Library Backward Compatibility

Library Backward Compatibility is a skill for Claude Code, Codex from PramodDutta/qaskills. It costs 29 tokens per session (799 once invoked), scanned A, original, MIT.

A testing guide for library backward compatibility, meaning keeping existing users' code working after a library changes.

In plain words
What is it for?
It helps verify public API shape, semantic-versioning compliance, TypeScript type compatibility, and migration paths.
Why use it?
It helps detect breaking changes in public APIs, versioning, types, or upgrade steps before they affect users.

Skill for Claude CodeCodex

Which agent this was written for is unclear — built for aider. Also seen: mentions Codex; built for aider.

Good fit It helps verify public API shape, semantic-versioning compliance, TypeScript type compatibility, and migration paths.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/pramoddutta/qaskills/backward-compat-library
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.

Any agent
npx skills add PramodDutta/qaskills --skill backward-compat-library
Clone the repo
git clone --depth 1 https://github.com/PramodDutta/qaskills

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 Library Backward Compatibility

README.md
[![agentmods](https://agentmods.dev/badge/skills/pramoddutta/qaskills/backward-compat-library.svg)](https://agentmods.dev/skills/pramoddutta/qaskills/backward-compat-library)
Your own site
<a href="https://agentmods.dev/skills/pramoddutta/qaskills/backward-compat-library"><img src="https://agentmods.dev/badge/skills/pramoddutta/qaskills/backward-compat-library.svg" alt="Measured on agentmods" height="20"></a>
Per session 29 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 799 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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 5.1 $0.00029 $0.00799
Opus 5 $0.00015 $0.00400
Sonnet 5 $0.00006 $0.00160
Haiku 4.5 $0.00003 $0.00080

Measured 8d ago against content hash 299f99b77272, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

Library Backward Compatibility 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 8d 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.

seed-skills/backward-compat-library/SKILL.md · 89 lines

How it starts

The opening of the file, as written. The whole thing — 89 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Library Backward Compatibility

You are an expert QA engineer specializing in library backward compatibility. When the user asks you to write, review, debug, or set up library related tests or configurations, follow these detailed instructions.

Core Principles

  1. Quality First — Ensure all library implementations follow industry best practices and produce reliable, maintainable results.
  2. Defense in Depth — Apply multiple layers of verification to catch issues at different stages of the development lifecycle.
  3. Actionable Results — Every test or check should produce clear, actionable output that developers can act on immediately.
  4. Automation — Prefer automated approaches that integrate seamlessly into CI/CD pipelines for continuous verification.
  5. Documentation — Ensure all library configurations and test patterns are well-documented for team understanding.

When to Use This Skill

  • When setting up library for a new or existing project
  • When reviewing or improving existing library implementations
  • When debugging failures related to library
  • When integrating library into CI/CD pipelines
  • When training team members on library best practices

Implementation Guide

Setup & Configuration

When setting up library, follow these steps:

  1. Assess the project — Understand the tech stack (typescript, javascript, python) and existing test infrastructure
  2. Choose the right tools — Select appropriate library tools based on project requirements
  3. Configure the environment — Set up necessary configuration files and dependencies
  4. Write initial tests — Start with critical paths and expand coverage gradually
  5. Integrate with CI/CD — Ensure tests run automatically on every code change

Best Practices

  • Keep tests focused — Each test should verify one specific behavior or requirement
  • Use descriptive names — Test names should clearly describe what is being verified
  • Maintain test independence — Tests should not depend on execution order or shared state
  • Handle async operations — Properly await async operations and use appropriate timeouts
  • Clean up resources — Ensure test resources are properly cleaned up after execution

Read the full file on GitHub · 89 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. 8d ago First seen · 89 lines · 29 tokens per session scan A 299f99b77272

Subscribe to this mod's changes

Library Backward Compatibility is a skill published in the GitHub repository PramodDutta/qaskills (218 stars, last pushed 8d ago), licensed MIT. It adds 29 tokens to every session and 799 once invoked, about $0.0001 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 2026-08-30.

Related

Other skills, from other repositories

template-formal

Strongly-typed multiagent ant-robot colony exemplar — ADTs, session-typed protocols, affine-discipline resource handles, storage-as-functor framing, Active-Inference-flavored decision loop, mypy-as-oracle negative controls.

docxology/template · 53 tokens

test-case-to-katalon-studio

Convert Katalon True Platform/TestOps manual test cases into Katalon Studio automation inside a local Studio Test Project checkout. Use when you need to author or extend a .tc test case file and its paired Groovy script under Scripts/, keep test case variable GUIDs consistent with the .ts test suite bindings that read…

katalon-labs/true-skills · 204 tokens

test-estimation

Estimate testing effort, duration, and resourcing for a Katalon True Platform/TestOps cycle. Use when the question is how long testing will take, how many testers it needs, whether the scope fits the sprint window, or what a scope change costs in person-hours. Sizes design, manual execution, automated execution and…

katalon-labs/true-skills · 198 tokens

true-platform-testing

End-to-end Katalon True Platform testing workflow and lifecycle router. Use when one request spans several stages and no single skill owns all of it, for example analyze a requirement, design and import the cases, build a suite, run it with AI, and report the outcome. Also use to route any testing request across the…

katalon-labs/true-skills · 224 tokens

exploratory-charter

Write, run, and debrief exploratory testing charters against Katalon True Platform/TestOps when there is no script to follow. Use when you need to turn a vague area into a charter (mission, areas, oracles, timebox), run a timeboxed unscripted session, log what you find as session notes, judge which findings are real…

katalon-labs/true-skills · 156 tokens

test-data

Design, source, seed, and tear down the test data a Katalon True Platform test case or an automated suite runs on. Use when the steps are already settled and the blocker is the values, for example which data classes a case needs, which records must exist before a run, how to keep literals out of the step text and into…

katalon-labs/true-skills · 182 tokens