Command-line tool

pipx install openbricks installs one console script, openbricks, which mirrors the pybricksdev workflow: flash firmware over USB, then run / upload / stop programs and pull logs over BLE. With the [sim] extra installed, openbricks sim … forwards to the MuJoCo-backed simulator.

A typical session:

$ openbricks flash --name RobotA     # port, chip and newest firmware auto-detected
$ openbricks list                    # hubs in BLE range
$ openbricks run -n RobotA main.py   # push + stream output
$ openbricks upload -n RobotA main.py  # stage; start it with the hub button
$ openbricks stop -n RobotA          # Ctrl-C a running program
$ openbricks log -n RobotA           # dump the most recent run log
$ openbricks docs hardware           # open this manual offline in your browser

Firmware versions and provenance

openbricks flash first reports the firmware already on the chip — version plus an (official) / (customized) suffix — before it looks up the newest release. Flashing the same version again, or an older one, asks for confirmation first; pass --yes to skip the prompt in scripts.

The default output is step-level (probe, download, erase, write, hub name, marker, reboot); pass --verbose / -v to also echo every underlying mpremote / esptool command line and the firmware cache paths — useful when reporting a flash problem.

Every firmware image published by CI is signed (Ed25519), and the CLI ships the matching public key. An image whose .bin.sig verifies is labeled (official); anything else — a self-built image, a missing or wrong signature — is (customized). Customized firmware flashes normally: the suffix is provenance, not a gate. After each flash the verdict is stored on the hub, which is how the next openbricks flash labels the current firmware.

The suffix follows the version everywhere it reaches you: the firmware 1.79.0 (official) banner at the top of every openbricks run, the started: header line in every run log (openbricks log), and the flash preflight above. On the hub, openbricks.firmware_label() returns the same string.

Programs are compiled on the host

Since 1.92.0, openbricks run and openbricks upload cross-compile your script with mpy-cross before connecting, and stage compiled bytecode instead of source (like Pybricks). Three things get better:

syntax errors surface in milliseconds, on your terminal, naming your file and line and quoting the offending source line — no BLE scan, no connect, no upload round-trip;
programs start faster: the hub loads bytecode directly and skips its on-device parse/compile step;
tracebacks name your real file and line (File "square.py", line 12) instead of File "<string>".

No flags, nothing to configure. Firmware older than 1.92.0 can’t run compiled programs, so the CLI probes the hub’s version in-session and sends plain source instead — announced on stderr, never silently. upload --path (custom boot flows) always stages your file verbatim, uncompiled, at the path you give.

The two commands use separate slots (since 1.97.0): upload stages the button’s program at /program.mpy; run stages its one-shot script at /run.mpy and the hub button never reads it. So running a calibration or a quick diagnostic no longer replaces the program your button launches — the earlier shared-slot behavior turned “upload, calibrate, press start” into the robot silently re-running the calibration.

Reference

The reference below is generated from the CLI’s own argument parser, so it always matches the installed version.

Host-side CLI for flashing and running code on openbricks hubs, plus a MuJoCo-backed simulator (openbricks sim …).

usage: openbricks [-h] [--version] COMMAND ...

Positional Arguments

COMMAND: Possible choices: flash, run, upload, stop, list, log, servo-id, paste-probe, docs, doc, sim

Named Arguments

--version: Print the openbricks package version and exit.

Sub-commands

flash

Flash a firmware image onto a hub (via esptool) and write the hub’s BLE advertising name into NVS (via mpremote). –name is mandatory so every hub gets a unique identifier — two hubs with the same name can’t be individually addressed over BLE.

openbricks flash [-h] --name NAME [--port PORT] [--firmware FIRMWARE]
                 [--chip CHIP] [--baud BAUD] [--skip-erase] [--yes]
                 [--verbose]

Named Arguments

--name

Hub identifier for BLE (required, <=20 chars recommended).

--port

Serial port (/dev/ttyUSB0, /dev/cu.usbserial-XXXX, COM5 …). Omit to auto-detect — works when exactly ONE ESP device is connected (Espressif native USB or a CP210x/CH340/FTDI bridge).

--firmware

Path to firmware.bin produced by scripts/build_firmware.sh or downloaded from the Releases page. Omit to download the newest release automatically for the detected chip (cached under ~/.cache/openbricks/firmware).

--chip

esptool –chip value (esp32, esp32s3, auto). Default: auto.

Default: 'auto'

--baud

esptool flash baud rate. Default: 460800.

Default: '460800'

--skip-erase

Skip erase_flash (faster dev loop; leaves stale NVS keys).

Default: False

--yes

Skip the confirmation prompt when the target firmware is the same version as (or older than) the current one.

Default: False

--verbose, -v

Echo every subprocess command line (mpremote/esptool) and cache paths. Default output is step-level only.

Default: False

run

Connect to the named hub over BLE, push SCRIPT to its REPL (via paste mode), and stream stdout/stderr back to this terminal until the script finishes. Ctrl-C interrupts the remote program.

openbricks run [-h] -n NAME [-c CODE] [--scan-timeout SCAN_TIMEOUT] [--debug]
               [SCRIPT]

Positional Arguments

SCRIPT: Path to the local Python script to run on the hub. Mutually exclusive with -c.

Named Arguments

-n, --name

Hub name baked in at flash time (openbricks flash --name).

-c, --code

Inline Python code to run on the hub (analogous to python -c CODE). Useful for quick diagnostics — e.g. openbricks run -n ls -c 'import openbricks; print(openbricks.__version__)'. Mutually exclusive with the SCRIPT positional.

--scan-timeout

How long to scan for the named hub before giving up. Default: 5.0 s.

