diff --git a/dd-trace-core/src/main/java/datadog/trace/core/DDSpan.java b/dd-trace-core/src/main/java/datadog/trace/core/DDSpan.java
index 772cbe90866..2c2e5d9d1f2 100644
--- a/dd-trace-core/src/main/java/datadog/trace/core/DDSpan.java
+++ b/dd-trace-core/src/main/java/datadog/trace/core/DDSpan.java
@@ -116,7 +116,8 @@ static DDSpan create(
    */
   private volatile int longRunningVersion = 0;
 
-  protected final List<AgentSpanLink> links;
+  private static final List<AgentSpanLink> EMPTY = Collections.emptyList();
+  protected volatile List<AgentSpanLink> links;
 
   /**
    * Spans should be constructed using the builder, not by calling the constructor directly.
@@ -144,7 +145,7 @@ private DDSpan(
       context.getTraceCollector().touch(); // external clock: explicitly update lastReferenced
     }
 
-    this.links = links == null ? new CopyOnWriteArrayList<>() : new CopyOnWriteArrayList<>(links);
+    this.links = links == null || links.isEmpty() ? EMPTY : new CopyOnWriteArrayList<>(links);
   }
 
   public boolean isFinished() {
@@ -764,12 +765,12 @@ public CharSequence getType() {
 
   @Override
   public void processServiceTags() {
-    context.earlyProcessTags(links);
+    context.earlyProcessTags(this);
   }
 
   @Override
   public void processTagsAndBaggage(final MetadataConsumer consumer) {
-    context.processTagsAndBaggage(consumer, longRunningVersion, links);
+    context.processTagsAndBaggage(consumer, longRunningVersion, this);
   }
 
   @Override
@@ -883,10 +884,44 @@ public TraceConfig traceConfig() {
     return context.getTraceCollector().getTraceConfig();
   }
 
+  List<? extends AgentSpanLink> getLinks() {
+    return this.links;
+  }
+
   @Override
   public void addLink(AgentSpanLink link) {
-    if (link != null) {
-      this.links.add(link);
+    if (link == null) {
+      return;
+    }
+
+    // If links are initially null / empty, then the shared placeholder List EMPTY is used.
+    // Bacause EMPTY is shared, EMPTY is safe for reading, but not for writing.
+    // On write - if links is the EMPTY placeholder, then need to create a CopyOnWriteArrayList
+    // owned by this DDSpan
+
+    // Creation of the CopyOnWriteArrayList is done via double checking locking using volatile &
+    // synchronized
+
+    // If before or inside the synchronized block, links no longer points to EMPTY,
+    // then this thread or another thread has already handled the list construction,
+    // so just add to the list
+
+    // If links still points to EMPTY inside the synchronized block, then construct a new
+    // CopyOnWriteArrayList containing the newly added link
+
+    List<AgentSpanLink> links = this.links;
+    if (links != EMPTY) {
+      links.add(link);
+      return;
+    }
+
+    synchronized (this) {
+      links = this.links;
+      if (links != EMPTY) {
+        links.add(link);
+      } else {
+        this.links = new CopyOnWriteArrayList<>(Collections.singletonList(link));
+      }
     }
   }
 
diff --git a/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java b/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java
index a17d7684a71..2b8dbccb738 100644
--- a/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java
+++ b/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java
@@ -24,7 +24,7 @@
 import datadog.trace.api.sampling.PrioritySampling;
 import datadog.trace.api.sampling.SamplingMechanism;
 import datadog.trace.bootstrap.instrumentation.api.AgentSpanContext;
-import datadog.trace.bootstrap.instrumentation.api.AgentSpanLink;
+import datadog.trace.bootstrap.instrumentation.api.AppendableSpanLinks;
 import datadog.trace.bootstrap.instrumentation.api.Baggage;
 import datadog.trace.bootstrap.instrumentation.api.ProfilerContext;
 import datadog.trace.bootstrap.instrumentation.api.ProfilingContextIntegration;
@@ -1087,19 +1087,24 @@ public <T> void setMetaStruct(final String field, final T value) {
     }
   }
 
-  public void earlyProcessTags(List<AgentSpanLink> links) {
+  void earlyProcessTags(AppendableSpanLinks links) {
     synchronized (unsafeTags) {
       TagsPostProcessorFactory.eagerProcessor().processTags(unsafeTags, this, links);
     }
   }
 
-  public void processTagsAndBaggage(
-      final MetadataConsumer consumer, int longRunningVersion, List<AgentSpanLink> links) {
+  void processTagsAndBaggage(
+      final MetadataConsumer consumer, int longRunningVersion, DDSpan restrictedSpan) {
+    // NOTE: The span is passed for the sole purpose of allowing updating & reading of the span
+    // links
+    // This is a compromise to avoid...
+    // - creating an extra wrapper object that would create significant allocation
+    // - implementing an interface to read the spans that require making the read method public
     synchronized (unsafeTags) {
       // Tags
-      TagsPostProcessorFactory.lazyProcessor().processTags(unsafeTags, this, links);
+      TagsPostProcessorFactory.lazyProcessor().processTags(unsafeTags, this, restrictedSpan);
 
