acme.sh is a pure Unix shell script ACME client for automating SSL and TLS certificate provisioning and renewal.
The tool solves the problem of obtaining and maintaining valid SSL/TLS certificates by implementing the ACME protocol entirely in shell script. This approach eliminates the need for external dependencies or compiled binaries, making it portable across Unix-like systems. The client handles certificate issuance, renewal, and revocation by communicating with ACME-compatible certificate authorities and managing the challenge-response flow required by the protocol.
The tool suits environments where simplicity and minimal dependencies are priorities, particularly on servers where installing additional software is constrained or undesirable. It works with multiple certificate authorities including Let's Encrypt, ZeroSSL, and Buypass. Developers managing their own infrastructure or embedded systems benefit from its shell-only implementation, which requires no runtime beyond a standard Unix shell. The project is suitable for both automated certificate management in production deployments and manual certificate handling on systems where heavier solutions like Certbot may be overkill.
The project maintains active engagement with its codebase through regular commits addressing bug fixes and feature additions. Development includes responsiveness to reported issues with timely investigation and resolution. The maintainers actively merge contributions that extend functionality and improve compatibility. The project demonstrates sustained attention to keeping the implementation current with ACME protocol developments and certificate authority requirements.
