Keyclasp is presented as a tool that lets local coding agents use real credentials without placing token values in prompts or copying secret-bearing output. The author says they previously handled credentials by either having the agent propose commands that they executed with stored credentials, or by letting the agent run commands directly and then dealing with secrets appearing in outputs, requiring token rotation and repeated cleanup.
Keyclasp stores credentials in a local encrypted vault. Agents interact with secret names and request only the specific secrets a command needs, passing the selected token to the child process via environment variables. Outlets describe that an agent can list available secret names without retrieving their values, and that operators can require authorization for secret use or allow selected secrets to run unattended. The tool is entirely local and open source.
Both sources also note limitations and safeguards: the command being run still receives the real credential, so it can write to disk or send data over the network, and Keyclasp does not sandbox or isolate secrets from other processes under the user’s OS account. An output guard scans stdout and stderr for exact injected values of at least eight characters and redacts and attempts to terminate the process group if detected. The project has not had a professional third-party security audit, supports Apple Silicon Macs and glibc Linux on arm64/x64, and is MIT licensed.