# Install onlykey-agent with Homebrew, Nix

Middleware that lets you use OnlyKey as a hardware SSH/GPG device. Version 1.1.15 via Homebrew; verified 2026-05-14. Also installable with nix: nix profile install nixpkgs#onlykey-agent.

## Install

```sh
sudo av install brew:onlykey-agent
```

Additional install commands:

### macOS

- Homebrew (100%):

```sh
brew install onlykey-agent
```

  Evidence: local Homebrew formula metadata

### Linux

- Nix (92%):

```sh
nix profile install nixpkgs#onlykey-agent
```

  Evidence: nixpkgs package indexes: pkgs/by-name/on/onlykey-agent/package.nix from https://api.github.com/repos/NixOS/nixpkgs/git/trees/master?recursive=1

## Package facts

- **Package key:** brew:onlykey-agent
- **Package manager:** Homebrew
- **Version:** 1.1.15
- **Source summary:** Middleware that lets you use OnlyKey as a hardware SSH/GPG device
- **Homepage:** <https://docs.crp.to/onlykey-agent.html>
- **Last updated:** 2026-05-14T10:23:53Z
- **Generated:** 2026-08-03T19:37:03+00:00

## Executables

- onlykey-agent (alias)
- onlykey-gpg (alias)
- onlykey-gpg-agent (alias)
- onlykey_agent.py (alias)

## Install behavior

- Bottle: not available

## Freshness

- Page generated: 2026-08-03
- Package-manager version: 1.1.15
## Project history and usage

onlykey-agent is middleware that lets an OnlyKey hardware token act as an SSH and GPG agent. It bridges standard developer/admin workflows such as SSH login, Git over SSH, GPG signing, and password-store decryption to keys generated or stored on the hardware device.

### Project history

The project is maintained by CryptoTrust/trustcrypto and described upstream as an SSH agent for OnlyKey. PyPI's release history starts with 0.0.2 on March 11, 2018, reaches 1.0.0 on November 14, 2019, and lists 1.1.15 on July 21, 2023.

OnlyKey's documentation positions the agent as a way to keep SSH and OpenPGP private keys off the computer while still using ordinary SSH and GnuPG workflows. The agent uses OnlyKey button presses or challenge codes to authorize signing and decrypt operations.

### Adoption history

onlykey-agent is available from PyPI and Homebrew, and Homebrew's formula exposes its native dependencies on GnuPG, hidapi, libusb, libsodium, and Python. Its audience is narrower than general FIDO/U2F tooling because it specifically serves OnlyKey users who want SSH-agent and gpg-agent style integration.

### How it is used

For SSH, users generate or expose a public key with onlykey-agent, add it to authorized_keys or a Git hosting account, and run commands inside an agent-backed shell or command wrapper. For GPG, users initialize a dedicated GNUPGHOME such as ~/.gnupg/onlykey and use onlykey-gpg for signing, encryption, and Git commit/tag signing.

The documentation distinguishes derived keys from stored keys. Derived keys are generated from identity@host-style inputs, while stored keys use key material loaded into OnlyKey slots, including ECC and RSA slots for SSH/GPG operations.

### Why package nerds care

The package is interesting because it turns a hardware-security product into normal Unix developer plumbing. The package exposes multiple executables, slots into SSH_AUTH_SOCK and GNUPGHOME conventions, and depends on USB/HID and cryptographic libraries rather than inventing a separate workflow.

### Timeline

- 2018-03-11: PyPI lists onlykey-agent 0.0.2.
- 2019-11-14: PyPI lists onlykey-agent 1.0.0.
- 2021-08-27: CryptoTrust published guidance for using OnlyKey with OpenPGP and SSH workflows.
- 2023-07-21: PyPI lists onlykey-agent 1.1.15.

### Related projects

- Related projects and technologies include OnlyKey firmware and desktop software, OpenSSH, GnuPG, pass, gopass, hidapi, libusb, and hardware-backed SSH/GPG agents.

### Sources

- <https://crp.to/2021/08/27/a-more-seamless-openpgp-and-ssh-experience-with-onlykey/>
- <https://docs.onlykey.io/onlykey-agent/>
- <https://formulae.brew.sh/formula/onlykey-agent>
- <https://github.com/trustcrypto/onlykey-agent>
- <https://pypi.org/project/onlykey-agent/>


## Security Notes

No matching local secret-handling manifest was found for onlykey-agent. Nucleus package metadata is still published here so future coverage has a stable package URL.



## Configuration and credential file locations

These source-backed paths show where this package keeps local settings or durable credentials. Automic Vault can use them as review targets for secret scanning, migration, and command approval.


## Configuration files

- Unix: ~/.ssh/config, ~/.gnupg/onlykey
## Other Package-Manager Records

- Nix - onlykey-agent: normalized package name match | nixpkgs package indexes: pkgs/by-name/on/onlykey-agent/package.nix from https://api.github.com/repos/NixOS/nixpkgs/git/trees/master?recursive=1


## Combined YAML source

View the package source record on GitHub. [combined/onlykey-agent.yml](https://github.com/mxcl/pkgdb/blob/main/combined/onlykey-agent.yml)


## Sources

- pkg.so package database
- Geiger risk classifier
- curated configuration and credential file locations
- curated package history
- pkgdb category and tag curation
- external package-manager database matches
- cross-ecosystem install command graph