Question

Why does response truncation happen even below token limits

Answer 1

Because the hard context window is only a portion of the generation pipeline, response truncation may occur even if you are below the advertised token limit. In reality, truncation is frequently brought on by

• Budgets for reserved output

• Tokens for hidden systems

• Caps for frameworks

• Interruptions to streaming

• Condition of stop

• Filters for safety

• token allocations and reasoning

• Limits of middleware

"128k context window" does not imply that you will always receive 128k useable tokens for prompt + output.