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.
npx skills add mohitmishra786/low-level-dev-skills --skill assembly-x86git clone --depth 1 https://github.com/mohitmishra786/low-level-dev-skillsWrote 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/skills/mohitmishra786/low-level-dev-skills/assembly-x86)<a href="https://agentmods.dev/skills/mohitmishra786/low-level-dev-skills/assembly-x86"><img src="https://agentmods.dev/badge/skills/mohitmishra786/low-level-dev-skills/assembly-x86/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/skills/mohitmishra786/low-level-dev-skills/assembly-x86"><img src="https://agentmods.dev/badge/skills/mohitmishra786/low-level-dev-skills/assembly-x86.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Socket pass
- Snyk pass
- NVIDIA SkillSpector pass
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 | $0.00093 | $0.02047 |
| Opus 5 | $0.00046 | $0.01024 |
| Sonnet 5 | $0.00019 | $0.00409 |
| Haiku 4.5 | $0.00009 | $0.00205 |
Grade A, and why
assembly-x86 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 — 176 lines — stays where its author put it; the contents beside it link to each section on GitHub.
x86-64 Assembly
Purpose
Guide agents through x86-64 assembly: reading compiler output, understanding the ABI, writing inline asm, and common patterns.
Triggers
- "How do I read the assembly GCC generated?"
- "What are the x86-64 registers?"
- "What is the calling convention on Linux/macOS?"
- "How do I write inline assembly in C?"
- "How do I use SSE/AVX intrinsics?"
- "This assembly uses
%rsp/%rbp— what does it mean?"
Workflow
1. Generate and read assembly
# AT&T syntax (GCC default)
gcc -S -O2 -fverbose-asm foo.c -o foo.s
# Intel syntax
gcc -S -masm=intel -O2 foo.c -o foo.s
# From GDB
(gdb) disassemble /s main # with source
(gdb) x/20i $rip
# From objdump
objdump -d -M intel -S prog # Intel + source (needs -g)
2. x86-64 registers
| 64-bit | 32-bit | 16-bit | 8-bit high | 8-bit low | Purpose |
|---|---|---|---|---|---|
%rax |
%eax |
%ax |
%ah |
%al |
Return value / accumulator |
%rbx |
%ebx |
%bx |
%bh |
%bl |
Callee-saved |
%rcx |
%ecx |
%cx |
%ch |
%cl |
4th arg / count |
%rdx |
%edx |
%dx |
%dh |
%dl |
3rd arg / 2nd return |
%rsi |
%esi |
%si |
— | %sil |
2nd arg |
%rdi |
%edi |
%di |
— | %dil |
1st arg |
%rbp |
%ebp |
%bp |
— | %bpl |
Frame pointer (callee-saved) |
%rsp |
%esp |
%sp |
— | %spl |
Stack pointer |
%r8–%r11 |
%r8d–%r11d |
%r8w–%r11w |
— | %r8b–%r11b |
5th–8th args / caller-saved |
%r12–%r15 |
%r12d–%r15d |
%r12w–%r15w |
— | %r12b–%r15b |
Callee-saved |
%rip |
Instruction pointer | ||||
%rflags |
%eflags |
Status flags | |||
%xmm0–%xmm7 |
FP/SIMD args and return | ||||
%xmm8–%xmm15 |
Caller-saved SIMD | ||||
%ymm0–%ymm15 |
AVX 256-bit | ||||
%zmm0–%zmm31 |
AVX-512 512-bit |
3. System V AMD64 ABI (Linux, macOS, FreeBSD)
Integer/pointer argument registers (in order):
%rdi, %rsi, %rdx, %rcx, %r8, %r9
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.
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 · 176 lines · 93 tokens per session scan A d4d383b3dd86
assembly-x86 is a skill published in the GitHub repository mohitmishra786/low-level-dev-skills (203 stars, last pushed 2mo ago), licensed MIT. It adds 93 tokens to every session and 2,047 once invoked, about $0.0005 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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