# Decision Log

Date: 2026-07-20

This log records material Axiom decisions that govern implementation. HQ is the constitutional and governance layer; Studio executes approved decisions; sprint documents define the current build scope.

## 2026-07-20 - Sprint 4A Implementation Plan Approved

- Decision: `Sprint4A_Implementation_Plan.md` is approved as the Sprint 4A implementation contract.
- Scope: strengthen the intelligence layer behind the frozen Sprint 3 UI.
- Approved capabilities:
  - Learning Engine
  - Decision Engine
  - Ask Axiom context
  - Evidence Explorer
  - portfolio-aware recommendation contract
  - Trade Review vertical slice
- Constraint: preserve the frozen Sprint 3 UI and reuse existing Research, OANDA, Recommendation, and Trade Review architecture.
- Safety boundary: OANDA remains practice-only; no live trading is authorized.
- Algorithm boundary: ADR-0006 remains active. No custom recommendation, ranking, scoring, learning, research, or trading algorithm is approved unless separately documented and reviewed by Girish.

## 2026-07-20 - Sprint 4A Implementation Completed

- Decision: Sprint 4A implementation and production validation are approved for Sprint 4 closeout.
- Completion evidence: `docs/Sprint4A_Completion_Report.md` records tests, build, production API validation, and production browser validation.
- Sprint 4 closure status: Sprint 4 is complete; remaining gaps are future v1.0/Sprint 5 work, not Sprint 4 blockers.
- Safety boundary remains unchanged: OANDA practice-only, human-controlled review, no live trading authorization.

## 2026-07-20 - Sprint 4 Production Acceptance Test Started

- Decision: Sprint 4 enters a one-week Production Acceptance Test as a Release Candidate.
- Product Owner acceptance is required before Sprint 4 is fully accepted and Sprint 5 begins.
- Maintenance mode applies during PAT: production bug fixes, regression fixes, documentation corrections, performance issues, security issues, and stability improvements only.
- Not allowed during PAT: new capabilities, Sprint 5 work, architecture changes, UI redesign, or discretionary refactoring.

## 2026-07-20 - HQ / Studio Operating Model Confirmed

- Decision: HQ is Axiom's constitutional and governance layer.
- HQ owns: Vision, Mission, Core Principles, AI-7, Capability Architecture, Command Center, HQ / Studio Operating Model, Three Roadmap Views, Decision Philosophy, Intelligence Evolution, and this Decision Log.
- Studio owns: implementation workflow, engineering status, validation process, and delivery execution for approved architecture.
- Sprint documentation owns: what is being built now.

## 2026-07-20 - Capability Architecture Hierarchy Confirmed

Approved hierarchy:

```text
AI Pattern
        -> Capability
        -> Phase
        -> Studio Implementation
```

Every implementation task should trace to an approved capability and AI pattern. Unmapped work belongs in the Parking Lot unless it is required infrastructure.