principle-migrate-callers-then-delete-legacy-apis

principle-migrate-callers-then-delete-legacy-apis is a skill for Claude Code from backnotprop/pstack. It costs 45 tokens per session (230 once invoked), scanned A, a copy of principle-migrate-callers-then-delete-legacy-apis, MIT.

A refactoring rule for projects that can change internal code together: move all internal users to a new API and remove the old API in the same change.

In plain words
What is it for?
It is for internal API changes, coordinated caller migrations, cleanup of legacy interfaces, and updating tests to check the new contract.
Why use it?
Keeping both versions creates two paths to maintain and allows temporary compatibility code to linger. This rule applies when there are no outside users who need the old interface.

Skill for Claude Code

Written for Claude Code: disable-model-invocation in frontmatter.

Good fit It is for internal API changes, coordinated caller migrations, cleanup of legacy interfaces, and updating tests to check the new contract.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/backnotprop/pstack/principle-migrate-callers-then-delete-legacy-apis
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 backnotprop/pstack --skill principle-migrate-callers-then-delete-legacy-apis
Clone the repo
git clone --depth 1 https://github.com/backnotprop/pstack

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 principle-migrate-callers-then-delete-legacy-apis

README.md
[![agentmods](https://agentmods.dev/badge/skills/backnotprop/pstack/principle-migrate-callers-then-delete-legacy-apis/github.svg)](https://agentmods.dev/skills/backnotprop/pstack/principle-migrate-callers-then-delete-legacy-apis)
Your own site
<a href="https://agentmods.dev/skills/backnotprop/pstack/principle-migrate-callers-then-delete-legacy-apis"><img src="https://agentmods.dev/badge/skills/backnotprop/pstack/principle-migrate-callers-then-delete-legacy-apis/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 principle-migrate-callers-then-delete-legacy-apis

Your own site · 80×15
<a href="https://agentmods.dev/skills/backnotprop/pstack/principle-migrate-callers-then-delete-legacy-apis"><img src="https://agentmods.dev/badge/skills/backnotprop/pstack/principle-migrate-callers-then-delete-legacy-apis.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 45 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 230 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 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 5.1 $0.00045 $0.00230
Opus 5 $0.00023 $0.00115
Sonnet 5 $0.00009 $0.00046
Haiku 4.5 $0.00005 $0.00023

Measured 11d ago against content hash e29b6b6534a2, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

principle-migrate-callers-then-delete-legacy-apis 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 11d 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 principle-migrate-callers-then-delete-legacy-apis — 0 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.

skills/principle-migrate-callers-then-delete-legacy-apis/SKILL.md · 23 lines

What it actually says

Migrate Callers Then Delete Legacy APIs

When we decide a new API is the right design, migrate callers and remove the old API in the same refactor wave instead of preserving compatibility layers.

Rule:

  • Do not keep legacy API paths alive only because internal callers still exist
  • Inventory callers, migrate them, and delete the old API immediately
  • Treat temporary adapters as exceptional and time-boxed, not default architecture
  • Update tests to assert the new contract, and delete tests that only protect pre-refactor implementation details

When this applies:

  • No external users depend on backward compatibility
  • The project can absorb coordinated breaking changes
  • The new API is part of a simplification or refactor initiative

Keeping both old and new APIs creates dual-path complexity, slows cleanup, and makes the codebase feel append-only.

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. 11d ago First seen · 23 lines · 45 tokens per session scan A e29b6b6534a2

Subscribe to this mod's changes

principle-migrate-callers-then-delete-legacy-apis is a skill published in the GitHub repository backnotprop/pstack (246 stars, last pushed 22d ago), licensed MIT. It adds 45 tokens to every session and 230 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to principle-migrate-callers-then-delete-legacy-apis, differing in 0 lines, and is treated as a copy.