Update PhoneAPI.cpp to reduce chattiness

Use distro provided Python at build time (instead of the `python` images from dockerhub) and install `grpcio-tools` using the distro provided packages.

This should speed up build times, ESPECIALLY on riscv64 (where prebuilt `grpcio-tools` wheels are not provided on pip).

Co-authored-by: Copilot <copilot@github.com>

.github/copilot-instructions.md

@@ -13,6 +13,7 @@ Meshtastic is an open-source LoRa mesh networking project for long-range, low-po
 - **RP2040/RP2350** - Raspberry Pi Pico variants
 - **STM32WL** - STM32 with integrated LoRa
 - **Linux/Portduino** - Native Linux builds (Raspberry Pi, etc.)
+- **macOS native** - Headless `meshtasticd` on Apple Silicon / x86_64; see `variants/native/portduino/platformio.ini` for Homebrew prereqs + CH341 LoRa setup
 
 ### Supported Radio Chips
 
@@ -369,7 +370,7 @@ To reduce avoidable agent mistakes, assume these tools are available (or install
 - **Required CLI basics**: `bash`, `git`, `find`, `grep`, `sed`, `awk`, `xargs`
 - **Strongly recommended**: `rg` (ripgrep) for fast file/text search, `jq` for JSON processing
 - **Build/test tools**: `python3`, `pip`, virtualenv (`python3 -m venv`), `platformio` (`pio`)
-- **Containerized native testing**: `docker` (especially important on macOS / non-Linux hosts)
+- **Containerized native testing**: `docker` (fallback for non-Linux hosts; macOS can also build natively via `pio run -e native-macos`)
 
 Fallback expectations for agents:
 
@@ -388,6 +389,7 @@ Build commands:
 pio run -e tbeam              # Build specific target
 pio run -e tbeam -t upload    # Build and upload
 pio run -e native             # Build native/Linux version
+pio run -e native-macos       # Build headless macOS meshtasticd (Homebrew prereqs in variants/native/portduino/platformio.ini)
 ```
 
 ### Build Manifest
@@ -573,6 +575,8 @@ Grouped by purpose. Full argument shapes in `mcp-server/README.md`; a few high-v
 
 `confirm=True` is a tool-level gate on top of whatever permission prompt your MCP host shows. **Don't bypass it** by asking the host to auto-approve — it exists specifically because MCP hosts sometimes remember "always allow this tool" and that's dangerous for `factory_reset`, `erase_and_flash`, `uhubctl_power(action='off')`, and `uhubctl_cycle`.
 
+**TCP / native-host nodes.** Setting `MESHTASTIC_MCP_TCP_HOST=<host[:port]>` makes `list_devices` surface a `meshtasticd` daemon (e.g. the `native-macos` build) as a synthetic `tcp://host:port` entry, and `connect()` routes through `meshtastic.tcp_interface.TCPInterface` instead of `SerialInterface`. Every read/write/admin tool that flows through `connect()` works against the daemon transparently. USB-only tools (`pio_flash`, `erase_and_flash`, `update_flash`, `touch_1200bps`, `serial_open`, `esptool_*`, `nrfutil_*`, `picotool_*`) raise a clear `ConnectionError` when handed a `tcp://` port; `pio_flash` against a `native*` env raises a `FlashError` (no upload step — use `build` and run the binary directly). The pytest harness still assumes USB-attached devices per role; TCP-aware fixtures are deferred. See `mcp-server/README.md` § "TCP / native-host nodes".
+
 ### Hardware test suite (`mcp-server/run-tests.sh`)
 
 The wrapper auto-detects connected devices (VID → role map: `0x239A` → `nrf52`, `0x303A`/`0x10C4` → `esp32s3`), maps each role to a PlatformIO env (`nrf52` → `rak4631`, `esp32s3` → `heltec-v3`, overridable via `MESHTASTIC_MCP_ENV_<ROLE>`), then invokes pytest. Zero pre-flight config needed from the operator.

.github/workflows/docker_build.yml

@@ -73,7 +73,9 @@ jobs:
       - name: Sanitize platform string
         id: sanitize_platform
         # Replace slashes with underscores
-        run: echo "cleaned_platform=${{ inputs.platform }}" | sed 's/\//_/g' >> $GITHUB_OUTPUT
+        env:
+          plat: ${{ inputs.platform }}
+        run: echo "cleaned_platform=${plat}" | sed 's/\//_/g' >> $GITHUB_OUTPUT
 
       - name: Docker login
         if: ${{ inputs.push }}

.github/workflows/docker_manifest.yml

@@ -43,6 +43,15 @@ jobs:
       push: true
     secrets: inherit
 
+  docker-debian-riscv64:
+    uses: ./.github/workflows/docker_build.yml
+    with:
+      distro: debian
+      platform: linux/riscv64
+      runs-on: ubuntu-24.04-arm
+      push: true
+    secrets: inherit
+
   docker-alpine-amd64:
     uses: ./.github/workflows/docker_build.yml
     with:
@@ -70,16 +79,27 @@ jobs:
       push: true
     secrets: inherit
 
+  docker-alpine-riscv64:
+    uses: ./.github/workflows/docker_build.yml
+    with:
+      distro: alpine
+      platform: linux/riscv64
+      runs-on: ubuntu-24.04-arm
+      push: true
+    secrets: inherit
+
   docker-manifest:
     needs:
       # Debian
       - docker-debian-amd64
       - docker-debian-arm64
       - docker-debian-armv7
+      - docker-debian-riscv64
       # Alpine
       - docker-alpine-amd64
       - docker-alpine-arm64
       - docker-alpine-armv7
+      - docker-alpine-riscv64
     runs-on: ubuntu-24.04
     steps:
       - name: Checkout code
@@ -162,6 +182,7 @@ jobs:
             meshtastic/meshtasticd@${{ needs.docker-debian-amd64.outputs.digest }}
             meshtastic/meshtasticd@${{ needs.docker-debian-arm64.outputs.digest }}
             meshtastic/meshtasticd@${{ needs.docker-debian-armv7.outputs.digest }}
+            meshtastic/meshtasticd@${{ needs.docker-debian-riscv64.outputs.digest }}
 
       - name: Docker meta (Alpine)
         id: meta_alpine
@@ -182,3 +203,4 @@ jobs:
             meshtastic/meshtasticd@${{ needs.docker-alpine-amd64.outputs.digest }}
             meshtastic/meshtasticd@${{ needs.docker-alpine-arm64.outputs.digest }}
             meshtastic/meshtasticd@${{ needs.docker-alpine-armv7.outputs.digest }}
+            meshtastic/meshtasticd@${{ needs.docker-alpine-riscv64.outputs.digest }}

.trunk/trunk.yaml

@@ -4,7 +4,7 @@ cli:
 plugins:
   sources:
     - id: trunk
-      ref: v1.7.6
+      ref: v1.8.0
       uri: https://github.com/trunk-io/plugins
 lint:
   enabled:
@@ -36,7 +36,7 @@ lint:
         - bin/**
 runtimes:
   enabled:
-    - python@3.10.8
+    - python@3.14.4
     - go@1.21.0
     - node@22.16.0
 actions:

AGENTS.md

@@ -11,8 +11,9 @@ This file (`AGENTS.md`) is a short pointer + quick reference for agents that don
 ## Quick command reference
 
 | Action                           | Command                                                                                                       |
-| -------------------------------- | ----------------------------------------------------------------------------------- |
+| -------------------------------- | ------------------------------------------------------------------------------------------------------------- |
 | Build a firmware variant         | `pio run -e <env>` (e.g. `pio run -e rak4631`, `pio run -e heltec-v3`)                                        |
+| Build native macOS host binary   | `pio run -e native-macos` (Homebrew prereqs + CH341 LoRa setup in `variants/native/portduino/platformio.ini`) |
 | Clean + rebuild                  | `pio run -e <env> -t clean && pio run -e <env>`                                                               |
 | Flash a device                   | `pio run -e <env> -t upload --upload-port <port>` (or use the `pio_flash` MCP tool)                           |
 | Run firmware unit tests (native) | `pio test -e native`                                                                                          |
@@ -121,14 +122,16 @@ Sequence these; don't parallelize on the same port.
 - **Device fully wedged (no DFU)?** `mcp__meshtastic__uhubctl_cycle(role="nrf52", confirm=True)` hard-power-cycles it via USB hub PPPS. Needs `uhubctl` installed (`brew install uhubctl` / `apt install uhubctl`); on Linux without udev rules, permission errors fail fast, so use `sudo uhubctl` yourself or configure udev access.
 - **Port busy?** `lsof <port>` to find the holder. Usually a stale `pio device monitor` or zombie `meshtastic_mcp` process. Kill it.
 - **Multiple MCP servers running?** `ps aux | grep meshtastic_mcp` — zombies hold ports. Kill all but the one your host spawned.
+- **macOS: `LIBUSB_ERROR_BUSY` on a CH341 LoRa adapter?** A third-party WCH `CH34xVCPDriver` is claiming interface 0. Find the bundle ID with `ioreg -p IOUSB -l -w 0 | grep -B2 -A30 0x5512`, then `sudo kmutil unload -b <bundleID>`. Apple's bundled CH34x kext targets the CH340 UART (PID 0x7523), not the SPI bridge — it's never the culprit.
