Just-in-Time Runner - CI/CD Glossary Definition

A just-in-time runner is registered with a one-time config token and runs a single job.

A just-in-time (JIT) runner is registered with a single-use configuration token from the GitHub API, so it can run exactly one job without a long-lived registration token stored on the machine.

JIT runners are created by requesting a config from the API and passing it to the runner at startup. Because the config is single-use, there is no persistent registration token to leak.

Security benefit

JIT configs remove the need to store a reusable registration token on runner hosts, which reduces the blast radius if a host image is compromised.

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