-      String linksTag = DDSpanLink.toTag(links);
+      String linksTag = DDSpanLink.toTag(restrictedSpan.getLinks());
       if (linksTag != null) {
         unsafeTags.put(SPAN_LINKS, linksTag);
       }
diff --git a/dd-trace-core/src/main/java/datadog/trace/core/DDSpanLink.java b/dd-trace-core/src/main/java/datadog/trace/core/DDSpanLink.java
index d6c16c7b02e..efcaafc7016 100644
--- a/dd-trace-core/src/main/java/datadog/trace/core/DDSpanLink.java
+++ b/dd-trace-core/src/main/java/datadog/trace/core/DDSpanLink.java
@@ -69,7 +69,7 @@ public static SpanLink from(ExtractedContext context, SpanAttributes attributes)
    * @param links The span link collection to encode.
    * @return The encoded tag value, {@code null} if no links.
    */
-  public static String toTag(List<AgentSpanLink> links) {
+  public static String toTag(List<? extends AgentSpanLink> links) {
     if (links == null || links.isEmpty()) {
       return null;
     }
diff --git a/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/HttpEndpointPostProcessor.java b/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/HttpEndpointPostProcessor.java
index 05ff83d8fda..340a5d82649 100644
--- a/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/HttpEndpointPostProcessor.java
+++ b/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/HttpEndpointPostProcessor.java
@@ -6,9 +6,8 @@
 
 import datadog.trace.api.TagMap;
 import datadog.trace.api.endpoint.EndpointResolver;
-import datadog.trace.bootstrap.instrumentation.api.AgentSpanLink;
+import datadog.trace.bootstrap.instrumentation.api.AppendableSpanLinks;
 import datadog.trace.core.DDSpanContext;
-import java.util.List;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -56,7 +55,7 @@ public HttpEndpointPostProcessor() {
 
   @Override
   public void processTags(
-      TagMap unsafeTags, DDSpanContext spanContext, List<AgentSpanLink> spanLinks) {
+      TagMap unsafeTags, DDSpanContext spanContext, AppendableSpanLinks spanLinks) {
     if (!endpointResolver.isEnabled()) {
       log.debug("EndpointResolver is not enabled, skipping HTTP endpoint post processing");
       return;
diff --git a/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/IntegrationAdder.java b/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/IntegrationAdder.java
index 87024d057bd..0aabbc29c47 100644
--- a/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/IntegrationAdder.java
+++ b/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/IntegrationAdder.java
@@ -3,14 +3,13 @@
 import static datadog.trace.api.DDTags.DD_INTEGRATION;
 
 import datadog.trace.api.TagMap;
-import datadog.trace.bootstrap.instrumentation.api.AgentSpanLink;
+import datadog.trace.bootstrap.instrumentation.api.AppendableSpanLinks;
 import datadog.trace.core.DDSpanContext;
-import java.util.List;
 
 public class IntegrationAdder extends TagsPostProcessor {
   @Override
   public void processTags(
-      TagMap unsafeTags, DDSpanContext spanContext, List<AgentSpanLink> spanLinks) {
+      TagMap unsafeTags, DDSpanContext spanContext, AppendableSpanLinks spanLinks) {
     final CharSequence instrumentationName = spanContext.getIntegrationName();
     if (instrumentationName != null) {
       unsafeTags.set(DD_INTEGRATION, instrumentationName);
diff --git a/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/InternalTagsAdder.java b/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/InternalTagsAdder.java
index 6fed132a68f..68b13d19faf 100644
--- a/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/InternalTagsAdder.java
+++ b/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/InternalTagsAdder.java
@@ -4,10 +4,9 @@
 
 import datadog.trace.api.DDTags;
 import datadog.trace.api.TagMap;
-import datadog.trace.bootstrap.instrumentation.api.AgentSpanLink;
+import datadog.trace.bootstrap.instrumentation.api.AppendableSpanLinks;
 import datadog.trace.bootstrap.instrumentation.api.UTF8BytesString;
 import datadog.trace.core.DDSpanContext;
-import java.util.List;
 import javax.annotation.Nullable;
 
 public final class InternalTagsAdder extends TagsPostProcessor {
@@ -21,7 +20,7 @@ public InternalTagsAdder(@Nullable final String ddService, @Nullable final Strin
 