 
 ## Environment variables (test harness)
 
 | Var                                  | Purpose                                                                                                                                                                                                    |
-| ------------------------------------ | ---------------------------------------------------------------------------------------------------------------------------------------------- |
+| ------------------------------------ | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
 | `MESHTASTIC_MCP_ENV_<ROLE>`          | Override PlatformIO env for a role (e.g. `MESHTASTIC_MCP_ENV_NRF52=rak4631-dap`). Default map: `nrf52→rak4631`, `esp32s3→heltec-v3`.                                                                       |
 | `MESHTASTIC_MCP_SEED`                | PSK seed for the session test profile. Defaults to `mcp-<user>-<host>`.                                                                                                                                    |
 | `MESHTASTIC_MCP_FLASH_LOG`           | File path to tee pio/esptool/nrfutil/picotool output. `run-tests.sh` sets this to `tests/flash.log` so the TUI can stream live flash progress.                                                             |
+| `MESHTASTIC_MCP_TCP_HOST`            | `host` or `host:port` of a `meshtasticd` daemon (e.g. the `native-macos` build). Surfaces it in `list_devices` as `tcp://host:port` so `connect()`-based tools target it transparently. Default port 4403. |
 | `MESHTASTIC_UHUBCTL_BIN`             | Absolute path to `uhubctl` binary. Default: PATH lookup.                                                                                                                                                   |
 | `MESHTASTIC_UHUBCTL_LOCATION_<ROLE>` | Pin a role to a specific uhubctl hub location (e.g. `1-1.3`). Wins over VID auto-detection — use when multiple devices share a VID.                                                                        |
 | `MESHTASTIC_UHUBCTL_PORT_<ROLE>`     | Pin a role to a specific hub port number. Required alongside `LOCATION_<ROLE>`.                                                                                                                            |

Dockerfile

@@ -3,15 +3,17 @@
 # trunk-ignore-all(hadolint/DL3008): Do not pin apt package versions
 # trunk-ignore-all(hadolint/DL3013): Do not pin pip package versions
 
-FROM python:3.14-slim-trixie AS builder
+FROM debian:trixie AS builder
 ARG PIO_ENV=native
 ENV DEBIAN_FRONTEND=noninteractive
 ENV TZ=Etc/UTC
 
 # Install Dependencies
 ENV PIP_ROOT_USER_ACTION=ignore
+ENV PIP_BREAK_SYSTEM_PACKAGES=1
 RUN apt-get update && apt-get install --no-install-recommends -y \
         curl wget g++ zip git ca-certificates pkg-config \
+        python3-pip python3-grpc-tools \
         libgpiod-dev libyaml-cpp-dev libbluetooth-dev libi2c-dev libuv1-dev \
         libusb-1.0-0-dev libulfius-dev liborcania-dev libssl-dev \
         libx11-dev libinput-dev libxkbcommon-x11-dev libsqlite3-dev libsdl2-dev \

alpine.Dockerfile

@@ -3,12 +3,19 @@
 # trunk-ignore-all(hadolint/DL3018): Do not pin apk package versions
 # trunk-ignore-all(hadolint/DL3013): Do not pin pip package versions
 
-FROM python:3.14-alpine3.22 AS builder
+# Ensure the Alpine version is updated in both stages of the container!
+FROM alpine:3.23 AS builder
 ARG PIO_ENV=native
-ENV PIP_ROOT_USER_ACTION=ignore
 
+# Enable Alpine community repository (for 'py3-grpcio-tools')
+RUN echo "https://dl-cdn.alpinelinux.org/alpine/v$(cut -d. -f1,2 /etc/alpine-release)/community" >> /etc/apk/repositories
+
+# Install Dependencies
+ENV PIP_ROOT_USER_ACTION=ignore
+ENV PIP_BREAK_SYSTEM_PACKAGES=1
 RUN apk --no-cache add \
         bash g++ libstdc++-dev linux-headers zip git ca-certificates libbsd-dev \
+        py3-pip py3-grpcio-tools \
         libgpiod-dev yaml-cpp-dev bluez-dev \
         libusb-dev i2c-tools-dev libuv-dev openssl-dev pkgconf argp-standalone \
         libx11-dev libinput-dev libxkbcommon-dev sqlite-dev sdl2-dev \

mcp-server/README.md

@@ -167,7 +167,7 @@ rather than auto-`sudo`'ing mid-run.
 ## Environment variables
 
 | Var                        | Default                                                     | Purpose                                                                                                          |
-| -------------------------- | ----------------------------------------------------------- | ------------------------------------------------------------------- |
+| -------------------------- | ----------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------- |
 | `MESHTASTIC_FIRMWARE_ROOT` | walks up from cwd for `platformio.ini`                      | Pin the firmware repo                                                                                            |
 | `MESHTASTIC_PIO_BIN`       | `~/.platformio/penv/bin/pio` → `$PATH` `pio` → `platformio` | Override `pio` location                                                                                          |
 | `MESHTASTIC_ESPTOOL_BIN`   | `<firmware>/.venv/bin/esptool` → `$PATH`                    | Override esptool                                                                                                 |
@@ -175,6 +175,64 @@ rather than auto-`sudo`'ing mid-run.
 | `MESHTASTIC_PICOTOOL_BIN`  | `$PATH`                                                     | Override picotool                                                                                                |
 | `MESHTASTIC_MCP_SEED`      | `mcp-<user>-<host>`                                         | PSK seed for test-harness session (CI override)                                                                  |
 | `MESHTASTIC_MCP_FLASH_LOG` | `<mcp-server>/tests/flash.log`                              | Tee target for pio/esptool/nrfutil subprocess output (TUI tails it)                                              |
+| `MESHTASTIC_MCP_TCP_HOST`  | unset                                                       | `host` or `host:port` of a `meshtasticd` daemon to surface as a TCP device (see "TCP / native-host nodes" below) |
+
+## TCP / native-host nodes
+
+The `native-macos` and `native` PlatformIO envs build a headless `meshtasticd`
+binary that runs on the host (Apple Silicon / Intel macOS, or Linux Portduino).
+The daemon exposes the meshtastic TCP API on port `4403` rather than a USB
+serial endpoint — point the MCP server at it via `MESHTASTIC_MCP_TCP_HOST`:
+
+```bash
+# 1. Build + run a daemon on this host (see variants/native/portduino/platformio.ini
+#    for full Homebrew prereqs and CH341 LoRa-adapter setup).
+pio run -e native-macos
+~/.meshtasticd/meshtasticd
+
+# 2. Point the MCP server at it.
+export MESHTASTIC_MCP_TCP_HOST=localhost     # or host:port, default port 4403
+```
+
+**First-run gotcha — MAC address.** `meshtasticd` derives its MAC from the
+USB adapter's serial-number / product strings. Many cheap CH341 dongles
+(MeshStick included — VID 0x1A86 / PID 0x5512) ship with `iSerialNumber=0`
+and `iProduct=0`, so the daemon aborts on boot with `*** Blank MAC Address
+not allowed!`. Set the MAC explicitly in `config.yaml`:
+
+```yaml
+# Under General:
+MACAddress: 02:CA:FE:BA:BE:01
+```
+
+Use a locally-administered address (first byte's second-LSB set, e.g.
+`02:*` / `06:*` / `0A:*` / `0E:*`) to avoid colliding with a real OUI.
+
+There is also a `--hwid AA:BB:CC:DD:EE:FF` CLI flag visible in
+`meshtasticd --help`, but it is **currently broken** in
+`MAC_from_string()` (`src/platform/portduino/PortduinoGlue.cpp`): the
+function strips colons from its parameter but then reads bytes from the
+global `portduino_config.mac_address`, so `--hwid` is silently overridden
+when `MACAddress:` is also set, and crashes the daemon (uncaught
+`std::invalid_argument: stoi: no conversion`) when it isn't. Use the YAML
+form until that's fixed upstream.
+
+`list_devices` will surface the daemon as `tcp://localhost:4403` with
+`likely_meshtastic=True`, so `device_info`, `list_nodes`, `get_config`,
+`set_config`, `set_owner`, `send_text`, `userprefs_*`, and the admin RPCs
+auto-select it when no `port` is passed. Pass `port="tcp://other-host:9999"`
+explicitly to target a different daemon.
+
+**Tools that don't apply to a TCP/native node** (no USB hardware to operate
+on) raise a clear `ConnectionError` rather than failing mysteriously:
+`pio_flash`, `erase_and_flash`, `update_flash`, `touch_1200bps`,
+`serial_open` (use info/admin tools directly), and the vendor escape hatches
+`esptool_*`, `nrfutil_*`, `picotool_*`. `pio_flash` against a `native*` env
+similarly raises — there's no upload step; use `build` and run the binary
+directly.
+
+The pytest harness in `tests/` still assumes USB-attached devices per role —
+TCP-aware fixtures are not part of this surface yet.
 
 ## Hardware Test Suite
 

mcp-server/src/meshtastic_mcp/connection.py

@@ -1,4 +1,4 @@
-"""Context manager for meshtastic.SerialInterface connections.
+"""Context manager for meshtastic interface connections (serial + TCP).
 
 Every info/admin tool goes through `connect(port)` so we have a single place
 that:
@@ -6,8 +6,16 @@ that:
   - fails fast if a serial_session is already holding the port,
   - guarantees `.close()` is called, even on exception.
 
-The `SerialInterface` blocks on construction waiting for the node database;
+Two transports:
-that's fine for v1 since every tool is a short-lived request.
+  - Serial: USB-attached firmware on `/dev/cu.*` / `/dev/ttyUSB*` / `COM*`.
+  - TCP: a `meshtasticd` daemon (e.g. the native macOS / Linux Portduino
+    headless build) addressed as `tcp://host[:port]` (default port 4403).
+    Surfaced by `devices.list_devices()` when `MESHTASTIC_MCP_TCP_HOST` is
+    set, so `resolve_port(None)` auto-selects it like a USB candidate.
+
+Both `SerialInterface` and `TCPInterface` block on construction waiting for
+the node database; that's fine for v1 since every tool is a short-lived
+request.
 """
 
 from __future__ import annotations
@@ -17,20 +25,107 @@ from typing import Iterator
 
 from . import devices, registry
 
+DEFAULT_TCP_PORT = 4403
+TCP_SCHEME = "tcp://"
+TCP_HOST_ENV = "MESHTASTIC_MCP_TCP_HOST"
+
 
 class ConnectionError(RuntimeError):
     pass
 
 
+def is_tcp_port(port: str | None) -> bool:
+    return bool(port) and port.startswith(TCP_SCHEME)
+
+
+def parse_tcp_port(port: str) -> tuple[str, int]:
+    """Parse `tcp://host[:port]` → (host, port). Defaults to 4403.
+
+    Validates host shape (non-empty, no path separators) and port range
+    (1..65535). Raises `ConnectionError` on malformed input — never lets
+    a raw `ValueError` bubble up to a tool surface.
+    """
+    if not port.startswith(TCP_SCHEME):
+        raise ConnectionError(
+            f"Invalid TCP endpoint {port!r}: expected '{TCP_SCHEME}host[:port]'."
+        )
+    rest = port[len(TCP_SCHEME) :]
+    if ":" in rest:
+        host, port_str = rest.rsplit(":", 1)
+        try:
+            tcp_port = int(port_str)
+        except ValueError as e:
+            raise ConnectionError(
+                f"Invalid TCP endpoint {port!r}: port {port_str!r} is not an integer."
+            ) from e
+    else:
+        host, tcp_port = rest, DEFAULT_TCP_PORT
+    if not host:
+        raise ConnectionError(f"Invalid TCP endpoint {port!r}: empty host.")
+    if any(c in host for c in ("/", "\\")):
+        raise ConnectionError(
+            f"Invalid TCP endpoint {port!r}: host {host!r} contains a path "
+            "separator. TCP hostnames cannot contain '/' or '\\' — did you "
+            "pass a serial port path or a Windows drive path by mistake?"
+        )
+    if not (1 <= tcp_port <= 65535):
+        raise ConnectionError(
+            f"Invalid TCP endpoint {port!r}: port {tcp_port} out of range "
+            "(must be 1..65535)."
+        )
+    return host, tcp_port
+
+
+def normalize_tcp_endpoint(endpoint: str) -> str:
+    r"""Normalize `host`, `host:port`, or `tcp://host[:port]` → canonical
+    `tcp://host:port` form. One place that owns the lock-key shape.
