_points_from_json() expected doc['data'] to be a list of {start, price_eur_mwh}. api.energy-charts.info/price?bzn=BE returns a columnar document - parallel unix_seconds and price arrays - so the shipped parser raised SourceUnavailable('the feed carried no data list') against every real response. generic_dayahead had never parsed one. With the three fabricated supplier URLs of TARIFF-07, that left manual_csv as the only working provider in a five-provider table.
It survived to release because every fixture fed the invented shape: test_price.py, test_price_history.py and test_static_tariff.py all built {'data':[{'start':...,'price_eur_mwh':...}]}, so the suite validated the parser against the parser's own assumption - a closed loop that cannot notice the assumption is wrong. Section 11.4 then made the failure silent: a parse error degrades to the static profile, which is correct and says nothing about the cause.
Verified live 2026-09-10, end to end: fetch -> parse -> assemble() -> TariffPlan returns 96 quarter-hourly points at 900 s, origin provider, product DAY_AHEAD, arbitrage allowed with a firm spread of 0.4645 EUR/kWh. First time the pipeline has completed against a real feed. Belgium moved to a 15-minute MTU on 2025-10-01, so FCST-04's H1 fix - the fill was decimating sub-hourly points to one per hour - was never theoretical; it is the shape of the live feed, and it is what makes this deliverable.
The columnar shape is read by a SECOND function, not a sniff, and feeding the row shape to generic_dayahead is now a graded no_data so the sniff cannot return quietly. Equal length refused in both directions with both lengths in the reason; the unit refused if not EUR/MWh, because MAX_PLAUSIBLE_EUR_KWH only bounds prices that are too large and a EUR/kWh switch would otherwise be invisible; nulls dropped with a count, an all-null body named as no_data; a deprecated feed warns while it still works.
Two real bodies captured as fixtures - unmodified bytes, with URL, retrieval time, unit, licence-as-returned and sha256 recorded, and the checksums RE-DERIVED by the replay rather than asserted. The invented fixtures are renamed synthetic_row_feed at every call site so the closed loop cannot re-form. Only one of four network providers has a capture, and a registry-derived check says so in its own sentence: the other three have nothing to capture, which is TARIFF-07.
Evidence: 29/29 green. 12 mutations, no survivors, purged tree and -B per TEST-15. One first-draft line was decoration and the mutation said so - the parser called brussels() per instant while assemble() already renders, so removing it changed nothing. The line was deleted rather than fenced with a check, and the mutation re-aimed at assemble() where the rule lives. MUTATION.md habit 19.
Follow-up filed as TARIFF-09: generic_dayahead ignores the since/until it is handed, so the feed supplies 24 h of a 48 h horizon and tomorrow is never firm.
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.