Architecture Decision Records
Every irreversible decision, why it was made, and what it saved. The register a CTO signs off on. Each decision includes costs, alternatives considered, and the trigger to reconsider.
How to read these ADRs
These ADRs document the key architectural decisions for xOps BC1. Each decision was evaluated by 4 ADLC agents (PO, CA, MEE, IE) with alternatives scored and deferred — not rejected.
| ADR | Decision | Status | Lead Agent |
|---|---|---|---|
| ADR-001 | SQLite + EFS unified data layer (not Aurora) | Accepted | CA |
| ADR-002 | LiteLLM provider abstraction (not direct Bedrock) | Accepted | CA |
| ADR-003 | Open WebUI as pipeline engine (not custom React) | Accepted | PO |
| ADR-004 | 2 docker services (not EKS microservices) | Accepted | CA |
| ADR-005 | Option C hybrid architecture (ECS + K3S) | Accepted | CA |
| ADR-006 | MCP validation methodology | Accepted | CA |
| ADR-020 | 7-phase to 5-stage lifecycle migration | Accepted | PO |
| ADR-021 | Additive Stage 6 "Deprecate" retirement capability | Accepted | PO |
| ADR-022 | assistant-ui + AG-UI as the customer product shell | Proposed | QA |
| ADR-023 | Measured context budget for wiring MCP servers | Proposed | CA |
| ADR-024 | Azure MCP Server only, reconciled 'live' rule, vendor-linked docs | Proposed | CA |
Format: Michael Nygard ADR template — Status, Context, Decision, Consequences, Alternatives Considered.
Source data: xops.jsx LAYERS[].whyNot[] arrays (17 alternatives evaluated with cost figures and upgrade triggers)
Relationship to other docs:
- Golden Paths references ADRs for "why this default"
- Evolution Architecture references ADRs for "when to reconsider"
- PR/FAQ FAQs are prose versions of these ADRs