+
+    Defers all validation to `parse_tcp_port`, so path-like inputs
+    (`/dev/cu.foo`, `C:\Windows\…`), empty hosts, non-integer ports,
+    and out-of-range ports raise `ConnectionError` here too.
+    """
+    if endpoint.startswith(TCP_SCHEME):
+        canonical = endpoint
+    elif ":" in endpoint:
+        canonical = f"{TCP_SCHEME}{endpoint}"
+    else:
+        canonical = f"{TCP_SCHEME}{endpoint}:{DEFAULT_TCP_PORT}"
+    host, port = parse_tcp_port(canonical)
+    return f"{TCP_SCHEME}{host}:{port}"
+
+
+def reject_if_tcp(port: str | None, tool_name: str) -> None:
+    """Raise if `port` is a TCP endpoint — for tools that need real USB
+    hardware (flash, bootloader, vendor escape hatches, serial monitor).
+
+    Only checks the explicit arg; auto-selection via env var is the caller's
+    responsibility to handle if it matters.
+    """
+    if is_tcp_port(port):
+        raise ConnectionError(
+            f"{tool_name} is not applicable to TCP/native nodes ({port}). "
+            "This tool requires USB-attached hardware."
+        )
+
+
 def resolve_port(port: str | None) -> str:
-    """Pick a port: explicit > sole likely_meshtastic candidate > error."""
+    """Pick a port: explicit > sole likely_meshtastic candidate > error.
+
+    A `tcp://` string passes through (after canonicalization). When `port`
+    is None and no USB candidates are present, `MESHTASTIC_MCP_TCP_HOST`
+    is consulted via `devices.list_devices()`.
+    """
     if port:
+        if is_tcp_port(port):
+            return normalize_tcp_endpoint(port)
         return port
     candidates = [d for d in devices.list_devices() if d["likely_meshtastic"]]
     if not candidates:
         raise ConnectionError(
-            "No Meshtastic devices detected. Plug one in or pass `port` explicitly. "
+            "No Meshtastic devices detected. Plug one in, set "
-            "Run `list_devices` with include_unknown=True to see all serial ports."
+            f"{TCP_HOST_ENV}=<host[:port]> for a meshtasticd daemon, "
+            "or pass `port` explicitly. Run `list_devices` with "
+            "include_unknown=True to see all serial ports."
         )
     if len(candidates) > 1:
         ports = ", ".join(c["port"] for c in candidates)
@@ -43,17 +138,62 @@ def resolve_port(port: str | None) -> str:
 
 @contextmanager
 def connect(port: str | None = None, timeout_s: float = 8.0) -> Iterator:
-    """Open a `meshtastic.SerialInterface` and always close it.
+    """Open a meshtastic interface (serial or TCP) and always close it.
 
-    Raises `ConnectionError` immediately if another serial session holds the
+    For serial: raises `ConnectionError` immediately if another serial
-    port (a `pio device monitor` in `serial_sessions/`, for instance).
+    session holds the port (a `pio device monitor` in `serial_sessions/`).
+    For TCP: no exclusive-access requirement, so the serial-session check
+    is skipped — but the `port_lock` still serializes parallel `connect()`
+    calls to the same daemon endpoint.
+
+    `timeout_s` is plumbed through to both `SerialInterface(timeout=...)`
+    and `TCPInterface(timeout=...)`. The meshtastic library uses the value
+    as the reply-wait deadline for `localNode.waitForConfig()` during
+    construction and for any subsequent admin RPC. `int()`-converted at
+    the boundary because the upstream API expects whole seconds.
     """
+    resolved = resolve_port(port)
+    timeout = int(timeout_s)
+
+    if is_tcp_port(resolved):
+        from meshtastic.tcp_interface import (
+            TCPInterface,  # type: ignore[import-untyped]
+        )
+
+        host, tcp_port = parse_tcp_port(resolved)
+        lock = registry.port_lock(resolved)
+        if not lock.acquire(blocking=False):
+            raise ConnectionError(
+                f"TCP endpoint {resolved} is busy — another device operation "
+                "is in flight. Retry shortly."
+            )
+
+        iface = None
+        try:
+            iface = TCPInterface(
+                hostname=host,
+                portNumber=tcp_port,
+                connectNow=True,
+                noProto=False,
+                timeout=timeout,
+            )
+            yield iface
+        finally:
+            if iface is not None:
+                try:
+                    iface.close()
+                except Exception:
+                    pass
+            try:
+                lock.release()
+            except RuntimeError:
+                pass
+        return
+
     from meshtastic.serial_interface import (
         SerialInterface,  # type: ignore[import-untyped]
     )
 
-    resolved = resolve_port(port)
-
     active = registry.active_session_for_port(resolved)
     if active is not None:
         raise ConnectionError(
@@ -70,7 +210,12 @@ def connect(port: str | None = None, timeout_s: float = 8.0) -> Iterator:
 
     iface = None
     try:
-        iface = SerialInterface(devPath=resolved, connectNow=True, noProto=False)
+        iface = SerialInterface(
+            devPath=resolved,
+            connectNow=True,
+            noProto=False,
+            timeout=timeout,
+        )
         yield iface
     finally:
         if iface is not None:

mcp-server/src/meshtastic_mcp/devices.py

@@ -1,13 +1,18 @@
-"""USB/serial device discovery.
+"""USB/serial + TCP device discovery.
 
 Combines the canonical `meshtastic.util.findPorts()` allowlist/blocklist with
 the richer metadata (`serial.tools.list_ports.comports()`) so callers see
 VID/PID, descriptions, and manufacturer strings alongside the "is this likely
 a Meshtastic device" signal.
+
+If `MESHTASTIC_MCP_TCP_HOST=<host[:port]>` is set, a synthetic entry for the
+`meshtasticd` daemon at that endpoint is prepended to the result, so
+`resolve_port(None)` auto-selects it like a USB candidate.
 """
 
 from __future__ import annotations
 
+import os
 from typing import Any
 
 from serial.tools import list_ports
@@ -19,6 +24,45 @@ def _to_hex(value: int | None) -> str | None:
     return f"0x{value:04x}"
 
 
+def _tcp_endpoint_from_env() -> dict[str, Any] | None:
+    """Synthesize a TCP device entry from MESHTASTIC_MCP_TCP_HOST, if set.
+
+    If the env var is malformed (non-integer port, path-like host, etc.),
+    return an entry with `likely_meshtastic=False` and the parser error in
+    the description, rather than raising — `list_devices` is the diagnostic
+    tool a user reaches for when their env var isn't working, so it must
+    not crash on misconfiguration.
+    """
+    host = os.environ.get("MESHTASTIC_MCP_TCP_HOST")
+    if not host:
+        return None
+    # Lazy import to avoid a circular dependency (connection imports devices).
+    from . import connection
+
+    try:
+        port = connection.normalize_tcp_endpoint(host)
+        description = "meshtasticd (TCP)"
+        likely = True
+    except connection.ConnectionError as e:
+        # Surface the raw env-var value plus the parser's reason so the
+        # user can see exactly what they set and why it was rejected.
+        # Don't double the scheme if the user already prefixed `tcp://`.
+        port = host if host.startswith(connection.TCP_SCHEME) else f"tcp://{host}"
+        description = f"meshtasticd (TCP) — invalid MESHTASTIC_MCP_TCP_HOST: {e}"
+        likely = False
+    return {
+        "port": port,
+        "vid": None,
+        "pid": None,
+        "description": description,
+        "manufacturer": None,
+        "product": None,
+        "serial_number": None,
+        "likely_meshtastic": likely,
+        "blacklisted": False,
+    }
+
+
 def list_devices(include_unknown: bool = False) -> list[dict[str, Any]]:
     """Return enriched info for serial ports, flagging Meshtastic candidates.
 
@@ -70,6 +114,22 @@ def list_devices(include_unknown: bool = False) -> list[dict[str, Any]]:
             }
         )
 
-    # Stable ordering: likely_meshtastic first, then by port path
+    # Append the TCP endpoint (if env var set) and sort everything together.
-    results.sort(key=lambda r: (not r["likely_meshtastic"], r["port"]))
+    tcp_entry = _tcp_endpoint_from_env()
+    if tcp_entry is not None:
+        results.append(tcp_entry)
+
+    # Stable ordering: likely_meshtastic first; within rank, TCP wins over
+    # USB (explicit env-var configuration takes precedence over USB
+    # enumeration); then by port path. A misconfigured TCP entry has
+    # likely_meshtastic=False and lands among the other ignored entries —
+    # it does NOT pre-empt real USB devices at the top of the list.
+    results.sort(
+        key=lambda r: (
+            not r["likely_meshtastic"],
+            not r["port"].startswith("tcp://"),
+            r["port"],
+        )
+    )
+
     return results

mcp-server/src/meshtastic_mcp/flash.py

@@ -17,7 +17,7 @@ from typing import Any
 
 import serial
 
-from . import boards, config, devices, pio, userprefs
+from . import boards, config, connection, devices, pio, userprefs
 
 # Meshtastic variants use both `esp32s3` and `esp32-s3` style names across
 # variants/*/platformio.ini (no consistency enforced). Accept both spellings.
@@ -46,6 +46,18 @@ def _require_confirm(confirm: bool, operation: str) -> None:
         )
 
 
+def _reject_native_env(env: str, operation: str) -> None:
+    """`native*` envs build a host executable, not firmware — there's no
+    upload step. The user wants `build` (or just runs the binary directly).
+    """
+    if env.startswith("native"):
+        raise FlashError(
+            f"{operation} is not applicable for env {env!r}: native envs "
+            "produce a host executable, not flashable firmware. Use `build` "
+            "instead, then run the resulting binary directly."
+        )
+
+
 def _artifacts_for(env: str) -> list[Path]:
     build_dir = config.firmware_root() / ".pio" / "build" / env
     if not build_dir.is_dir():
@@ -141,6 +153,8 @@ def flash(
     that pio performs will pick up the injected values.
     """
     _require_confirm(confirm, "flash")
+    _reject_native_env(env, "flash")
+    connection.reject_if_tcp(port, "flash")
     with userprefs.temporary_overrides(userprefs_overrides) as effective:
         result = pio.run(
             ["run", "-e", env, "-t", "upload", "--upload-port", port],
@@ -200,6 +214,7 @@ def erase_and_flash(
     in that case) since a cached factory.bin would not reflect the new prefs.
     """
     _require_confirm(confirm, "erase_and_flash")
+    connection.reject_if_tcp(port, "erase_and_flash")
     _check_esp32_env(env)
 
     if userprefs_overrides and skip_build:
@@ -257,6 +272,7 @@ def update_flash(
     overrides are provided we always force a rebuild.
     """
     _require_confirm(confirm, "update_flash")
+    connection.reject_if_tcp(port, "update_flash")
     _check_esp32_env(env)
 
     if userprefs_overrides and skip_build:
@@ -391,6 +407,7 @@ def touch_1200bps(
 
     Returns `{ok, former_port, new_port, new_port_vid_pid, attempts}`.
