Development¶

The rules for every change are in CLAUDE.md; the work queue and the catalogue of tasks in docs/dev/.

Structure¶

run.py                 launcher (server + window)
SignalViewer.spec     PyInstaller build definition (build.bat / build.sh)
tools/benchmark.py     performance benchmark
tests/e2e/             end-to-end browser tests
backend/app/main.py    local API, 127.0.0.1 only (wires the routes, local-only guard, UI files)
backend/app/routes/    the API endpoints, one module per area (files, data, analysis, compare...)
backend/app/store.py   loaded files with stable ids
backend/svcore/        computation core: loaders, decimation, analysis, compare, sync
backend/tests/         pytest suite
frontend/src/          React + TypeScript UI (uPlot, zustand)
frontend/dist/         built UI served by the backend
examples/              demo files (tools/make_demo_data.py)
docs/images, docs/media  screenshots and clips used in this README

Environment variables: SV_FLOAT32, SV_CACHE, SV_CACHE_MIN_MB, SV_MAX_POINTS. Workspace autosave and the binary cache live in ~/.signalviewer/; the error log in ~/.signalviewer/logs/ (Help > Copy error details puts its end on the clipboard; SV_LOG_DIR moves it).

Tests: numbers and real logs¶

cd backend && python -m pytest -q runs everything that needs no network, including the numerical validation (tests/test_validation.py; after changing a case, rewrite the page with python tools/make_validation_doc.py).

Real flight logs (tests/test_real_logs.py): logs recorded by real vehicles, not only the ones our own tools write, checked against their projects' own readers - ArduPilot DataFlash against pymavlink's DFReader (every numeric field), .tlog against pymavlink (every sample, on the autopilot's clock), PX4 .ulg against pyulog (every field of every topic) - and for invariants (finite, non-decreasing time; the health check runs). The public logs are pinned to a commit and a SHA-256 and kept outside the repository (their licences differ from ours):

python tools/fetch_real_logs.py                          # once: ~/.cache/signalviewer-test-logs
cd backend && python -m pytest -q tests/test_real_logs.py
SV_REAL_LOGS=/path/to/your/logs python -m pytest -q tests/test_real_logs.py   # your own logs too

Without the download those tests are skipped; the regression test for radio delay always runs.

Icon¶

assets/icon.svg (full) and assets/icon-small.svg (simplified for 16–32 px), rendered to assets/png/, assets/icon.ico (Windows) and assets/icon.icns (macOS). Used for the executable, the window and the browser tab. A signal trace read by the amber measurement cursor, the same visual language as the app.