book-of-eternity

book-of-eternity is a skill for Claude Code, Codex from IvanSkainet/arena-agent. It costs 0 tokens per session (1,435 once invoked), scanned A, original, MIT.

An integration that lets an already-running Arena.ai Agent Mode session act as the Game Master for The Book of Eternity: Reborn through Skainet Bridge.

In plain words
What is it for?
Use it to relay player actions and current game context to the Arena agent, which reasons about and writes the Game Master's responses.
Why use it?
It connects the player's game actions with the Arena agent while keeping the game's rules and saved state in the game itself.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: mentions Codex.

Good fit Use it to relay player actions and current game context to the Arena agent, which reasons about and writes the Game Master's responses.

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Install with agentmods
npx agentmods add skills/ivanskainet/arena-agent/book-of-eternity
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.

Any agent
npx skills add IvanSkainet/arena-agent --skill book-of-eternity
Clone the repo
git clone --depth 1 https://github.com/IvanSkainet/arena-agent

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for book-of-eternity

README.md
[![agentmods](https://agentmods.dev/badge/skills/ivanskainet/arena-agent/book-of-eternity/github.svg)](https://agentmods.dev/skills/ivanskainet/arena-agent/book-of-eternity)
Your own site
<a href="https://agentmods.dev/skills/ivanskainet/arena-agent/book-of-eternity"><img src="https://agentmods.dev/badge/skills/ivanskainet/arena-agent/book-of-eternity/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for book-of-eternity

Your own site · 80×15
<a href="https://agentmods.dev/skills/ivanskainet/arena-agent/book-of-eternity"><img src="https://agentmods.dev/badge/skills/ivanskainet/arena-agent/book-of-eternity.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 0 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,435 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00000 $0.01435
Opus 5 $0.00000 $0.00718
Sonnet 5 $0.00000 $0.00287
Haiku 4.5 $0.00000 $0.00144

Measured 12d ago against content hash d2b86ce85991, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

book-of-eternity 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 12d 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.

skills/book-of-eternity/SKILL.md · 140 lines

How it starts

The opening of the file, as written. The whole thing — 140 lines — stays where its author put it; the contents beside it link to each section on GitHub.

The Book of Eternity: Reborn — Arena Agent Mode GM

Use an already-running Arena.ai Agent Mode session as the external Game Master for The Book of Eternity: Reborn through Skainet Bridge.

The integration uses the normal Bridge surface: relay.*, fs.*, exec.*, and any other generally available tool the task needs. A game-only token or a hard-coded narrow tool subset is not required. The operator's global Bridge profile remains the only capability policy layer.

Authority boundary

Skainet Bridge is transport and host access, not a second game engine.

  • The game owns rules, validation, progression, canonical state, request correlation, and terminal-signal formats.
  • The daemon packet and its current gm_context_pack own turn instructions.
  • The Arena agent owns reasoning and authorship.
  • Do not copy C# validators, dice rules, realm matrices, or narrative rules into Bridge code or this skill.
  • Do not treat chat history as canonical game memory. Read current host files.

No Codex process is required. Do not start or automate an Arena browser session; the relay is a durable mailbox for a session the player started themselves.

Transport chain

player action
  -> game client writes canonical request
  -> game_master_daemon.ps1 builds the current packet
  -> BookOfEternityGMBridge hosts persistent arena-relay terminal in ConPTY
  -> generic authenticated relay mailbox
  -> active Arena Agent Mode session
  -> ordinary fs.* / exec.* host work
  -> game-owned terminal signal
  -> correlated relay.reply releases the terminal
  -> client validates and renders

Connect Arena Agent Mode

Two supported paths expose the same full Bridge tool catalog.

Browser-extension path

  1. Install chat_extension/ and configure the Bridge HTTPS URL and token.
  2. On arena.ai, copy extension instructions with catalog scope GM: relay. + fs. + exec.***.
  3. Start Agent Mode yourself and paste this skill/bootstrap instruction.
  4. Tool blocks execute through /v1/extension/execute; the extension does not automate login, model selection, or session creation.

Read the full file on GitHub · 140 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. 12d ago First seen · 140 lines · 0 tokens per session scan A d2b86ce85991

Subscribe to this mod's changes

book-of-eternity is a skill published in the GitHub repository IvanSkainet/arena-agent (6 stars, last pushed yesterday), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 1,435 tokens. 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 2026-08-31.

Related

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