     """
+    connection.reject_if_tcp(port, "touch_1200bps")
     before_list = devices.list_devices(include_unknown=True)
     before_ports = {d["port"] for d in before_list}
 

mcp-server/src/meshtastic_mcp/hw_tools.py

@@ -16,7 +16,7 @@ import subprocess
 from pathlib import Path
 from typing import Any, Sequence
 
-from . import config, pio
+from . import config, connection, pio
 
 _TIMEOUT_SHORT = 30
 _TIMEOUT_LONG = 600
@@ -102,6 +102,7 @@ def _parse_esptool_chip_info(stdout: str) -> dict[str, Any]:
 
 
 def esptool_chip_info(port: str) -> dict[str, Any]:
+    connection.reject_if_tcp(port, "esptool_chip_info")
     binary = config.esptool_bin()
     # `chip_id` prints chip + mac + crystal + features. `flash_id` adds flash.
     combined = _run(binary, ["--port", port, "flash_id"], timeout=_TIMEOUT_SHORT)
@@ -116,6 +117,7 @@ def esptool_chip_info(port: str) -> dict[str, Any]:
 def esptool_erase_flash(port: str, confirm: bool = False) -> dict[str, Any]:
     """Full-chip erase. Leaves the device unbootable until reflashed."""
     _require_confirm(confirm, "esptool_erase_flash")
+    connection.reject_if_tcp(port, "esptool_erase_flash")
     binary = config.esptool_bin()
     # esptool v5 uses `erase-flash`, older uses `erase_flash`. Try the new name
     # first; if it fails with unknown command, retry old.
@@ -134,6 +136,7 @@ def esptool_raw(
     """Raw esptool passthrough. Destructive subcommands require confirm=True."""
     if not args:
         raise ToolError("args must not be empty")
+    connection.reject_if_tcp(port, "esptool_raw")
     # Find the first non-flag arg (the subcommand).
     subcommand = next((a for a in args if not a.startswith("-")), None)
     if subcommand and subcommand.replace("-", "_") in {
@@ -156,6 +159,7 @@ NRFUTIL_DESTRUCTIVE = {"dfu", "settings"}
 
 def nrfutil_dfu(port: str, package_path: str, confirm: bool = False) -> dict[str, Any]:
     _require_confirm(confirm, "nrfutil_dfu")
+    connection.reject_if_tcp(port, "nrfutil_dfu")
     pkg = Path(package_path).expanduser()
     if not pkg.is_file():
         raise ToolError(f"Package not found: {pkg}")
@@ -213,6 +217,7 @@ def _parse_picotool_info(stdout: str) -> dict[str, Any]:
 def picotool_info(port: str | None = None) -> dict[str, Any]:
     """Read device info from a Pico in BOOTSEL mode. `port` is informational
     only — picotool auto-detects."""
+    connection.reject_if_tcp(port, "picotool_info")
     binary = config.picotool_bin()
     res = _run(binary, ["info", "-a"], timeout=_TIMEOUT_SHORT)
     if res["exit_code"] != 0:

mcp-server/src/meshtastic_mcp/serial_session.py

@@ -71,6 +71,10 @@ def open_session(
     If `env` is supplied, pio resolves baud and filters from platformio.ini.
     Otherwise uses the supplied `baud` and `filters` (default `['direct']`).
     """
+    # Lazy import to avoid circular: registry imports serial_session.
+    from . import connection
+
+    connection.reject_if_tcp(port, "serial_open")
     args = ["device", "monitor", "--port", port, "--no-reconnect"]
     effective_filters: list[str]
     effective_baud: int = baud

mcp-server/tests/unit/test_connection_tcp.py

@@ -0,0 +1,383 @@
+"""TCP transport plumbing in connection.py + devices.py.
+
+Pure-Python tests — no real device or daemon required. Mocks `TCPInterface`
+when exercising `connect()`.
+"""
+
+from __future__ import annotations
+
+from unittest.mock import patch
+
+import pytest
+from meshtastic_mcp import connection, devices
+
+# ---------- helpers --------------------------------------------------------
+
+
+class TestIsTcpPort:
+    def test_tcp_scheme(self) -> None:
+        assert connection.is_tcp_port("tcp://localhost") is True
+        assert connection.is_tcp_port("tcp://localhost:4403") is True
+        assert connection.is_tcp_port("tcp://192.168.1.50:9999") is True
+
+    def test_serial_paths(self) -> None:
+        assert connection.is_tcp_port("/dev/cu.usbmodem1234") is False
+        assert connection.is_tcp_port("/dev/ttyUSB0") is False
+        assert connection.is_tcp_port("COM3") is False
+
+    def test_empty_or_none(self) -> None:
+        assert connection.is_tcp_port(None) is False
+        assert connection.is_tcp_port("") is False
+
+
+class TestParseTcpPort:
+    def test_default_port(self) -> None:
+        assert connection.parse_tcp_port("tcp://localhost") == ("localhost", 4403)
+
+    def test_explicit_port(self) -> None:
+        assert connection.parse_tcp_port("tcp://localhost:9999") == (
+            "localhost",
+            9999,
+        )
+
+    def test_ip_with_port(self) -> None:
+        assert connection.parse_tcp_port("tcp://192.168.1.50:4403") == (
+            "192.168.1.50",
+            4403,
+        )
+
+
+class TestNormalizeTcpEndpoint:
+    def test_bare_host(self) -> None:
+        assert connection.normalize_tcp_endpoint("localhost") == "tcp://localhost:4403"
+
+    def test_host_port(self) -> None:
+        assert (
+            connection.normalize_tcp_endpoint("localhost:5000")
+            == "tcp://localhost:5000"
+        )
+
+    def test_full_url(self) -> None:
+        assert (
+            connection.normalize_tcp_endpoint("tcp://1.2.3.4") == "tcp://1.2.3.4:4403"
+        )
+        assert (
+            connection.normalize_tcp_endpoint("tcp://1.2.3.4:9999")
+            == "tcp://1.2.3.4:9999"
+        )
+
+    def test_idempotent(self) -> None:
+        once = connection.normalize_tcp_endpoint("localhost:4403")
+        twice = connection.normalize_tcp_endpoint(once)
+        assert once == twice == "tcp://localhost:4403"
+
+    def test_path_like_endpoint_rejected(self) -> None:
+        # Serial port paths and Windows drive paths are common config typos
+        # (someone passes a serial path to MESHTASTIC_MCP_TCP_HOST). Reject
+        # rather than producing a nonsense `tcp:///dev/cu.foo:4403` URL.
+        with pytest.raises(connection.ConnectionError, match="path separator"):
+            connection.normalize_tcp_endpoint("/dev/cu.foo")
+        with pytest.raises(connection.ConnectionError):
+            connection.normalize_tcp_endpoint("tcp:///dev/cu.foo:4403")
+        with pytest.raises(connection.ConnectionError):
+            connection.normalize_tcp_endpoint(r"C:\Windows\System32")
+
+    def test_non_integer_port_rejected(self) -> None:
+        with pytest.raises(connection.ConnectionError, match="not an integer"):
+            connection.normalize_tcp_endpoint("tcp://host:notaport")
+        with pytest.raises(connection.ConnectionError, match="not an integer"):
+            connection.normalize_tcp_endpoint("host:notaport")
+
+    def test_empty_host_rejected(self) -> None:
+        with pytest.raises(connection.ConnectionError, match="empty host"):
+            connection.normalize_tcp_endpoint("tcp://:4403")
+
+    def test_port_out_of_range_rejected(self) -> None:
+        with pytest.raises(connection.ConnectionError, match="out of range"):
+            connection.normalize_tcp_endpoint("tcp://host:0")
+        with pytest.raises(connection.ConnectionError, match="out of range"):
+            connection.normalize_tcp_endpoint("tcp://host:65536")
+        with pytest.raises(connection.ConnectionError, match="out of range"):
+            connection.normalize_tcp_endpoint("host:99999")
+
+
+class TestParseTcpPortValidation:
+    def test_missing_scheme_rejected(self) -> None:
+        # parse_tcp_port is a low-level helper that requires the scheme.
+        # Misuse should fail loudly rather than silently mis-parsing.
+        with pytest.raises(connection.ConnectionError, match="expected"):
+            connection.parse_tcp_port("localhost:4403")
+
+    def test_negative_port_rejected(self) -> None:
+        with pytest.raises(connection.ConnectionError, match="out of range"):
+            connection.parse_tcp_port("tcp://host:-1")
+
+
+# ---------- reject_if_tcp --------------------------------------------------
+
+
+class TestRejectIfTcp:
+    def test_rejects_tcp(self) -> None:
+        with pytest.raises(connection.ConnectionError, match="not applicable"):
+            connection.reject_if_tcp("tcp://localhost", "esptool_chip_info")
+
+    def test_passes_through_serial(self) -> None:
+        connection.reject_if_tcp("/dev/cu.usbmodem1", "esptool_chip_info")  # no raise
+
+    def test_passes_through_none(self) -> None:
+        # None means "auto-detect"; not the explicit-arg case we guard.
+        connection.reject_if_tcp(None, "esptool_chip_info")  # no raise
+
+
+# ---------- resolve_port ---------------------------------------------------
+
+
+class TestResolvePort:
+    def test_explicit_serial_passthrough(self) -> None:
+        assert connection.resolve_port("/dev/cu.usbmodem999") == "/dev/cu.usbmodem999"
+
+    def test_explicit_tcp_normalized(self) -> None:
+        assert connection.resolve_port("tcp://localhost") == "tcp://localhost:4403"
+
+    def test_no_port_no_devices_errors(self, monkeypatch: pytest.MonkeyPatch) -> None:
+        monkeypatch.delenv("MESHTASTIC_MCP_TCP_HOST", raising=False)
+        with patch.object(devices, "list_devices", return_value=[]):
+            with pytest.raises(
+                connection.ConnectionError, match="No Meshtastic devices"
+            ):
+                connection.resolve_port(None)
+
+    def test_no_port_one_candidate_selected(
+        self, monkeypatch: pytest.MonkeyPatch
+    ) -> None:
+        monkeypatch.delenv("MESHTASTIC_MCP_TCP_HOST", raising=False)
+        fake = [{"port": "/dev/cu.usbmodem1", "likely_meshtastic": True}]
+        with patch.object(devices, "list_devices", return_value=fake):
+            assert connection.resolve_port(None) == "/dev/cu.usbmodem1"
+
+    def test_no_port_multiple_candidates_errors(
+        self, monkeypatch: pytest.MonkeyPatch
+    ) -> None:
+        monkeypatch.delenv("MESHTASTIC_MCP_TCP_HOST", raising=False)
+        fake = [
+            {"port": "/dev/cu.usbmodem1", "likely_meshtastic": True},
+            {"port": "/dev/cu.usbmodem2", "likely_meshtastic": True},
+        ]
+        with patch.object(devices, "list_devices", return_value=fake):
+            with pytest.raises(connection.ConnectionError, match="Multiple"):
+                connection.resolve_port(None)
+
+    def test_env_var_surfaces_tcp_via_devices(
+        self, monkeypatch: pytest.MonkeyPatch
+    ) -> None:
+        monkeypatch.setenv("MESHTASTIC_MCP_TCP_HOST", "localhost")
+        # Don't patch list_devices — let the real env-var path run, but stub
+        # the USB enumeration to keep the test hermetic.
