protocol-reverse

protocol-reverse is a skill for Claude Code, Codex from xAmirHamza77/ReverseOps-Skill. It costs 30 tokens per session (1,021 once invoked), scanned A, original, MIT.

A workflow for recovering the format and behavior of custom network messages from traffic captures or program behavior. It covers formats such as Protobuf, gRPC, WebSocket frames, and other private protocols.

In plain words
What is it for?
Use it to analyze packet captures, identify message fields, study checksums and sequence numbers, and document client-server protocol behavior.
Why use it?
It helps explain undocumented communication when there is no protocol specification. A recovered message layout and state sequence make the traffic easier to inspect and reproduce in authorized research.

Skill for Claude CodeCodex

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

Good fit Use it to analyze packet captures, identify message fields, study checksums and sequence numbers, and document client-server protocol behavior.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/xamirhamza77/reverseops-skill/protocol-reverse
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 xAmirHamza77/ReverseOps-Skill --skill protocol-reverse
Clone the repo
git clone --depth 1 https://github.com/xAmirHamza77/ReverseOps-Skill

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 protocol-reverse

README.md
[![agentmods](https://agentmods.dev/badge/skills/xamirhamza77/reverseops-skill/protocol-reverse/github.svg)](https://agentmods.dev/skills/xamirhamza77/reverseops-skill/protocol-reverse)
Your own site
<a href="https://agentmods.dev/skills/xamirhamza77/reverseops-skill/protocol-reverse"><img src="https://agentmods.dev/badge/skills/xamirhamza77/reverseops-skill/protocol-reverse/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 protocol-reverse

Your own site · 80×15
<a href="https://agentmods.dev/skills/xamirhamza77/reverseops-skill/protocol-reverse"><img src="https://agentmods.dev/badge/skills/xamirhamza77/reverseops-skill/protocol-reverse.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 30 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,021 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 $0.00030 $0.01021
Opus 5 $0.00015 $0.00511
Sonnet 5 $0.00006 $0.00204
Haiku 4.5 $0.00003 $0.00102

Measured 5d ago against content hash de8e15e2c6cc, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

protocol-reverse 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 5d 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.

skills/protocol-reverse/SKILL.md · 99 lines

How it starts

The opening of the file, as written. The whole thing — 99 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Protocol Reverse Engineering

ACTION REQUIRED (execute immediately after reading)

  1. NOW: Read ../field-journal/precedent-reverse.md — confirm authorization and routine-operation boundaries
  2. NOW: Confirm whether the task is protocol/traffic/serialization format reversing (pure Web parameter signing → go to js-reverse/)
  3. NOW: If target network interaction is involved → run ../scripts/case-init.ps1 to complete the scope; ACT against the target is forbidden unless auth is granted
  4. NEXT: Read ../tool-index.md; bootstrap missing tools (tshark/wireshark etc. may require manual installation)
  5. ACT: Enter workflow Phase 1 and produce a frame layout or message dictionary draft

Applicable scenarios

  • Custom TCP/UDP binary protocols
  • Protobuf / gRPC / FlatBuffers / MessagePack
  • WebSocket / MQTT / private RPC
  • Recovering fields and state machines from PCAP / PCAPNG
  • Client-server checksums, sequence numbers, encrypted frame headers

When not to use this skill

Situation Where to go
Only HTTP parameter signing / JS encryption js-reverse/
Only TLS certificate issues pentest-tools/ or browser proxy
Deep dive into an in-firmware protocol stack + emulation firmware-pentest/ first, then return to this skill

Workflow

Phase 1 — Collection and triage

□ Obtain samples: PCAP / proxy export / client logs / binaries
□ Mark direction: C→S / S→C; whether there is handshake, heartbeat, reconnect
□ Fixed header? Magic number? Length field? TLV? Fixed size?
□ Compression (zlib/gzip/lz4) or encryption (AES/ChaCha within the frame)?
□ tshark -r cap.pcap -T fields -e frame.number -e ip.src -e tcp.payload

Phase 2 — Frame layout recovery

□ Align multiple messages of the same type; find invariant bytes / auto-incrementing sequence numbers
□ Length field: big-endian/little-endian, including header/not including header
□ Checksums: position of CRC16/32, checksum, HMAC
□ Draw the state machine: Connect → Auth → Ready → Request/Response → Close
□ Tools: Wireshark custom dissector draft / ImHex / 010 Editor template / Kaitai Struct

Read the full file on GitHub · 99 lines

Files

What ships with it

1 file 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. 5d ago First seen · 99 lines · 30 tokens per session scan A de8e15e2c6cc

Subscribe to this mod's changes

protocol-reverse is a skill published in the GitHub repository xAmirHamza77/ReverseOps-Skill (4 stars, last pushed 1mo ago), licensed MIT. It adds 30 tokens to every session and 1,021 once invoked, about $0.0002 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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