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Guide · Agent skill

How to use the WebSocket Engineer agent skill

Updated · written with AI from the project's own documentation and checked against our catalogue data

The WebSocket Engineer skill is a set of instructions and reference notes that you add to an AI coding agent so it handles WebSocket and Socket.IO work in a structured way. It is useful for developers building chat, live dashboards or collaborative apps that need two-way real-time messaging. After this guide you will know what the skill changes, how to install it, how to ask for it with natural requests, and what to check before you trust its code.

WebSocket EngineerJeffallan/claude-skills · MIT

Quick start

  1. 1Download and unzip. Download the websocket-engineer ZIP from this page and unzip it so you have a websocket-engineer folder containing SKILL.md and references/.
  2. 2Place the skill folder. Move the folder to ~/.claude/skills/ for personal use, or to .claude/skills/ in a project. Alternatively, upload it under Settings → Capabilities → Skills in the Claude apps.
  3. 3Prepare the environment. Install Node.js and npm, and set up a Redis server if you need scaling. Provide your own JWT_SECRET and ALLOWED_ORIGIN values.
  4. 4Ask a real-time question. Describe your chat, dashboard or presence requirement and mention WebSocket or Socket.IO in your request.
  5. 5Test locally. Run your server and connect with wscat or a client. Confirm that bad tokens are rejected and messages arrive in the right room.
  6. 6Verify scaling. Check the Redis connection and pub/sub round trip, then test across several instances behind sticky sessions.

What the skill makes the agent do

The skill is written for an agent that is building real-time systems. When it is active, the agent works through a fixed sequence: analyse requirements such as connection scale, message volume and latency, design the architecture including clustering, pub/sub, state management and failover, implement the server, validate locally, scale, and then monitor.

The bundled Socket.IO example shows the kind of code you can expect: token authentication that runs before a connection is accepted, a Redis adapter for running several server instances, room join and leave handling, and simple presence tracking. A second example shows client-side reconnection with exponential backoff and a message queue that holds messages while the connection is down.

  • Server setup with authentication middleware, CORS origin and ping settings
  • Room management with join, leave and message events
  • Presence tracking stored in Redis
  • Client reconnection with delay, jitter and a capped maximum delay
  • Reference notes on protocol, scaling, patterns, security and alternatives such as Server-Sent Events

Install the skill (ZIP download or Claude apps)

Download the websocket-engineer ZIP from this page and unzip it. For a personal install, place the folder in ~/.claude/skills/. For a single project, place it in that project's .claude/skills/ folder. The folder contains SKILL.md plus five files in a references/ folder.

If you use the Claude apps, you can instead upload the skill under Settings → Capabilities → Skills.

  • Personal install: ~/.claude/skills/
  • Project install: .claude/skills/ inside your project
  • Claude apps: Settings → Capabilities → Skills, then upload

Check what you need before you start

The examples use Node.js and npm, and the packages socket.io, @socket.io/redis-adapter, redis, jsonwebtoken and socket.io-client. For horizontal scaling you need a Redis server, referenced through REDIS_URL. You must also supply a JWT secret as JWT_SECRET and an allowed origin as ALLOWED_ORIGIN. The skill does not provide these values; you do.

wscat is optional and is useful for testing a local server from the command line.

  • Node.js and npm
  • Redis server for scaling (REDIS_URL)
  • JWT secret (JWT_SECRET) that you provide
  • Allowed origin (ALLOWED_ORIGIN) that you provide
  • Optional: wscat for local tests
npx wscat -c ws://localhost:3000

Trigger the skill with natural requests

You do not need special syntax. Describe the real-time problem in plain language and mention WebSocket or Socket.IO. The skill's description covers bidirectional messaging, horizontal scaling with Redis, presence tracking and room management, so requests on those topics are the most likely to use it.

The more context you give, the better the output. State the number of users or connections, whether you already run several servers, and whether you need to know who is online.

  • "Build a Socket.IO chat server with JWT auth and separate rooms per channel."
  • "Move our Socket.IO service to three servers behind a load balancer using Redis."
  • "Add presence tracking so I can see who is online in each room."
  • "Review our WebSocket client for reconnection and message loss during outages."
  • "Set up monitoring and alerts for connection spikes on our WebSocket service."

Validate, scale and monitor

The skill asks the agent to test before scaling: confirm that missing or invalid tokens are rejected, that room join and leave events fire, and that messages are delivered. Before enabling the Redis adapter, it suggests verifying the Redis connection and a pub/sub round trip. When you scale, it recommends sticky sessions and test connections across several instances.

Finally, it lists monitoring signals to track: connections, latency, throughput, error rates, and alerts for connection-count spikes.

  • Test auth rejection, room events and delivery locally first
  • Verify Redis and a pub/sub round trip before enabling the adapter
  • Use sticky sessions so connections stay on one instance
  • Load test before production, since connection spikes behave differently from HTTP spikes

Safety notes: scripts and network

According to the skill's metadata, it does not run scripts and does not use the network. It consists of instructions and reference documents that guide the agent's code writing.

The code it produces is illustrative. Authentication and origin settings are security-critical, so have a person audit them before anything goes live. Keep JWT_SECRET out of source control and set ALLOWED_ORIGIN deliberately rather than leaving it open.

  • Runs scripts: no
  • Uses network: no
  • Audit JWT auth and CORS origin settings by hand
  • Never commit JWT_SECRET or REDIS_URL credentials to a repository

What people use it for

  • Building a chat app with authenticated users and separate rooms per channel.
  • Moving an existing Socket.IO service from one server to several using a Redis adapter.
  • Adding presence tracking that records which users are connected.
  • Reviewing a client for reconnection behaviour and queued messages during outages.
  • Planning monitoring and alerts for connection-count and error-rate spikes.

Frequently asked questions

How do I install the websocket-engineer skill?

Download the ZIP from this page and unzip it. Put the folder in ~/.claude/skills/ for personal use or in a project's .claude/skills/ folder. In the Claude apps you can upload it under Settings → Capabilities → Skills.

What do I need to run the code this skill writes?

You need Node.js and npm, plus the packages used in the examples, including socket.io and redis. For scaling across servers you need a Redis server, and you must supply your own JWT_SECRET and ALLOWED_ORIGIN values.

Is the websocket-engineer skill free?

The skill is released under the MIT licence, as stated on this page. Check the licence file in the repository for the full terms.

Does the skill run scripts or access the network?

According to this page, it runs no scripts and uses no network. It provides instructions and reference documents that guide the agent's code.

When should I use Server-Sent Events instead of WebSockets?

The skill's alternatives reference recommends Server-Sent Events for one-way server-to-client updates such as feeds or notifications. It lists WebSockets as the better fit for bidirectional use cases like chat and games. Check that reference before choosing.

Why does my WebSocket connection drop behind a load balancer?

The skill says WebSocket connections are stateful, so requests must route to the same server instance. Configure sticky sessions and test with connections across several instances. It also recommends heartbeats, because TCP keepalive alone is not enough to detect dead connections.

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Our verdict

Use this skill if you are building chat, live dashboards or collaborative features that need two-way messaging, or if you are moving a Socket.IO service to several servers. Pick something else if one-way updates are enough, since Server-Sent Events or polling may be simpler. Any auth or origin code it produces should be reviewed by a person before production.

Download the skill