Legacy Modernization Pattern — Context

Pattern: Legacy Modernization
Component: context.md
Version: 1.2 | Updated: 2026-07-29

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Purpose

Define the minimum evidence package required before the Legacy Modernization pattern may start — and when to refuse to start.

Required before activation

• Strangler boundary diagram and owner
• Characterization/golden test baseline
• Slice plan with behavior-preservation gates
• Legacy pack with trust labels (not a dump)

Refuse to start when

• Rewrite start with zero characterization coverage
• No named seam owner
• Write tools spanning legacy and modern trees in one session

Trust and data class

• Label segments as trusted, internal, or untrusted for Legacy Modernization packs.
• Keep untrusted retrieval out of the Legacy Modernization system channel.
• Legacy Modernization MCP enablement follows data class in mcps.md.

Pack shape for Legacy Modernization

1. Trigger / AC (human-owned)
2. Ranked evidence inside the Legacy Modernization budget
3. Constraints and non-goals for this activation
4. Open questions (empty before irreversible Legacy Modernization steps)

Related

• Context pattern when packing is itself the hard problem
• Prompt variable bindings
• Skills activation triggers

Changelog

• 1.2 (2026-07-29): Legacy Modernization context gates (required/refuse) rewritten for this envelope.