Buy It Once. Keep Using It.
Transparent perpetual licensing designed for individual engineers, machine builders, and commercial OEMs.
SMFlow Free
Fully functional and free forever. Build real projects, test hardware drivers, and evaluate the full workflow.
- ✓ Up to 12 nodes per flow
- ✓ Full microcontroller target support (ESP32, STM32, RP2040, AVR, Linux)
- ✓ Full driver, peripheral & protocol ecosystem (GPIO, I²C, SPI, CAN)
- ✓ Desktop simulator with live scan cycle inspection
- ✓ Visual IDE & standalone CLI tools
- ✓ Never takes files hostage (always open & edit any size project)
SMFlow Pro
For engineers, machine builders, system integrators, and commercial controller developers.
- ✓ Unlimited nodes per flow
- ✓ Commercial use rights included
- ✓ 3 device activations per seat
- ✓ 100% offline-capable after activation
- ✓ Cross-platform: Windows, Linux, macOS
- ✓ Headless CI/CD build agent support (`SMFLOW_LICENSE_DIR`)
- ✓ Zero runtime fees, zero royalties on compiled binaries
Frequently Asked Questions
Why is the Free limit 12 nodes per flow?
12 nodes is enough to build real, working projects—such as a multi-stage pump sequencer, an automated interlock, or an environmental monitoring loop—and thoroughly evaluate the compiler, simulation, and hardware deployment workflows. When a project grows into a full-scale commercial controller, upgrading to Pro is a natural next step.
What happens if my project exceeds 12 nodes in Free?
SMFlow never locks your files or takes projects hostage. You can always open, inspect, edit, rearrange, and save projects of any size on the Free edition. Only compiling ahead-of-time and flashing hardware requires a Pro license once the node cap is exceeded.
Are there any runtime device fees or royalties?
Never. The C++17 code emitted by SMFlow compiles into standalone bare-metal machine code. You can deploy it onto 1, 1,000, or 100,000 microcontrollers with zero device fees or royalties.
How does offline activation work?
When you activate with your key via the editor or CLI (smflow license activate <KEY>), SMFlow downloads a cryptographically signed ECDSA P-256 certificate bound to your machine. Subsequent builds verify this certificate locally without requiring any ongoing internet connection.
How many seats / activations are included with Pro?
Each Pro license includes 3 active machine activations (e.g., your office desktop, workbench laptop, and lab machine). You can self-service deactivate a machine anytime using smflow license deactivate.