   @Override
   public void processTags(
-      TagMap unsafeTags, DDSpanContext spanContext, List<AgentSpanLink> spanLinks) {
+      TagMap unsafeTags, DDSpanContext spanContext, AppendableSpanLinks spanLinks) {
     if (spanContext == null || ddService == null) {
       return;
     }
diff --git a/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/PayloadTagsProcessor.java b/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/PayloadTagsProcessor.java
index c04c8239e44..0fdb962aa12 100644
--- a/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/PayloadTagsProcessor.java
+++ b/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/PayloadTagsProcessor.java
@@ -7,7 +7,7 @@
 import datadog.trace.api.ConfigDefaults;
 import datadog.trace.api.TagMap;
 import datadog.trace.api.telemetry.LogCollector;
-import datadog.trace.bootstrap.instrumentation.api.AgentSpanLink;
+import datadog.trace.bootstrap.instrumentation.api.AppendableSpanLinks;
 import datadog.trace.core.DDSpanContext;
 import datadog.trace.core.util.JsonStreamParser;
 import datadog.trace.payloadtags.PayloadTagsData;
@@ -72,7 +72,7 @@ public static PayloadTagsProcessor create(Config config) {
 
   @Override
   public void processTags(
-      TagMap unsafeTags, DDSpanContext spanContext, List<AgentSpanLink> spanLinks) {
+      TagMap unsafeTags, DDSpanContext spanContext, AppendableSpanLinks spanLinks) {
     int spanMaxTags = maxTags + unsafeTags.size();
     for (Map.Entry<String, RedactionRules> tagPrefixRedactionRules :
         redactionRulesByTagPrefix.entrySet()) {
diff --git a/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/PeerServiceCalculator.java b/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/PeerServiceCalculator.java
index 9a4e9377cb9..ed1fee8b2d6 100644
--- a/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/PeerServiceCalculator.java
+++ b/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/PeerServiceCalculator.java
@@ -5,10 +5,9 @@
 import datadog.trace.api.TagMap;
 import datadog.trace.api.naming.NamingSchema;
 import datadog.trace.api.naming.SpanNaming;
-import datadog.trace.bootstrap.instrumentation.api.AgentSpanLink;
+import datadog.trace.bootstrap.instrumentation.api.AppendableSpanLinks;
 import datadog.trace.bootstrap.instrumentation.api.Tags;
 import datadog.trace.core.DDSpanContext;
-import java.util.List;
 import java.util.Map;
 import javax.annotation.Nonnull;
 
@@ -34,7 +33,7 @@ public PeerServiceCalculator() {
 
   @Override
   public void processTags(
-      TagMap unsafeTags, DDSpanContext spanContext, List<AgentSpanLink> spanLinks) {
+      TagMap unsafeTags, DDSpanContext spanContext, AppendableSpanLinks spanLinks) {
     Object peerService = unsafeTags.getObject(Tags.PEER_SERVICE);
     // the user set it
     if (peerService != null) {
diff --git a/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/PostProcessorChain.java b/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/PostProcessorChain.java
index 77374d742cb..2a2668e1b6b 100644
--- a/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/PostProcessorChain.java
+++ b/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/PostProcessorChain.java
@@ -1,9 +1,8 @@
 package datadog.trace.core.tagprocessor;
 
 import datadog.trace.api.TagMap;
-import datadog.trace.bootstrap.instrumentation.api.AgentSpanLink;
+import datadog.trace.bootstrap.instrumentation.api.AppendableSpanLinks;
 import datadog.trace.core.DDSpanContext;
-import java.util.List;
 import java.util.Objects;
 import javax.annotation.Nonnull;
 
@@ -16,7 +15,7 @@ public PostProcessorChain(@Nonnull final TagsPostProcessor... processors) {
 
   @Override
   public void processTags(
-      TagMap unsafeTags, DDSpanContext spanContext, List<AgentSpanLink> spanLinks) {
+      TagMap unsafeTags, DDSpanContext spanContext, AppendableSpanLinks spanLinks) {
     for (final TagsPostProcessor tagsPostProcessor : chain) {
       tagsPostProcessor.processTags(unsafeTags, spanContext, spanLinks);
     }
diff --git a/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/QueryObfuscator.java b/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/QueryObfuscator.java
index 37bbd470596..a1594e33eb6 100644
--- a/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/QueryObfuscator.java
+++ b/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/QueryObfuscator.java
@@ -5,11 +5,10 @@
 import com.google.re2j.PatternSyntaxException;
 import datadog.trace.api.DDTags;
 import datadog.trace.api.TagMap;
-import datadog.trace.bootstrap.instrumentation.api.AgentSpanLink;
+import datadog.trace.bootstrap.instrumentation.api.AppendableSpanLinks;
 import datadog.trace.bootstrap.instrumentation.api.Tags;
 import datadog.trace.core.DDSpanContext;
 import datadog.trace.util.Strings;
-import java.util.List;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -59,7 +58,7 @@ private String obfuscate(String query) {
 
