# Cache Module — Known Issues

Open issues against the current cache implementation. The cache uses
HMAC-derived keys with **no reverse indexes** (scoped purge recomputes the key;
broad purge is a prefix SCAN+UNLINK), so there are no index/sub-index races to
track. Resolved items are removed once their fix lands.

## Correctness

### Cross-language stringification divergence
Python `str(True)` → `"True"` vs JS `String(true)` → `"true"`. `_normalize`
canonicalizes `True`/`False`/`None` today, but the rules for the remaining
value types are not yet pinned in the protocol spec — so Python and
TypeScript HMAC keys can still diverge on an un-normalized type.

## Performance / Operability

### No thundering-herd protection
Concurrent cold misses on the same key all execute and write. No
single-flight / request-coalescing.
