Borrowing it
Nothing to install: this file belongs to basher83/lunar-claude. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/basher83/lunar-claude/main/.claude/commands/design-validation/premortem-design-validation.mdgit clone --depth 1 https://github.com/basher83/lunar-claudeWrote 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.
[](https://agentmods.dev/commands/basher83/lunar-claude/premortem-design-validation)<a href="https://agentmods.dev/commands/basher83/lunar-claude/premortem-design-validation"><img src="https://agentmods.dev/badge/commands/basher83/lunar-claude/premortem-design-validation/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.
<a href="https://agentmods.dev/commands/basher83/lunar-claude/premortem-design-validation"><img src="https://agentmods.dev/badge/commands/basher83/lunar-claude/premortem-design-validation.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00011 | $0.01325 |
| Opus 5 | $0.00005 | $0.00662 |
| Sonnet 5 | $0.00002 | $0.00265 |
| Haiku 4.5 | $0.00001 | $0.00133 |
Grade A, and why
premortem-design-validation 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.
How it starts
The opening of the file, as written. The whole thing — 210 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Purpose
Conduct a pre-mortem analysis by imagining the design has failed catastrophically, then working backward to identify what went wrong. This technique surfaces risks and blind spots that optimistic forward-thinking often misses.
Use this command to stress-test a design BEFORE committing to implementation.
Variables
DESIGN_DOCUMENT: $1
OUTPUT_DIR: docs/reviews/design-validation/premortem/
FILE_NAME: <two-to-three-words-from-DESIGN_DOCUMENT-filename>.md
Instructions
- IMPORTANT: If no
DESIGN_DOCUMENTis provided, stop and ask the user to provide it. - Read and understand the design document thoroughly before starting.
- Verify
OUTPUT_DIRexists, create it if it doesn't. - Save output from analysis to
OUTPUT_DIR/FILE_NAME. - Adopt a pessimistic mindset - assume failure happened and work backward.
Workflow
Step 1: Extract Design Context
From the design document, identify and summarize:
- Design Summary: What is being proposed (1-2 sentences)
- Problem Statement: What problem this solves
- Key Components: Main technical pieces
Step 2: Pre-Mortem Exercise
Imagine this design has been implemented and failed catastrophically.
Working backward from this imagined failure, identify exactly 3 critical failure scenarios.
For each scenario, document:
- Failure Point: The specific technical limitation, wrong assumption, or missing requirement
- Root Cause: What we missed during design that led to this failure
- Warning Signs: Early indicators we should have noticed
- Precedent: Similar projects/tools that failed this way (cite specific examples)
Step 3: Research Gaps Analysis
Identify what should have been researched first:
- Existing solutions, tools, or patterns not investigated
- Technical constraints or limitations not validated
- Stakeholder needs or edge cases not explored
- Industry standards or best practices overlooked
Step 4: Build vs. Integrate Reality Check
Answer explicitly:
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.
- 9d ago First seen · 210 lines · 11 tokens per session scan A f5a4d4152962
premortem-design-validation is a command published in the GitHub repository basher83/lunar-claude (23 stars, last pushed today), licensed MIT. It adds 11 tokens to every session and 1,325 once invoked, about $0.0001 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 2026-08-30.
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