All attempts (losers already pruned, branches disposed)
Lowest-perplexity branch — still alive, caller owns cleanup
Text output from the best attempt
Shared prefix length in tokens (for KV savings calculation)
Number of batched commit steps
Sum of all attempt token counts
Aggregate result from diverge
The
bestbranch is still alive; all other attempt branches have been pruned. The caller owns cleanup — typically via Session.promote to make the best branch the new conversation trunk.