Camera Control Clients for NetCam

Client libraries and command-line tools for the NetCam phone app's JSON WebSocket API, in six languages. Every port speaks protocol version 4 over verified TLS, and every one exposes the same three commands — read status, capture one photo, run a time lapse — with the same flags and the same reconnect behavior.

The protocol itself is documented in api.md.

App Stores

Apple App Store, Google Play Store

Ports

Language	Directory	Library entry point	Transport	Runtime dependencies
Python	python/	camera_control.CameraControlClient	websockets (sync)	1
Go	go/	cameracontrol.Client	github.com/coder/websocket	1
Rust	rust/	camera_control::Client	tokio-tungstenite + rustls	tokio stack
Java	java/	app.flutterdev.cameracontrol.CameraControlClient	java.net.http.WebSocket	none
Node.js	nodejs/	CameraControlClient	ws	1
Dart	dart/	CameraControlClient	dart:io WebSocket	1 (CLI only)

The Java port bundles its own JSON reader, so the built JAR has no runtime dependencies at all. The Dart port's library half depends only on dart:io, which means it also runs inside a Flutter app on every non-web platform.

Each directory has its own README covering installation, the CLI, and library usage in that language.

Quick start

Pick a port, then point it at the wss:// URL the app shows. Every client reads the password from an environment variable so it never lands in process arguments or shell history:

export CAMERA_CONTROL_PASSWORD='your password'

Download the app's local CA and verify its fingerprint against the phone before trusting it — this is the one step you should not skip:

curl --insecure --output camera-control-local-ca.crt \
  https://192.168.1.50:8080/ca.crt
openssl x509 -in camera-control-local-ca.crt -noout -fingerprint -sha256

--insecure applies only to that first download. From then on every client verifies the chain against exactly this CA and nothing else.

Capture one photo:

# Python
camera-control capture wss://192.168.1.50:8080/ws --ca camera-control-local-ca.crt

# Go
go run ./cmd/camera-control capture wss://192.168.1.50:8080/ws -ca camera-control-local-ca.crt

# Rust
cargo run -- capture wss://192.168.1.50:8080/ws --ca camera-control-local-ca.crt

# Java
java -jar target/camera-control-client-0.1.0.jar \
  capture wss://192.168.1.50:8080/ws --ca camera-control-local-ca.crt

# Node.js
node bin/camera-control.js capture wss://192.168.1.50:8080/ws --ca camera-control-local-ca.crt

# Dart
dart run bin/camera_control.dart capture wss://192.168.1.50:8080/ws --ca camera-control-local-ca.crt

The shared command line

camera-control <command> <wss-url> [options]

Command	What it does
status	Print camera, device, capture-session, and reliability status
capture	Capture and save one JPEG through the idempotent job API
time-lapse	Start a capture session, follow it, and cancel it cleanly

Option	Applies to	Default
--ca FILE	all	required
--password-env NAME	all	CAMERA_CONTROL_PASSWORD
--timeout SECONDS	all	30
--reconnect-attempts N	all	5
--compact	status	off
--camera N	capture, time-lapse	1
--resolution NAME	capture, time-lapse	high
--flash MODE	capture, time-lapse	off
--jpeg-quality N	capture, time-lapse	unset
--output FILE	capture	photo.jpg
--request-id ID	capture	generated
--interval SECONDS	time-lapse	required
--count N	time-lapse	unbounded
--duration SECONDS	time-lapse	unbounded
--poll SECONDS	time-lapse	1

Resolutions are low, medium, high, veryHigh, ultraHigh, and max. Flash modes are off, auto, always, and torch. The Go CLI accepts both -flag and --flag; the others take --flag.

What every port guarantees

• Verified TLS only. A ws:// URL is refused outright, and the CA file you supply is the only trusted root — never the platform store.
• Protocol version pinning. A hello that isn't version 4 is rejected, and so is an authentication result that doesn't confirm the same version.
• Serialized requests with an event queue. Unsolicited events that arrive between a request and its response are queued and replayed to the next matching wait, rather than being dropped or mistaken for a response.
• Bounded reconnect. Idempotent actions retry across a dropped socket with exponential backoff capped at ten seconds. startCaptureSession and the legacy direct capture are never retried.
• Idempotent capture. captureJob replays reuse the same semantic requestId, so the running app deduplicates an ambiguous reconnect instead of taking a second photo.
• The same three error kinds: a structured API error carrying the server's code, a protocol error for malformed or unsupported messages, and a connection-interrupted error.

Do not reuse a request ID with different capture settings. If the phone app itself restarts, its in-memory idempotency history is lost — check status before replaying an ambiguous capture.

Development

Each port has an injectable transport, so the protocol logic is tested offline against a scripted in-memory channel; no phone or network is needed.

cd python && PYTHONPATH=src python3 -m unittest discover -s tests
cd go     && go vet ./... && go test ./...
cd rust   && cargo test && cargo clippy --all-targets
cd java   && mvn test
cd nodejs   && npm install && npm test
cd dart   && dart pub get && dart analyze && dart test

Ignore rules are split: the root .gitignore holds shared entries (editors, OS files, secrets, certificates, and captured photos), and each port directory carries its own language-specific rules.