   @Override
   public void processTags(
-      TagMap unsafeTags, DDSpanContext spanContext, List<AgentSpanLink> spanLinks) {
+      TagMap unsafeTags, DDSpanContext spanContext, AppendableSpanLinks spanLinks) {
     Object query = unsafeTags.getObject(DDTags.HTTP_QUERY);
     if (query instanceof CharSequence) {
       query = obfuscate(query.toString());
diff --git a/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/RemoteHostnameAdder.java b/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/RemoteHostnameAdder.java
index 7bd45cd2c92..41947b375d8 100644
--- a/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/RemoteHostnameAdder.java
+++ b/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/RemoteHostnameAdder.java
@@ -2,9 +2,8 @@
 
 import datadog.trace.api.DDTags;
 import datadog.trace.api.TagMap;
-import datadog.trace.bootstrap.instrumentation.api.AgentSpanLink;
+import datadog.trace.bootstrap.instrumentation.api.AppendableSpanLinks;
 import datadog.trace.core.DDSpanContext;
-import java.util.List;
 import java.util.function.Supplier;
 
 public final class RemoteHostnameAdder extends TagsPostProcessor {
@@ -16,7 +15,7 @@ public RemoteHostnameAdder(Supplier<String> hostnameSupplier) {
 
   @Override
   public void processTags(
-      TagMap unsafeTags, DDSpanContext spanContext, List<AgentSpanLink> spanLinks) {
+      TagMap unsafeTags, DDSpanContext spanContext, AppendableSpanLinks spanLinks) {
     if (spanContext.getSpanId() == spanContext.getRootSpanId()) {
       unsafeTags.put(DDTags.TRACER_HOST, hostnameSupplier.get());
     }
diff --git a/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/ServiceNameSourceAdder.java b/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/ServiceNameSourceAdder.java
index 0d1eb95a570..4b081889039 100644
--- a/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/ServiceNameSourceAdder.java
+++ b/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/ServiceNameSourceAdder.java
@@ -3,14 +3,13 @@
 import static datadog.trace.api.DDTags.DD_SVC_SRC;
 
 import datadog.trace.api.TagMap;
-import datadog.trace.bootstrap.instrumentation.api.AgentSpanLink;
+import datadog.trace.bootstrap.instrumentation.api.AppendableSpanLinks;
 import datadog.trace.core.DDSpanContext;
-import java.util.List;
 
 public class ServiceNameSourceAdder extends TagsPostProcessor {
   @Override
   public void processTags(
-      TagMap unsafeTags, DDSpanContext spanContext, List<AgentSpanLink> spanLinks) {
+      TagMap unsafeTags, DDSpanContext spanContext, AppendableSpanLinks spanLinks) {
     final CharSequence serviceNameSource = spanContext.getServiceNameSource();
     if (serviceNameSource != null) {
       unsafeTags.set(DD_SVC_SRC, serviceNameSource);
diff --git a/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/SpanPointersProcessor.java b/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/SpanPointersProcessor.java
index 8282583cbf2..b0d252db980 100644
--- a/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/SpanPointersProcessor.java
+++ b/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/SpanPointersProcessor.java
@@ -13,6 +13,7 @@
 
 import datadog.trace.api.TagMap;
 import datadog.trace.bootstrap.instrumentation.api.AgentSpanLink;
+import datadog.trace.bootstrap.instrumentation.api.AppendableSpanLinks;
 import datadog.trace.bootstrap.instrumentation.api.SpanAttributes;
 import datadog.trace.bootstrap.instrumentation.api.SpanLink;
 import datadog.trace.core.DDSpanContext;
@@ -21,7 +22,6 @@
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
 import java.util.Arrays;
-import java.util.List;
 import java.util.Map;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -38,16 +38,16 @@ public class SpanPointersProcessor extends TagsPostProcessor {
 
   @Override
   public void processTags(
-      TagMap unsafeTags, DDSpanContext spanContext, List<AgentSpanLink> spanLinks) {
+      TagMap unsafeTags, DDSpanContext spanContext, AppendableSpanLinks spanLinks) {
     // DQH - TODO - There's a lot room to optimize this using TagMap's capabilities
     AgentSpanLink s3Link = handleS3SpanPointer(unsafeTags);
     if (s3Link != null) {
-      spanLinks.add(s3Link);
+      spanLinks.addLink(s3Link);
     }
 
