---
name: michael-denyer-principle-migrate-callers-then-delete-legacy-apis
description: "Apply when introducing a new internal API while old callers still exist. Migrate callers and delete the old API in the same wave instead of preserving compatibility layers."
license: "MIT"
metadata:
  decimalai-skill-id: "2f2687ce-be9d-4f11-8035-d2d269afc21a"
  decimalai-version-id: "e6322fd3-12dc-4a86-a5b4-2685452b9eba"
  decimalai-version: "1"
  decimalai-body-sha256: "f4e080f4f04e944f6c6cf0e545614db20bc34fa8dd75b6d1d6cca286e6dc8bdb"
  decimalai-name: "michael-denyer/principle-migrate-callers-then-delete-legacy-apis"
  decimalai-format: "1"
  decimalai-invocation: "model"
  decimalai-category: "coding"
  decimalai-source: "https://app.decimal.ai/s/michael-denyer-principle-migrate-callers-then-delete-legacy-apis@1/SKILL.md"
---
# Migrate Callers Then Delete Legacy APIs

- 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