop the agent runs itself. (tutorial, intermediate, verified 2026-07-02)
- [How to Run Cloudflare Tunnel in Front of Traefik](https://codenx.com/traefik/cloudflare-tunnel-traefik/): Expose Docker services through Cloudflare with no inbound ports open — cloudflared plus Traefik, the forwarded-header setting that trips people up, and how to verify the firewall is closed. (tutorial, advanced, verified 2026-06-26)
- [Zero-Downtime Deploys in Dokploy with Docker Health Checks](https://codenx.com/dokploy/dokploy-zero-downtime-health-checks/): Dokploy runs apps as Docker Swarm services, so rolling updates are already there — they just need a real health check and an update policy. Plus how to prove no request was dropped. (configuration-guide, advanced, verified 2026-06-12)
- [How to Deploy an Astro Site to Cloudflare Workers](https://codenx.com/astro/deploy-astro-cloudflare-workers/): Ship a static or server-rendered Astro site to Cloudflare Workers with Wrangler — adapter setup, wrangler.jsonc, nodejs_compat, secrets, custom domains and the errors you hit on the first deploy. (deployment-guide, intermediate, verified 2026-07-14)
- [How to Back Up Docker Volumes Automatically](https://codenx.com/docker/backup-docker-volumes-automatically/): A nightly backup for a self-hosted Docker host: database dumps taken with the right tools, file volumes snapshotted with restic, a systemd timer to run it, and a restore test that proves it works. (tutorial, intermediate, verified 2026-07-06)
- [Dokploy vs Coolify: Choosing a Self-Hosting Platform](https://codenx.com/dokploy/dokploy-vs-coolify-self-hosting/): Both put a Heroku-style deploy UI on your own VPS, but on different container primitives. What that means for zero-downtime deploys, multi-server growth and the day the control plane breaks. (comparison, intermediate, verified 2026-07-22)
- [How to Fix the Docker Too Many Open Files Error on Ubuntu](https://codenx.com/troubleshooting/fix-docker-too-many-open-files/): Diagnose which file descriptor limit you actually hit — container, daemon or kernel — then raise it properly, and work out whether the real problem is a leak rather than a limit. (troubleshooting, intermediate, verified 2026-05-28)
- [How to Secure a VPS That Runs Docker Containers](https://codenx.com/vps/secure-vps-running-docker/): SSH hardening, a default-deny firewall, and the fix for the problem that catches almost everyone — Docker publishing container ports straight past UFW into the public internet. (deployment-guide, intermediate, verified 2026-07-08)
- [How to Point a Cloudflare Domain at Your VPS](https://codenx.com/cloudflare/point-cloudflare-domain-to-vps/): Create the A record, pick the right proxy status, set the SSL mode to Full (strict) and lock the origin so only Cloudflare can reach it — plus what errors 521, 522, 525 and 526 actually mean. (configuration-guide, beginner, verified 2026-05-14)
- [How to Deploy n8n on an Ubuntu VPS with Docker](https://codenx.com/n8n/deploy-n8n-vps-docker/): A production n8n install on Ubuntu 24.04 using Docker Compose, PostgreSQL and Caddy for automatic TLS — with the encryption key, webhook URL and backup steps most quickstarts leave out. (tutorial, intermediate, verified 2026-06-20)

## Learning paths

- [Self-Hosting Foundations](https://codenx.com/learning-paths/self-hosting-foundations/): Take a blank Ubuntu VPS to a server that runs containerised applications safely: firewalls that cover Docker, a real deployment, restorable backups, and a pipeline that ships changes. (8 lessons)
- [Cloudflare for Developers](https://codenx.com/learning-paths/cloudflare-for-developers/): The parts of Cloudflare you use when you run your own infrastructure — DNS and proxy status, deploying to Workers, and replacing inbound firewall rules with a tunnel. (3 lessons)
- [AI-Assisted Development](https://codenx.com/learning-paths/ai-assisted-development/): Put a coding agent to work on a codebase you already have, and keep the output reviewable — project setup, permission boundaries, task scoping and the review discipline that makes it safe to merge. (2 lessons)
- [n8n in Production](https://codenx.com/learning-paths/n8n-in-production/): Run self-hosted n8n as infrastructure rather than a hobby project — Postgres storage, TLS, encryption key handling, host hardening and backups that include the things a database dump misses. (3 lessons)
- [Production Data Layer](https://codenx.com/learning-paths/production-data-layer/): Run the stateful half of a self-hosted stack properly — PostgreSQL with least privilege and TLS, Meilisearch with scoped API keys, and backups you have restored at least once. (4 lessons)

## Authors

- [Ayush](https://codenx.com/authors/ayush/): Infrastructure Writer. Writes about Ubuntu server administration and hardening, PostgreSQL and Meilisearch in production, Reverse proxies and TLS termination, GitHub Actions deployment pipelines.
- [Swadesh Behera](https://codenx.com/authors/swadesh/): Founding Editor. Writes about AI-assisted development workflows, Cloudflare DNS, tunnels and Workers, Self-hosted deployment on Linux VPS hosts, Docker and Docker Compose operations, Ecommerce systems, Node.js and TypeScript.

## Feeds and indexes

- [RSS feed](https://codenx.com/rss.xml): all articles, newest first.
- [Sitemap index](https://codenx.com/sitemap-index.xml): every indexable URL.
- [Full text](https://codenx.com/llms-full.txt): direct answers and metadata for every guide.
- [robots.txt](https://codenx.com/robots.txt): crawl policy.

## Contact

- Corrections and questions: hello@codenx.com
- Source repository: https://github.com/itswadesh/codenx.com

Generated 2026-07-23 from 14 published guides.