glenn schrooyenandClaude Opus 5
65cddf35f1
REJECTED because a survivor undoes AC 5, and it survived for the recurring
reason: two fixture values that must be distinguishable were EQUAL.
THE SURVIVOR. app/main.py:282 mutated from `self.inverters[0].name` to `UNIT_A`
left the full 19-file suite green. `inverter.UNIT_A == "inverter-a"`, and every
two-pack fixture in test_maintenance.py named its first roster entry
"inverter-a" - so the two expressions were the same string in every check that
existed. main.py's own comment made the distinction load-bearing and nothing in
the repository could see whether that comment was true.
THE FAILURE IS REAL. `build_roster()` names a declared roster's entries from the
config and numbers a nameless one POSITIONALLY (`inverter-1`), so "inverter-a"
is not even the fallback. On ["garage","shed"] with a flat last_completed of
2026-08-07 the mutant migrates into unit/inverter-a/, pack 0 reads back None,
and both packs come up believing they have never been recalibrated.
AND IT FAILED SILENTLY, which was the worse half: `_verify_moves()` read back
the keys it had just WRITTEN, under the namespace it had just been HANDED, was
satisfied, and MAINT_SCHEMA_KEY was stamped - so the next start skipped the
migration too. A postcondition that reads back the namespace it was handed
cannot detect being handed the wrong one.
WHAT CHANGED
1. THE POSTCONDITION IS GRADED AGAINST THE ROSTER. `_verify_moves()` takes the
names the MACHINES read and reports a namespace that is not among them as
`misdirected` - a new, differently-named failure from `lost`:
* `lost` is "the store took the write and dropped it" - a storage fault,
with a harmless-default case (a dropped `last_completed: None` loses
nothing, because absent and never-recalibrated are the same statement);
* `misdirected` is "the store did exactly as it was told, by a caller that
was wrong". There is no harmless-default version of it - a write nobody
reads is not information whatever its value - so it fails `ok` alone.
`ok` gates the marker, so a misdirected migration is NOT stamped and the next
start re-runs it. Asymmetric on purpose: a re-run is recoverable (rule 1
makes it a no-op, rule 2 left the flat keys to recover from), a silent skip
is not. Part 9b MEASURES the recovery rather than asserting it.
2. `migrate_maint_keys()` TAKES THE ROSTER IN PLACE OF AN `n_units` COUNT. The
count was `len(self.inverters)` at the only call site, so the roster carries
it, and a count beside the names is a second opinion about how many packs
there are.
3. THE FIXTURES CAN NOW REACH THE FAILURE THEY NAME. Parts 9 and 11 run on
["garage","shed"], each behind a PRECONDITION check that the first name is
not UNIT_A - so an edit that makes them equal again goes red instead of
making the claims vacuous. Part 11's fixture date is relative to `now`, not
a literal, so "history preserved" and "history lost" cannot converge as the
file ages past `interval_days`.
MUTATION LEDGER - all red, purged tree, none at +0 B, full detail on the PR:
M1 main.py inverters[0].name -> UNIT_A -16 B 4 checks red
M2 store.py drop `roster=names` from _verify_moves -14 B 5 checks red
M3 store.py drop the misdirected.append -37 B 5 checks red
M4 store.py ok: drop `and not self.misdirected` -25 B 3 checks red
M5 fixture garage -> inverter-a (the trap itself) +4 B 5 checks red
M6 store.py parts[1] -> parts[-1] +1 B 1 check red
FOUND AND NOT FIXED - `migrate_unit_keys()` HAS THE SAME HOLE AND IT IS A LATCH.
It runs BEFORE `build_roster()` (each Inverter restores its latch in its
constructor), so it is handed the constant UNIT_A with no roster to grade
against. On a declared roster a pre-DEV-02 `sign_tripped: true` lands under
unit/inverter-a/sign_tripped, which no unit reads - and
`_grade_store_migration()`, whose whole job is to re-arm exactly this, is
DEFEATED BY THE KEY THE DEFECT WROTE: its "is anything namespaced latched" test
is satisfied by the misdirected value itself. Measured, with the flat-config
counterfactual, and pinned as a running check (test_maintenance.py part 13)
whose assertions state the WRONG behaviour on purpose. It wants its own card:
the remedy is in inverter.py and SAFETY-02's semantics, and a silent expansion
into a safety latch is how a rejected PR becomes a broken one.
Suite: 19/19 PASS, purged tree, bind-mounted :ro in goodwe-addon-ci.
No hardware was touched; every fixture here is SIMULATED and pack B's 3000 W
remains a marked hypothesis.
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
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
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.