Claude Opus 5
17b7b447c4
`generic_dayahead.fetch()` accepted `since` and `until` and requested the
bare `?bzn=BE`, which answers ONE Brussels day. Everything past today was
then filled from yesterday's profile by FCST-04, flagged provisional, and
§8.3 drops provisional hours from the trade set -- so the optimiser never
saw tomorrow as firm, at any hour of any day, and nothing reported it.
Measured on 4257e38 at 2026-09-10T09:00+02:00, 48 h horizon, live feed,
yesterday seeded through the shipped read path:
60 firm points (15 whole hours) + 33 carried hours of 48 requested
carried: 24 h on 2026-09-11, 9 h on 2026-09-12
arbitrage(0.10): buy 11:45 and sell 19:45 -- BOTH on 2026-09-10
firm local days = [2026-09-10]
The ceiling was structural: with a one-day window, at hour H a 48 h horizon
is at most 24-H firm and 24+H carried. At 23:00 that is 1 and 47, and the
remaining firm spread (0.0464 EUR/kWh) no longer clears the default 0.10
threshold, so arbitrage is refused outright. FCST-04's fill covers the
window until the ~13:00-14:00 CET auction; it was never meant to cover
every hour of every day.
The data exists and the endpoint serves it: verified 2026-09-10T07:45:49Z,
`?bzn=BE&start=2026-09-09&end=2026-09-10` returns 192 quarter-hours across
two local days. Committed unmodified beside TARIFF-08's captures, with the
URL, retrieval time and sha256 recorded and RE-DERIVED by the replay.
THE RANGE IS DERIVED ON THE BRUSSELS CALENDAR, not the UTC one. 22:30 UTC
in summer is already tomorrow in Belgium, so a UTC-derived start asks for
the day the controller has just left and drops the day it is standing in,
for the last one or two hours of every day. That is `_bdate()`'s lesson one
layer up with a worse consequence: `_bdate()` misfiles an hour, this never
fetches it. `until` is exclusive, so local midnight belongs to the day
before it; an inverted window collapses to one day rather than a backwards
range. Both ends are graded and both are driven red by mutation.
After, same code path and window, a feed serving both days: 39 firm hours
and 9 carried (was 15 and 33), firm across TWO Brussels days, and the
permitted cycle buys on one day and sells on the next.
`price_feed_url` IS THE EXACT URL AND THE PLUGIN APPENDS NOTHING. `start`/
`end` are this feed's spelling and the provider declares a second host
whose parameters are different, so merging would produce a request nobody
typed and the short horizon anyway. The cost is real, so it is not silent:
a WARNING on the shipped logger at fetch time names the consequence and the
start..end that would otherwise have been asked for. `dated_feed_url()`
refuses to append to a base that already carries a query string, so the
blind-append shape cannot come back by edit.
DECISIONS/TARIFF-09-the-range-and-the-override.md argues the alternative.
Before publication nothing regresses and it is graded, not assumed: at
09:46 CEST the two-day request came back byte-identical to the one-day
body, and that stays a `series` of what exists with FCST-04 filling the
rest. A `no_data` there would switch a working site's arbitrage off every
morning -- the mutation that adds that rule is red by name.
The plugin contract is still NOT enforced: three shipped plugins point at
endpoints nobody has verified, and a rule obliging them to pass a range
would be satisfied by an invented parameter name -- TARIFF-08's defect
moved from the response to the request. Which plugins consume the range is
pinned as a literal instead.
11 mutations, all red, no survivors; each applied to a fresh copy of the
tree rather than reverted, through tools/mutation_run.sh. One is +0 B (a
single price digit inside the committed capture) and the re-derived sha256
catches it. MUTATION.md habit 20 records why a fixture could never have
reached this: a captured body is the answer to a URL, and no property of a
body says which URL was asked for. All 29 suites green.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BwRLw7eKYj2byVdwB6kbjU
GoodWe RS485 Controller — Home Assistant add-on repository
Replaces a GoodWe battery inverter's vendor controller with a local one: holds net grid exchange at zero by emulating the inverter's smart meter over RS485, and runs the monthly battery maintenance cycle the vendor box was doing.
