power-platform-github-copilot-kit d365-webresources.instructions.md

A set of guidelines for writing JavaScript used in Dynamics 365 and Power Platform web resources, which are browser-based scripts added to business forms and pages. It covers supported APIs, code structure, security, performance, and compatibility with platform updates.

In plain words
What is it for?
Use it when building form scripts, ribbon actions, and other client-side Dynamics 365 web resources, especially when deciding where business logic should live and how solutions should be versioned.
Why use it?
It helps avoid deprecated or unsupported interfaces and keeps business logic maintainable and testable. It also reduces slow form loading and problems during platform upgrades.

Instructions file for GitHub Copilot

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 instructions/calsora/power-platform-github-copilot-kit/d365-webresources
Clone the repo
git clone --depth 1 https://github.com/calsora/power-platform-github-copilot-kit

Made for: GitHub Copilot.

Per session 1,295 This file is loaded in full into every session.
When invoked 1,295 The same file — it is already loaded in full.
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 $0.01295 $0.01295
Opus 5 $0.00647 $0.00647
Sonnet 5 $0.00259 $0.00259
Haiku 4.5 $0.00129 $0.00129

Measured 2d ago against content hash 634f2179e5e4, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

power-platform-github-copilot-kit d365-webresources.instructions.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 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.

.github/instructions/d365-webresources.instructions.md · 141 lines

How it starts

The opening of the file, as written. The whole thing — 141 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Dynamics 365 JavaScript Web Resource Best Practices

This guidance describes reusable patterns and anti-patterns for client-side JavaScript used in Dynamics 365 / Power Platform web resources.

Severity levels:

  • CRITICAL — Code that creates functional failure, security risk, or unsupported behavior in Dynamics 365.
  • IMPORTANT — Code that reduces maintainability, performance, or compatibility with platform upgrades.
  • SUGGESTION — Improvements for readability, tooling, or developer experience.

Core principles

  • Use supported client API and avoid unsupported DOM or internal Xrm object access.
  • Keep business logic out of web resources when possible; prefer Power Fx, business rules, plugins, or Power Automate for process logic.
  • Build modular, testable JavaScript with clear namespace/closure boundaries.
  • Use solution-aware web resources and version them with solution layering.
  • Optimize for performance on form load and ribbon actions.

Supported API and platform compatibility

Rule Summary Severity
Use formContext instead of global Xrm.Page Xrm.Page is deprecated. Use the execution context to get the form context. IMPORTANT
Avoid unsupported DOM selectors Do not query or modify DOM elements directly with document.querySelector or getElementById. CRITICAL
Use supported client-side events only Register code through form event handlers or ribbon commands, not by attaching custom DOM listeners to internal controls. IMPORTANT
Avoid proprietary browser APIs Target the browser support model for Dynamics 365 and avoid APIs not supported by supported browsers. SUGGESTION

Code structure anti-patterns (C1-C5)

C1: Global variables without namespace

  • Severity: IMPORTANT
  • Detection: var myValue = ... or window.myValue in a web resource.
  • Use a single namespace object or Immediately Invoked Function Expression (IIFE) to avoid collisions.
// GOOD
var MyApp = MyApp || {};
MyApp.ContactForm = {
  onLoad: function (executionContext) {
    var formContext = executionContext.getFormContext();
  }
};

Read the full file on GitHub · 141 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 · 141 lines · 1,295 tokens per session scan A 634f2179e5e4

Subscribe to this mod's changes

power-platform-github-copilot-kit d365-webresources.instructions.md is an instructions file published in the GitHub repository calsora/power-platform-github-copilot-kit (6 stars, last pushed 2mo ago), licensed MIT. It adds 1,295 tokens to every session, about $0.0065 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.