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 agentmods add instructions/jamesrochabrun/xcodetracemcp/agents-mdgit clone --depth 1 https://github.com/jamesrochabrun/XcodeTraceMCPWrote 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/instructions/jamesrochabrun/xcodetracemcp/agents-md)<a href="https://agentmods.dev/instructions/jamesrochabrun/xcodetracemcp/agents-md"><img src="https://agentmods.dev/badge/instructions/jamesrochabrun/xcodetracemcp/agents-md.svg" alt="Measured on agentmods" height="20"></a>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 | $0.03155 | $0.03155 |
| Opus 5 | $0.01577 | $0.01577 |
| Sonnet 5 | $0.00631 | $0.00631 |
| Haiku 4.5 | $0.00315 | $0.00315 |
Grade A, and why
XcodeTraceMCP AGENTS.md 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 4d 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.
Copies of this mod
1 near-identical copy found in the catalogue:
- XcodeTraceMCP CLAUDE.md — 98% identical, 3 lines differ
How it starts
The opening of the file, as written. The whole thing — 177 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Agent Guide
This repository contains a local Model Context Protocol (MCP) server for Xcode Instruments profiling. Treat it as an honest xcrun xctrace companion, not a replacement for Instruments.app. The server records, opens saved traces in Instruments.app by default, symbolicates, exports, parses, and analyzes what Apple exposes through xctrace, then reports unsupported or non-exportable data explicitly.
Project Architecture
The repo is a pnpm workspace with two packages:
packages/core: reusable TypeScript library forxcrun xctracecapability checks, recording/exporting, symbolication, trace parsing, analysis, recommendations, and Time Profiler comparisons.packages/mcp-server: MCP stdio server that exposes the core library as assistant-callable tools.
High-level flow:
- An MCP client calls a tool such as
profile_running_app. - The MCP server validates arguments and delegates to
@xctrace-analyzer/core. - Core runs
xcrun xctraceusingexecFileargument arrays. - Core parses
xctrace export --toc, TOC-driven XPath table XML, and HAR output when available. - Core returns typed analysis objects with support status and export attempts.
- The MCP server formats those objects into Markdown, JSON, or both.
User-Facing Skill
This repo includes a bundled skill at skills/xctrace-profiler. Use it as the primary human-facing entry point for profiling, trace analysis, hangs, CPU bottlenecks, leaks, allocations, network, energy, startup slowness, and trace comparisons.
Users should be able to say simple prompts like:
Profile this app.
Find why this app is slow.
Profile this app for hangs.
Profile this app for hangs and tell me which of my code is responsible.
Check this build for leaks and allocation churn.
Analyze network activity.
Launch this app and profile startup hangs.
Analyze this trace.
Compare these two traces.
The skill should hide MCP JSON and tool names. It is the planning layer. It chooses between profile_running_app, track_running_app, analyze_trace, compare_traces, check_xctrace, list_templates, and list_devices, records or analyzes with outputFormat: "both" when diagnostics matter, reads Support Matrix / Export Diagnostics, and can rerun analyze_trace with timeRangeMs around the longest hang so ## Top User-Code Frames answers the app-owned code question.
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.
- 4d ago First seen · 177 lines · 3,155 tokens per session scan A bfdae6c1bd7a
XcodeTraceMCP AGENTS.md is an instructions file published in the GitHub repository jamesrochabrun/XcodeTraceMCP (44 stars, last pushed 3mo ago), licensed MIT. It adds 3,155 tokens to every session, about $0.0158 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.
Other instructions, from other repositories
vscode buildNext.instructions.md
Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).
spec-kit AGENTS.md
AGENTS.md instructions for github/spec-kit, covering agents.md, about spec kit and specify, quickstart — add a new integration in 5 steps, integration architecture and integrationmanifest — file tracking.
codex AGENTS.md
AGENTS.md instructions for openai/codex, covering rust/codex-rs, the codex-core crate, code review rules, crate api surface and model visible context.
langchain AGENTS.md
AGENTS.md instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.
vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, applying the notice (cutover) and fallback chain (never fail the build).
next.js AGENTS.md
Instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.