FlowMap ships unsigned installers — an Apple Developer ID and a Windows publisher certificate both cost money this project does not have. So your OS will warn you, and it is right to: an unsigned binary from an unknown developer is, on its face, indistinguishable from malware. "The source is open" is not an answer, because the source is not what you downloaded.

This file is the answer. Everything below is checkable — by you, without trusting me.

Every installer in a release is signed with a SLSA build-provenance attestation at build time (.github/workflows/release.yml). The attestation is a Sigstore-backed statement that binds the file's SHA-256 digest to this repository, this workflow file, and the exact commit it was built from. GitHub stores it publicly; nothing on the release page can forge it.

# needs the GitHub CLI: https://cli.github.com
gh attestation verify ~/Downloads/<the-file-you-downloaded> -R nazmiefearmutcu/flowmap

A pass prints the workflow and commit that produced the file. A failure means the file did not come from this repository — do not run it.

Attestations and SHA256SUMS are produced by the release workflow from the next tagged release onward. Assets on v1.3.0 and earlier were built before this existed and will not verify — that is their age, not tampering, and it is exactly the gap this closes.

Each release also carries a SHA256SUMS asset covering every installer, for a check that needs no tooling at all:

shasum -a 256 -c SHA256SUMS      # run it in the folder you downloaded into

The checksums tell you the file arrived intact. The attestation tells you where it came from. Prefer the attestation; the checksums are the fallback.

Once a download verifies, the OS warning is about a missing certificate — not about the file being unknown to you. Getting past it:

• macOS: right-click → Open (confirm once), or xattr -cr /Applications/FlowMap.app.
• Windows: SmartScreen → More info → Run anyway.

Do this after gh attestation verify passes, not before. If you are not willing to do it in that order, run from source instead — it is a supported path, not a fallback:

./scripts/dev.sh          # Python 3.13 + uv, Node 22 + npm; no binary to trust

A market-data viewer. It reads public market data and draws it. It places no orders, holds no funds, and has no code path that could.

Outbound traffic is market data, and it is driven by what you subscribe to:

• Crypto — the public REST/WebSocket endpoints of the venue you pick, reached through Crocodile (native connectors for binance, bybit, coinbase, deribit, okx; every other venue via ccxt). Public endpoints: no key, no account.
• Crypto history backfill — api.binance.com, fapi.binance.com, dapi.binance.com (server/src/flowmap_server/core/backfill.py).
• US equities — Yahoo 1-minute bars for the keyless SYNTH tier.
• US equities, optional upgrades — Alpaca (ALPACA_API_KEY + ALPACA_API_SECRET) and Finnhub (FINNHUB_API_KEY), read from the environment if present and simply absent if not. These are market-data credentials; FlowMap never sends an order endpoint a request.
• The sim:SIM-DEMO feed — no network at all. Use it to watch what the app does before giving it a live venue.

The WebGL2 client loads no external origin: no CDN, no web fonts, no analytics. Everything it renders comes from the loopback server.

~/.flowmap/recordings/{market}/{symbol}/…parquet — its own session recordings, so you can replay them. A global cap (default 20 GB, FLOWMAP_RECORDING_GB_CAP) deletes the oldest files as it fills. Set FLOWMAP_RECORDING_ENABLED=0 to write nothing, or point FLOWMAP_DATA_DIR elsewhere. It writes nowhere else in your home directory.

The installers are large (100–430 MB) because they are self-contained: the built WebGL2 client, a relocatable CPython 3.13 from astral-sh/python-build-standalone, the Python dependencies from server/pyproject.toml, and the Tauri shell. Nothing is fetched at first run.

The dependency set is deliberately small and pinned: the market-data engine is pinned to an exact git commit (crocodile rev in server/pyproject.toml), and the rest are mainstream libraries — aiohttp, certifi, msgspec, numpy, polars, fastapi, uvicorn. Every GitHub Action used in CI is pinned to a commit SHA rather than a moving tag.

Open a private security advisory — that keeps the report non-public until there is a fix. Please do not open a public issue for a vulnerability. Include what you ran, what you observed, and how to reproduce it.

Only the latest release is supported; fixes go out as a new tagged release.