§01
Overview
- What it is: "Popper" — a supervision/policy layer: receives supervision requests from the AI engine (deutsch), applies policy packs (YAML DSL), computes HTV thresholds, issues decisions (approve/route/reject) with mandatory audit. Named after Karl Popper (epistemology of refutation — a shared theme with deutsch/HTV). Part of the US healthtech platform ecosystem; shared protocol is
@regain/hermes. - Type / status / role: api (policy/supervision engine + server) · active · lead — the user is the primary author (72 of 112 commits); the US healthtech platform team: Anton Kim <anton@US healthtech platform> (18), Harsh Manwani (17), aniashev/Anna Shevtsova (8).
- Activity period: 2026-01-25 → 2026-02-14 — an intense ~3-week sprint, active. Full OSS scaffolding (LICENSE, VISION, GOVERNANCE, CODE_OF_CONDUCT, CONTRIBUTING, TRADEMARK, CERTIFICATION, PRD.md 51 KB).
§02
Stack
- Languages: TypeScript (strictest tsconfig), SQL (TimescaleDB).
- Frameworks/libraries: Bun 1.3+; Elysia.js (HTTP, apps/server); TimescaleDB (PostgreSQL 16, hypertables) + Drizzle ORM; Turborepo; Biome 2 (lint/format); lefthook (git hooks);
@regain/hermes(npm package for contracts: types, AJV validation, builders, HTV utilities, fixtures). apps: server, queue, web; packages: core (policy engine + DSL parser), db, auth, cache. - Infra/deploy: multi-region — Helm dual-mode secrets (HashiCorp Vault for KSA/Saudi Arabia + AWS Secrets Manager for US), GitHub Actions deploy US + SA, AWS ECS (task definitions with ARN-rewrite during account migration), OTEL/LGTM observability (Loki/Grafana/Tempo/Mimir). config/policies (YAML policy packs), docs/specs (PRD + Popper/Hermes specs).
- Data: TimescaleDB (time-series audit with compression / retention 7 years / continuous aggregates).
§03
What was shipped
Major commits authored by the user (per diffs) — primarily platform/infra/governance:
- Dual-mode secrets for data residency (
187423c, +528): Helm support for Vault (KSA) and AWS Secrets Manager (US) — meeting regional data-residency requirements. - Multi-region CI/CD: AWS US deploy workflow (
b4cf6cb+124), Dockerfile path fixes (56d6d5e), ARN-rewrite during AWS account migration (86cb1bd,41714b6), DATABASE_URL via Turbo for server tests (2d38ac1). - Observability: OTEL config/logging (
0e44db2,99631f8), LGTM section in the SA deployment guide (2a1c467). - Runtime: switch from bun compile to the Bun runtime for env support (
3b7d546). - Policy engine + Hermes contracts: core (DSL parser, policy packs),
@regain/hermesintegration (supervision types, HTV). - Volume: 112 commits over 3 weeks; the user is the lead on infra/deploy/governance.
§04
Technical challenges
By code/diffs (user authorship):
- Multi-region deployment with data residency (
187423c): one Helm chart, two secret modes — Vault (Saudi Arabia, KSA) vs AWS Secrets Manager (US) — so data/keys never leave the region. → Serious infra/compliance engineering (medical data, distinct jurisdictions). - TimescaleDB hypertables for audit (CLAUDE.md workflow): composite PK with partition column timestamp, segment_by/order_by, compression after 7 days, 7-year retention (audit), continuous aggregates (hourly dashboards / daily baselines), real-time aggregation off. → Sound time-series design driven through
pg aiguide. - Policy/supervision engine (packages/core): YAML policy pack DSL parser, application to supervision requests, HTV thresholds, decisions with audit. Contracts via
@regain/hermes(AJV validation, type guards). → Governance engine supervising AI (responsible AI). - Observability-first: OTEL + the LGTM stack (Loki/Grafana/Tempo/Mimir) in both regions. → Production observability for a distributed system.
- Engineering culture: strictest TS, Biome, lefthook, Turborepo, full OSS governance kit.
§05
AI-assisted development
- Sessions found: 0 in the local Claude Code sessions directory (verified by normalizing the full path). API-driven testing was done in popper-cookbook (#51) — sessions are to be found there. CLAUDE.md describes in detail the workflow with MCP (
pg aiguide) and skills (pg:setup-timescaledb-hypertables). - What was done with AI: development against SAL-* tickets (supervision API et al.), DB design via the pg-aiguide MCP.
- AI workflow patterns: MCP tooling for TimescaleDB schema design, skills, cookbook-driven testing, detailed specs/PRD as context. A mature AI-native process.
§06
Achievements & metrics
- Governance engine for a real health-AI product, US healthtech platform; multi-region (KSA + US) with data residency; TimescaleDB audit with 7-year retention; OTEL/LGTM observability; full OSS documentation set (PRD 51 KB).
- 5-person team, user is the lead author (72/112) on infra/deploy/governance.