error-states

A guide for designing the states a Next.js page shows while data loads, is missing, fails, or does not exist. It also covers feedback after actions such as saving or deleting.

In plain words
What is it for?
Adding loading placeholders, empty messages, retryable errors, real not-found pages, and success or failure feedback for user actions.
Why use it?
It prevents pages from showing blank areas, unexplained errors, or endless loading when something goes wrong or there is no data.

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/m-binimran/dev-pack/error-states
Any agent
npx skills add m-binimran/dev-pack --skill error-states
Clone the repo
git clone --depth 1 https://github.com/m-binimran/dev-pack

Made for: Claude Code, Codex.

Per session 53 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 369 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 $0.00053 $0.00369
Opus 5 $0.00026 $0.00185
Sonnet 5 $0.00011 $0.00074
Haiku 4.5 $0.00005 $0.00037

Measured yesterday against content hash 78e5059a62ef, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

error-states 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 yesterday.

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.

skills/error-states/SKILL.md · 31 lines

What it actually says

error-states

Most apps ship the happy path and forget the other three. A surface isn't done until loading, empty, and error are all handled.

The four states for every data surface

  1. Loadingloading.tsx or <Suspense fallback>. Use skeletons that match the final layout (no CLS), not a bare spinner where possible.
  2. Empty — designed empty state with a next action ("No projects yet — create one"), not a blank box.
  3. Errorerror.tsx (client error boundary) with a human message + a retry (reset()); log the real error server-side. Never show a raw stack trace to users.
  4. Not foundnot-found.tsx + notFound() for missing resources (real 404, not a 200 with "nothing here").

Feedback for actions

  • Mutations show pending state (disabled + spinner) and a success/error toast (aria-live for errors).
  • Optimistic updates roll back visibly on failure (see state-architect).

Output

  • The loading/empty/error/not-found treatments for the surface, and the action feedback.
  • State which of the four are implemented and which are N/A.

Guardrails

  • No surface ships with only the happy path.
  • Error UI must not leak internal details; log them server-side instead.
  • Skeletons must reserve the real layout's space to avoid layout shift.
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. yesterday First seen · 31 lines · 53 tokens per session scan A 78e5059a62ef

Subscribe to this mod's changes

error-states is a skill published in the GitHub repository m-binimran/dev-pack (2 stars, last pushed 2mo ago), licensed MIT. It adds 53 tokens to every session and 369 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.

Related

Other skills, from other repositories

investigate-issue

Investigate a GitHub issue by fetching details, analyzing the codebase, researching documentation, and presenting an actionable implementation plan with test guidance. Use when asked to investigate, analyze, triage, or plan work for a GitHub issue. Invoked with /investigate-issue or /investigate-issue (prompts for ID).

maximhq/bifrost · 78 tokens

resolve-pr-comments-stack

Resolve unresolved PR review comments across an entire Graphite (gt) stack of many PRs, bottom-up, in one working directory. Use when asked to "go through this stack and resolve comments", "clean up review comments across the whole stack", or given a list/range of PR numbers that form (or partially form) a gt stack.…

maximhq/bifrost · 99 tokens

resolve-pr-comments

Skill "resolve-pr-comments" from maximhq/bifrost, covering resolve pr comments, usage, workflow overview, step 1: detect repository and step 2: fetch unresolved comments (graphql).

maximhq/bifrost · 0 tokens

harness-test-writer

Add regression test cases to the Bifrost provider harness (the Postman collection run via make run-provider-harness-test) based on a merged PR or a GitHub issue. Fetches the PR/issue, traces the affected wire path in the codebase, checks existing harness coverage, designs cases following harness conventions, inserts…

maximhq/bifrost · 133 tokens

trulens-blocking-guardrails

Configure and use feedback functions as runtime blocking guardrails.

truera/trulens · 19 tokens

review-pr

Reviews a PR or diff with multi-angle finders and adversarial verification, then reports a findings table, a merge/no-merge recommendation, required followups, and offers to create a follow-up PR. Use when the user types /review-pr [PR# | branch | path].

maximhq/bifrost · 60 tokens