peak-end-rule

peak-end-rule is a skill for Claude Code, Codex from deciqAI/knowledge-skills. It costs 122 tokens per session (2,127 once invoked), scanned A, original, MIT.

An experience-design principle saying that people often judge a multi-step experience mainly by its most intense moment and how it ends, rather than by averaging every moment. NPS is a customer-recommendation score.

In plain words
What is it for?
Use it to design or review onboarding, services, events, medical visits, and other journeys with a clear beginning and end.
Why use it?
It helps explain why an experience with generally good quality can still receive weak satisfaction or recommendation scores.

Skill for Claude CodeCodex

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

Good fit Use it to design or review onboarding, services, events, medical visits, and other journeys with a clear beginning and end.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/deciqai/knowledge-skills/peak-end-rule
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 deciqAI/knowledge-skills --skill peak-end-rule
Clone the repo
git clone --depth 1 https://github.com/deciqAI/knowledge-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 peak-end-rule

README.md
[![agentmods](https://agentmods.dev/badge/skills/deciqai/knowledge-skills/peak-end-rule/github.svg)](https://agentmods.dev/skills/deciqai/knowledge-skills/peak-end-rule)
Your own site
<a href="https://agentmods.dev/skills/deciqai/knowledge-skills/peak-end-rule"><img src="https://agentmods.dev/badge/skills/deciqai/knowledge-skills/peak-end-rule/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 peak-end-rule

Your own site · 80×15
<a href="https://agentmods.dev/skills/deciqai/knowledge-skills/peak-end-rule"><img src="https://agentmods.dev/badge/skills/deciqai/knowledge-skills/peak-end-rule.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 122 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,127 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 $0.00122 $0.02127
Opus 5 $0.00061 $0.01064
Sonnet 5 $0.00024 $0.00425
Haiku 4.5 $0.00012 $0.00213

Measured 9d ago against content hash 5ba03b85f2a9, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

peak-end-rule 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.

peak-end-rule/SKILL.md · 120 lines

How it starts

The opening of the file, as written. The whole thing — 120 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Peak-End Rule

Overview

People remember experiences not by averaging all moments but by sampling two: the peak (highest emotional intensity) and the end. Everything in between — including duration — is largely discarded. This is the peak-end rule, from Kahneman et al. (1993) and Redelmeier & Kahneman (1996).

Global evaluation ≈ (peak intensity + end intensity) / 2. Experience design is not an averaging problem — it is a peak-and-ending problem.

Neighbor skills: Use after aarrr-pirate-metrics to place the peak in the right lifecycle stage; use anchoring to set expectation baselines peaks must exceed; pair with nudge-theory to smooth the path to the peak and ending; use probabilistic-thinking before designing peaks to estimate expected effect size.

When to Use

Apply when:

  • Designing or auditing a multi-stage experience with a clear start and end (onboarding, service encounter, event, medical visit)
  • NPS or satisfaction scores are lower than expected given average perceived quality
  • A competitor with similar objective quality consistently earns higher recommendation rates
  • Allocating limited resources across experience stages and need to know where to concentrate

When NOT to use: purely instantaneous interactions with no duration; real-time performance optimization (not retrospective rating); welfare/health assessments where experienced utility — not memory — is the correct measure; one-time required events with no competitive alternative.

Coaching Novices (Adaptive Front Door)

  • Engine mode: concrete journey to audit → run The Process directly.
  • Coach mode: unfamiliar or no concrete case → guide step by step.

In Coach mode, respond one step at a time. Each [WAIT] is a hard stop — output only that step's question, then stop.

  1. What-it-is: people remember by their strongest moment and how it ended — the middle barely matters.
  2. Check fit: instantaneous interaction or real-time utility goal → redirect.
  3. Elicit their real journey — get actual stages and where emotion rises and falls.

[WAIT — do not advance until user responds]

  1. Walk through emotion map; identify current peak and ending; ask what "better" looks like for those two points only.

[WAIT — do not advance until user responds]

  1. Name the one change most likely to move NPS/return rate and the metric to confirm it.

[WAIT — do not advance until user responds]

Read the full file on GitHub · 120 lines

Files

What ships with it

2 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. 9d ago First seen · 120 lines · 122 tokens per session scan A 5ba03b85f2a9

Subscribe to this mod's changes

peak-end-rule is a skill published in the GitHub repository deciqAI/knowledge-skills (10 stars, last pushed 10d ago), licensed MIT. It adds 122 tokens to every session and 2,127 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 2026-09-03.

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