+        with patch("meshtastic_mcp.devices.list_ports.comports", return_value=[]):
+            assert connection.resolve_port(None) == "tcp://localhost:4403"
+
+
+# ---------- devices.list_devices TCP entry --------------------------------
+
+
+class TestDevicesTcpEntry:
+    def test_no_env_var_no_tcp_entry(self, monkeypatch: pytest.MonkeyPatch) -> None:
+        monkeypatch.delenv("MESHTASTIC_MCP_TCP_HOST", raising=False)
+        with patch("meshtastic_mcp.devices.list_ports.comports", return_value=[]):
+            ds = devices.list_devices()
+        assert all(not d["port"].startswith("tcp://") for d in ds)
+
+    def test_env_var_adds_tcp_entry(self, monkeypatch: pytest.MonkeyPatch) -> None:
+        monkeypatch.setenv("MESHTASTIC_MCP_TCP_HOST", "myhost:9999")
+        with patch("meshtastic_mcp.devices.list_ports.comports", return_value=[]):
+            ds = devices.list_devices()
+        tcp = [d for d in ds if d["port"].startswith("tcp://")]
+        assert len(tcp) == 1
+        assert tcp[0]["port"] == "tcp://myhost:9999"
+        assert tcp[0]["likely_meshtastic"] is True
+        assert tcp[0]["description"] == "meshtasticd (TCP)"
+
+    def test_tcp_entry_first_in_results(self, monkeypatch: pytest.MonkeyPatch) -> None:
+        monkeypatch.setenv("MESHTASTIC_MCP_TCP_HOST", "localhost")
+        with patch("meshtastic_mcp.devices.list_ports.comports", return_value=[]):
+            ds = devices.list_devices()
+        assert ds, "expected at least the TCP entry"
+        assert ds[0]["port"].startswith("tcp://")
+
+    def test_invalid_env_var_does_not_break_list_devices(
+        self, monkeypatch: pytest.MonkeyPatch
+    ) -> None:
+        # `list_devices` is the diagnostic tool reached for when an env var
+        # isn't working — it must not throw on misconfiguration.
+        monkeypatch.setenv("MESHTASTIC_MCP_TCP_HOST", "host:notaport")
+        with patch("meshtastic_mcp.devices.list_ports.comports", return_value=[]):
+            ds = devices.list_devices(include_unknown=True)
+        tcp = [d for d in ds if "TCP" in (d["description"] or "")]
+        assert len(tcp) == 1
+        assert tcp[0]["likely_meshtastic"] is False
+        assert "invalid MESHTASTIC_MCP_TCP_HOST" in tcp[0]["description"]
+        assert "not an integer" in tcp[0]["description"]
+
+    def test_invalid_env_var_excluded_from_resolve_port_autodetect(
+        self, monkeypatch: pytest.MonkeyPatch
+    ) -> None:
+        # `likely_meshtastic=False` keeps the bad TCP entry out of the
+        # auto-select path — `resolve_port(None)` should still report
+        # "no Meshtastic devices" rather than picking a broken endpoint.
+        monkeypatch.setenv("MESHTASTIC_MCP_TCP_HOST", "host:notaport")
+        with patch("meshtastic_mcp.devices.list_ports.comports", return_value=[]):
+            with pytest.raises(connection.ConnectionError, match="No Meshtastic"):
+                connection.resolve_port(None)
+
+    def test_invalid_env_var_does_not_double_tcp_scheme(
+        self, monkeypatch: pytest.MonkeyPatch
+    ) -> None:
+        # If a user mistakenly sets `MESHTASTIC_MCP_TCP_HOST=tcp://host:bad`,
+        # the diagnostic entry must surface the raw value as-is rather than
+        # producing `tcp://tcp://host:bad`.
+        monkeypatch.setenv("MESHTASTIC_MCP_TCP_HOST", "tcp://host:notaport")
+        with patch("meshtastic_mcp.devices.list_ports.comports", return_value=[]):
+            ds = devices.list_devices(include_unknown=True)
+        tcp = [d for d in ds if "TCP" in (d["description"] or "")]
+        assert len(tcp) == 1
+        assert tcp[0]["port"] == "tcp://host:notaport"
+        assert "tcp://tcp://" not in tcp[0]["port"]
+
+    def test_invalid_env_var_does_not_pre_empt_real_usb_devices(
+        self, monkeypatch: pytest.MonkeyPatch
+    ) -> None:
+        # Sort ordering: a misconfigured TCP env var must NOT take position 0
+        # ahead of real USB candidates. Position 0 is reserved for the highest
+        # rank (likely_meshtastic=True), with TCP-before-USB as a tiebreaker
+        # within rank.
+        monkeypatch.setenv("MESHTASTIC_MCP_TCP_HOST", "host:notaport")
+
+        # Stub a USB Meshtastic candidate (Espressif VID, port present in
+        # findPorts).
+        class FakeInfo:
+            def __init__(self, device: str, vid: int, pid: int) -> None:
+                self.device = device
+                self.vid = vid
+                self.pid = pid
+                self.description = "Heltec V3"
+                self.manufacturer = "Espressif"
+                self.product = "USB JTAG/serial"
+                self.serial_number = "abc"
+
+        fake_port = FakeInfo("/dev/cu.usbmodem4201", 0x303A, 0x1001)
+        with patch(
+            "meshtastic_mcp.devices.list_ports.comports", return_value=[fake_port]
+        ), patch(
+            "meshtastic.util.findPorts",
+            return_value=["/dev/cu.usbmodem4201"],
+        ):
+            ds = devices.list_devices(include_unknown=True)
+
+        assert ds, "expected at least the USB + TCP entries"
+        # Real USB candidate must be at position 0 — it's likely_meshtastic.
+        assert ds[0]["port"] == "/dev/cu.usbmodem4201"
+        assert ds[0]["likely_meshtastic"] is True
+        # The malformed TCP entry exists but lands among the unlikely entries.
+        tcp = [d for d in ds if "TCP" in (d["description"] or "")]
+        assert len(tcp) == 1
+        assert tcp[0]["likely_meshtastic"] is False
+        assert ds.index(tcp[0]) > 0
+
+    def test_likely_tcp_entry_wins_tiebreak_over_usb(
+        self, monkeypatch: pytest.MonkeyPatch
+    ) -> None:
+        # Conversely, a *valid* TCP env var should sort ahead of USB
+        # candidates of equal likely_meshtastic rank — explicit env-var
+        # configuration is a precedence signal.
+        monkeypatch.setenv("MESHTASTIC_MCP_TCP_HOST", "localhost:4403")
+
+        class FakeInfo:
+            def __init__(self, device: str, vid: int, pid: int) -> None:
+                self.device = device
+                self.vid = vid
+                self.pid = pid
+                self.description = "Heltec V3"
+                self.manufacturer = "Espressif"
+                self.product = "USB JTAG/serial"
+                self.serial_number = "abc"
+
+        fake_port = FakeInfo("/dev/cu.usbmodem4201", 0x303A, 0x1001)
+        with patch(
+            "meshtastic_mcp.devices.list_ports.comports", return_value=[fake_port]
+        ), patch(
+            "meshtastic.util.findPorts",
+            return_value=["/dev/cu.usbmodem4201"],
+        ):
+            ds = devices.list_devices()
+
+        assert ds[0]["port"] == "tcp://localhost:4403"
+        assert ds[0]["likely_meshtastic"] is True
+
+
+# ---------- connect() routing ---------------------------------------------
+
+
+class TestConnectRoutesTcp:
+    def test_connect_uses_tcp_interface_for_tcp_port(
+        self, monkeypatch: pytest.MonkeyPatch
+    ) -> None:
+        """Verify the TCP branch instantiates `TCPInterface(hostname, portNumber)`
+        and never touches `SerialInterface`."""
+        # Make sure the env var doesn't leak in and confuse resolve_port.
+        monkeypatch.delenv("MESHTASTIC_MCP_TCP_HOST", raising=False)
+
+        with patch("meshtastic.tcp_interface.TCPInterface") as mock_tcp, patch(
+            "meshtastic.serial_interface.SerialInterface"
+        ) as mock_serial:
+            mock_tcp.return_value.close.return_value = None
+            with connection.connect(port="tcp://example.com:1234", timeout_s=12.0):
+                pass
+
+        mock_tcp.assert_called_once_with(
+            hostname="example.com",
+            portNumber=1234,
+            connectNow=True,
+            noProto=False,
+            timeout=12,
+        )
+        mock_serial.assert_not_called()
+
+    def test_connect_plumbs_timeout_to_serial_interface(
+        self, monkeypatch: pytest.MonkeyPatch
+    ) -> None:
+        """Verify the serial branch also propagates `timeout_s` so callers
+        passing a custom timeout to `device_info` / `list_nodes` / etc. don't
+        silently get the library default."""
+        monkeypatch.delenv("MESHTASTIC_MCP_TCP_HOST", raising=False)
+
+        with patch("meshtastic.serial_interface.SerialInterface") as mock_serial, patch(
+            "meshtastic.tcp_interface.TCPInterface"
+        ) as mock_tcp:
+            mock_serial.return_value.close.return_value = None
+            with connection.connect(port="/dev/cu.fake", timeout_s=20.0):
+                pass
+
+        mock_serial.assert_called_once_with(
+            devPath="/dev/cu.fake",
+            connectNow=True,
+            noProto=False,
+            timeout=20,
+        )
+        mock_tcp.assert_not_called()
+
+    def test_connect_releases_lock_on_tcp_failure(
+        self, monkeypatch: pytest.MonkeyPatch
+    ) -> None:
+        monkeypatch.delenv("MESHTASTIC_MCP_TCP_HOST", raising=False)
+        with patch("meshtastic.tcp_interface.TCPInterface") as mock_tcp:
+            mock_tcp.side_effect = RuntimeError("boom")
+            with pytest.raises(RuntimeError, match="boom"):
+                with connection.connect(port="tcp://locktest:4403"):
+                    pass
+
+        # Lock should be released — a second connect attempt must not fail
+        # with "busy".
