Getting it into your agent
It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.
git clone --depth 1 https://github.com/event4u-app/agent-confignpx agentmods add skills/event4u-app/agent-config/form-handlerWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/event4u-app/agent-config/form-handler)<a href="https://agentmods.dev/skills/event4u-app/agent-config/form-handler"><img src="https://agentmods.dev/badge/skills/event4u-app/agent-config/form-handler/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/event4u-app/agent-config/form-handler"><img src="https://agentmods.dev/badge/skills/event4u-app/agent-config/form-handler.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 1 finding, up to high
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- high System Prompt Leakage · line 108 Skill contains instructions that could directly expose system prompts, internal rules, or hidden instructions to users or external parties.Fix: Remove any instructions that reveal, print, or output system prompts or internal rules. System instructions should never be exposed to end users.
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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00042 | $0.01390 |
| Opus 5 | $0.00021 | $0.00695 |
| Sonnet 5 | $0.00008 | $0.00278 |
| Haiku 4.5 | $0.00004 | $0.00139 |
Grade A, and why
form-handler 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 9d 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.
How it starts
The opening of the file, as written. The whole thing — 150 lines — stays where its author put it; the contents beside it link to each section on GitHub.
form-handler
Pick the validation timing, lay out error placement, sequence the submission lifecycle, and decide where (and whether) to use optimistic UI. Stack-agnostic — Livewire, Inertia, React Hook Form, server-rendered Blade — the lens is the same. Pair with
laravel-validationfor server-side rules andaccessibility-auditorfor label / error a11y.
When to use
- A new form is being designed (login, signup, settings, multi-step wizard) and the validation strategy is unsettled.
- A form bug shows up: double-submission, lost data on validation fail, error not announced, optimistic update flicker.
- A wizard or multi-step flow needs state across steps and the ownership of dirty / pristine state is unclear.
- German triggers: "Formular bauen", "wann validieren?", "Submit feuert doppelt".
Do NOT use when:
- The screen is read-only / display-only — no form, skip.
- The question is purely server-side validation rules — route to
laravel-validation(or the stack equivalent). - The question is form layout / spacing — route to
fe-designortailwind-engineer.
Procedure
1. Identify field types, pick validation timing
Inspect every field on the form (text, password, async-checked, file, multi-step) before choosing timing. Three knobs, picked per field:
| Timing | When |
|---|---|
| On submit only | Forms with privacy concerns (passwords); short forms |
| On blur | Default — feedback when the user finishes the field |
| On change (debounced) | Typing-feedback fields (username availability, password strength) |
Avoid validate-on-change for the whole form — premature errors shame the user. Username-availability is the canonical exception.
2. Lock the error display contract
Per field: error message location (below field), text-based
(never colour-only), aria-describedby wired, focus moves to
first error on submit-fail. Per form: a summary box at top
that lists every error with anchor links — required for forms
5 fields and any wizard step.
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.
- 9d ago First seen · 150 lines · 42 tokens per session scan A 1ebf53e50e35
form-handler is a skill published in the GitHub repository event4u-app/agent-config (10 stars, last pushed today), licensed MIT. It adds 42 tokens to every session and 1,390 once invoked, about $0.0002 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 2026-09-03.
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