aigon-dev-server

A development-server manager for starting, stopping, inspecting, and opening a project's local web server.

In plain words
What is it for?
Use it to start or stop the server, view or follow logs, list running servers, and open the project in a browser.
Why use it?
It prevents port conflicts when several worktrees or agents run the same project. It also provides a consistent URL and health check for the running server.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/jayvee/aigon/aigon-dev-server
Any agent
npx skills add jayvee/aigon --skill aigon-dev-server
Clone the repo
git clone --depth 1 https://github.com/jayvee/aigon

Made for: Claude Code, Codex.

Per session 16 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 576 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00016 $0.00576
Opus 5 $0.00008 $0.00288
Sonnet 5 $0.00003 $0.00115
Haiku 4.5 $0.00002 $0.00058

Measured 2d ago against content hash 68805cc44d10, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

aigon-dev-server scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.agents/skills/aigon-dev-server/SKILL.md · 84 lines

How it starts

The opening of the file, as written. The whole thing — 84 lines — stays where its author put it; the contents beside it link to each section on GitHub.

aigon-dev-server

Manage the dev server for the current project. Handles port allocation, process lifecycle, proxy registration, and log viewing.

CRITICAL: NEVER run the project's dev command directly. ALWAYS use aigon dev-server start. Running the dev command directly bypasses port allocation and will cause port conflicts in worktrees.

Usage

Run the appropriate subcommand based on what's needed:

Start the dev server

aigon dev-server start

This will:

  • Allocate a unique port (each agent gets its own offset from the project's base port)
  • Start the dev server process in the background with PORT=<allocated>
  • Register with the local proxy for a custom subdomain URL (e.g. http://cx-121.myapp.test)
  • Wait for the server to become healthy
  • Print the URL to access the app — always use this URL

Check dev server logs

aigon dev-server logs

Use -f to follow logs in real time:

aigon dev-server logs -f

Stop the dev server

aigon dev-server stop

List all running dev servers

aigon dev-server list

Open in browser

aigon dev-server open

Opens the dev server URL in the default browser. Uses the proxy subdomain URL if available, otherwise falls back to localhost.

You can also auto-open when starting the server:

aigon dev-server start --open

Get the URL for the current context

aigon dev-server url

Prints the proxy subdomain URL (or localhost fallback) for use in testing and browser access.

Notes

  • The dev server command is read from devProxy.command in .aigon/config.json (set this to whatever the project uses)
  • Port is allocated automatically — agents get offsets from the base port (cc=+1, ag=+2, cx=+3, cu=+4)
  • The base port is configured per-project in .aigon/config.json (devProxy.basePort). Worktree agents get offsets from this.
  • If the proxy is running (aigon proxy install), the server gets a named URL like http://cx-121.myapp.localhost
  • Without the proxy, it falls back to http://localhost:<port>
  • Use aigon dev-server logs to diagnose startup issues — all stdout/stderr is captured
  • To check what's running: aigon dev-server list shows all active servers with their ports and URLs

Read the full file on GitHub · 84 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 84 lines · 16 tokens per session scan A 68805cc44d10

Subscribe to this mod's changes

aigon-dev-server is a skill published in the GitHub repository jayvee/aigon (23 stars, last pushed 2d ago), licensed Apache-2.0. It adds 16 tokens to every session and 576 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.