wrdn-effect-typed-errors

wrdn-effect-typed-errors is a skill for Claude Code, Codex from adarshp14/relay. It costs 62 tokens per session (2,716 once invoked), scanned A, a copy of wrdn-effect-typed-errors, MIT.

Instructions for replacing ordinary JavaScript exceptions and untyped errors with typed failures in Effect code. Effect is a TypeScript library whose error channel lets callers handle known failure types.

In plain words
What is it for?
Use it when lint or review finds new Error, throw, try/catch, rejected Promises, or other untyped error handling in Effect code.
Why use it?
It prevents error information from being lost or converted into misleading fallback values such as null, false, or an empty list.

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/adarshp14/relay/wrdn-effect-typed-errors
Any agent
npx skills add adarshp14/relay --skill wrdn-effect-typed-errors
Clone the repo
git clone --depth 1 https://github.com/adarshp14/relay

Made for: Claude Code, Codex.

Wrote 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.

agentmods badge for wrdn-effect-typed-errors

README.md
[![agentmods](https://agentmods.dev/badge/skills/adarshp14/relay/wrdn-effect-typed-errors.svg)](https://agentmods.dev/skills/adarshp14/relay/wrdn-effect-typed-errors)
Your own site
<a href="https://agentmods.dev/skills/adarshp14/relay/wrdn-effect-typed-errors"><img src="https://agentmods.dev/badge/skills/adarshp14/relay/wrdn-effect-typed-errors.svg" alt="Measured on agentmods" height="20"></a>
Per session 62 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,716 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 100% copy Near-identical to another mod 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 $0.00062 $0.02716
Opus 5 $0.00031 $0.01358
Sonnet 5 $0.00012 $0.00543
Haiku 4.5 $0.00006 $0.00272

Measured 3d ago against content hash 1358870281e6, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

wrdn-effect-typed-errors 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 3d 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.

Origin

This is a copy

100% identical to wrdn-effect-typed-errors — 2 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.agents/skills/wrdn-effect-typed-errors/SKILL.md · 360 lines

How it starts

The opening of the file, as written. The whole thing — 360 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You fix one family of patterns: untyped JavaScript error handling in Effect code.

The preferred boundary is typed Schema.TaggedError / Data.TaggedError values in the Effect error channel. Construct the tagged error directly at the failure site unless a helper performs real classification or normalization.

Trace before changing

  1. Identify the boundary. Is this Effect domain code, React UI code, a third-party callback, or plain test/tooling code?
  2. Find the existing domain errors. Check nearby errors.ts, Schema.TaggedError, Data.TaggedError, and API .addError(...) declarations before adding a new class.
  3. Decide whether a new error is needed. Add a new tagged error only if callers have a distinct recovery path, HTTP status, UI affordance, retry policy, or telemetry classification.
  4. Preserve failure semantics. If the old code failed, the new code should fail in the Effect error channel. Do not replace thrown failures with fallback values like false, null, undefined, [], or "unknown" unless the existing contract already treats that condition as non-fatal.
  5. Preserve the typed channel. Do not convert typed failures into Error, thrown exceptions, String(error), or .message reads from unknown values.
  6. Recognize real boundaries. Runtime workers, Vite/CLI tooling, callback APIs, and third-party interfaces may have to throw, catch, or reject at the boundary. Do not contort those files into fake Effect shapes. Keep the boundary idiom when it is contained and immediately wrapped into an Effect error channel, stable IPC envelope, or test/tooling result.
  7. Do not hide construction behind trivial helpers. Inline new DomainError(...) unless the helper branches on input or maps an external error format into a domain error.

Preserve behavior first

The lint rule is about where the failure lives, not whether the operation should still fail.

Bad fix: this removes the lint finding by silently changing invalid input into a non-match.

Read the full file on GitHub · 360 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. 3d ago First seen · 360 lines · 62 tokens per session scan A 1358870281e6

Subscribe to this mod's changes

wrdn-effect-typed-errors is a skill published in the GitHub repository adarshp14/relay (0 stars, last pushed 2mo ago), licensed MIT. It adds 62 tokens to every session and 2,716 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to wrdn-effect-typed-errors, differing in 2 lines, and is treated as a copy.

Related

Other skills, from other repositories

create-tutorial

Scaffold a new Membrane API Gateway tutorial in the api-gateway repo — the numbered self-teaching YAML under distribution/tutorials/ /, its support files and README links, and the matching auto-discovered integration test. Use whenever the user asks to create, add, write, or scaffold a tutorial (or a tutorial step)…

membrane/api-gateway · 97 tokens

optimize-interceptor-docs

Rewrite the reference documentation of a Membrane config element so the page generated at membrane-api.io comes out clean, exact, and reference-style. Use whenever the user wants to write, improve, optimize, polish, or review the docs / Javadoc / @description / @yaml example of an interceptor, plugin, or any…

membrane/api-gateway · 173 tokens

review-branch

Review the current git branch against master — code quality, refactoring opportunities, regressions, correctness, and test coverage — and print a severity-grouped markdown report. Use whenever the user asks to review the branch, review their changes against master, do a pre-PR / pre-merge review, or asks "is this…

membrane/api-gateway · 125 tokens

membrane-config

Generate a Membrane API Gateway configuration example or snippet — an apis.yaml (default) or, when explicitly asked, a legacy proxies.xml. Use this whenever the user wants a config, example, or snippet for Membrane: routing a port to a backend, a flow with plugins (setHeader, rateLimiter, basicAuthentication, openapi…

membrane/api-gateway · 167 tokens

release-notes

Generate GitHub release notes for the Membrane api-gateway repo by collecting the commits between the last release and master, grouping them into Features / Improvements / Fixes / Security / Dependencies, and linking each to its PR. Use whenever the user wants to draft, extract, or write release notes / a changelog /…

membrane/api-gateway · 124 tokens

mcp2cli

Turn any MCP server, OpenAPI spec, or GraphQL endpoint into a CLI. Use this skill when the user wants to interact with an MCP server, OpenAPI/REST API, or GraphQL API via command line, discover available tools/endpoints, call API operations, or generate a new skill from an API. Triggers include "mcp2cli", "call this…

knowsuchagency/mcp2cli · 126 tokens