[priyanka-0206]

Issue

If the user who started the workflow had no public SSH key on GitHub, the action opened the debug session to anyone with the connection string. The connection string is in the job log. On a public repository, anyone who can read the log could get a shell on the runner.

Fix

• limit-access-to-actor now defaults to true instead of auto.
• If the user has no public SSH key, the step fails with an error that says how to fix it. It no longer opens the session to everyone.
• Only limit-access-to-actor: false turns the check off.
• README updated, including that the web shell is off while access is restricted.

Decisions

• Workflows that used the default, run by a user with no SSH key, will now fail. To fix it, add an SSH key on GitHub or set limit-access-to-actor: false.
• auto still works but now behaves like true.
• When access is restricted, tmate turns off the web shell. Users connect by SSH only.

Testing

• npm test: 13 passed. New tests cover a user with a key, a user with no key, and false.
• lib/index.js rebuilt with npm run build. A clean rebuild matches it.
• End to end with the Manual test workflow on this branch, on ubuntu-24.04:
  • No SSH key, auto: the step fails with the new error and no session starts.
  • One SSH key, true: that key connects and a different key gets Permission denied (publickey). The tmate server logs show Restricting ssh access, num_keys=1, ssh_only=true and one client.
  • false: the session opens without a key check.

Ticket: WARP-1192

🤖 Generated with Claude Code

[linear-code]

WARP-1192

[abhijit-hota]

we should release a major version since this is a breaking change.