Names of policies scoped to object without answer (never result-covered by the engine alone).
Process input messages before they are sent to the LLM
Either:
Process the complete output result after streaming/generate is finished
Either:
Process output stream chunks with built-in state management This allows processors to accumulate chunks and make decisions based on larger context Return null or undefined to skip emitting the part
Mastra Processor implementing input/output policy gating — see the module comment for the phase/channel model.
Under the supported
@mastra/corepeer, a final output result has no structured-object field. The constructor therefore requires an audit sink when a policy selectsobjectwithoutanswer. A final-result call fails closed unless this engine actually evaluated an object chunk. Policies that includeanswerinspect JSON carried as answer text.The constructor also rejects an explicit input policy whose channels exclude
answer, because input evaluation has no other channel.