diff

A command that compares two binary files, which are compiled program files, to identify changes between them.

In plain words
What is it for?
Use it for patch analysis to compare file sizes, bytes, sections, imports, exports, and functions, including changes that may indicate a security fix.
Why use it?
It shows what changed between versions without requiring a manual byte-by-byte review.

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/ogrodev/fsociety/diff
Clone the repo
git clone --depth 1 https://github.com/ogrodev/fsociety
Per session 10 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 487 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 $0.00010 $0.00487
Opus 5 $0.00005 $0.00244
Sonnet 5 $0.00002 $0.00097
Haiku 4.5 $0.00001 $0.00049

Measured 2d ago against content hash 435d7bdbefb8, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

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 2d 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.

romero/commands/diff.md · 81 lines

What it actually says

Storage Policy: ALL output files MUST be saved in the project directory. NEVER write to /tmp/ or any system temporary directory.

Binary Diffing

Parse $ARGUMENTS for two binary paths (space-separated).

Step 1 — Hash Both Binaries

node "${CLAUDE_PLUGIN_ROOT}/scripts/binary-hasher.js" hash "<binary1>"
node "${CLAUDE_PLUGIN_ROOT}/scripts/binary-hasher.js" hash "<binary2>"

If hashes are identical, report "Binaries are identical" and exit.

Step 2 — File Size Comparison

Compare file sizes and report delta.

Step 3 — Byte-Level Diff

radiff2 <binary1> <binary2>

This shows byte-level differences between the two files.

Step 4 — Section Comparison

r2 -qc 'iS' <binary1>
r2 -qc 'iS' <binary2>

Compare section names, sizes, entropy, and virtual addresses.

Step 5 — Import/Export Diff

r2 -qc 'ii' <binary1> > imports1.txt
r2 -qc 'ii' <binary2> > imports2.txt
diff imports1.txt imports2.txt

Compare new imports, removed imports, and changed ordinals.

Step 6 — Function-Level Diff

r2 -qc 'aaa; afl' <binary1>
r2 -qc 'aaa; afl' <binary2>

Compare function lists: new functions, removed functions, changed sizes.

Step 7 — ssdeep Similarity

ssdeep <binary1> <binary2>

Report similarity percentage.

Step 8 — Report

Save report to diff-<name1>-vs-<name2>.md with sections:

  • File Identification (both binaries)
  • Size Delta
  • Section Differences
  • Import/Export Changes
  • Function Changes
  • ssdeep Similarity Score
  • Security-Relevant Changes (if any)
  • Recommendations
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. 2d ago First seen · 81 lines · 10 tokens per session scan A 435d7bdbefb8

Subscribe to this mod's changes

diff is a command published in the GitHub repository ogrodev/fsociety (20 stars, last pushed 5mo ago), licensed MIT. It adds 10 tokens to every session and 487 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.