Default: 5.0

--debug

Print every BLE notify packet (timestamp + hex + ascii) to stderr as it arrives. Use to diagnose ‘timed out reading from hub’ errors — tells you whether the hub is sending anything at all.

Default: False

upload

Upload SCRIPT to the hub’s filesystem (default path /program.py). The uploaded code does NOT run automatically — the hub’s frozen main.py watches the hub button and exec’s the staged script on each short press. Second short-press stops a running program. (Pybricks calls this same operation download from the hub’s perspective; we name by direction-of-data-travel — bytes flow up to the hub.)

openbricks upload [-h] -n NAME [--path PATH] [--scan-timeout SCAN_TIMEOUT]
                  SCRIPT

Positional Arguments

SCRIPT: Path to the local Python script to stage.

Named Arguments

-n, --name

Hub name baked in at flash time.

--path

Destination path on the hub’s filesystem; the file is staged VERBATIM there (no compilation) for custom boot flows. Default: compile with mpy-cross and stage /program.mpy (which the frozen launcher runs; older firmware gets the source at /program.py).

--scan-timeout

BLE scan timeout. Default: 5.0 s.

Default: 5.0

stop

Connect to the named hub over BLE and send a single Ctrl-C, which MicroPython surfaces as KeyboardInterrupt. Use when a long-running openbricks run has already ended and you just want the hub to idle again.

openbricks stop [-h] -n NAME [--scan-timeout SCAN_TIMEOUT]

Named Arguments

-n, --name

Hub name.

--scan-timeout

BLE scan timeout. Default: 5.0 s.

Default: 5.0

list

Run a BLE scan and print every device found, sorted by RSSI (strongest first). Unnamed devices are shown with a placeholder so you can still spot a hub whose name wasn’t flashed.

openbricks list [-h] [--timeout TIMEOUT] [--all]

Named Arguments

--timeout

Scan duration in seconds. Default: 5.0.

Default: 5.0

--all

Show every BLE device, not just those with names. Useful when debugging a hub that came up without a flashed name.

Default: False

log

Every program executed via the launcher (button press OR openbricks run) gets its stdout / stderr tee’d to a flash file under /openbricks_logs/. Ten rotating slots are kept. With no flags this prints the most recent run; --list shows the index; --run N selects a specific slot. Useful for post-mortem on an untethered run where no live console was attached.

openbricks log [-h] -n NAME [--list] [--run RUN] [--scan-timeout SCAN_TIMEOUT]

Named Arguments

-n, --name

Hub name baked in at flash time.

--list

List the available run indices + their on-flash size, instead of dumping a run’s contents.

Default: False

--run

Specific run index to dump. Defaults to the most recent.

--scan-timeout

BLE scan timeout. Default: 5.0 s.

Default: 5.0

servo-id

Scans the bus (IDs 0..253), rewrites the servo’s EEPROM ID register, and verifies the result. With several servos attached, –old-id is required so the tool never guesses which one to re-ID. Wire the servo to a USB half-duplex adapter (e.g. the URT-2 board) — this talks directly to the adapter’s serial port, no hub involved.

openbricks servo-id [-h] [-p PORT] [-n NAME] [--tx TX] [--rx RX]
                    [--scan-timeout SCAN_TIMEOUT] [--scan] [--old-id OLD_ID]
                    [--baudrate BAUDRATE] [--timeout TIMEOUT]
                    [new_id]

Positional Arguments

new_id: Bus ID to assign (0..253). Omit with –scan.

Named Arguments

-p, --port

Serial port of the USB adapter, e.g. /dev/cu.usbmodem123. Omitted (and no -n): auto-detected when exactly one USB serial device is connected.

-n, --name

Hub name: run the scan/re-ID THROUGH THE HUB over BLE instead of a USB adapter — the servo stays wired to the robot. Mutually exclusive with -p.

--tx

Hub path only: servo-bus TX pin (default 14).

Default: 14

--rx

Hub path only: servo-bus RX pin (default 41).

Default: 41

--scan-timeout

Hub path only: BLE scan timeout. Default: 5.0 s.

Default: 5.0

--scan

Just list the IDs that answer on the bus; change nothing.

Default: False

--old-id

Current ID of the servo to re-ID. Required when more than one servo is attached; otherwise auto-detected.

--baudrate

Bus baudrate. Default: 1000000 (Feetech factory).

Default: 1000000

--timeout

Per-ping serial read timeout in seconds. Default: 0.02 (a full 254-ID scan takes ~5 s).

Default: 0.02

paste-probe

Pastes padded no-op programs of increasing size through the real raw-paste path and reports the largest that completes, plus how each failure presents (truncated vs hung). Use before changing the firmware’s MICROPY_REPL_STDIN_BUFFER_MAX: two windows may be in flight at once, so that setting is only safe at or below the measured limit.

openbricks paste-probe [-h] -n NAME [--scan-timeout SCAN_TIMEOUT] [--max MAX]
                       [--timeout TIMEOUT]

Named Arguments

-n, --name

Hub BLE name.

--scan-timeout

BLE scan timeout in seconds. Default: 5.

Default: 5.0

--max

Largest size to try, bytes. Default: 8192.

Default: 8192

--timeout

Per-size timeout in seconds. Default: 15.

Default: 15.0

docs (doc)

Opens the full manual in your browser — the same Sphinx build as docs.openbricks.dev, API reference included, bundled and served from disk so no internet is needed. Pass a topic to jump straight to that page.

openbricks docs [-h] [topic]

Positional Arguments

topic: Page to open (e.g. install, hardware, robotics). Guides and API pages both work. Omit for the index.

sim

Forwards all remaining arguments to the MuJoCo-backed simulator’s CLI. Use openbricks sim --help to see the sim’s own subcommand list.

openbricks sim