logic-diff

A code-comparison command that checks whether two implementations produce the same results and side effects.

In plain words
What is it for?
Use it to compare two versions of a function, feature, or program and identify differences outside any intentionally changed behavior.
Why use it?
It helps detect behavior changes after a refactor, rewrite, or migration.

Command

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 commands/hyhmrright/logic-lens/logic-diff
Clone the repo
git clone --depth 1 https://github.com/hyhmrright/logic-lens
Per session 16 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 52 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 $0.00016 $0.00052
Opus 5 $0.00008 $0.00026
Sonnet 5 $0.00003 $0.00010
Haiku 4.5 $0.00002 $0.00005

Measured yesterday against content hash ad24292d79c4, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

logic-diff 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 yesterday.

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.

commands/logic-diff.md · 7 lines

What it actually says

Use the Skill tool to invoke logic-lens:logic-diff, then follow its instructions exactly. $ARGUMENTS

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. yesterday First seen · 7 lines · 16 tokens per session scan A ad24292d79c4

Subscribe to this mod's changes

logic-diff is a command published in the GitHub repository hyhmrright/logic-lens (21 stars, last pushed 2d ago), licensed MIT. It adds 16 tokens to every session and 52 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.