+        with patch("meshtastic.tcp_interface.TCPInterface") as mock_tcp:
+            mock_tcp.return_value.close.return_value = None
+            with connection.connect(port="tcp://locktest:4403"):
+                pass

platformio.ini

@@ -126,7 +126,7 @@ lib_deps =
 [device-ui_base]
 lib_deps =
 	# renovate: datasource=git-refs depName=meshtastic/device-ui packageName=https://github.com/meshtastic/device-ui gitBranch=master
-	https://github.com/meshtastic/device-ui/archive/1ddcc9da2e60c013d6fc515fb73fb63fac75f9fd.zip
+	https://github.com/meshtastic/device-ui/archive/4bf593a82100b911ff816dddf7158ffdee2114cd.zip
 
 ; Common libs for environmental measurements in telemetry module
 [environmental_base]

src/mesh/PhoneAPI.cpp

@@ -512,11 +512,6 @@ size_t PhoneAPI::getFromRadio(uint8_t *buf)
             // LOG_INFO("nodeinfo: num=0x%x, lastseen=%u, id=%s, name=%s", nodeInfoForPhone.num, nodeInfoForPhone.last_heard,
             // nodeInfoForPhone.user.id, nodeInfoForPhone.user.long_name);
 
-            // Occasional progress logging. (readIndex==2 will be true for the first non-us node)
-            if (readIndex == 2 || readIndex % 20 == 0) {
-                LOG_DEBUG("nodeinfo: %d/%d", readIndex, nodeDB->getNumMeshNodes());
-            }
-
             fromRadioScratch.which_payload_variant = meshtastic_FromRadio_node_info_tag;
             fromRadioScratch.node_info = infoToSend;
             prefetchNodeInfos();
@@ -647,9 +642,11 @@ void PhoneAPI::releaseQueueStatusPhonePacket()
 void PhoneAPI::prefetchNodeInfos()
 {
     bool added = false;
+    bool wasEmpty = false;
     // Keep the queue topped up so BLE reads stay responsive even if DB fetches take a moment.
     {
         concurrency::LockGuard guard(&nodeInfoMutex);
+        wasEmpty = nodeInfoQueue.empty();
         while (nodeInfoQueue.size() < kNodePrefetchDepth) {
             auto nextNode = nodeDB->readNextMeshNode(readIndex);
             if (!nextNode)
@@ -663,11 +660,15 @@ void PhoneAPI::prefetchNodeInfos()
             info.via_mqtt = isUs ? false : info.via_mqtt;
             info.is_favorite = info.is_favorite || isUs;
             nodeInfoQueue.push_back(info);
+            // Log progress here (at fetch time) so readIndex is accurate and each value logs only once.
+            if (readIndex == 2 || readIndex % 20 == 0) {
+                LOG_DEBUG("nodeinfo: %d/%d", readIndex, nodeDB->getNumMeshNodes());
+            }
             added = true;
         }
     }
 
-    if (added)
+    if (added && wasEmpty)
         onNowHasData(0);
 }
 

src/mesh/generated/meshtastic/apponly.pb.h

@@ -55,7 +55,7 @@ extern const pb_msgdesc_t meshtastic_ChannelSet_msg;
 
 /* Maximum encoded size of messages (where known) */
 #define MESHTASTIC_MESHTASTIC_APPONLY_PB_H_MAX_SIZE meshtastic_ChannelSet_size
-#define meshtastic_ChannelSet_size               682
+#define meshtastic_ChannelSet_size               685
 
 #ifdef __cplusplus
 } /* extern "C" */

src/mesh/generated/meshtastic/config.pb.h

@@ -618,6 +618,8 @@ typedef struct _meshtastic_Config_LoRaConfig {
     bool config_ok_to_mqtt;
     /* Set where LORA FEM is enabled, disabled, or not present */
     meshtastic_Config_LoRaConfig_FEM_LNA_Mode fem_lna_mode;
+    /* Don't use radiolib to initialize the radio, instead listen for a serialHal connection */
+    bool serial_hal_only;
 } meshtastic_Config_LoRaConfig;
 
 typedef struct _meshtastic_Config_BluetoothConfig {
@@ -779,7 +781,7 @@ extern "C" {
 #define meshtastic_Config_NetworkConfig_init_default {0, "", "", "", 0, _meshtastic_Config_NetworkConfig_AddressMode_MIN, false, meshtastic_Config_NetworkConfig_IpV4Config_init_default, "", 0, 0}
 #define meshtastic_Config_NetworkConfig_IpV4Config_init_default {0, 0, 0, 0}
 #define meshtastic_Config_DisplayConfig_init_default {0, _meshtastic_Config_DisplayConfig_DeprecatedGpsCoordinateFormat_MIN, 0, 0, 0, _meshtastic_Config_DisplayConfig_DisplayUnits_MIN, _meshtastic_Config_DisplayConfig_OledType_MIN, _meshtastic_Config_DisplayConfig_DisplayMode_MIN, 0, 0, _meshtastic_Config_DisplayConfig_CompassOrientation_MIN, 0, 0, 0}
-#define meshtastic_Config_LoRaConfig_init_default {0, _meshtastic_Config_LoRaConfig_ModemPreset_MIN, 0, 0, 0, 0, _meshtastic_Config_LoRaConfig_RegionCode_MIN, 0, 0, 0, 0, 0, 0, 0, 0, 0, {0, 0, 0}, 0, 0, _meshtastic_Config_LoRaConfig_FEM_LNA_Mode_MIN}
+#define meshtastic_Config_LoRaConfig_init_default {0, _meshtastic_Config_LoRaConfig_ModemPreset_MIN, 0, 0, 0, 0, _meshtastic_Config_LoRaConfig_RegionCode_MIN, 0, 0, 0, 0, 0, 0, 0, 0, 0, {0, 0, 0}, 0, 0, _meshtastic_Config_LoRaConfig_FEM_LNA_Mode_MIN, 0}
 #define meshtastic_Config_BluetoothConfig_init_default {0, _meshtastic_Config_BluetoothConfig_PairingMode_MIN, 0}
 #define meshtastic_Config_SecurityConfig_init_default {{0, {0}}, {0, {0}}, 0, {{0, {0}}, {0, {0}}, {0, {0}}}, 0, 0, 0, 0}
 #define meshtastic_Config_SessionkeyConfig_init_default {0}
@@ -790,7 +792,7 @@ extern "C" {
 #define meshtastic_Config_NetworkConfig_init_zero {0, "", "", "", 0, _meshtastic_Config_NetworkConfig_AddressMode_MIN, false, meshtastic_Config_NetworkConfig_IpV4Config_init_zero, "", 0, 0}
 #define meshtastic_Config_NetworkConfig_IpV4Config_init_zero {0, 0, 0, 0}
 #define meshtastic_Config_DisplayConfig_init_zero {0, _meshtastic_Config_DisplayConfig_DeprecatedGpsCoordinateFormat_MIN, 0, 0, 0, _meshtastic_Config_DisplayConfig_DisplayUnits_MIN, _meshtastic_Config_DisplayConfig_OledType_MIN, _meshtastic_Config_DisplayConfig_DisplayMode_MIN, 0, 0, _meshtastic_Config_DisplayConfig_CompassOrientation_MIN, 0, 0, 0}
-#define meshtastic_Config_LoRaConfig_init_zero   {0, _meshtastic_Config_LoRaConfig_ModemPreset_MIN, 0, 0, 0, 0, _meshtastic_Config_LoRaConfig_RegionCode_MIN, 0, 0, 0, 0, 0, 0, 0, 0, 0, {0, 0, 0}, 0, 0, _meshtastic_Config_LoRaConfig_FEM_LNA_Mode_MIN}
+#define meshtastic_Config_LoRaConfig_init_zero   {0, _meshtastic_Config_LoRaConfig_ModemPreset_MIN, 0, 0, 0, 0, _meshtastic_Config_LoRaConfig_RegionCode_MIN, 0, 0, 0, 0, 0, 0, 0, 0, 0, {0, 0, 0}, 0, 0, _meshtastic_Config_LoRaConfig_FEM_LNA_Mode_MIN, 0}
 #define meshtastic_Config_BluetoothConfig_init_zero {0, _meshtastic_Config_BluetoothConfig_PairingMode_MIN, 0}
 #define meshtastic_Config_SecurityConfig_init_zero {{0, {0}}, {0, {0}}, 0, {{0, {0}}, {0, {0}}, {0, {0}}}, 0, 0, 0, 0}
 #define meshtastic_Config_SessionkeyConfig_init_zero {0}
@@ -877,6 +879,7 @@ extern "C" {
 #define meshtastic_Config_LoRaConfig_ignore_mqtt_tag 104
 #define meshtastic_Config_LoRaConfig_config_ok_to_mqtt_tag 105
 #define meshtastic_Config_LoRaConfig_fem_lna_mode_tag 106
+#define meshtastic_Config_LoRaConfig_serial_hal_only_tag 107
 #define meshtastic_Config_BluetoothConfig_enabled_tag 1
 #define meshtastic_Config_BluetoothConfig_mode_tag 2
 #define meshtastic_Config_BluetoothConfig_fixed_pin_tag 3
@@ -1029,7 +1032,8 @@ X(a, STATIC,   SINGULAR, BOOL,     pa_fan_disabled,  15) \
 X(a, STATIC,   REPEATED, UINT32,   ignore_incoming, 103) \
 X(a, STATIC,   SINGULAR, BOOL,     ignore_mqtt,     104) \
 X(a, STATIC,   SINGULAR, BOOL,     config_ok_to_mqtt, 105) \
-X(a, STATIC,   SINGULAR, UENUM,    fem_lna_mode,    106)
+X(a, STATIC,   SINGULAR, UENUM,    fem_lna_mode,    106) \
+X(a, STATIC,   SINGULAR, BOOL,     serial_hal_only, 107)
 #define meshtastic_Config_LoRaConfig_CALLBACK NULL
 #define meshtastic_Config_LoRaConfig_DEFAULT NULL
 
@@ -1086,7 +1090,7 @@ extern const pb_msgdesc_t meshtastic_Config_SessionkeyConfig_msg;
 #define meshtastic_Config_BluetoothConfig_size   10
 #define meshtastic_Config_DeviceConfig_size      100
 #define meshtastic_Config_DisplayConfig_size     36
-#define meshtastic_Config_LoRaConfig_size        88
+#define meshtastic_Config_LoRaConfig_size        91
 #define meshtastic_Config_NetworkConfig_IpV4Config_size 20
 #define meshtastic_Config_NetworkConfig_size     204
 #define meshtastic_Config_PositionConfig_size    62

src/mesh/generated/meshtastic/deviceonly.pb.h

@@ -361,7 +361,7 @@ extern const pb_msgdesc_t meshtastic_BackupPreferences_msg;
 /* Maximum encoded size of messages (where known) */
 /* meshtastic_NodeDatabase_size depends on runtime parameters */
 #define MESHTASTIC_MESHTASTIC_DEVICEONLY_PB_H_MAX_SIZE meshtastic_BackupPreferences_size
-#define meshtastic_BackupPreferences_size        2429
+#define meshtastic_BackupPreferences_size        2432
 #define meshtastic_ChannelFile_size              718
 #define meshtastic_DeviceState_size              1737
 #define meshtastic_NodeInfoLite_size             196

src/mesh/generated/meshtastic/localonly.pb.h

@@ -205,7 +205,7 @@ extern const pb_msgdesc_t meshtastic_LocalModuleConfig_msg;
 
 /* Maximum encoded size of messages (where known) */
 #define MESHTASTIC_MESHTASTIC_LOCALONLY_PB_H_MAX_SIZE meshtastic_LocalModuleConfig_size
-#define meshtastic_LocalConfig_size              754
+#define meshtastic_LocalConfig_size              757
 #define meshtastic_LocalModuleConfig_size        820
 
 #ifdef __cplusplus

src/mesh/generated/meshtastic/serial_hal.pb.cpp

@@ -0,0 +1,19 @@
+/* Automatically generated nanopb constant definitions */
+/* Generated by nanopb-0.4.9.1 */
+
+#include "meshtastic/serial_hal.pb.h"
+#if PB_PROTO_HEADER_VERSION != 40
+#error Regenerate this file with the current version of nanopb generator.