repository.yaml add-on repository metadata
goodwe_controller/ the add-on
config.yaml manifest + options schema (the per-site config form)
app/ the controller
control.py the control law — pure functions, no I/O
maintenance.py the monthly cycle state machine
hass.py Supervisor/Core API access
store.py persistent state in /data
mqtt.py optional status entities
web.py ingress UI — routes only, status and configuration
config_page.py the configuration page's markup, style and script
configui.py its field model, built from the Supervisor's own
schema + translations — owns no key, label or rule
selfconfig.py reading and writing this add-on's own options,
with the validate-first / compare-and-swap gate
main.py orchestration, heartbeat, failsafe behaviour
test_control.py runnable checks — no framework needed
test_maintenance.py runnable checks — walks a full cycle in fake time
DOCS.md the add-on's documentation tab
MUTATION.md how to run a mutation so the result means something
tools/mutation_run.sh the mutation harness - purges bytecode, then grades
tools/supervisor_selfapi_probe.py what the Supervisor really permits and
returns, run against its own release image
firmware/goodwe-master.yaml ESPHome config for the T-CAN485
estop/rs485_log.py optional RS485 e-stop / bus witness
docs/GoodWe-RS485-Field-Guide.pdf the guide techs carry (10pp, A4)
docs/build_guide.py its single source - rebuilds the HTML and PDF
FIELD-GUIDE.md how to edit and rebuild the guide
Picking this up after a break? Read HANDOVER.md first — current state,
what is known broken, and what to do next.
Install
Settings → Add-ons → Add-on store → ⋮ → Repositories → add
https://gittea.kammenstraatha.duckdns.org/admin/goodwe-addon
then install GoodWe RS485 Controller.
⚠️ The repository must be PUBLIC for this to work. Home Assistant clones it
anonymously; against a private repo the store shows nothing and gives no useful
error. If it must stay private, install locally instead: copy
goodwe_controller/ into the machine's /addons/ folder, then
ha store reload — it appears as a Local add-on.
⚠️ Bump version: in goodwe_controller/config.yaml for every change.
Supervisor keys the built image by that version, so without a bump it silently
reuses the old image and your fix appears not to work — on your bench and on
every client's machine.
Requires Home Assistant OS or Supervised. Add-ons cannot be installed on HA Container or Core.
Read this first
The inverter holds its last command forever. It has no meter-timeout of its own — a controller that dies mid-command leaves the battery running until a human intervenes. Measured on real hardware: 5 kW of discharge held for 113 seconds after a controller went silent.
Three layers exist because of that, and only the third covers the Home Assistant machine itself dying:
- ESP32 watchdog — no fresh setpoint for ~30 s → command 0 W, and keep commanding it.
- Wind-down before firmware updates — 0 W written before the update starts.
- RS485 e-stop (optional) — writes 0 W after 30 s of total bus silence.
Sites sold without the e-stop must have the acknowledgement in FIELD-GUIDE.md
§10 signed.
Development
The control law and the maintenance machine are pure Python with no Home Assistant imports, so they run anywhere:
cd goodwe_controller
python3 test_control.py
python3 test_maintenance.py
Both must pass before shipping any change. To prove a check bites - the way
almost every claim in this repository was established - mutate the module and
run tools/mutation_run.sh, which clears __pycache__ first. It is not
optional: a same-size edit reverted inside one second leaves CPython reusing the
old bytecode, and the run grades code that is not there. goodwe_controller/MUTATION.md
has the mechanism, the measurement, and what the flags do not do. They are not unit-test theatre —
each assertion corresponds to a rule whose absence produced an observed failure
on real hardware, and the comments in control.py say which.
Compatibility
Check the serial number, not the model name. Characters 6-8 of the serial are the platform tag:
| tag | platform | verdict |
|---|---|---|
ESU EMU ESA BPS BPU EMJ IJL |
105 — ES/EM/BP, AA55-era meter bus | supported |
SPB SPN |
745 — SBP G2 (GW…-SBP-20) |
no |
ESN ESC |
745 — ES G2 (GW…-ES-20) |
no |
ETU EHU BTU … |
205/745/753 — ET/EH/BT hybrids | no |
SDT DST MSU NSU … |
PV-only inverters — no battery to control | no |
A "-20" or "G2" suffix means a different platform with a different meter
protocol. The tags come from the goodwe library's PLATFORM_105_MODELS, which
is also what Home Assistant's own integration uses to pick a protocol.
- GoodWe ES / BP family inverters (AA55 / RS485 meter-bus generation)
- The protocol is reverse-engineered. There is no vendor contract, and a firmware change on GoodWe's side could break every installation at once. Say so when you sell it.