mlnet

Guidance for using ML.NET, Microsoft’s machine-learning framework for .NET applications, to train models and use them for predictions.

In plain words
What is it for?
It helps build training and prediction pipelines, load and refresh models, review generated C# code, and measure results on representative data.
Why use it?
It helps avoid trusting a model just because sample code runs by checking data quality, evaluation results, deployment, and model versioning.

Skill for Claude CodeCodex

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.

agentmods
npx agentmods add skills/managedcode/dotnet-skills/mlnet
Any agent
npx skills add managedcode/dotnet-skills --skill mlnet
Clone the repo
git clone --depth 1 https://github.com/managedcode/dotnet-skills

Made for: Claude Code, Codex.

Per session 105 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 430 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00105 $0.00430
Opus 5 $0.00053 $0.00215
Sonnet 5 $0.00021 $0.00086
Haiku 4.5 $0.00011 $0.00043

Measured yesterday against content hash 50cfc0de2da0, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

mlnet 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 yesterday.

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.

catalog/Frameworks/ML.NET/skills/mlnet/SKILL.md · 40 lines

What it actually says

ML.NET

Trigger On

  • integrating machine learning into a .NET application
  • training or retraining ML.NET models from local data
  • reviewing inference pipelines, model loading, or AutoML-generated code

Workflow

  1. Start from the prediction task and data quality, not the algorithm or package list.
  2. Separate training code from inference code so the production path stays lean and predictable.
  3. Review feature engineering, normalization, label quality, and evaluation metrics before trusting model output.
  4. Use Model Builder or the ML.NET CLI when they speed up exploration, but inspect the generated C# before treating it as production architecture.
  5. Plan how the model is loaded, versioned, and refreshed in the application lifecycle.
  6. Validate with representative datasets and explicit evaluation, not only with a sample that happens to run.

Deliver

  • ML.NET pipelines that fit the prediction task
  • production-usable inference integration
  • evaluation evidence tied to the business scenario

Validate

  • model quality is measured, not assumed
  • training and inference responsibilities are separated
  • deployment and versioning expectations are explicit

References

  • patterns.md - Data loading, training pipelines, evaluation metrics, deployment strategies, and feature engineering patterns
  • examples.md - Complete examples for sentiment analysis, price prediction, image classification, anomaly detection, recommendations, clustering, fraud detection, text classification, object detection, and AutoML
Files

What ships with it

3 files 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.

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. yesterday First seen · 40 lines · 105 tokens per session scan A 50cfc0de2da0

Subscribe to this mod's changes

mlnet is a skill published in the GitHub repository managedcode/dotnet-skills (477 stars, last pushed 2d ago), licensed MIT. It adds 105 tokens to every session and 430 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 2026-08-30.

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