     AgentSpanLink dynamoDbLink = handleDynamoDbSpanPointer(unsafeTags);
     if (dynamoDbLink != null) {
-      spanLinks.add(dynamoDbLink);
+      spanLinks.addLink(dynamoDbLink);
     }
   }
 
diff --git a/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/TagsPostProcessor.java b/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/TagsPostProcessor.java
index d0acedb40ee..e0c27e50aec 100644
--- a/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/TagsPostProcessor.java
+++ b/dd-trace-core/src/main/java/datadog/trace/core/tagprocessor/TagsPostProcessor.java
@@ -1,23 +1,10 @@
 package datadog.trace.core.tagprocessor;
 
 import datadog.trace.api.TagMap;
-import datadog.trace.bootstrap.instrumentation.api.AgentSpanLink;
+import datadog.trace.bootstrap.instrumentation.api.AppendableSpanLinks;
 import datadog.trace.core.DDSpanContext;
-import java.util.List;
-import java.util.Map;
 
 public abstract class TagsPostProcessor {
-  /*
-   * DQH - For testing purposes only
-   */
-  @Deprecated
-  final Map<String, Object> processTags(
-      Map<String, Object> unsafeTags, DDSpanContext context, List<AgentSpanLink> links) {
-    TagMap map = TagMap.fromMap(unsafeTags);
-    this.processTags(map, context, links);
-    return map;
-  }
-
   public abstract void processTags(
-      TagMap unsafeTags, DDSpanContext spanContext, List<AgentSpanLink> spanLinks);
+      TagMap unsafeTags, DDSpanContext spanContext, AppendableSpanLinks spanLinks);
 }
diff --git a/dd-trace-core/src/test/groovy/datadog/trace/core/tagprocessor/HttpEndpointPostProcessorTest.groovy b/dd-trace-core/src/test/groovy/datadog/trace/core/tagprocessor/HttpEndpointPostProcessorTest.groovy
index f343620dd48..ca43d9b6236 100644
--- a/dd-trace-core/src/test/groovy/datadog/trace/core/tagprocessor/HttpEndpointPostProcessorTest.groovy
+++ b/dd-trace-core/src/test/groovy/datadog/trace/core/tagprocessor/HttpEndpointPostProcessorTest.groovy
@@ -2,6 +2,7 @@ package datadog.trace.core.tagprocessor
 
 import datadog.trace.api.TagMap
 import datadog.trace.bootstrap.instrumentation.api.Tags
+import datadog.trace.bootstrap.instrumentation.api.AppendableSpanLinks
 import datadog.trace.core.DDSpanContext
 import datadog.trace.api.endpoint.EndpointResolver
 import spock.lang.Specification
@@ -15,6 +16,7 @@ class HttpEndpointPostProcessorTest extends Specification {
     def endpointResolver = new EndpointResolver(true, false)
     def processor = new HttpEndpointPostProcessor(endpointResolver)
     def mockContext = Mock(DDSpanContext)
+    def mockSpanLinks = Mock(AppendableSpanLinks)
     def tags = TagMap.fromMap([
       (Tags.HTTP_METHOD): "GET",
       (Tags.HTTP_ROUTE): "/greeting",
@@ -22,7 +24,7 @@ class HttpEndpointPostProcessorTest extends Specification {
     ])
 
     when:
-    processor.processTags(tags, mockContext, [])
+    processor.processTags(tags, mockContext, mockSpanLinks)
 
     then:
     0 * mockContext.setResourceName(_, _)
@@ -35,6 +37,7 @@ class HttpEndpointPostProcessorTest extends Specification {
     def endpointResolver = new EndpointResolver(true, false)
     def processor = new HttpEndpointPostProcessor(endpointResolver)
     def mockContext = Mock(DDSpanContext)
+    def mockSpanLinks = Mock(AppendableSpanLinks)
     def tags = TagMap.fromMap([
       (Tags.HTTP_METHOD): "GET",
       (Tags.HTTP_ROUTE): "*",  // catch-all — ineligible per RFC-1051
@@ -42,7 +45,7 @@ class HttpEndpointPostProcessorTest extends Specification {
     ])
 
     when:
-    processor.processTags(tags, mockContext, [])
+    processor.processTags(tags, mockContext, mockSpanLinks)
 
     then:
     0 * mockContext.setResourceName(_, _)
@@ -54,12 +57,13 @@ class HttpEndpointPostProcessorTest extends Specification {
     def endpointResolver = new EndpointResolver(true, false)
     def processor = new HttpEndpointPostProcessor(endpointResolver)
     def mockContext = Mock(DDSpanContext)
-    def tags = [
+    def mockSpanLinks = Mock(AppendableSpanLinks)
+    def tags = TagMap.fromMap([
       "db.statement": "SELECT * FROM users"
-    ]
+    ])
 
     when:
-    processor.processTags(tags, mockContext, [])
+    processor.processTags(tags, mockContext, mockSpanLinks)
 
