Decommissioning and Sunset Plan

Scope: Temporary controls and legacy adapters in thegent Date: 2026-02-14 Related: WP-6006, docs/RUNBOOK.md §5

1. Overview

This plan identifies temporary architectural shims, legacy adapters, and transitional controls that should be sunset as the platform matures.

2. Target Components for Sunset

Component	Reason	Sunset Trigger	Target
GenericOutputAdapter	Loose normalization	100% provider coverage with XMLOutputAdapter	v1.2
fallback-plain policy	Low confidence	95% normalization success rate over 30 days	v1.2
--override flag (unlimited)	Security risk	Implementation of TTL-based policy overrides	v1.1
Static model lists	Brittle	Stable ModelScraper performance for all providers	v1.2
history-legacy command	Hidden, superseded	Already hidden	v1.1

3. Migration Path

1. Deprecation Phase:
   • Emit warnings via ContractTelemetry when sunset components are used.
   • Update CONTRACT_AUTHORITY.md to mark versions as deprecated.
2. Dual-Run Phase:
   • Run legacy and new components in parallel where possible.
   • Log drift via ContractTelemetry.detect_drift() and thegent govern conformance --check-drift.
3. Decommission Phase:
   • Remove code from src/thegent.
   • Update conformance tests to ensure no regressions.

4. Rollback Strategy

In case of critical failures after sunset:

• Retain code in git history for rapid revert.
• Maintain v-1 version compatibility in ContractRegistry for one major release.