dart-helper-utils agent plugin

Teaches AI coding agents the dart_helper_utils Dart package: the exact 7.x member names and what they do, the lifecycle rules of its async tools, and how to upgrade a project from any older release. It installs in Claude Code, Codex, and Google Antigravity from this repository.

The plugin contains skills only: markdown instructions, with no hooks, MCP servers, scripts, or network access.

Skills

Skill	Loads for requests about
`use-dart-helper-utils`	Member names and semantics across maps, strings, casing, MIME checks, collections, numbers, dates, durations, intl, and URIs, plus the one-import re-export model
`async-with-dart-helper-utils`	`Debouncer` and throttle lifecycles, stream transformers (`rateLimit`, `bufferCount`, `asPausable`, `retry`), Future `minWait`, `timeoutOrNull`, and `retry`, bounded concurrency, and their ordering and disposal traps
`migrate-dart-helper-utils-v6-to-v7`	The 7.0 upgrade: `dart fix --apply` for the renames, then the behavior checklist (UTC and daylight-saving date rules, exact `int` statistics, MIME precision, typed debouncer history, stringo 3)
`migrate-dart-helper-utils-v5-to-v6`	The 6.0 upgrade: conversion moved to convert_object, renames, removals, and silent behavior changes
`upgrade-dart-helper-utils`	Finding the installed version and ordering the hops for any upgrade, from 2.x through 7.x

An agent loads a skill when a request matches it. In Claude Code you can also call one directly, for example /dart-helper-utils:use-dart-helper-utils.

Install, update, and remove

Claude Code

In a session:

/plugin marketplace add omar-hanafy/dart_helper_utils
/plugin install dart-helper-utils@dart-helper-utils-tools

Or from a shell:

claude plugin marketplace add omar-hanafy/dart_helper_utils
claude plugin install dart-helper-utils@dart-helper-utils-tools

Run /reload-plugins or start a new session to load it.

Update: claude plugin marketplace update dart-helper-utils-tools, then claude plugin update dart-helper-utils@dart-helper-utils-tools. Claude Code leaves automatic updates off for third-party marketplaces; to turn them on, run /plugin, open Marketplaces, select dart-helper-utils-tools, and choose Enable auto-update.
Remove: claude plugin uninstall dart-helper-utils@dart-helper-utils-tools, or claude plugin marketplace remove dart-helper-utils-tools to remove the marketplace and its plugin together.

Codex

codex plugin marketplace add omar-hanafy/dart_helper_utils
codex plugin add dart-helper-utils@dart-helper-utils-tools

Start a new Codex session; an open session does not pick up new skills.

Update: codex plugin marketplace upgrade dart-helper-utils-tools refreshes the marketplace and the installed copy.
Remove: codex plugin remove dart-helper-utils@dart-helper-utils-tools. To drop the marketplace as well, run codex plugin marketplace remove dart-helper-utils-tools afterwards; on its own, that command leaves the plugin installed.

Where a Codex surface has no plugin support, its $skill-installer skill can install the folders under tooling/ai/dart-helper-utils/skills/ directly.

Google Antigravity

agy plugin install https://github.com/omar-hanafy/dart_helper_utils/tree/main/tooling/ai/dart-helper-utils

The command installs the plugin into ~/.gemini/config/plugins/, which the agy CLI, the Antigravity IDE, and the desktop app all read. Start a new session to load it. Use the full URL above: the plugin lives in a subfolder, so the bare repository URL finds nothing to install.

Update: run the same install command again; it replaces the installed copy. Antigravity has no third-party marketplace yet, so nothing updates on its own.
Remove: agy plugin uninstall dart-helper-utils.

Other agents

The plugin has an Agent Plugins 1.0 manifest (plugin.json), and each skill is a standard Agent Skills folder, so agents that read either format can load this folder directly. Only the three hosts above are tested.

Example prompts

"Upgrade this project from dart_helper_utils 6.1.0 to 7 and check the behavior changes that affect us."
"Debounce this search field with dart_helper_utils and make sure nothing leaks when the widget is disposed."
"Read db.pool.size from this nested config map with dart_helper_utils, defaulting to 10."
"Upload these files with at most 4 at a time and keep the results in input order."

Permissions and trust

The skills tell the agent to run ordinary Dart tooling in your project, such as dart pub get, dart fix --dry-run, dart analyze, dart test, and grep, through your agent's usual approval prompts. The plugin itself runs nothing and sends nothing anywhere.

Compatibility

Documents dart_helper_utils 7.x; the plugin version always equals the package version it documents. The migration skills also cover projects on 1.x through 6.x.
Installation is tested with Claude Code 2.1.312, Codex 0.165.0, and the Antigravity CLI 1.3.3 and 1.4.9 (October 2026). A weekly CI job repeats the test with each host's current release.

For maintainers

tooling/ai/dart-helper-utils/
  plugin.json                  Agent Plugins 1.0 manifest: Codex, Antigravity, other clients
  .claude-plugin/plugin.json   Claude Code manifest
  .codex-plugin/plugin.json    legacy manifest for Codex releases before Agent Plugins
  assets/icon.png              icon for all three manifests
  skills/<skill>/SKILL.md      one folder per skill
  evals/<case>/                cases for claude plugin eval

The marketplace catalogs live at the repository root: .claude-plugin/marketplace.json for Claude Code and .agents/plugins/marketplace.json for Codex. Antigravity installs the plugin folder itself.

Rules:

The three manifests share their metadata, and their version equals the pubspec.yaml version; bump them together.
Codex reads its interface (display name, prompts, icons) from extensions["com.openai"].interface in plugin.json, and older releases read the legacy manifest's interface; keep the two identical.
Skill facts must match the source. Change a skill in the same pull request as the behavior it describes; test/agent_skill_claims_test.dart checks the claims against the API.
A breaking package release ships its migration hop, as a new migrate-dart-helper-utils-vX-to-vY skill or an entry in upgrade-dart-helper-utils, before it is tagged.

Checks, run from the repository root:

Check	Command	Where it runs
Files, manifests, catalogs, and README commands	`dart run tool/validate_agent_plugin.dart`	CI on every pull request
Install in each host, plus each host's strict validator	`dart run tool/verify_agent_hosts.dart --require claude,codex,agy`	Agent plugin workflow: pull requests and pushes to `main` that touch the plugin, weekly, and on demand
Install from GitHub the way users do	`dart run tool/verify_agent_hosts.dart --github main`	Agent plugin workflow on `main`: pushes that touch the plugin, weekly, and on demand
Skill behavior against a no-plugin baseline	`claude plugin eval tooling/ai/dart-helper-utils --no-publish`	By hand; it calls the model on your account

The host check uses throwaway profiles, so it never touches your own Claude Code, Codex, or Antigravity setup and needs no sign-in. Without --require, it skips any host that is not on PATH.

Keeping it current

Hosts and their plugin formats change every few weeks. When the weekly Agent plugin workflow fails, and before each package release:

Read what changed in each host since the versions listed under Compatibility (agy changelog prints Antigravity's notes), and check agent-plugins.org and agentskills.io for new spec versions.
Run the three checks above, and claude plugin details dart-helper-utils@dart-helper-utils-tools after a local install to see the always-on token cost (about 690 tokens at 7.0.0).
Run the eval suite and compare it with the last run. At 7.0.0, all five cases pass with the plugin, and the four package cases score 0.5 to 1.0 higher than without it.
Update the tested versions under Compatibility and in the package README.