+#endif
+
+PB_BIND(meshtastic_SerialHalCommand, meshtastic_SerialHalCommand, 2)
+
+
+PB_BIND(meshtastic_SerialHalResponse, meshtastic_SerialHalResponse, 2)
+
+
+
+
+
+
+

src/mesh/generated/meshtastic/serial_hal.pb.h

@@ -0,0 +1,135 @@
+/* Automatically generated nanopb header */
+/* Generated by nanopb-0.4.9.1 */
+
+#ifndef PB_MESHTASTIC_MESHTASTIC_SERIAL_HAL_PB_H_INCLUDED
+#define PB_MESHTASTIC_MESHTASTIC_SERIAL_HAL_PB_H_INCLUDED
+#include <pb.h>
+
+#if PB_PROTO_HEADER_VERSION != 40
+#error Regenerate this file with the current version of nanopb generator.
+#endif
+
+/* Enum definitions */
+typedef enum _meshtastic_SerialHalCommand_Type {
+    meshtastic_SerialHalCommand_Type_UNSET = 0,
+    meshtastic_SerialHalCommand_Type_PIN_MODE = 1,
+    meshtastic_SerialHalCommand_Type_DIGITAL_WRITE = 2,
+    meshtastic_SerialHalCommand_Type_DIGITAL_READ = 3,
+    meshtastic_SerialHalCommand_Type_ATTACH_INTERRUPT = 4,
+    meshtastic_SerialHalCommand_Type_DETACH_INTERRUPT = 5,
+    meshtastic_SerialHalCommand_Type_SPI_TRANSFER = 6,
+    meshtastic_SerialHalCommand_Type_NOOP = 7
+} meshtastic_SerialHalCommand_Type;
+
+typedef enum _meshtastic_SerialHalResponse_Result {
+    meshtastic_SerialHalResponse_Result_OK = 0,
+    meshtastic_SerialHalResponse_Result_ERROR = 1,
+    meshtastic_SerialHalResponse_Result_BAD_REQUEST = 2,
+    meshtastic_SerialHalResponse_Result_UNSUPPORTED = 3
+} meshtastic_SerialHalResponse_Result;
+
+/* Struct definitions */
+typedef PB_BYTES_ARRAY_T(512) meshtastic_SerialHalCommand_data_t;
+typedef struct _meshtastic_SerialHalCommand {
+    /* Host-assigned request id. Replies echo this id back in
+ SerialHalResponse.transaction_id. */
+    uint32_t transaction_id;
+    meshtastic_SerialHalCommand_Type type;
+    uint32_t pin;
+    uint32_t value;
+    uint32_t mode;
+    meshtastic_SerialHalCommand_data_t data;
+} meshtastic_SerialHalCommand;
+
+typedef PB_BYTES_ARRAY_T(512) meshtastic_SerialHalResponse_data_t;
+typedef struct _meshtastic_SerialHalResponse {
+    /* Matches the originating SerialHalCommand.transaction_id for normal
+ request/response traffic.
+
+ A value of 0 indicates an unsolicited interrupt notification generated by
+ the device. In that case, the host should interpret value as the GPIO pin
+ that triggered. */
+    uint32_t transaction_id;
+    meshtastic_SerialHalResponse_Result result;
+    /* Used by DIGITAL_READ replies and interrupt notifications. For interrupt
+ notifications (transaction_id == 0), this carries the pin number. */
+    uint32_t value;
+    meshtastic_SerialHalResponse_data_t data;
+    char error[80];
+} meshtastic_SerialHalResponse;
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Helper constants for enums */
+#define _meshtastic_SerialHalCommand_Type_MIN meshtastic_SerialHalCommand_Type_UNSET
+#define _meshtastic_SerialHalCommand_Type_MAX meshtastic_SerialHalCommand_Type_NOOP
+#define _meshtastic_SerialHalCommand_Type_ARRAYSIZE ((meshtastic_SerialHalCommand_Type)(meshtastic_SerialHalCommand_Type_NOOP+1))
+
+#define _meshtastic_SerialHalResponse_Result_MIN meshtastic_SerialHalResponse_Result_OK
+#define _meshtastic_SerialHalResponse_Result_MAX meshtastic_SerialHalResponse_Result_UNSUPPORTED
+#define _meshtastic_SerialHalResponse_Result_ARRAYSIZE ((meshtastic_SerialHalResponse_Result)(meshtastic_SerialHalResponse_Result_UNSUPPORTED+1))
+
+#define meshtastic_SerialHalCommand_type_ENUMTYPE meshtastic_SerialHalCommand_Type
+
+#define meshtastic_SerialHalResponse_result_ENUMTYPE meshtastic_SerialHalResponse_Result
+
+
+/* Initializer values for message structs */
+#define meshtastic_SerialHalCommand_init_default {0, _meshtastic_SerialHalCommand_Type_MIN, 0, 0, 0, {0, {0}}}
+#define meshtastic_SerialHalResponse_init_default {0, _meshtastic_SerialHalResponse_Result_MIN, 0, {0, {0}}, ""}
+#define meshtastic_SerialHalCommand_init_zero    {0, _meshtastic_SerialHalCommand_Type_MIN, 0, 0, 0, {0, {0}}}
+#define meshtastic_SerialHalResponse_init_zero   {0, _meshtastic_SerialHalResponse_Result_MIN, 0, {0, {0}}, ""}
+
+/* Field tags (for use in manual encoding/decoding) */
+#define meshtastic_SerialHalCommand_transaction_id_tag 1
+#define meshtastic_SerialHalCommand_type_tag     2
+#define meshtastic_SerialHalCommand_pin_tag      3
+#define meshtastic_SerialHalCommand_value_tag    4
+#define meshtastic_SerialHalCommand_mode_tag     5
+#define meshtastic_SerialHalCommand_data_tag     6
+#define meshtastic_SerialHalResponse_transaction_id_tag 1
+#define meshtastic_SerialHalResponse_result_tag  2
+#define meshtastic_SerialHalResponse_value_tag   3
+#define meshtastic_SerialHalResponse_data_tag    4
+#define meshtastic_SerialHalResponse_error_tag   5
+
+/* Struct field encoding specification for nanopb */
+#define meshtastic_SerialHalCommand_FIELDLIST(X, a) \
+X(a, STATIC,   SINGULAR, UINT32,   transaction_id,    1) \
+X(a, STATIC,   SINGULAR, UENUM,    type,              2) \
+X(a, STATIC,   SINGULAR, UINT32,   pin,               3) \
+X(a, STATIC,   SINGULAR, UINT32,   value,             4) \
+X(a, STATIC,   SINGULAR, UINT32,   mode,              5) \
+X(a, STATIC,   SINGULAR, BYTES,    data,              6)
+#define meshtastic_SerialHalCommand_CALLBACK NULL
+#define meshtastic_SerialHalCommand_DEFAULT NULL
+
+#define meshtastic_SerialHalResponse_FIELDLIST(X, a) \
+X(a, STATIC,   SINGULAR, UINT32,   transaction_id,    1) \
+X(a, STATIC,   SINGULAR, UENUM,    result,            2) \
+X(a, STATIC,   SINGULAR, UINT32,   value,             3) \
+X(a, STATIC,   SINGULAR, BYTES,    data,              4) \
+X(a, STATIC,   SINGULAR, STRING,   error,             5)
+#define meshtastic_SerialHalResponse_CALLBACK NULL
+#define meshtastic_SerialHalResponse_DEFAULT NULL
+
+extern const pb_msgdesc_t meshtastic_SerialHalCommand_msg;
+extern const pb_msgdesc_t meshtastic_SerialHalResponse_msg;
+
+/* Defines for backwards compatibility with code written before nanopb-0.4.0 */
+#define meshtastic_SerialHalCommand_fields &meshtastic_SerialHalCommand_msg
+#define meshtastic_SerialHalResponse_fields &meshtastic_SerialHalResponse_msg
+
+/* Maximum encoded size of messages (where known) */
+#define MESHTASTIC_MESHTASTIC_SERIAL_HAL_PB_H_MAX_SIZE meshtastic_SerialHalResponse_size
+#define meshtastic_SerialHalCommand_size         541
+#define meshtastic_SerialHalResponse_size        610
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+#endif

src/platform/portduino/PortduinoGlue.cpp

@@ -13,6 +13,7 @@
 #include <ErriezCRC32.h>
 #include <Utility.h>
 #include <assert.h>
+#include <cctype>
 #include <filesystem>
 #include <fstream>
 #include <iostream>
@@ -1052,17 +1053,31 @@ static bool ends_with(std::string_view str, std::string_view suffix)
 bool MAC_from_string(std::string mac_str, uint8_t *dmac)
 {
     mac_str.erase(std::remove(mac_str.begin(), mac_str.end(), ':'), mac_str.end());
-    if (mac_str.length() == 12) {
+    if (mac_str.length() != 12) {
-        dmac[0] = std::stoi(portduino_config.mac_address.substr(0, 2), nullptr, 16);
-        dmac[1] = std::stoi(portduino_config.mac_address.substr(2, 2), nullptr, 16);
-        dmac[2] = std::stoi(portduino_config.mac_address.substr(4, 2), nullptr, 16);
-        dmac[3] = std::stoi(portduino_config.mac_address.substr(6, 2), nullptr, 16);
-        dmac[4] = std::stoi(portduino_config.mac_address.substr(8, 2), nullptr, 16);
-        dmac[5] = std::stoi(portduino_config.mac_address.substr(10, 2), nullptr, 16);
-        return true;
-    } else {
         return false;
     }
+    // Validate every character is a hex digit before parsing. std::stoi
+    // would otherwise skip leading whitespace and silently truncate at the
+    // first non-digit, which is too lenient for a MAC address.