     then:
     0 * mockContext.setResourceName(_, _)
@@ -71,13 +75,14 @@ class HttpEndpointPostProcessorTest extends Specification {
     def endpointResolver = new EndpointResolver(false, false)
     def processor = new HttpEndpointPostProcessor(endpointResolver)
     def mockContext = Mock(DDSpanContext)
-    def tags = [
+    def mockSpanLinks = Mock(AppendableSpanLinks)
+    def tags = TagMap.fromMap([
       (Tags.HTTP_METHOD): "GET",
       (Tags.HTTP_ROUTE): "/greeting"
-    ]
+    ])
 
     when:
-    processor.processTags(tags, mockContext, [])
+    processor.processTags(tags, mockContext, mockSpanLinks)
 
     then:
     0 * mockContext.setResourceName(_, _)
@@ -89,6 +94,7 @@ class HttpEndpointPostProcessorTest extends Specification {
     def endpointResolver = new EndpointResolver(true, true)
     def processor = new HttpEndpointPostProcessor(endpointResolver)
     def mockContext = Mock(DDSpanContext)
+    def mockSpanLinks = Mock(AppendableSpanLinks)
     def tags = TagMap.fromMap([
       (Tags.HTTP_METHOD): "GET",
       (Tags.HTTP_ROUTE): "/greeting",
@@ -96,7 +102,7 @@ class HttpEndpointPostProcessorTest extends Specification {
     ])
 
     when:
-    processor.processTags(tags, mockContext, [])
+    processor.processTags(tags, mockContext, mockSpanLinks)
 
     then:
     0 * mockContext.setResourceName(_, _)
diff --git a/dd-trace-core/src/test/groovy/datadog/trace/core/tagprocessor/IntegrationAdderTest.groovy b/dd-trace-core/src/test/groovy/datadog/trace/core/tagprocessor/IntegrationAdderTest.groovy
index 1e044aebfec..e8a17de339f 100644
--- a/dd-trace-core/src/test/groovy/datadog/trace/core/tagprocessor/IntegrationAdderTest.groovy
+++ b/dd-trace-core/src/test/groovy/datadog/trace/core/tagprocessor/IntegrationAdderTest.groovy
@@ -1,6 +1,6 @@
 package datadog.trace.core.tagprocessor
 
-
+import datadog.trace.api.TagMap
 import datadog.trace.core.DDSpanContext
 import datadog.trace.test.util.DDSpecification
 
@@ -11,14 +11,14 @@ class IntegrationAdderTest extends DDSpecification {
     def spanContext = Mock(DDSpanContext)
 
     when:
-
-    def enrichedTags = calculator.processTags(["_dd.integration": "bad"], spanContext, [])
+    def unsafeTags = TagMap.fromMap(["_dd.integration": "bad"])
+    calculator.processTags(unsafeTags, spanContext, {link -> })
 
     then:
     1 * spanContext.getIntegrationName() >> (isSet ? "test" : null)
 
     and:
-    assert enrichedTags == (isSet ? ["_dd.integration": "test"] : [:])
+    assert unsafeTags == (isSet ? ["_dd.integration": "test"] : [:])
 
     where:
     isSet  << [true, false]
diff --git a/dd-trace-core/src/test/groovy/datadog/trace/core/tagprocessor/InternalTagsAdderTest.groovy b/dd-trace-core/src/test/groovy/datadog/trace/core/tagprocessor/InternalTagsAdderTest.groovy
index 6416b23e67e..5429a9e8b24 100644
--- a/dd-trace-core/src/test/groovy/datadog/trace/core/tagprocessor/InternalTagsAdderTest.groovy
+++ b/dd-trace-core/src/test/groovy/datadog/trace/core/tagprocessor/InternalTagsAdderTest.groovy
@@ -2,6 +2,8 @@ package datadog.trace.core.tagprocessor
 
 import static datadog.trace.bootstrap.instrumentation.api.Tags.VERSION
 
+import datadog.trace.api.TagMap
+import datadog.trace.bootstrap.instrumentation.api.AppendableSpanLinks
 import datadog.trace.bootstrap.instrumentation.api.UTF8BytesString
 import datadog.trace.core.DDSpanContext
 import datadog.trace.test.util.DDSpecification
@@ -11,15 +13,17 @@ class InternalTagsAdderTest extends DDSpecification {
     setup:
     def calculator = new InternalTagsAdder("test", null)
     def spanContext = Mock(DDSpanContext)
+    def links = Mock(AppendableSpanLinks)
 
     when:
-    def enrichedTags = calculator.processTags([:], spanContext, [])
+    def unsafeTags = TagMap.fromMap([:])
+    calculator.processTags(unsafeTags, spanContext, links)
 
     then:
     1 * spanContext.getServiceName() >> serviceName
 
     and:
-    assert enrichedTags == expectedTags
+    assert unsafeTags == expectedTags
 
     where:
     serviceName  | expectedTags
@@ -32,15 +36,17 @@ class InternalTagsAdderTest extends DDSpecification {
     setup:
     def calculator = new InternalTagsAdder("same", ddVersion)
     def spanContext = Mock(DDSpanContext)
+    def links = Mock(AppendableSpanLinks)
 
