OpentronsOT2ChatterboxBackend: a dry-run OT-2 backend with I/O logging, via a transport seam#1132
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OpentronsOT2ChatterboxBackend: a dry-run OT-2 backend with I/O logging, via a transport seam#1132BioCam wants to merge 5 commits into
OpentronsOT2ChatterboxBackend: a dry-run OT-2 backend with I/O logging, via a transport seam#1132BioCam wants to merge 5 commits into
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Characterization tests ahead of the transport-seam refactor (Phase 0). The existing suite already asserts the pickup/drop/aspirate/dispense wire calls; this adds the four remaining ot_api call sites so the seam refactor cannot change them silently: - home() issues one ot_api.health.home() - list_connected_modules() returns ot_api.modules.list_connected_modules() verbatim - stop() cancels the active run via the requestor and clears mounted pipettes - a discard to the deck trash at api_version >= 7.1.0 routes through the addressable area (move_to_addressable_area_for_drop_tip + drop_tip_in_place), not drop_tip No production code changes. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Introduces a single transport seam (Phase 1): every ot_api call - including the run-cancel requestor calls in stop() - now goes through self._ot, set to the ot_api module in __init__. Behaviour is unchanged (self._ot is ot_api), but a subclass can now dry-run the backend by swapping the handle for a recording stand-in, the way STARChatterboxBackend overrides STAR's transport. The dedicated `import ot_api.requestor as _req` is dropped; ot_api.requestor is reachable through the handle (self._ot.requestor). Guarded by the Phase 0 characterization tests, which patch ot_api.* and stay green because self._ot is the same module object. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
…nsport seam Phase 2. A chatterbox sibling to OpentronsOT2Backend that swaps the self._ot transport handle for a recorder, so the real backend logic - pipette selection, tip and volume tracking, the per-operation wire calls - runs unchanged with no hardware and no ot_api library. Mirrors STARChatterboxBackend (transport-only override) rather than OpentronsOT2Simulator (which reimplements the high-level methods single-channel). Issued calls are printed and collected in .commands. The recorder returns canned data for the reads setup() and the operations make back (mounted pipettes, api version, labware define, save_position, modules). Exported from backends/__init__. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
…mulator Phase 3. Direct tests run the chatterbox with no ot_api installed: setup resolves both mounts, a pickup -> aspirate -> dispense -> trash-discard records exactly one wire call per operation, an unknown pipette name raises, and serialize() captures the mounts. A differential audit runs the same single-channel protocol through the chatterbox and the reference OpentronsOT2Simulator and asserts identical tracked outcomes (tip mounted, source/destination volumes). The audit is scoped to the single-channel overlap, since the simulator cannot represent a multi-channel head. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
BioCam
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OpentronsOT2Backend: route all ot_api I/O through a self._ot handleOpentronsOT2ChatterboxBackend: a dry-run OT-2 backend, via a transport seam
The OT-2 talks HTTP through ot_api rather than a pylabrobot.io transport, so its wire traffic never reached the IO log other backends produce. Wrap the real ot_api handle in a transparent _IOLogger proxy that logs every call (submodules recursed, plain attributes passed through) at LOG_LEVEL_IO. The chatterbox recorder logs the same way, so a dry run captures the same wire trace as a real run. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
This was referenced Jun 30, 2026
BioCam
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OpentronsOT2ChatterboxBackend: a dry-run OT-2 backend, via a transport seamOpentronsOT2ChatterboxBackend: a dry-run OT-2 backend with I/O logging, via a transport seam
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Adds
OpentronsOT2ChatterboxBackend, a dry-run backend for the OT-2 that runs the real backend logic with no hardware and noot_apilibrary, mirroring howSTARChatterboxBackenddry-runsSTARBackend. UnlikeOpentronsOT2Simulator(which overrides the high-level methods with single-channel stubs), the chatterbox replaces only the transport, so pipette selection, tip/volume tracking, and the per-operation wire calls all run unchanged.To enable that, the backend routes every
ot_apicall - including the run-cancel calls instop()- through a singleself._ottransport handle. The real handle wrapsot_apiin a transparent_IOLoggerproxy that logs every HTTP call atLOG_LEVEL_IO, like other backends get from their io object; the chatterbox swaps the handle for a recorder that logs the same way, so a dry run captures the same wire trace as a real run.Characterization tests pin the existing wire calls (home / stop-cancel / list_connected_modules / addressable-area trash drop) so the seam refactor cannot change them silently; chatterbox tests run a full protocol with no
ot_apiinstalled and assert the recorded calls.Foundation of the OT-2 series; depends on nothing else in it.
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