source-driven-development

A guide for making .NET and C# implementation decisions using current official documentation, such as Microsoft Learn or library documentation. It keeps framework-specific code tied to sources that can be checked.

In plain words
What is it for?
Use it when building or reviewing code with EF Core, ASP.NET Core, Avalonia, Blazor, MAUI, NuGet packages, or other .NET frameworks and libraries.
Why use it?
Framework APIs and recommended patterns change between versions, so relying on memory can produce outdated or incorrect code.

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/peterblazejewicz/claude-plugins/source-driven-development
Any agent
npx skills add peterblazejewicz/claude-plugins --skill source-driven-development
Clone the repo
git clone --depth 1 https://github.com/peterblazejewicz/claude-plugins

Made for: Claude Code, Codex.

Per session 70 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,628 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 $0.00070 $0.03628
Opus 5 $0.00035 $0.01814
Sonnet 5 $0.00014 $0.00726
Haiku 4.5 $0.00007 $0.00363

Measured 2d ago against content hash 88598358fccd, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

source-driven-development 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 2d 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.

plugins/dotnet-skills/skills/source-driven-development/SKILL.md · 248 lines

How it starts

The opening of the file, as written. The whole thing — 248 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Source-Driven Development

Overview

Every framework-specific code decision must be backed by official documentation. Don't implement from memory — verify, cite, and let the user see your sources. Training data goes stale, APIs get deprecated, best practices evolve. In the .NET ecosystem this hits especially hard: EF Core, ASP.NET Core, and Avalonia ship material API changes between major versions, and a pattern that was correct in net6.0 is often deprecated or removed in net8.0. This skill ensures the user gets code they can trust because every pattern traces back to an authoritative source they can check.

When to Use

  • The user wants code that follows current best practices for a given framework
  • Building boilerplate, starter code, or patterns that will be copied across a solution
  • The user explicitly asks for documented, verified, or "correct" implementation
  • Implementing features where the framework's recommended approach matters (EF Core queries, ASP.NET Core middleware, Avalonia bindings, Blazor render modes, MAUI lifecycle)
  • Reviewing or improving code that uses framework-specific patterns
  • Any time you are about to write framework-specific code from memory

When NOT to use:

  • Correctness does not depend on a specific version (renaming variables, fixing typos, moving files)
  • Pure logic that works the same across all versions (loops, conditionals, System.Collections.Generic)
  • The user explicitly wants speed over verification ("just do it quickly")

The Process

DETECT ──→ FETCH ──→ IMPLEMENT ──→ CITE
  │          │           │            │
  ▼          ▼           ▼            ▼
 What       Get the    Follow the   Show your
 stack?     relevant   documented   sources
            docs       patterns

Step 1: Detect Stack and Versions

Read the full file on GitHub · 248 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. 2d ago First seen · 248 lines · 70 tokens per session scan A 88598358fccd

Subscribe to this mod's changes

source-driven-development is a skill published in the GitHub repository peterblazejewicz/claude-plugins (7 stars, last pushed 2mo ago), licensed MIT. It adds 70 tokens to every session and 3,628 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 2026-08-31.

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