compress otel payloads

braintrust-java-agent/smoke-test/dd-agent/src/main/java/dev/braintrust/smoketest/ddagent/MockBraintrustBackend.java

@@ -8,6 +8,7 @@
 import io.opentelemetry.proto.trace.v1.ResourceSpans;
 import io.opentelemetry.proto.trace.v1.ScopeSpans;
 import io.opentelemetry.proto.trace.v1.Span;
+import java.io.ByteArrayInputStream;
 import java.io.IOException;
 import java.net.InetSocketAddress;
 import java.util.ArrayList;
@@ -18,6 +19,7 @@
 import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
+import java.util.zip.GZIPInputStream;
 
 /**
  * A mock Braintrust OTLP backend that captures trace export requests sent to {@code POST
@@ -219,6 +221,7 @@ private void handleTraces(HttpExchange exchange) throws IOException {
             return;
         }
         byte[] body = exchange.getRequestBody().readAllBytes();
+        body = maybeDecompress(exchange, body);
         List<OtlpSpan> spans = new ArrayList<>();
         try {
             ExportTraceServiceRequest request = ExportTraceServiceRequest.parseFrom(body);
@@ -269,4 +272,13 @@ private void handleDefault(HttpExchange exchange) throws IOException {
         exchange.sendResponseHeaders(404, -1);
         exchange.close();
     }
+
+    /** Decompress the body if the request has {@code Content-Encoding: gzip}. */
+    private static byte[] maybeDecompress(HttpExchange exchange, byte[] body) throws IOException {
+        var encoding = exchange.getRequestHeaders().getFirst("Content-Encoding");
+        if ("gzip".equalsIgnoreCase(encoding)) {
+            return new GZIPInputStream(new ByteArrayInputStream(body)).readAllBytes();
+        }
+        return body;
+    }
 }

braintrust-java-agent/smoke-test/otel-agent/src/main/java/dev/braintrust/smoketest/otelagent/MockOtlpCollector.java

@@ -8,6 +8,7 @@
 import io.opentelemetry.proto.trace.v1.ResourceSpans;
 import io.opentelemetry.proto.trace.v1.ScopeSpans;
 import io.opentelemetry.proto.trace.v1.Span;
+import java.io.ByteArrayInputStream;
 import java.io.IOException;
 import java.net.InetSocketAddress;
 import java.util.ArrayList;
@@ -17,6 +18,7 @@
 import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
+import java.util.zip.GZIPInputStream;
 
 /**
  * A minimal mock OTLP/HTTP collector that captures {@code POST /v1/traces} requests.
@@ -150,6 +152,7 @@ private void handleTraces(HttpExchange exchange) throws IOException {
             return;
         }
         byte[] body = exchange.getRequestBody().readAllBytes();
+        body = maybeDecompress(exchange, body);
         List<OtlpSpan> spans = new ArrayList<>();
         try {
             ExportTraceServiceRequest req = ExportTraceServiceRequest.parseFrom(body);
@@ -187,4 +190,13 @@ private void handleDefault(HttpExchange exchange) throws IOException {
         exchange.sendResponseHeaders(404, -1);
         exchange.close();
     }
+
+    /** Decompress the body if the request has {@code Content-Encoding: gzip}. */
+    private static byte[] maybeDecompress(HttpExchange exchange, byte[] body) throws IOException {
+        var encoding = exchange.getRequestHeaders().getFirst("Content-Encoding");
+        if ("gzip".equalsIgnoreCase(encoding)) {
+            return new GZIPInputStream(new ByteArrayInputStream(body)).readAllBytes();
+        }
+        return body;
+    }
 }

braintrust-sdk/src/main/java/dev/braintrust/config/BraintrustConfig.java

@@ -40,6 +40,9 @@ public final class BraintrustConfig extends BaseConfig {
             Duration.ofSeconds(getConfig("BRAINTRUST_REQUEST_TIMEOUT", 30));
     private final Boolean filterAISpans = getConfig("BRAINTRUST_FILTER_AI_SPANS", false);
 
+    /** compress otel data before exporting to braintrust */
+    private final Boolean compressOtelPayload = getConfig("BRAINTRUST_COMPRESS_OTEL_PAYLOAD", true);
+
     /** Custom SSL context for OTLP exporter. Builder-only field, not backed by envars. */
     private final SSLContext sslContext;
 
@@ -190,6 +193,11 @@ public Builder filterAISpans(boolean value) {
             return this;
         }
 
+        public Builder compressOtelPayload(boolean value) {
+            envOverrides.put("BRAINTRUST_COMPRESS_OTEL_PAYLOAD", String.valueOf(value));
+            return this;
+        }
+
         public Builder sslContext(SSLContext value) {
             this.sslContext = value;
             return this;

braintrust-sdk/src/main/java/dev/braintrust/trace/BraintrustLogExporter.java

@@ -74,7 +74,8 @@ private CompletableResultCode exportWithParent(String parent, List<LogRecordData
                                                 .addHeader(
                                                         "Authorization",
                                                         "Bearer " + config.apiKey())
-                                                .setTimeout(config.requestTimeout());
+                                                .setTimeout(config.requestTimeout())
+                                                .setCompression("gzip");
 
                                 // Add x-bt-parent header if we have a parent
                                 if (!p.isEmpty()) {

braintrust-sdk/src/main/java/dev/braintrust/trace/BraintrustSpanExporter.java

@@ -78,7 +78,9 @@ private CompletableResultCode exportWithParent(String parent, List<SpanData> spa
                                                         "Authorization",
                                                         "Bearer " + config.apiKey())
                                                 .setTimeout(config.requestTimeout());
-
+                                if (config.compressOtelPayload()) {
+                                    exporterBuilder.setCompression("gzip");
+                                }
                                 // Add x-bt-parent header if we have a parent
                                 if (!p.isEmpty()) {
                                     exporterBuilder.addHeader("x-bt-parent", p);