Error2 reports
Fix KeyReuseError
in JAX
✅ Solution
The "KeyReuseError" in jax arises when the same PRNGKey is used multiple times within a jax transformation (like vmap or pmap) without being split, which leads to non-deterministic or potentially correlated random numbers. To fix this, ensure that each PRNGKey used within a transformed function is uniquely split using `jax.random.split` before each use, generating new keys for subsequent operations, effectively preventing key reuse. Always split your PRNGKey before passing it to JAX functions that use randomness within loops or vmapped code.
Related Issues
Real GitHub issues where developers encountered this error:
Timeline
First reported:May 19, 2026
Last reported:22h ago