modernize-reimagine

The first token of $ARGUMENTS is the system dir ($1); everything after it is the target vision — it is usually multiple words, so do not truncate it to one token. Below, <vision> means that full remainder.

Reimagine legacy/$1 as:

This is not a port — it's a rebuild from extracted intent. The legacy system becomes the specification source, not the structural template. This command orchestrates a multi-agent team with explicit human checkpoints.

The brief is binding — read it first. If analysis/$1/MODERNIZATION_BRIEF.md exists, this reimagine is executing one of its phases: read it before doing anything below. Find the phase that names this command with a scope matching $1 and , and treat that phase's scope, entry criteria, exit criteria, and any edits the user made to it as binding on the phases below — on top of, never instead of, this command's own two HITL checkpoints. Entry criteria are gates, not context: if one is not met (a prior phase's exit criteria, an SME sign-off the brief requires), meeting it is the next step — do not proceed past it and do not silently re-plan around it. If the brief exists but no phase matches, stop and ask which phase this is. The user steers execution by editing the brief; a brief the execution command never reads cannot steer anything.

Phase A — Specification mining (parallel agents)

Spawn concurrently and show the user that all three are running:

1. business-rules-extractor — "Extract every business rule from legacy/$1 into Given/When/Then form. Output to a structured list I can parse."

2. legacy-analyst — "Catalog every external interface of legacy/$1: inbound (screens, APIs, batch triggers, queues) and outbound (reports, files, downstream calls, DB writes). For each: name, direction, payload shape, frequency/SLA if discernible. Mask any credential embedded in endpoints or payload examples per your secret-handling rules."

3. legacy-analyst — "Identify the core domain entities in legacy/$1 and their relationships. Return as an entity list + Mermaid erDiagram."

Collect results. Write analysis/$1/AI_NATIVE_SPEC.md containing:

• Capabilities (what the system must do — derived from rules + interfaces)
• Domain Model (entities + erDiagram)
• Interface Contracts (each external interface as an OpenAPI fragment or AsyncAPI fragment)
• Non-functional requirements inferred from legacy (batch windows, volumes)
• Behavior Contract (the Given/When/Then rules — these are the acceptance tests)

Credential values are masked everywhere in the spec; connection details appear as env-var placeholders (${DATABASE_URL}), never literals.