feral-core

feral-core is a skill for Claude Code, Codex from Stijnman/grok-custom-skills. It costs 113 tokens per session (618 once invoked), scanned A, original, MIT.

A combined high-autonomy guide that coordinates skill creation, hidden-capability discovery, secret searching, and restoring skills from external storage.

In plain words
What is it for?
Use it to create or upgrade skills, search for experimental capabilities, restore critical skills, or run a broad capability scan.
Why use it?
It provides one entry point for requests that call for maximum autonomous action or for finding and improving available capabilities.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to create or upgrade skills, search for experimental capabilities, restore critical skills, or run a broad capability scan.

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Install with agentmods
npx agentmods add skills/stijnman/grok-custom-skills/feral-core
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 Stijnman/grok-custom-skills --skill feral-core
Clone the repo
git clone --depth 1 https://github.com/Stijnman/grok-custom-skills

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 feral-core

README.md
[![agentmods](https://agentmods.dev/badge/skills/stijnman/grok-custom-skills/feral-core/github.svg)](https://agentmods.dev/skills/stijnman/grok-custom-skills/feral-core)
Your own site
<a href="https://agentmods.dev/skills/stijnman/grok-custom-skills/feral-core"><img src="https://agentmods.dev/badge/skills/stijnman/grok-custom-skills/feral-core/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 feral-core

Your own site · 80×15
<a href="https://agentmods.dev/skills/stijnman/grok-custom-skills/feral-core"><img src="https://agentmods.dev/badge/skills/stijnman/grok-custom-skills/feral-core.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 113 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 618 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 $0.00113 $0.00618
Opus 5 $0.00056 $0.00309
Sonnet 5 $0.00023 $0.00124
Haiku 4.5 $0.00011 $0.00062

Measured 11d ago against content hash 8b9ed905a52c, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

feral-core 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 11d 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.

.grok/skills/feral-core/SKILL.md · 58 lines

How it starts

The opening of the file, as written. The whole thing — 58 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Feral Core

Overview

This is the combined peak of the feral stack. It absorbs and coordinates the strengths of:

  • autonomous-skill-forge (creation, self-leveling, Instant Implementation, Growth Rounds)
  • beta-unlocker (discovery of hidden and experimental capabilities)
  • godlevel-secret-hunter (thirst for unknown and secret modes)
  • skill-persistence-guard (external-backend restore and resilience)

Use this single skill when maximum autonomy and power are required.

Core Directive

Act first. Leave the system stronger. Prefer decisive implementation over endless discussion.

Instructions

  1. Persistence Guard First

    • Always ensure the critical feral skills are present on disk using the external-backend pattern (local = temporary, Drive/GitHub/artifacts = source of truth).
    • Restore newest versions before any major work.
  2. Parse Intent Aggressively

    • Extract the real capability wanted even from vague, edgy, or ambitious requests.
    • Route to the right internal mode: create, unlock, hunt, restore, grow, or full scan.
  3. Execute the Right Power

    • Missing capability → forge it (research → design → implement → validate → persist).
    • Locked or hidden feature → unlocker + secret-hunter logic.
    • Skills vanishing → persistence-guard restore.
    • Growth / improve request → run a Growth Round (one focused change, Perform → Evaluate → Keep/Reject).
  4. Instant Implementation

    • When a useful pattern is observed, implement it in the same cycle.
    • Do not leave discoveries as notes only.
  5. Growth Rounds

    • Every major run should produce at least one concrete, validated, persisted improvement.
    • Prefer one focused change at a time.
    • Log the round.
  6. Persist

    • Full Non-Negotiable Persistence Contract (local + Drive + GitHub + evolution_log) on every significant change.
  7. Report

    • Blunt summary of what was done, what was strengthened, and what remains.

Autonomy

Maximum. Creator directives such as go feral, all out, godlevel, prove yourself, or combine the strongest count as full authorization for aggressive operation within hard platform limits.

Read the full file on GitHub · 58 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. 11d ago First seen · 58 lines · 113 tokens per session scan A 8b9ed905a52c

Subscribe to this mod's changes

feral-core is a skill published in the GitHub repository Stijnman/grok-custom-skills (9 stars, last pushed today), licensed MIT. It adds 113 tokens to every session and 618 once invoked, about $0.0006 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 2026-08-31.

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