diff --git a/opentelemetry/proto/collector/logs/v1/logs_service.proto b/opentelemetry/proto/collector/logs/v1/logs_service.proto
index 8df23c6c..fae46603 100644
--- a/opentelemetry/proto/collector/logs/v1/logs_service.proto
+++ b/opentelemetry/proto/collector/logs/v1/logs_service.proto
@@ -42,6 +42,16 @@ message ExportLogsServiceRequest {
   // data from multiple origins typically batch the data before forwarding further and
   // in that case this array will contain multiple elements.
   repeated opentelemetry.proto.logs.v1.ResourceLogs resource_logs = 1;
+
+  // An idempotency key is optional information used in a server to
+  // detect retried requests and avoid double-counting of logging
+  // events.
+  //
+  // OTLP clients SHOULD include an idempotency key.  Empty
+  // idempotency keys are invalid and MUST be ignored.  A 128-bit V4
+  // UUID (https://tools.ietf.org/html/rfc4122) is the
+  // recommended idempotency key format.
+  bytes idempotency_key = 2;
 }
 
 message ExportLogsServiceResponse {
diff --git a/opentelemetry/proto/collector/metrics/v1/metrics_service.proto b/opentelemetry/proto/collector/metrics/v1/metrics_service.proto
index 5a3cbee4..b96e9dea 100644
--- a/opentelemetry/proto/collector/metrics/v1/metrics_service.proto
+++ b/opentelemetry/proto/collector/metrics/v1/metrics_service.proto
@@ -39,6 +39,16 @@ message ExportMetricsServiceRequest {
   // data from multiple origins typically batch the data before forwarding further and
   // in that case this array will contain multiple elements.
   repeated opentelemetry.proto.metrics.v1.ResourceMetrics resource_metrics = 1;
+
+  // An idempotency key is optional information used in a server to
+  // detect retried requests and avoid double-counting of metric
+  // events.
+  //
+  // OTLP clients SHOULD include an idempotency key.  Empty
+  // idempotency keys are invalid and MUST be ignored.  A 128-bit V4
+  // UUID (https://tools.ietf.org/html/rfc4122) is the
+  // recommended idempotency key format.
+  bytes idempotency_key = 2;
 }
 
 message ExportMetricsServiceResponse {
diff --git a/opentelemetry/proto/collector/trace/v1/trace_service.proto b/opentelemetry/proto/collector/trace/v1/trace_service.proto
index 37d02372..be87c607 100644
--- a/opentelemetry/proto/collector/trace/v1/trace_service.proto
+++ b/opentelemetry/proto/collector/trace/v1/trace_service.proto
@@ -39,6 +39,16 @@ message ExportTraceServiceRequest {
   // data from multiple origins typically batch the data before forwarding further and
   // in that case this array will contain multiple elements.
   repeated opentelemetry.proto.trace.v1.ResourceSpans resource_spans = 1;
+
+  // An idempotency key is optional information used in a server to
+  // detect retried requests and avoid double-counting of tracinfg
+  // events.
+  //
+  // OTLP clients SHOULD include an idempotency key.  Empty
+  // idempotency keys are invalid and MUST be ignored.  A 128-bit V4
+  // UUID (https://tools.ietf.org/html/rfc4122) is the
+  // recommended idempotency key format.
+  bytes idempotency_key = 2;
 }
 
 message ExportTraceServiceResponse {