Plan Kimi K2.7-coder----Own plan

Plan: Tesla Cheapest-Hours Charge Planner

Build a minimal Dockerized Node.js app that charges a Tesla during the cheapest Danish electricity hours, keeps the car ready by a configurable morning time, and stays within the Tesla Fleet API $10 individual-developer credit by polling SOC only twice daily (18:00 and 20:00) and issuing only start/stop commands.

Decisions

• Price source: Energi Data Service (energidataservice.dk), region DK1/DK2 configurable.
• Tariffs: editable tiers in the web UI.
• Car state: poll SOC at 18:00 and 20:00; assume car is home at planning time.
• Target SOC: default 80%, user-configurable; battery capacity via dropdown (Model Y Standard 2026 default); charger kW user-configurable.
• Algorithm: compute hours needed from SOC gap, battery kWh, charger kW, and efficiency; find cheapest contiguous window before departure time; issue charge_start at start and charge_stop at end.
• Stack: Node.js + Express backend, in-process node-cron, plain HTML/vanilla JS frontend (no build), JSON file storage in mounted ./data.
• Tesla integration: copy simplified OAuth PKCE flow from the existing Tesla app, AES-encrypt tokens, use a separate Vehicle Command Proxy (VCP) sidecar for command signing.
• Containers: 2 containers — combined backend+frontend, plus VCP sidecar.
• Scheduling: fetch prices once daily; SOC poll at 18:00/20:00; command execution at planned window boundaries.
• UI settings: departure time, target SOC, active days bitmask, region, tariff tiers, charger kW, car model.
• Notifications: optional ntfy.sh.
• Overrides: charge now, stop charging, skip tonight.
• API usage tracking: log and display Fleet API call counts.
• Deployment: Cloudflare Tunnel for public HTTPS OAuth callback; SERVER_URL configurable.

Phases

1. Scaffold project — package.json, Express server, Dockerfiles, docker-compose.yml, VCP sidecar.
2. Storage & config — JSON file helpers, config schema, API usage log.
3. Tesla auth — OAuth PKCE, token refresh, encrypted token storage, public key endpoint.
4. Tesla commands — VCP client, start/stop charging, wake-up, SOC read.
5. Price fetcher — Energi Data Service client, price cache, tariff editor.
6. Optimizer — hours-needed calculation, cheapest contiguous window search.
7. Scheduler — node-cron jobs for prices, SOC polls, command execution.
8. Web UI — settings page, schedule view, status, manual overrides, API usage view.
9. Notifications — ntfy.sh integration.
10. Deployment docs — Cloudflare Tunnel setup, Tesla developer app registration, env vars.

Relevant files to create

• package.json
• src/index.js — Express server, static UI, API routes
• src/config.js — JSON config storage
• src/tesla/auth.js — OAuth PKCE, token refresh
• src/tesla/client.js — VCP/Fleet API wrapper, start/stop/SOC
• src/tesla/keys.js — EC key generation
• src/prices/energidata.js — Energi Data Service fetcher
• src/prices/tariffs.js — tariff calculation
• src/scheduler/optimizer.js — cheapest window calculation
• src/scheduler/jobs.js — node-cron jobs
• src/notifications/ntfy.js — ntfy.sh sender
• public/index.html — settings/status UI
• public/app.js — frontend logic
• Dockerfile
• vcp/Dockerfile
• docker-compose.yml
• .env.example
• README.md

Verification

1. docker-compose up --build starts backend and VCP without errors.
2. OAuth flow completes and stores encrypted tokens.
3. Price fetcher returns hourly DK1/DK2 prices.
4. Optimizer selects cheapest contiguous window for a sample SOC/departure.
5. Scheduler triggers start/stop commands at correct times in a test environment.
6. Web UI shows config, planned schedule, status, and API call count.
7. ntfy.sh notifications sent on start/stop/error.

Scope excluded

• Geofencing / home detection (assumed home at 18:00/20:00).
• Per-day departure/SOC schedules (active-days bitmask only).
• Multiple vehicles.
• Cloud hosting instructions beyond Cloudflare Tunnel.
• Advanced telemetry or analytics.