3.40.0

Issues

• Bug: CachePersistenceLayer raises IdempotencyValidationError on retries with the same payload when payload_validation_jmespath is set

  buggood first issueidempotency
  aws-powertools/powertools-lambda-python#8655 · Filter by author thebadalov opened on Oct 22, 2026 · 3.40.0
  5

  

• Bug: batch processor crashes with AttributeError when a model validator raises a non-ValueError

  batchbuggood first issue
  aws-powertools/powertools-lambda-python#8660 · Filter by author soujasK opened on Oct 25, 2026 · 3.40.0
  2

  

• Bug: SqsFifoPartialProcessor fails the whole batch when a short-circuited record doesn't match the model

  batchbuggood first issue
  aws-powertools/powertools-lambda-python#8661 · Filter by author soujasK opened on Oct 25, 2026 · 3.40.0
  2

  

• Bug: idempotent functions sharing a persistence layer silently use the first function's IdempotencyConfig

  bugidempotency
  aws-powertools/powertools-lambda-python#8659 · Filter by author soujasK opened on Oct 25, 2026 · 3.40.0
  4

  

• Bug: Kafka ProtobufDeserializer reads Confluent message indexes as plain varints, dropping fields or failing for non-first message types

  bugevent_sources
  aws-powertools/powertools-lambda-python#8665 · Filter by author alphasafal opened on Oct 25, 2026 · 3.40.0
  4

  

• Bug: POWERTOOLS_METRICS_DISABLED is ignored by single_metric, the cold start metric, add_metric auto-flush and Datadog's lambda_metric

  bugmetrics
  aws-powertools/powertools-lambda-python#8667 · Filter by author soujasK opened on Oct 25, 2026 · 3.40.0
  2

  

• fix(idempotency): keep the payload hash when completing records in the Redis layer

  size/Mtests
  Unread
  aws-powertools/powertools-lambda-python#8656·thebadalov opened Oct 24, 2026 · Updated Oct 25, 2026
  2

  

• fix(batch): report records that fail model conversion with non-validation errors

  size/Mtests
  Unread
  aws-powertools/powertools-lambda-python#8662·soujasK opened Oct 25, 2026 · Updated Oct 26, 2026
  2

  

• fix(batch): report short-circuited FIFO records that don't match the model

  size/Mtests
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  aws-powertools/powertools-lambda-python#8663·soujasK opened Oct 25, 2026 · Updated Oct 26, 2026
  1

  

• fix(idempotency): warn when a persistence layer is reused with a different config

  documentationsize/Mtests
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  aws-powertools/powertools-lambda-python#8664·soujasK opened Oct 25, 2026 · Updated Oct 25, 2026
  1

  

• fix(metrics): respect POWERTOOLS_METRICS_DISABLED in every emission path

  metricssize/Ltests
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  aws-powertools/powertools-lambda-python#8668·soujasK opened Oct 25, 2026 · Updated Oct 25, 2026
  1

  

• fix(kafka): decode Confluent Protobuf message indexes as zigzag varints

  size/Mtests
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  aws-powertools/powertools-lambda-python#8670·alphasafal opened Oct 25, 2026 · Updated Oct 25, 2026
  2