What is write-vfunc-as-yaml?

A reverse-engineering skill for saving information about a virtual function and its place in a class's virtual-function table as YAML. A virtual function is a class method selected at runtime through a table of function entries.

It helps record a virtual function's class, table index, offset, address, and signatures after IDA Pro analysis.

It preserves the discovered function and table details in a standard file so the results can be reused outside the analysis session.

write-vfunc-as-yaml — Skill for Claude Code by HLND2T

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 HLND2T/CS2_VibeSignatures --skill write-vfunc-as-yaml

Clone the repo

git clone --depth 1 https://github.com/HLND2T/CS2_VibeSignatures

Made for: Claude Code.

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/hlnd2t/cs2_vibesignatures/write-vfunc-as-yaml/github.svg)](https://agentmods.dev/skills/hlnd2t/cs2_vibesignatures/write-vfunc-as-yaml)

Your own site

<a href="https://agentmods.dev/skills/hlnd2t/cs2_vibesignatures/write-vfunc-as-yaml"><img src="https://agentmods.dev/badge/skills/hlnd2t/cs2_vibesignatures/write-vfunc-as-yaml/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/hlnd2t/cs2_vibesignatures/write-vfunc-as-yaml"><img src="https://agentmods.dev/badge/skills/hlnd2t/cs2_vibesignatures/write-vfunc-as-yaml.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 50 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 2,226 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. Third-party audits

NVIDIA SkillSpector pass 7 Sept 2026

How audits are shown

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.

Model	Per session	Once invoked
Fable 5.1	$0.00050	$0.02226
Opus 5.5	$0.00020	$0.00890
Sonnet 5.5	$0.00010	$0.00445
Haiku 4.5	$0.00005	$0.00223

Measured 15d ago against content hash 58e2000433c3, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

write-vfunc-as-yaml 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 15d 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.

.claude/skills/write-vfunc-as-yaml/SKILL.md · 184 lines

How it starts

The opening of the file, as written. The whole thing — 184 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Write Virtual Function IDA Analysis Output as YAML

Persist virtual function analysis results to a YAML file beside the binary using IDA Pro MCP.

Prerequisites

Before using this skill, you should have:

Identified and renamed the target virtual function
Generated a unique signature using /generate-signature-for-function
Obtained vtable information using /get-vtable-index
An IDA Pro MCP session, resolved per mcp-ida-session.md: idb_list → idb_open (script fallback only if the endpoint is unreachable). Honor its IDB save discipline — an idle-TTL self-exit does not save.

Required Parameters

Parameter	Description	Example
`func_name`	Name of the function	`CCSPlayerController_ChangeTeam`
`vtable_name`	Class name for vtable	`CCSPlayerController`
`vfunc_offset`	Offset from vtable start	`0x330`
`vfunc_index`	Index in vtable	`102`

Optional Parameters

Parameter	Description	Example
`func_addr`	Virtual address of the function (use `None` to omit)	`0x180999830`
`artifact_name`	Stable filename stem from the caller's expected output; defaults to `func_name`. This may be a legacy key with a corrected semantic name.	`INetworkServerService_GetServerSerializersCRC`
`func_sig`	Unique byte signature to locate function body (use `None` to omit)	`48 89 5C 24 08`
`vfunc_sig`	Unique byte signature to determine vfunc offset (use `None` to omit)	`FF 90 80 04 00 00 4C 8B AC 24 ?? ?? ?? ??`
`vfunc_sig_disp`	Byte displacement from signature start to the target instruction. `0` or `None` means signature starts at the target instruction. Non-zero means backward expansion was used by `/generate-signature-for-vfuncoffset`. (use `None` to omit)	`3`

When func_addr is None, the following fields will be omitted from output: func_va, func_rva, func_size. When func_sig is None, the func_sig field will be omitted from output. When vfunc_sig is None, the vfunc_sig field will be omitted from output. When vfunc_sig_disp is None or 0, the vfunc_sig_disp field will be omitted from output.

Read the full file on GitHub · 184 lines

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.

15d ago Changed · +6 lines 58e2000433c3
1mo ago Changed · +1 lines 366a9320c445
2mo ago Changed · +4 lines 8424f6940641
2mo ago First seen · 173 lines · 50 tokens per session scan A e29b39e7f23e

Subscribe to this mod's changes

write-vfunc-as-yaml is a skill published in the GitHub repository HLND2T/CS2_VibeSignatures (67 stars, last pushed today), licensed MIT. It adds 50 tokens to every session and 2,226 once invoked, about $0.0002 per session on Opus 5.5. 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.

write-vfunc-as-yaml next to 6 skills from other repositories
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write-vfunc-as-yamlHLND2T/CS2_VibeSignatures	Skill	67	today	MIT	A	50	Claude Code
imagegenopenai/codex	Skill	133k	yesterday	Apache-2.0	A	113	Codex
playwright-climicrosoft/playwright	Skill	99k	yesterday	Apache-2.0	A	19	Claude Code
local-ai-agentsmicrosoft/ai-agents-for-beginners	Skill	79k	4d ago	MIT	A	200	Claude Code, Codex
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