     when:
-    def enrichedTags = calculator.processTags(tags, spanContext, [])
+    def unsafeTags = TagMap.fromMap(tags)
+    calculator.processTags(unsafeTags, spanContext, links)
 
     then:
     1 * spanContext.getServiceName() >> serviceName
 
     and:
-    assert enrichedTags?.get(VERSION)?.toString() == expected
+    assert unsafeTags?.get(VERSION)?.toString() == expected
 
 
     where:
diff --git a/dd-trace-core/src/test/groovy/datadog/trace/core/tagprocessor/PayloadTagsProcessorTest.groovy b/dd-trace-core/src/test/groovy/datadog/trace/core/tagprocessor/PayloadTagsProcessorTest.groovy
index b5f97c053ca..5b871052d99 100644
--- a/dd-trace-core/src/test/groovy/datadog/trace/core/tagprocessor/PayloadTagsProcessorTest.groovy
+++ b/dd-trace-core/src/test/groovy/datadog/trace/core/tagprocessor/PayloadTagsProcessorTest.groovy
@@ -6,6 +6,7 @@ import datadog.trace.payloadtags.PayloadTagsData.PathAndValue
 import datadog.trace.util.json.PathCursor
 import datadog.trace.test.util.DDSpecification
 import datadog.trace.api.Config
+import datadog.trace.api.TagMap
 import okio.Buffer
 import java.time.Instant
 
@@ -81,8 +82,12 @@ class PayloadTagsProcessorTest extends DDSpecification {
       "payload": new PayloadTagsData([] as PathAndValue[])
     ]
 
-    expect:
-    ptp.processTags(spanTags, null, []) == ["foo": "bar", "tag1": 1]
+    when:
+    def unsafeTags = TagMap.fromMap(spanTags)
+    ptp.processTags(unsafeTags, null, {link -> })
+
+    then:
+    unsafeTags == ["foo": "bar", "tag1": 1]
   }
 
   static PathAndValue pv(PathCursor path, Object value) {
@@ -106,8 +111,12 @@ class PayloadTagsProcessorTest extends DDSpecification {
       "payload": payloadData([pv(pc().push("tag1"), 0)])
     ]
 
-    expect:
-    ptp.processTags(spanTags, null, []) == ["foo": "bar", "tag1": 1, "payload.tag1": 0]
+    when:
+    def unsafeTags = TagMap.fromMap(spanTags)
+    ptp.processTags(unsafeTags, null, {link -> })
+
+    then:
+    unsafeTags == ["foo": "bar", "tag1": 1, "payload.tag1": 0]
   }
 
   def "expand preserving tag types"() {
@@ -123,8 +132,12 @@ class PayloadTagsProcessorTest extends DDSpecification {
       pv(pc().push("tag6"), false),
     ])
 
-    expect:
-    ptp.processTags(st, null, []) == [
+    when:
+    def unsafeTags = TagMap.fromMap(st)
+    ptp.processTags(unsafeTags, null, {link -> })
+
+    then:
+    unsafeTags == [
       "payload.tag1": 11,
       "payload.tag2.Value": 2342l,
       "payload.tag3.0": 3.14d,
@@ -141,8 +154,12 @@ class PayloadTagsProcessorTest extends DDSpecification {
 
     def st = spanTags("payload", [pv(pc().push("tag7"), unknownValue),])
 
-    expect:
-    ptp.processTags(st, null, []) == [
+    when:
+    def unsafeTags = TagMap.fromMap(st)
+    ptp.processTags(unsafeTags, null, {link ->})
+
+    then:
+    unsafeTags == [
       "payload.tag7": unknownValue.toString(),
     ]
   }
@@ -158,8 +175,12 @@ class PayloadTagsProcessorTest extends DDSpecification {
       pv(pc().push("j4"), "{'foo': 'bar', 'baz': 42}"),
     ])
 
-    expect:
-    ptp.processTags(st, null, []) == [
+    when:
+    def unsafeTags = TagMap.fromMap(st)
+    ptp.processTags(unsafeTags, null, {link ->})
+
+    then:
+    unsafeTags == [
       "p.j3.0": "1",
       "p.j3.1": 2,
       "p.j3.2": 3.14d,
@@ -203,8 +224,12 @@ class PayloadTagsProcessorTest extends DDSpecification {
 
     def st = spanTags("dd", [pv(pc(), json),])
 
-    expect:
-    ptp.processTags(st, null, []) == [
+    when:
+    def unsafeTags = TagMap.fromMap(st)
+    ptp.processTags(unsafeTags, null, {link ->})
+
+    then:
+    unsafeTags == [
       'dd.a'                    : 33,
       'dd.Message.id'           : 45,
       'dd.Message.user.a'       : 1.15d,
@@ -219,8 +244,12 @@ class PayloadTagsProcessorTest extends DDSpecification {
 
     def st = spanTags("p", [pv(pc().push("key"), invalidJson),])
 
