Python and JS SDKs — 429 WAIT signal lost at exception boundary, no Retry-After

[SirBrenton]

Finding

Three files map 429 responses to typed exceptions with no Retry-After consulted and no WAIT vs STOP distinction:

• packages/python-sdk/e2b/api/__init__.py
• packages/python-sdk/e2b/envd/api.py
• packages/js-sdk/src/envd/api.ts

Same pattern across both Python and JavaScript SDKs.

The consequence

When a provider returns Retry-After: 60, the signal is swallowed at the exception boundary. The caller receives a typed error with no timing information. Retry decisions default to local backoff inside the cooldown window.

Expected behavior

• Preserve Retry-After across the exception boundary
• Surface retry timing to the caller
• Distinguish WAIT (transient throttle) from STOP (quota exhaustion) before retrying

Related pattern

WAIT-signal-lost-at-exception-boundary

Corpus reference: https://github.com/SirBrenton/pitstop-truth

[linear-code]

ENG-4008