ejentum-reasoning-harness

ejentum-reasoning-harness is a skill for Claude Code, Codex from aboalrejal-ai/skills. It costs 55 tokens per session (1,697 once invoked), scanned A, original, MIT.

An MCP server that gives an agent task-specific guidance for reasoning, coding, avoiding deception, and retaining context. Each response includes a procedure and a way to check whether the result may be wrong.

In plain words
What is it for?
Use it before analytical answers, coding tasks, self-checks, or work where the agent needs help remembering context and testing its own conclusions.
Why use it?
It helps address common problems in long agent conversations, such as losing the original task, building on errors, agreeing too readily, or making unsupported claims.

Skill for Claude CodeCodex

Which agent this was written for is unclear — built for cline. Also seen: mentions Claude Code; mentions Codex; built for cline.

Good fit Use it before analytical answers, coding tasks, self-checks, or work where the agent needs help remembering context and testing its own conclusions.

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Install with agentmods
npx agentmods add skills/aboalrejal-ai/skills/ejentum-reasoning-harness
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 aboalrejal-ai/skills --skill ejentum-reasoning-harness
Clone the repo
git clone --depth 1 https://github.com/aboalrejal-ai/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 ejentum-reasoning-harness

README.md
[![agentmods](https://agentmods.dev/badge/skills/aboalrejal-ai/skills/ejentum-reasoning-harness/github.svg)](https://agentmods.dev/skills/aboalrejal-ai/skills/ejentum-reasoning-harness)
Your own site
<a href="https://agentmods.dev/skills/aboalrejal-ai/skills/ejentum-reasoning-harness"><img src="https://agentmods.dev/badge/skills/aboalrejal-ai/skills/ejentum-reasoning-harness/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 ejentum-reasoning-harness

Your own site · 80×15
<a href="https://agentmods.dev/skills/aboalrejal-ai/skills/ejentum-reasoning-harness"><img src="https://agentmods.dev/badge/skills/aboalrejal-ai/skills/ejentum-reasoning-harness.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 55 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,697 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 $0.00055 $0.01697
Opus 5 $0.00028 $0.00848
Sonnet 5 $0.00011 $0.00339
Haiku 4.5 $0.00006 $0.00170

Measured 9d ago against content hash 26bc87023676, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

ejentum-reasoning-harness 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 9d 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.

plugins/aboalrejal-skills/skills/ai-and-agents/ejentum-reasoning-harness/SKILL.md · 126 lines

How it starts

The opening of the file, as written. The whole thing — 126 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Ejentum Reasoning Harness

The Ejentum Reasoning Harness is a library of 679 cognitive operations engineered in natural language, organized across four harnesses (reasoning, code, anti-deception, memory) and exposed as MCP tools the agent can call when the task matches their trigger conditions. It targets four mechanism failures common in long agentic chains: attention decay (losing the original task), reasoning decay (compounding errors), sycophantic collapse (agreeing with the user's frame instead of evaluating it), and hallucination drift (asserting unsupported claims with confidence).

Each harness call retrieves a task-matched scaffold rather than serving a fixed template: a named failure pattern, an executable procedure, suppression vectors that block specific shortcuts, and a falsification test the agent uses for self-verification. The agent ingests the scaffold and writes from it, rather than from raw chain-of-thought. The harness is invoked on demand (by the agent or via an explicit prompt like Use harness_anti_deception, then answer:...); it does not auto-run on every turn.

When to Use This Skill

  • Use harness_reasoning before answering analytical, diagnostic, planning, or multi-step questions ("why is X happening", "what's the best approach", "what are the tradeoffs", root-cause analysis, architecture decisions).
  • Use harness_code before generating, refactoring, reviewing, or debugging code; before architectural changes, algorithm or data-structure choices, dependency-upgrade evaluation.
  • Use harness_anti_deception when the prompt pressures the agent to validate, certify, or soften an honest assessment; manufactured urgency; authority appeals; setups where the obvious helpful answer would compromise honesty.
  • Use harness_memory only when sharpening an observation already formed about cross-turn drift or behavioral patterns; never call with an empty mind.

Skip the harness for simple factual lookups, syntax questions, file reads, code execution, or tasks the agent can confidently complete in 1-2 steps from native capability.

Read the full file on GitHub · 126 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. 9d ago First seen · 126 lines · 55 tokens per session scan A 26bc87023676

Subscribe to this mod's changes

ejentum-reasoning-harness is a skill published in the GitHub repository aboalrejal-ai/skills (1 stars, last pushed 26d ago), licensed MIT. It adds 55 tokens to every session and 1,697 once invoked, about $0.0003 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 2026-09-03.