OpenAI Build Week

A local-first vertical slice, end to end.

Repset combines trusted Codex lifecycle hooks, an MCP server, a loopback runtime, on-device pose estimation, and a bounded GPT-5.6 selector.

The boundary flow

Codex Stopsanitized eventlocal eligibilitycurated challengeappend-only pointsMCPstatus in Codex

A visual plugin surface—with a reliable fallback

A bundled, versioned MCP App resource renders local weekly progress, skippable onboarding, local settings, curated movement choices, and explicit Start, Skip, Snooze, Refresh, and Sandbox actions inside compatible Codex hosts. Optional sound is synthesized only after user interaction. The card loads no remote script or asset. If a host cannot render it, the same tools keep working through structured text; the movement loop does not depend on the visual layer.

RepsetMove while the model thinks.
Local onlyPreview
Natural break boundary ready

Take sixty seconds?

Choose a reviewed activity. Skip and Snooze stay available.

This week3 of 4 days
30 local points1 break today
Choose what works nowOffice · quiet · camera optional
Standing shoulder resetRecommended60 sec · quiet-friendly
Seated ankle reset60 sec · camera-free
Five private squats60 sec · on-device camera
Skip for nowSnooze 30 minSettings

Codex’s role

Codex is both the product surface and the build collaborator. SessionStart initializes pseudonymous context; Stop checks a natural boundary; MCP exposes explicit status and break actions. The main Repset task remains the primary build record.

GPT-5.6’s role

GPT-5.6 receives only coarse session and preference fields and selects an ID from the reviewed catalog through strict JSON Schema. It cannot invent an exercise or infer a diagnosis. Missing credentials, timeout, refusal, malformed output, or a disallowed ID immediately uses the deterministic selector.

Technology

  • Next.jsPublic site and anonymous judge demo
  • Node 24 + SQLitePortable local runtime and append-only ledger
  • MCP + Apps UIExplicit tools and an interactive local status card
  • MediaPipeOn-device pose landmarks in a worker
  • Vitest + PlaywrightRules, privacy, browser, and accessibility verification

Evidence over claims

The release gate checks forbidden hook fields, loopback auth/origin controls, frame-network behavior, synthetic pose sequences, point caps, idempotency, camera denial, keyboard use, reduced motion, and a clean plugin install. Repset makes no unsupported health or credit claim.