+    for (char c : mac_str) {
+        if (!isxdigit(static_cast<unsigned char>(c))) {
+            return false;
+        }
+    }
+    // Parse into a temporary so dmac is not partially modified if a later
+    // byte fails. At least one caller in getMacAddr() ignores the bool
+    // return, so leaving stale bytes in dmac on failure would silently
+    // produce a wrong MAC.
+    uint8_t tmp[6];
+    try {
+        for (int i = 0; i < 6; i++) {
+            tmp[i] = static_cast<uint8_t>(std::stoi(mac_str.substr(i * 2, 2), nullptr, 16));
+        }
+    } catch (const std::exception &) {
+        return false;
+    }
+    memcpy(dmac, tmp, 6);
+    return true;
 }
 
 std::string exec(const char *cmd)

test/test_mac_from_string/test_main.cpp

@@ -0,0 +1,195 @@
+// Unit tests for MAC_from_string in src/platform/portduino/PortduinoGlue.cpp.
+//
+// Regression coverage for when the function stripped colons from
+// its mac_str parameter but then read bytes from the global
+// portduino_config.mac_address. Symptoms: --hwid silently ignored when
+// MACAddress: was also set, and SIGABRT (stoi: no conversion) when --hwid
+// was used without MACAddress: in config.yaml.
+#include "Arduino.h"
+#include "TestUtil.h"
+#include <cstdint>
+#include <cstring>
+#include <string>
+#include <unity.h>
+
+// Forward-declare instead of including PortduinoGlue.h to avoid pulling in
+// LR11x0Interface, USBHal, mesh.pb.h, yaml-cpp, and the full portduino_config
+// struct just to test a self-contained string parser. The symbol is defined
+// in PortduinoGlue.cpp and resolved at link time.
+bool MAC_from_string(std::string mac_str, uint8_t *dmac);
+
+void setUp(void) {}
+void tearDown(void) {}
+
+// --- Happy-path parsing ---
+
+void test_colon_separated_uppercase()
+{
+    uint8_t dmac[6] = {0};
+    TEST_ASSERT_TRUE(MAC_from_string("AA:BB:CC:DD:EE:FF", dmac));
+    TEST_ASSERT_EQUAL_HEX8(0xAA, dmac[0]);
+    TEST_ASSERT_EQUAL_HEX8(0xBB, dmac[1]);
+    TEST_ASSERT_EQUAL_HEX8(0xCC, dmac[2]);
+    TEST_ASSERT_EQUAL_HEX8(0xDD, dmac[3]);
+    TEST_ASSERT_EQUAL_HEX8(0xEE, dmac[4]);
+    TEST_ASSERT_EQUAL_HEX8(0xFF, dmac[5]);
+}
+
+void test_colon_separated_lowercase()
+{
+    uint8_t dmac[6] = {0};
+    TEST_ASSERT_TRUE(MAC_from_string("02:ca:fe:ba:be:01", dmac));
+    TEST_ASSERT_EQUAL_HEX8(0x02, dmac[0]);
+    TEST_ASSERT_EQUAL_HEX8(0xCA, dmac[1]);
+    TEST_ASSERT_EQUAL_HEX8(0xFE, dmac[2]);
+    TEST_ASSERT_EQUAL_HEX8(0xBA, dmac[3]);
+    TEST_ASSERT_EQUAL_HEX8(0xBE, dmac[4]);
+    TEST_ASSERT_EQUAL_HEX8(0x01, dmac[5]);
+}
+
+void test_no_colons_packed_hex()
+{
+    // The CLI form produced by some tools — 12 hex chars, no separators.
+    uint8_t dmac[6] = {0};
+    TEST_ASSERT_TRUE(MAC_from_string("AABBCCDDEEFF", dmac));
+    TEST_ASSERT_EQUAL_HEX8(0xAA, dmac[0]);
+    TEST_ASSERT_EQUAL_HEX8(0xFF, dmac[5]);
+}
+
+void test_two_distinct_inputs_yield_distinct_outputs()
+{
+    // Direct regression for the original bug: parsing two different MAC
+    // strings in succession must produce two different byte sequences.
+    // Pre-fix, both calls would have produced identical bytes derived from
+    // the (untouched) global portduino_config.mac_address.
+    uint8_t a[6] = {0};
+    uint8_t b[6] = {0};
+    TEST_ASSERT_TRUE(MAC_from_string("AA:BB:CC:DD:EE:FF", a));
+    TEST_ASSERT_TRUE(MAC_from_string("02:CA:FE:BA:BE:01", b));
+    TEST_ASSERT_NOT_EQUAL(0, std::memcmp(a, b, 6));
+    TEST_ASSERT_EQUAL_HEX8(0xAA, a[0]);
+    TEST_ASSERT_EQUAL_HEX8(0x02, b[0]);
+}
+
+void test_does_not_read_external_state()
+{
+    // The function must derive every byte from its parameter, not from any
+    // global. Provide a unique MAC and verify all six bytes match the input
+    // exactly — leaves no room for the function to be smuggling bytes from
+    // elsewhere.
+    uint8_t dmac[6] = {0};
+    TEST_ASSERT_TRUE(MAC_from_string("12:34:56:78:9A:BC", dmac));
+    const uint8_t expected[6] = {0x12, 0x34, 0x56, 0x78, 0x9A, 0xBC};
+    TEST_ASSERT_EQUAL_HEX8_ARRAY(expected, dmac, 6);
+}
+
+// --- Rejected inputs ---
+// Pre-fix, the empty/short cases either crashed (stoi exception on substr("")
+// of the empty global) or silently filled dmac with stale bytes. Post-fix,
+// the length guard rejects them cleanly with `false` and dmac is unchanged.
+
+void test_empty_string_returns_false()
+{
+    uint8_t dmac[6] = {0xDE, 0xAD, 0xBE, 0xEF, 0x00, 0x11};
+    uint8_t before[6];
+    std::memcpy(before, dmac, 6);
+    TEST_ASSERT_FALSE(MAC_from_string("", dmac));
+    // dmac must be untouched on failure.
+    TEST_ASSERT_EQUAL_HEX8_ARRAY(before, dmac, 6);
+}
+
+void test_too_short_returns_false()
+{
+    uint8_t dmac[6] = {0xDE, 0xAD, 0xBE, 0xEF, 0x00, 0x11};
+    uint8_t before[6];
+    std::memcpy(before, dmac, 6);
+    TEST_ASSERT_FALSE(MAC_from_string("AA:BB:CC", dmac));
+    TEST_ASSERT_EQUAL_HEX8_ARRAY(before, dmac, 6);
+}
+
+void test_too_long_returns_false()
+{
+    uint8_t dmac[6] = {0};
+    // 14 hex chars after colon-strip > 12.
+    TEST_ASSERT_FALSE(MAC_from_string("AA:BB:CC:DD:EE:FF:00", dmac));
+}
+
+void test_only_colons_returns_false()
+{
+    uint8_t dmac[6] = {0xDE, 0xAD, 0xBE, 0xEF, 0x00, 0x11};
+    uint8_t before[6];
+    std::memcpy(before, dmac, 6);
+    TEST_ASSERT_FALSE(MAC_from_string(":::::", dmac));
+    TEST_ASSERT_EQUAL_HEX8_ARRAY(before, dmac, 6);
+}
+
+void test_extra_colons_still_parses()
+{
+    // Colon stripping happens before length check, so an unconventional
+    // grouping that totals 12 hex chars after stripping is still accepted.
+    uint8_t dmac[6] = {0};
+    TEST_ASSERT_TRUE(MAC_from_string("AABB:CCDD:EEFF", dmac));
+    TEST_ASSERT_EQUAL_HEX8(0xAA, dmac[0]);
+    TEST_ASSERT_EQUAL_HEX8(0xFF, dmac[5]);
+}
+
+void test_non_hex_input_returns_false()
+{
+    // 12 chars of non-hex would have made std::stoi throw before the
+    // try/catch wrapper was added, killing the daemon. Now must return false
+    // and leave dmac untouched.
+    uint8_t dmac[6] = {0xDE, 0xAD, 0xBE, 0xEF, 0x00, 0x11};
+    uint8_t before[6];
+    std::memcpy(before, dmac, 6);
+    TEST_ASSERT_FALSE(MAC_from_string("ZZ:ZZ:ZZ:ZZ:ZZ:ZZ", dmac));
+    TEST_ASSERT_EQUAL_HEX8_ARRAY(before, dmac, 6);
+}
+
+void test_partial_hex_failure_preserves_dmac()
+{
+    // First five bytes are valid hex; the sixth ("ZZ") is not. Without the
+    // temp-buffer staging, dmac would be partially overwritten with the five
+    // good bytes plus stale data in slot 5 — silently producing a wrong MAC
+    // since the only caller that uses this in getMacAddr() ignores the bool
+    // return value.
+    uint8_t dmac[6] = {0xDE, 0xAD, 0xBE, 0xEF, 0x00, 0x11};
+    uint8_t before[6];
+    std::memcpy(before, dmac, 6);
+    TEST_ASSERT_FALSE(MAC_from_string("AA:BB:CC:DD:EE:ZZ", dmac));
+    TEST_ASSERT_EQUAL_HEX8_ARRAY(before, dmac, 6);
+}
+
+void test_embedded_non_hex_returns_false()
+{
+    // std::stoi tolerates leading whitespace and a "0x" prefix, so a stray
+    // space inside a 2-char window like " F" would silently parse as 0xF.
+    // The per-character isxdigit() pre-check rejects these. The 14-char
+    // "0xAABBCCDDEEFF" is also rejected by the length check.
+    uint8_t dmac[6] = {0};
+    TEST_ASSERT_FALSE(MAC_from_string("AA:BB:CC:DD:EE: F", dmac));
+    TEST_ASSERT_FALSE(MAC_from_string("0xAABBCCDDEEFF", dmac));
+}
+
+// --- Unity lifecycle ---
+
+void setup()
+{
+    initializeTestEnvironment();
+    UNITY_BEGIN();
+    RUN_TEST(test_colon_separated_uppercase);
+    RUN_TEST(test_colon_separated_lowercase);
+    RUN_TEST(test_no_colons_packed_hex);
+    RUN_TEST(test_two_distinct_inputs_yield_distinct_outputs);
+    RUN_TEST(test_does_not_read_external_state);
+    RUN_TEST(test_empty_string_returns_false);
+    RUN_TEST(test_too_short_returns_false);
+    RUN_TEST(test_too_long_returns_false);
+    RUN_TEST(test_only_colons_returns_false);
+    RUN_TEST(test_extra_colons_still_parses);
+    RUN_TEST(test_non_hex_input_returns_false);
+    RUN_TEST(test_partial_hex_failure_preserves_dmac);
+    RUN_TEST(test_embedded_non_hex_returns_false);
+    exit(UNITY_END());
+}
+
+void loop() {}