A tool for finding what limits a game's frame rate in Unreal Engine— the processor, graphics card, or a particular engine thread—and for recording Unreal Insights traces.

Use it to inspect game, render, GPU, and RHI timing, check performance against a target FPS, deliberately create test hitches, capture traces, and write performance reports.

It replaces guesswork about low FPS with frame-time measurements and a CPU-versus-GPU diagnosis.

profiling — Skill for Claude Code and Codex by kevinpbuckley

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 kevinpbuckley/VibeUE --skill profiling

Clone the repo

git clone --depth 1 https://github.com/kevinpbuckley/VibeUE

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/kevinpbuckley/vibeue/profiling.svg)](https://agentmods.dev/skills/kevinpbuckley/vibeue/profiling)

Your own site

<a href="https://agentmods.dev/skills/kevinpbuckley/vibeue/profiling"><img src="https://agentmods.dev/badge/skills/kevinpbuckley/vibeue/profiling.svg" alt="Measured on agentmods" height="20"></a>

Per session 57 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 4,120 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	$0.00057	$0.04120
Opus 5	$0.00028	$0.02060
Sonnet 5	$0.00011	$0.00824
Haiku 4.5	$0.00006	$0.00412

Measured 8d ago against content hash 4cab72ae93c1, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

profiling 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 8d 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.

Content/Skills/profiling/SKILL.md · 347 lines

How it starts

The opening of the file, as written. The whole thing — 347 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Profiling Skill

Unreal 5.8's native toolsets have no performance or tracing tools, so this is VibeUE's net-new capability: unreal.PerformanceService answers "are we CPU- or GPU-bound?" and drives Unreal Insights captures from Python with no C++ required. Run everything here through execute_python_code.

The whole API is small — read the live signatures once with discover_python_class(class_name="unreal.PerformanceService"):

Method	Purpose
`frame_timing(target_fps=60.0)`	Game/Render/GPU/RHI thread ms + a CPU-vs-GPU `bound` verdict + a `hint`, plus a per-thread `budget` breakdown gated against `target_fps` (`budget.meets_target` PASS/FAIL). Run FIRST.
`force_hitch(thread="game", ms=250.0, frames=1)`	Validation helper — deliberately stall a KNOWN thread (`"game"`/`"render"`/`"both"`/`"gpu"`) to confirm the verdict fires. CPU paths are self-measuring: validate from the SAME response (`observed_peak_*_ms`, `verdict_matched_expect`) — do NOT follow up with `frame_timing`. Only the async `gpu` path is read back on a following frame. Clamped (≤5000 ms, ~10 s total) for safety.
`report(title=..., source="both", file="")`	Write a self-contained, shareable HTML report (live verdict + budget + analyse stats + a data-driven "fix in this order" list) to `Saved/VibeUE/Performance/report_<timestamp>.html`.
`start_pie()` / `stop_pie()`	In-process PIE so `frame_timing`/`force_hitch` read a live game world (PIE starts on the next tick — read on a following frame, `pie_running` flips true). Quick checks only; prefer `start_standalone` when the numbers must be trusted.
`start_trace(name="mcp_capture", channels="")`	Start an Insights trace to file (default channel set if `channels` empty).
`stop_trace()`	Stop the active trace; returns the trace file path + size.
`get_trace_status()`	Whether a trace is active and which channels are enabled.
`bookmark(name)`	Drop a point-in-time bookmark in the active trace.
`region_start(name)` / `region_end(name)`	Begin / end a named region span in the active trace.
`analyse(source="both", file="")`	Read back trace and/or log → frame stats, worst frames, hitches, notable log lines.
`start_standalone(name="standalone_capture", channels="")`	Launch the game as a separate standalone process with a trace attached (representative readings the editor viewport can't give).
`stop_standalone()`	Stop the standalone process and finalise its trace/log.
`get_standalone_status()`	Whether a standalone session is running and which trace/log it writes.

All methods return a JSON string. For a representative reading, profile under PIE or a standalone session (start_standalone), not the bare editor viewport.

Read the full file on GitHub · 347 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.

8d ago First seen · 347 lines · 57 tokens per session scan A 4cab72ae93c1

Subscribe to this mod's changes

profiling is a skill published in the GitHub repository kevinpbuckley/VibeUE (656 stars, last pushed 3d ago), licensed MIT. It adds 57 tokens to every session and 4,120 once invoked, about $0.0003 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.

GPU Game development bad fps cpu cpu bound fps frame time gpu bound low fps performance profiling trace unreal insights

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