Sutra

Sutra is the thread: a desktop app (Tauri + React) that connects you, and an LLM, to a device's serial console.

sūtra (Sanskrit सूत्र): "thread"; that which threads things together.

It pairs with Duta firmware over the shared skrit protocol, but also drives any plain COM port.

What you can do with it

A Duta and Sutra together are a general-purpose bridge between you (or an LLM) and whatever hardware is in front of you. A few of the things people reach for it to do:

• A real KVM for the rack. Drop a Duta on your homelab's console ports (a headless box's serial header, a switch/router/PDU console) and reach them remotely over WiFi (mDNS-discovered) or Bluetooth. It's out-of-band serial access, the KVM-over-IP equivalent, with no OpenGear/Avocent appliance and no trudging over to the rack with a USB-serial dongle. An LLM can hold the console too.
• Turn an MCU into a Wireshark capture board. Port a Duta build to your own radio/bus hardware and it becomes a live, named Wireshark interface (BLE, 802.15.4/Zigbee/Thread, I²C, raw serial), dissected in real time over sutra-extcap. No proprietary sniffer app.
• Automate arduous hardware testing. Script the tedious bring-up and QA loops with macros (WAITFOR, RUN with exit-code capture, IF/ELSE, SET, WAITIO), watch the run queue, record results to pcap, and hand the whole thing to an LLM over MCP to run unattended.
• Replace sketchy manufacturer apps. Instead of a vendor's one-off configurator, describe a board's panel once as a .yantra (buttons, sliders, and readouts, scripted in Lua) and get a clean, reusable control surface that travels with your project.
• …or just use it as a serial console. Point it at any plain COM port and you've got a fast, modern terminal. No Duta required.

Features

• Universal serial console (ghostty-web): connect a Duta device or any COM port; baud/parity/stop, named connection profiles, link online/offline.
• Bluetooth LE: the toolbar's Bluetooth button scans for a Duta and connects over BLE (two skrit GATT services: DATA console + CMD); from there the console, controls, and macros all work identically to a serial link. (Scaffold, see duta/zephyr.)
• Network (WebSocket): the globe button connects a Duta over ws:///wss:// (the skrit-mux stream over WS binary frames), authenticating with the device password (default duta, prompts to change). The host reference is a runnable WS server.
• Macros: saved, reorderable command scripts (line-based Bash Bunny / DuckyScript) plus an expect engine: WAITFOR, RUN (with exit-code capture), IF OK…ELSE…END, SET an output, WAITIO on an input, $call another macro. A run queue shows in-flight macros (e.g. blocked on WAITFOR) and lets you cancel them. Macros flagged secret are never readable by the LLM and are redacted from console reads. Full language + tier reference: MACROS.md.
• Device-driven controls: the UI renders what the device self-describes, typed by behavior: a toggle for digital IO, a 0-1023 slider + frequency/resolution badge for PWM, a per-pixel color picker for addressable RGB, live input readouts, all by name, with no per-board UI.
• Yantra control surfaces: ship a .yantra (YAML) describing a device's panel of buttons/sliders/readouts/tables laid out on a responsive canvas, each wired to what it sends (UART/I²C/INVOKE/CFG/outputs) and filled from (the live console or other widgets). A visual editor builds them; readouts/emitters give a reactive data flow; and a sandboxed Lua layer scripts logic, orchestration, and presentation. Full reference: YANTRA.md.
• Configure device (runtime provisioning): on firmware that advertises the provision flag, re-pin the device's IO from the app: a per-pin role/name picker constrained to what each pin supports (strapping/dual-use pins warned, fixed pins locked), persisted on-device, applied on reboot. No reflashing.
• MCP server: per-tool toggles; lets an LLM read the console, run/author macros (run-by-name only), drive outputs (incl. PWM config + RGB), provision IO, and manage the connection.
• Workspace: pick a project folder (header, top-left) and Sutra keeps a .sutra/ directory inside it: macros (macros.json) and capture exports (captures/*.pcap) live there, so a project's automation and recordings travel with the folder. Without one, macros fall back to the app data dir.
• Wireshark integration: the bundled sutra-extcap binary turns every Duta into a live Wireshark capture interface, whether USB-attached (probed and listed by name) or network (mDNS-discovered, auth-gated), with the DATA stream delivered as pcap packets. A WiFi capture coexists with a Sutra USB session, so you can drive the target while Wireshark watches. See EXTCAP.md.

_{Live 802.15.4 / Zigbee capture from a Duta, dissected in Wireshark via sutra-extcap.}

Run

bun install
bun run tauri dev

Protocol & MCP

The app mirrors the skrit contract in src-tauri/src/protocol.rs and src/lib/skrit.ts; the spec is vendored in PROTOCOL.md (canonical home: the skrit repo). MCP usage is in MCP.md.