web-widgets AGENTS.md

AGENTS.md instructions for mendix/web-widgets, covering mendix web widgets, conventions, e2e test rules (playwright), development setup and constraints.

Instructions file for CodexOpenCode

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/mendix/web-widgets/agents-md
Clone the repo
git clone --depth 1 https://github.com/mendix/web-widgets

Made for: Codex, OpenCode.

Per session 642 This file is loaded in full into every session.
When invoked 642 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
Origin unknown 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 $0.00642 $0.00642
Opus 5 $0.00321 $0.00321
Sonnet 5 $0.00128 $0.00128
Haiku 4.5 $0.00064 $0.00064

Measured today against content hash 9369c168bb7f, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

web-widgets 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 today.

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.

AGENTS.md · 62 lines

How it starts

The opening of the file, as written. The whole thing — 62 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Mendix Web Widgets

Monorepo of official Mendix pluggable web widgets. pnpm workspaces + Turbo.

Conventions

  • TypeScript strict, React functional components + hooks
  • Mendix Pluggable Widgets API: EditableValue, ActionValue, ListValue, DynamicValue
  • Check ActionValue.canExecute before execute()
  • Render loading/empty states until values are ready
  • SCSS for styling, prefer Atlas UI classes, BEM-like naming with widget prefix
  • Conventional commits enforced: type(scope): description
  • Semver + CHANGELOG.md per package for pluggable widgets and modules, not for shared packages
  • Changelogs for users: include only widget behavior, not implementation details
  • Changelogs added during development, version bumps only at release time
  • Jest + RTL for unit tests (src/*/tests/.spec.ts)
  • Playwright for E2E (e2e/*.spec.js)

E2E Test Rules (Playwright)

  • docs/requirements/e2e-test-guidelines.md — Full rules + template

Development Setup

  • Node >=24, pnpm 10.x
  • Set MX_PROJECT_PATH to Mendix project dir for live reload
  • Run pnpm start inside widget package for dev build

Constraints

  • Never modify dist/, generated files, or lockfiles
  • OpenSpec specs/changes are PER-PACKAGE — never create them at the monorepo root. Always cd packages/<type>/<name> before any openspec new/init/archive. The root openspec/ directory is off-limits (enforced by .claude/hooks/validate-openspec-path.sh).
  • XML property keys: lowerCamelCase, must match TypeScript props exactly
  • Don't override core Atlas UI classes
  • Prefer tree-shakable imports for new dependencies

Documentation

Essential reading (consult for any widget work):

  • docs/repo-layout.md — To understand the repository
  • docs/widget-scripts.md - How to build/test/lint packages
  • docs/requirements/tech-stack.md — Full technology stack
  • docs/requirements/frontend-guidelines.md — CSS/SCSS/Atlas UI guidelines
  • docs/requirements/app-flow.md — Widget lifecycle and Studio Pro integration
  • docs/requirements/backend-structure.md — Data flow and Mendix runtime
  • docs/requirements/project-requirements-document.md — Goals and scope

Read the full file on GitHub · 62 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. today First seen · 62 lines · 642 tokens per session scan A 9369c168bb7f

Subscribe to this mod's changes

web-widgets AGENTS.md is an instructions file published in the GitHub repository mendix/web-widgets (40 stars, last pushed yesterday), licensed Apache-2.0. It adds 642 tokens to every session, about $0.0032 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 2026-09-01.