imgtool
MCUboot's image signing and key management
Decision gist · record as of 2026-08-14
Yes. imgtool is a focused, actively maintained utility with low install friction and no known vulnerabilities. Install it if you are working with MCUboot or need to sign firmware images for microcontroller bootloaders. The Apache Software License poses no barrier to commercial use.AI-flagged interpretation of the facts on this page — verify before relying
Before you install
- Requires a cryptographic key file and input firmware binary; Python 3.6 or later (requires_python: >=3.6).
- Low install friction with a pure-Python wheel and five runtime dependencies.
- The project is actively maintained with recent commits and steady releases since first release in 2018.
License · maintenance · safety
Apache Software License (permissive) — Apache Software License is permissive, allowing commercial and private use with minimal restrictions; you must retain license and copyright notices in distributions.
last release 2026-04-09 (127 days) · last repo commit 2026-08-13 · 2,029 stars
0 known vulnerabilities (OSV.dev, 2026-08-14) · 846,591 downloads/mo, #4,915 on PyPI
Alternatives
Verify before relying
pip install imgtool
from imgtool import main
main(['sign', '--key', 'key.pem', '--version', 'X.Y', 'input.bin', 'output.bin'])- Whether the package provides a command-line interface or is intended primarily as a library.
- What key formats and signing algorithms are supported beyond what the fact sheet indicates.
- Whether hardware-specific MCUboot ports require additional setup beyond imgtool itself.
- Specific usage patterns and API surface for programmatic key management.
What it is and what it does
imgtool is the image signing and key management utility for MCUboot, a secure bootloader for 32-bit microcontrollers. It handles the cryptographic signing of firmware images so that MCUboot can verify their authenticity before booting them on target hardware. The package is part of the MCUboot project, which provides a common bootloader infrastructure across multiple embedded operating systems and SoCs.
The tool relies on five runtime dependencies: cbor2, click, cryptography, intelhex, and pyyaml. It is actively maintained with no known security vulnerabilities and supports current Python versions. The project has a stable release cadence and is used in embedded systems development.
Use it for
- Sign firmware binaries before deployment to ensure MCUboot can authenticate them during boot.
- Manage and rotate cryptographic keys used for firmware image validation across device fleets.
- Integrate firmware signing into embedded CI/CD pipelines for automated secure builds.
- Generate signed firmware images compatible with MCUboot on supported platforms.
- Validate firmware integrity and authenticity in over-the-air update workflows.
Worth the install?
AI-flagged interpretation of the facts on this page. Verify before relying on it.
Yes.
imgtool is a focused, actively maintained utility with low install friction and no known vulnerabilities. Install it if you are working with MCUboot or need to sign firmware images for microcontroller bootloaders. The Apache Software License poses no barrier to commercial use.
Install
imgtool on PyPI
Before you install
Low install friction with a pure-Python wheel and five runtime dependencies. The project is actively maintained with recent commits and steady releases since first release in 2018.
Requires a cryptographic key file and input firmware binary; Python 3.6 or later (requires_python: >=3.6).
License in practice
Apache Software License is permissive, allowing commercial and private use with minimal restrictions; you must retain license and copyright notices in distributions.
Quickstart
pip install imgtool
from imgtool import main
main(['sign', '--key', 'key.pem', '--version', 'X.Y', 'input.bin', 'output.bin'])Verify before relying
- Whether the package provides a command-line interface or is intended primarily as a library.
- What key formats and signing algorithms are supported beyond what the fact sheet indicates.
- Whether hardware-specific MCUboot ports require additional setup beyond imgtool itself.
- Specific usage patterns and API surface for programmatic key management.
Package facts
| License | Apache Software License permissive |
| Python support | Supports the current Python release >=3.6 |
| Install friction | Low. Pure-Python wheel |
| Runtime dependencies | 5 packagescbor2clickcryptographyintelhexpyyaml |
| Maintenance | Actively maintained 127 days since the last release |
| Last repo commit | |
| First released | |
| Downloads | 846,591 / month, #4,915 on PyPI 30-day window, as of 2026-08-14 |
| Known vulnerabilities | None known OSV.dev, checked 2026-08-14 |
| Classifiers | Development Status :: 4 - BetaLicense :: OSI Approved :: Apache Software LicenseProgramming Language :: Python :: 3Topic :: Software Development :: Build Tools |
Evidence: imgtool-2.4.0-py3-none-any.whl
Tags
Let your AI agent find packages like this
Example. Real query, live index.
You found this page by searching. An agent finds it by wishing: SkillFed indexes 14,416 PyPI packages by what they can do, searchable in plain language.
wish › “firmware image signing tool”
- imgtoolimgtool signs and manages cryptographic keys for MCUboot firmware…
- pyimg4PyIMG4 parses Apple's Image4 format through a Python library and CLI…
- universal-silabs-flasherFlashes firmware onto Silicon Labs radios (EmberZNet, CPC, Spinel) by…
Give your agent the search over MCP, or paste the wish link into any chat.
More Build Tools packages
Provides reusable utilities for Python packaging interoperability, including version handling, specifiers, markers, requirements, tags, and metadata parsing according to standards like PEP 440 and PEP 425.
Wraps any iterable to display a real-time progress bar in the terminal or Jupyter notebook, showing iteration count, elapsed time, and estimated time remaining.
pip is the standard installer for Python packages, enabling you to download and install packages from the Python Package Index and other indexes into your Python environment.
Hatchling is a standards-compliant Python build backend that handles packaging, metadata, and distribution of Python projects when configured in a project's pyproject.toml file.
Generates Python gRPC service stubs and message classes from Protocol Buffer definitions, enabling developers to build gRPC clients and servers.
pre-commit is a framework for installing and running git hooks written in any language before commits are made, automating code quality and validation checks across multi-language projects.
Install it if your team needs consistent, automated validation at commit time.
See also esptool · universal-silabs-flasher · libuuu · smpclient · smpmgr · pyobjc-framework-SecurityFoundation · pytest-embedded-qemu · hsms · pytest-embedded-serial-esp · pioarduino