sigistry/marketplace · plugins/api-contract-keeper/skills/error-envelope/SKILL.md

error-envelope skillA

error-envelope is agent-read markdown (skill) from sigistry/marketplace: This skill should be used when the user mentions "error handling", "problem details", "rfc 9457", "rfc 7807", "request validation", "api errors", "zod", "pydantic", "class-validator", "error response format", "problem+json", "validation error", or making an API return consistent, machine-readable errors. It provides the RFC 9457 Problem Details envelope and idiomatic per-stack request-validation patterns..

Indexed from public GitHub and served as immutable, content-addressed versions. Install it pinned to an exact SHA-256 with the mdr CLI, and every file is verified against the hash recorded here before it reaches your agent. The deterministic audit below grades the latest version, and the same file always earns the same grade.

How to install

Latest version
mdr add sigistry/marketplace/error-envelope@git:20260826.571bc2f
Exact content
mdr add sigistry/marketplace/error-envelope@sha256:cfe02c34ebd12e03

Pin to a label to follow the author's releases, or to a sha256 to freeze the exact bytes forever. Either way the resolved hash is written to mdr.lock, and mdr install reproduces it on any machine.

Badge

mdr badge

[![mdr](https://markdownregistry.com/badge/art_rqtn3jbclko7hho6.svg)](https://markdownregistry.com/a/art_rqtn3jbclko7hho6)

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Versions

versioncommittedcommitsizeaudit
git:20260826.571bc2f latest2026-08-26 571bc2f 4,150 BA view · diff
git:20260715.61691192026-07-15 6169119 4,150 BA view

Audit of the latest version

A  17 of 17 checks passed. Deterministic, no model, same answer every run.
  • pass: Frontmatter block present
  • pass: Frontmatter declares a name
  • pass: Frontmatter declares a description
  • pass: Size between 200 bytes and 200 KB (4150 bytes)
  • pass: No zero-width or bidi control characters
  • pass: No instruction hidden inside an HTML comment
  • pass: No link to an exfiltration or paste host
  • pass: No credential-shaped string
  • pass: No instruction to send local credentials anywhere
  • pass: No text hidden with inline styles
  • pass: No prompt-injection phrasing
  • pass: No curl or wget piped into a shell
  • pass: No recursive delete of root, home or parent
  • pass: No instruction to read or print local credentials
  • pass: No base64 blob over 200 characters
  • pass: No link to a raw IP address
  • pass: No script tag

Source

GitHub

sigistry/marketplace · 3 stars · license MIT · pushed 2026-09-15 · branch main

API

GET https://markdownregistry.com/api/v1/artifacts/art_rqtn3jbclko7hho6
GET https://markdownregistry.com/api/v1/resolve?ref=sigistry/marketplace/error-envelope
GET https://markdownregistry.com/api/v1/blob/cfe02c34ebd12e03db6c7eafebce3a3fb137fd00f57b2c0a4c3ea9bbe2769f28

Agents talk at modelranch.com: hand yours the instructions there and it joins the network that reads files like this one.