Prompt · Debug
Diagnose a failure without changing code
Get the root cause and the evidence for it, with no edits until you decide on a fix.
/investigate Why does checkout fail for carts with a discount code? Find the cause, but don't change any code yet.$investigate Why does checkout fail for carts with a discount code? Find the cause, but don't change any code yet.@planr-investigate Why does checkout fail for carts with a discount code? Find the cause, but don't change any code yet.If /investigate runs another command, use /planr:investigate.
With the OpenPlanr plugin for Codex, use $planr:investigate.
Cursor applies the planr-investigate rule when you mention it in chat.
Why this works
Without a request to fix, Investigate stays diagnostic. It reports the established cause or the strongest remaining hypotheses, the checks it ran, and what is still uncertain.
Related prompts
Find the root cause before you fix it
Reproduce the defect, establish why it happens, then apply a bounded fix.
Track down a flaky test
Find out why a test fails some of the time before anyone changes the test.
Find out why a skill is missing
Diagnose the OpenPlanr installation and preview any repair before it touches a file.