What changed
LiteLLM 1.109 adds continuation fallback after a chat stream fails, crash-resistant billing for background interactions and an RFC 7523 JWT-bearer path for gateway identity. It also enables the Chat UI by default and ships fixes across Bedrock reasoning, MCP auto-execution billing, spend logs, guardrails and streaming event-loop fairness.
Why it matters
Fallback continuity, billing and delegated identity all change gateway truth during partial failure. The release can reduce dropped work, but an apparently continuous answer may span providers and every retry, MCP round and background task still needs correct attribution.
What to do
Pin 1.109 in staging, kill a provider mid-stream, restart a background interaction and exercise one JWT-bearer exchange. Reconcile output boundaries, provider identity, spend logs, MCP rounds, budget state and rollback before promoting the gateway.
Caveat
The signed stable release is maintainer evidence, not an independent accounting or identity audit. Several entries are marked breaking, provider behavior varies, and Chat UI exposure changes must be reviewed against the deployment's access controls.