memorylens

memorylens is a skill for Claude Code, Codex from MarcelRoozekrans/memorylens-mcp. It costs 27 tokens per session (901 once invoked), scanned A, original, MIT.

A method for investigating memory use in .NET applications, especially suspected memory leaks. It relies on the MemoryLens MCP server to inspect an already-running process.

In plain words
What is it for?
Use it to list running .NET processes, take and compare heap snapshots, and analyze memory findings. The required MCP server must be available.
Why use it?
It provides a systematic way to examine high memory use, out-of-memory errors, slow garbage collection, or memory that keeps growing.

Skill for Claude CodeCodex

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

Part of the memorylens plugin — 1 skill, 1 MCP server shipped together

Good fit Use it to list running .NET processes, take and compare heap snapshots, and analyze memory findings. The required MCP server must be available.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/marcelroozekrans/memorylens-mcp/memorylens
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 MarcelRoozekrans/memorylens-mcp --skill memorylens
Clone the repo
git clone --depth 1 https://github.com/MarcelRoozekrans/memorylens-mcp

Made for: Claude Code, Codex.

Or install memorylens, the plugin that ships this one along with the rest of its 1 skill, 1 MCP server.

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 memorylens

README.md
[![agentmods](https://agentmods.dev/badge/skills/marcelroozekrans/memorylens-mcp/memorylens.svg)](https://agentmods.dev/skills/marcelroozekrans/memorylens-mcp/memorylens)
Your own site
<a href="https://agentmods.dev/skills/marcelroozekrans/memorylens-mcp/memorylens"><img src="https://agentmods.dev/badge/skills/marcelroozekrans/memorylens-mcp/memorylens.svg" alt="Measured on agentmods" height="20"></a>
Per session 27 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 901 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 $0.00027 $0.00901
Opus 5 $0.00014 $0.00451
Sonnet 5 $0.00005 $0.00180
Haiku 4.5 $0.00003 $0.00090

Measured 8d ago against content hash ccd29869624d, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

memorylens 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.

skills/memorylens/SKILL.md · 95 lines

How it starts

The opening of the file, as written. The whole thing — 95 lines — stays where its author put it; the contents beside it link to each section on GitHub.

MemoryLens — Memory Profiling Skill

Prerequisites

This skill requires the memorylens MCP server tools (list_processes, snapshot, compare_snapshots, analyze, get_rules). Collection happens in-process over EventPipe, so there is nothing to install or verify before profiling — if the MCP tools aren't available at all, inform the user to install the memorylens plugin.

When to Use

  • On demand: User requests memory analysis (/memorylens)
  • During debugging: When systematic-debugging identifies symptoms like high memory usage, OutOfMemoryException, slow GC, or growing memory over time
  • During brainstorming: When designing performance-sensitive features that involve caching, event systems, or long-lived objects

Announce Line

"MemoryLens activated. I'll profile your application's memory and suggest concrete fixes."

Workflow

Step 1: Identify target

MemoryLens attaches to an already-running .NET process. It cannot launch one.

  • Call list_processes and let the user pick, or take a pid the user supplies.
  • If the app is not running yet, ask the user to start it first, then re-run list_processes.
  • snapshot and compare_snapshots both require a pid. Do not pass command — the parameter is accepted for compatibility but is not implemented, and a call without a pid returns an error.

Step 2: Choose profiling mode

Based on the user's ask:

  • "How does my memory look?" → Single snapshot
  • "Is there a leak?" / "What changed?"compare_snapshots
  • Unclear → Ask: "Do you want a single snapshot of current state, or a before/after comparison to detect growth?"

Step 3: Capture

Execute snapshot or compare_snapshots with the target parameters.

Step 4: Analyze

Call analyze with the returned snapshotId and nothing else — the id is all it needs.

Rule configuration is not a parameter. The server reads .memorylens.json from its own working directory once at startup; changing that file needs a server restart to take effect. Use get_rules to see which rules are currently active.

Read the full file on GitHub · 95 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.

  1. 8d ago First seen · 95 lines · 27 tokens per session scan A ccd29869624d

Subscribe to this mod's changes

memorylens is a skill published in the GitHub repository MarcelRoozekrans/memorylens-mcp (10 stars, last pushed today), licensed MIT. It adds 27 tokens to every session and 901 once invoked, about $0.0001 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 2026-08-31.

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