api-versioning

api-versioning is a skill for Claude Code from SebastianLuser/claude-code-arcane. It costs 36 tokens per session (625 once invoked), scanned A, original, no licence file.

Guidance for changing APIs without unexpectedly breaking existing users. An API is an interface that lets software communicate with another program or service.

In plain words
What is it for?
Use it when introducing API versions such as v2 or managing version changes in Go/Gin, NestJS, Fastify, or GraphQL.
Why use it?
It helps separate breaking changes from safe changes and plan deprecations, sunset dates, and new versions.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter.

Good fit Use it when introducing API versions such as v2 or managing version changes in Go/Gin, NestJS, Fastify, or GraphQL.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/sebastianluser/claude-code-arcane/api-versioning
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 SebastianLuser/claude-code-arcane --skill api-versioning
Clone the repo
git clone --depth 1 https://github.com/SebastianLuser/claude-code-arcane

Made for: Claude Code.

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 api-versioning

README.md
[![agentmods](https://agentmods.dev/badge/skills/sebastianluser/claude-code-arcane/api-versioning/github.svg)](https://agentmods.dev/skills/sebastianluser/claude-code-arcane/api-versioning)
Your own site
<a href="https://agentmods.dev/skills/sebastianluser/claude-code-arcane/api-versioning"><img src="https://agentmods.dev/badge/skills/sebastianluser/claude-code-arcane/api-versioning/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.

agentmods 80×15 button for api-versioning

Your own site · 80×15
<a href="https://agentmods.dev/skills/sebastianluser/claude-code-arcane/api-versioning"><img src="https://agentmods.dev/badge/skills/sebastianluser/claude-code-arcane/api-versioning.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 36 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 625 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.
Origin unknown 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 $0.00036 $0.00625
Opus 5.5 $0.00014 $0.00250
Sonnet 5.5 $0.00007 $0.00125
Haiku 4.5 $0.00004 $0.00063

Measured 1mo ago against content hash 025a1e95a739, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

api-versioning 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 1mo 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.

skills/api-versioning/SKILL.md · 52 lines

The source is not reproduced here

A licence we could not identify

The repository carries a LICENSE file, but it is custom or dual enough that GitHub cannot name it and neither can this catalogue. Unknown terms are not permission, so the body is not copied here. Read the licence at the source and decide for yourself.

Read it on GitHub

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 1mo ago First seen · 52 lines · 36 tokens per session scan A 025a1e95a739

Subscribe to this mod's changes

api-versioning is a skill published in the GitHub repository SebastianLuser/claude-code-arcane (3 stars, last pushed yesterday), with no licence file. It adds 36 tokens to every session and 625 once invoked, about $0.0001 per session on Opus 5.5. 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.

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