Review of PR #16 wrote a double-counting plugin four ways. PluginOptions blocked one. The one that decided it touched nothing but PRICE_OPTION_DEFAULTS - a public dict in the module every plugin must already import for register() - so "the number is not in scope" was simply false, and an absolute guarantee a reviewer trusts is worse than a stated limit, because they stop checking. register() now refuses, AT IMPORT, any plugin whose own code mentions a framework-owned name: FRAMEWORK_KEYS plus PRICE_OPTION_DEFAULTS, price_option and _o. code_leaks() parses the class and drops every docstring node before searching, because every plugin is REQUIRED to name its sourced components in prose - engie_dynamic says "markup" in its docstring and a raw text scan false-positives on the documentation the same file mandates. A check that fires on required documentation is a check somebody deletes. test_price.py asserts that a raw scan really would have false-positived, so the strip is proven load-bearing rather than asserted. It fails OPEN if inspect.getsource() cannot find the .py, which the add-on image always can. Refusing to start a battery controller because a static analysis could not run would trade a real outage for a hypothetical accounting error - so instead the checks assert source was found for all five shipped plugins, and a build that lost it is a red check rather than a quietly disarmed guard. All three reachable attacks are written out as plugins in the suite and each must be refused at registration. The cost is measured, not asserted: honest wholesale 0.188, every attack 0.219 - one markup high, every hour, invisible in every log this add-on writes. The guarantee is now stated at its true size everywhere it appears: the framework adds the complement exactly once, GIVEN A CORRECT sources DECLARATION. A plugin that declares {ENERGY} while its feed is all-in still doubles while touching no framework name, and no code can catch that - the declaration is an unverifiable claim about somebody else's tariff. Measured in the suite (0.276) so the limit is a number rather than a caveat. The docstring/declaration check verifies that a plugin's two claims AGREE, not that either is true; that now says so. The three surviving mutations: M3 - _NoData's reason taking a default. This is the identical survivor left open on RIG-01's _Unread.cause: the shape was borrowed from sim/riglock.py including its blind spot, which is what borrowing a shape does if nobody re-runs the mutations against the copy. Closed by SIGNATURE - no constructor or handler of an outcome type may carry a default - so the next one is red without anyone writing a new case. M5 - the ENERGY-required guard was untested. Its consequence is that adds becomes {ENERGY, TAXES} and the emitted price silently omits the energy it is pricing. M7 - deleting the TLS refusal went green AND the check named for it still passed, because the old parser stripped a fixed len("https://") and mangled http://api.energy-charts.info/p into the host pi.energy-charts.info, which then failed the ALLOW-LIST. An assertion that does not test what it names, inside a security check. Fixed on both sides: the scheme is parsed as a scheme, so an http URL now resolves to its real and declared host and only the TLS rule can refuse it; and the check asserts the REASON. Fixing it surfaced M7b - the no-scheme guard was survivable the same way - found by mutating my own fix, and closed the same way. Also carried forward: rule 7's refusal is correct forever but its stated reason ("the provider decides nothing") expires the moment TARIFF-03 or OPT-04 lands. test_price.py section 12 now greps app/ by AST for a load_prices consumer and goes red when one appears, telling whoever lands it to update the message in the same commit. The first draft of that tripwire used a substring and matched the comment in validate.py explaining the tripwire - the same false-positive class as the plugin docstrings, hit twice in one ticket, and fixed the same way. Documented rather than coded around: vars(read).get("points", []) and bool(read) both still get past the absence type, and neither is worth code - defining __bool__ would turn a line that reads like a guard into one that IS a guard by accident, which is how .get(k, default) got here in the first place. Stated plainly in DOCS/CHANGELOG/PR: every fixture is synthetic, so the five feed URLs and JSON shapes are verified against a belief about what those suppliers publish rather than against the feeds. A wrong shape degrades to no-price-data, not to a wrong price. Review's own DST verification recorded: 149,040 hourly instants, 2020-2036, zero mismatches against zoneinfo. The residual is political, not arithmetic, and the docstring now says so. 24 mutations driven through the suite, 0 survivors. Whole add-on suite green. No deleted lines outside this ticket's own files; main.py still untouched. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_015VXjA3LWccN1rJsk3okyPC
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
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
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. 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.