# pyocd/pyOCD

Open source Python library for programming and debugging Arm Cortex-M microcontrollers

Repository: https://github.com/pyocd/pyOCD
Canonical: https://ross.abutalabs.com/products/pyocd
Homepage: https://pyocd.io
Language: Python
License: Apache-2.0
License Family: permissive
Topics: embedded, python, cortex-m, arm, debug, cmsis-dap, mcu, microcontroller, stlink, pyocd, gdb-server, jlink, cortex-debug
Last push: 2026-07-24T13:34:43+00:00

## Health v2 (maintenance only)
Score: 91/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 94, release rhythm 82, longevity 100
- inputs: {"age_days": 4695, "days_push": 40, "days_rel": 43, "gap_med": 34, "n_releases_24m": 12}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1449, forks 556 (observed 2026-08-28T04:04:45.696493+00:00)

## What it is
pyOCD is an open-source Python library and command-line tool for programming and debugging Arm Cortex-M microcontrollers across a wide range of debug probes (CMSIS-DAP, ST-Link, J-Link, and more). It supports 70+ built-in devices plus nearly any Cortex-M target via CMSIS Device Family Packs, and offers a GDB server, flash programming, RTT/SWO streaming, and a Python API for automation.

## Use cases
- flash firmware onto a Cortex-M microcontroller from the command line
- debug embedded firmware with gdb or an IDE like VS Code
- erase or program MCU flash in a CI pipeline
- inspect and control a microcontroller interactively from a Python REPL
- stream Segger RTT output over any debug probe
- share a debug probe over TCP/IP for remote debugging
- build custom automated test tools for embedded targets using the Python API

## When to choose
- you need to program or debug Arm Cortex-M devices cross-platform from Python or the CLI
- you want GDB server support with many probe types (CMSIS-DAP, ST-Link, J-Link)
- you need scripted/automated flash programming and target control for CI or test tooling
- you want broad device support via Open-CMSIS-Pack

## When to avoid
- you are debugging non-Cortex-M architectures such as Cortex-A/R or RISC-V
- you need a graphical flashing tool with no command-line involvement
- your probe is unsupported and no vendor driver plugin exists

## Facets
- artifact type: library
- maturity: active
- function: developer-tools, cli, sdk, testing
- domain: embedded-systems, developer-tools, hardware
- platform: python, windows, cross-platform, cli
- tags: cortex-m, arm, debug-probe, gdbserver, flash-programming, cmsis-dap, jlink, stlink, cmsis-packs, rtt, firmware-flashing, command-line, linux, macos

## Member repositories
- pyocd/pyOCD (main) score 91

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:04:45.696493+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T04:36:01.135573+00:00, confidence not recorded.
  - readme: https://github.com/pyocd/pyOCD (fetched 2026-08-28T04:04:45.696493+00:00, sha 25669cfc29e1)
  - homepage: https://pyocd.io (fetched 2026-08-29T11:45:44.369622+00:00, sha 5b5f361124ff)
  - site_page: https://pyocd.io/docs (fetched 2026-08-29T11:45:44.379186+00:00, sha 7144467a22bb)
  - site_page: https://pyocd.io/docs/installing (fetched 2026-08-29T11:45:44.381176+00:00, sha 6e3dcea714c9)
  - site_page: https://pyocd.io/docs/index (fetched 2026-08-29T11:45:44.383102+00:00, sha b3683e65a340)
  - registry_pypi: https://pypi.org/pypi/pyocd/json (fetched 2026-08-29T11:45:44.384924+00:00, sha 68352e474a6b)
- Data as of 2026-08-30T08:39:29.467469+00:00.