apex-learn

apex-learn is a skill for Claude Code, Codex from OthmanAdi/APEX. It costs 79 tokens per session (1,012 once invoked), scanned A, original, MIT.

A self-improvement routine for coding agents that reviews completed work and records reusable lessons in AGENTS.md, a file containing project instructions. It includes a rule for saving a lesson after repeated corrections.

In plain words
What is it for?
Use it after difficult tasks, repeated corrections, or when a new project convention is discovered. It helps identify friction, turn it into a rule, and verify that the rule was saved.
Why use it?
It reduces the chance of repeating the same mistake across tasks or agent sessions. The written rules give the wider agent team a shared record of useful discoveries and preferences.

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/othmanadi/apex/apex-learn
Any agent
npx skills add OthmanAdi/APEX --skill apex-learn
Clone the repo
git clone --depth 1 https://github.com/OthmanAdi/APEX

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 apex-learn

README.md
[![agentmods](https://agentmods.dev/badge/skills/othmanadi/apex/apex-learn.svg)](https://agentmods.dev/skills/othmanadi/apex/apex-learn)
Your own site
<a href="https://agentmods.dev/skills/othmanadi/apex/apex-learn"><img src="https://agentmods.dev/badge/skills/othmanadi/apex/apex-learn.svg" alt="Measured on agentmods" height="20"></a>
Per session 79 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,012 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 $0.00079 $0.01012
Opus 5 $0.00039 $0.00506
Sonnet 5 $0.00016 $0.00202
Haiku 4.5 $0.00008 $0.00101

Measured 5d ago against content hash 837e8a4e1267, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

apex-learn 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 5d ago.

The scan reads SKILL.md. This mod also ships 2 executable files (scripts/append-learning.ps1, scripts/append-learning.sh), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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/apex-learn/SKILL.md · 134 lines

How it starts

The opening of the file, as written. The whole thing — 134 lines — stays where its author put it; the contents beside it link to each section on GitHub.

APEX Learn

Analyze what happened during a task, extract reusable knowledge, and persist it to AGENTS.md so the entire agent team improves over time.

When to Use

Run this skill in any of these situations:

  • After completing a Tier 1, 2, or 3 task
  • When the human corrected you on the same issue twice (two-strike rule)
  • When you discovered a non-obvious pattern or convention
  • When a task took significantly longer than expected
  • When the human explicitly asks to update the rules

The Two-Strike Rule

This is the core mechanism. If you are corrected on the same type of issue twice:

  1. First correction — Fix the issue, note it mentally
  2. Second correction — Fix the issue AND run apex-learn to add a permanent rule

This prevents the same mistake from recurring across sessions.

Workflow

  1. Identify friction points
  2. Classify the learning
  3. Draft the rule
  4. Append to AGENTS.md
  5. Verify the update

Step 1: Identify Friction Points

Ask yourself these questions about the completed task:

## Friction Analysis

1. Where did I get stuck or make mistakes?
2. What did the human correct me on?
3. What took longer than expected and why?
4. What assumptions did I make that were wrong?
5. What patterns did I discover that aren't documented?

Step 2: Classify the Learning

Each learning falls into one of these categories:

Category Example Where it Goes in AGENTS.md
Code style "Always use named exports" ## Code Style section
Architecture "Services never call controllers" ## Architecture Rules section
Workflow "Always run tests before committing" ## Workflow section
Boundaries "Never modify the auth module" ## Boundaries section
Preferences "Prefer descriptive over short names" ## Preferences section
Tool usage "Use pnpm, not npm" ## Tools section

Step 3: Draft the Rule

Write the rule in imperative form. Be specific and actionable:

Read the full file on GitHub · 134 lines

Files

What ships with it

3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 5d ago First seen · 134 lines · 79 tokens per session scan A 837e8a4e1267

Subscribe to this mod's changes

apex-learn is a skill published in the GitHub repository OthmanAdi/APEX (2 stars, last pushed 5mo ago), licensed MIT. It adds 79 tokens to every session and 1,012 once invoked, about $0.0004 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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