failure-postcards

failure-postcards is a skill for Claude Code, Codex from pyros-projects/limitless. It costs 112 tokens per session (717 once invoked), scanned A, original, MIT.

A risk-review method that turns possible product failures into realistic support tickets, complaints, reviews, or postmortem notes.

In plain words
What is it for?
Use it to pressure-test a feature, user flow, or product promise and connect each failure to a broken assumption and possible design change.
Why use it?
It makes vague risks easier to understand by showing how users might experience the failure.

Skill for Claude CodeCodex

Part of the after-hours plugin — 7 skills shipped together

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/pyros-projects/limitless/failure-postcards
Any agent
npx skills add pyros-projects/limitless --skill failure-postcards
Clone the repo
git clone --depth 1 https://github.com/pyros-projects/limitless

Made for: Claude Code, Codex.

Or install after-hours, the plugin that ships this one along with the rest of its 7 skills.

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 failure-postcards

README.md
[![agentmods](https://agentmods.dev/badge/skills/pyros-projects/limitless/failure-postcards.svg)](https://agentmods.dev/skills/pyros-projects/limitless/failure-postcards)
Your own site
<a href="https://agentmods.dev/skills/pyros-projects/limitless/failure-postcards"><img src="https://agentmods.dev/badge/skills/pyros-projects/limitless/failure-postcards.svg" alt="Measured on agentmods" height="20"></a>
Per session 112 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 717 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 $0.00112 $0.00717
Opus 5 $0.00056 $0.00358
Sonnet 5 $0.00022 $0.00143
Haiku 4.5 $0.00011 $0.00072

Measured 4d ago against content hash d15532a3306f, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

failure-postcards 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 4d 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/after-hours/skills/failure-postcards/SKILL.md · 91 lines

How it starts

The opening of the file, as written. The whole thing — 91 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Failure Postcards

Overview

This skill turns abstract risk into something a builder can feel.

Instead of listing generic failure modes, it writes little artifacts from the future: support emails, bug reports, confused user notes, one-star reviews, postmortem fragments. The point is to make the failure legible fast.

When to Use

Use this when:

  • a design sounds good on paper but you do not trust it yet
  • the team is discussing risks too abstractly
  • you want a pre-mortem without corporate workshop energy
  • a key user flow needs pressure-testing from the user's side

Do not use this as theatre. The goal is not to be dramatic. The goal is to expose real fragility.

What to Produce

Generate a small set of future artifacts such as:

  • support tickets
  • angry or disappointed emails
  • confused first-user messages
  • one-star reviews
  • short postmortem fragments

Then explain:

  • what failure each artifact reveals
  • what assumption broke
  • what design change might prevent it

Working Loop

  1. Choose the fragile promise. Pick the feature, flow, or assumption that sounds good but may be hiding a break.

  2. Jump forward in time. Imagine the moment after the failure has already happened.

  3. Write the artifact from the human side. Let the support email, review, or postmortem fragment reveal what the builder failed to notice.

  4. Decode the postcard. Explain the hidden assumption, why it broke, and what design move would reduce the chance of that future.

Suggested Output Shape

  • Postcard
  • What this reveals
  • Broken assumption
  • What to change before this becomes real

Tiny Example

  • Postcard: "I uploaded the file three times and nothing changed except the spinner. I still don't know if you have it or not."
  • What this reveals: The flow hides system state right when the user most needs reassurance.
  • Broken assumption: The team assumed a spinner counts as feedback.
  • What to change before this becomes real: Show upload progress, success confirmation, and a visible retry state.

Read the full file on GitHub · 91 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. 4d ago First seen · 91 lines · 112 tokens per session scan A d15532a3306f

Subscribe to this mod's changes

failure-postcards is a skill published in the GitHub repository pyros-projects/limitless (9 stars, last pushed 21d ago), licensed MIT. It adds 112 tokens to every session and 717 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.