-    expect:
-    ptp.processTags(st, null, []) == [
+    when:
+    def unsafeTags = TagMap.fromMap(st)
+    ptp.processTags(unsafeTags, null, {link ->})
+
+    then:
+    unsafeTags == [
       "p.key": invalidJson,
     ]
 
@@ -245,8 +274,12 @@ class PayloadTagsProcessorTest extends DDSpecification {
       pv(pc().push("j2"), new ByteArrayInputStream("[1, true]".bytes)),
     ])
 
-    expect:
-    ptp.processTags(st, null, []) == [
+    when:
+    def unsafeTags = TagMap.fromMap(st)
+    ptp.processTags(unsafeTags, null, {link ->})
+
+    then:
+    unsafeTags == [
       "p.j1.foo": "bar",
       "p.j2.0": 1,
       "p.j2.1": true,
@@ -260,8 +293,11 @@ class PayloadTagsProcessorTest extends DDSpecification {
     when:
     def st = spanTags("p", [pv(pc().push("v"), new ByteArrayInputStream("""{ "inner": $innerJson}""".bytes))])
 
+    def unsafeTags = TagMap.fromMap(st)
+    ptp.processTags(unsafeTags, null, {link ->})
+
     then:
-    ptp.processTags(st, null, []) == [
+    unsafeTags == [
       "p.v.inner.a": 1.15d,
       "p.v.inner.password": "my-secret-password",
     ]
@@ -282,8 +318,12 @@ class PayloadTagsProcessorTest extends DDSpecification {
 
     def st = spanTags("p", [pv(pc().push("key"), new ByteArrayInputStream(invalidJson.bytes)),])
 
-    expect:
-    ptp.processTags(st, null, []) == [
+    when:
+    def unsafeTags = TagMap.fromMap(st)
+    ptp.processTags(unsafeTags, null, {link ->})
+
+    then:
+    unsafeTags == [
       "p.key": "<binary>",
     ]
 
@@ -302,8 +342,12 @@ class PayloadTagsProcessorTest extends DDSpecification {
       pv(pc().push("j4"), "{'foo': 'bar', 'baz': 42}"),
     ])
 
-    expect:
-    ptp.processTags(st, null, []) == [
+    when:
+    def unsafeTags = TagMap.fromMap(st)
+    ptp.processTags(unsafeTags, null, {link ->})
+
+    then:
+    unsafeTags == [
       "p.j3.0": "redacted",
       "p.j3.1": 2,
       "p.j3.2": 3.14d,
@@ -325,8 +369,12 @@ class PayloadTagsProcessorTest extends DDSpecification {
       pv(pc().push("j4"), "{'foo': 'bar', 'baz': 42}"),
     ])
 
-    expect:
-    ptp.processTags(st, null, []) == [
+    when:
+    def unsafeTags = TagMap.fromMap(st)
+    ptp.processTags(unsafeTags, null, {link ->})
+
+    then:
+    unsafeTags == [
       "p.j3.0": "redacted",
       "p.j3.1": 2,
       "p.j3.2": 3.14d,
@@ -344,8 +392,12 @@ class PayloadTagsProcessorTest extends DDSpecification {
       pv(pc().push("j4"), "{'foo': 'bar', 'baz': 42, 'nested': { 'a': 1, 'b': { 'c': 2 } } }"),
     ])
 
-    expect:
-    ptp.processTags(st, null, []) == [
+    when:
+    def unsafeTags = TagMap.fromMap(st)
+    ptp.processTags(unsafeTags, null, {link -> })
+
+    then:
+    unsafeTags == [
       "p.j3.0": "redacted",
       "p.j3.1": 2,
       "p.j3.2": 3.14d,
diff --git a/dd-trace-core/src/test/groovy/datadog/trace/core/tagprocessor/PeerServiceCalculatorTest.groovy b/dd-trace-core/src/test/groovy/datadog/trace/core/tagprocessor/PeerServiceCalculatorTest.groovy
index bc8281835bb..2ddf8770d1e 100644
--- a/dd-trace-core/src/test/groovy/datadog/trace/core/tagprocessor/PeerServiceCalculatorTest.groovy
+++ b/dd-trace-core/src/test/groovy/datadog/trace/core/tagprocessor/PeerServiceCalculatorTest.groovy
@@ -2,6 +2,7 @@ package datadog.trace.core.tagprocessor
 
 import datadog.trace.api.Config
 import datadog.trace.api.DDTags
+import datadog.trace.api.TagMap
 import datadog.trace.api.config.TracerConfig
 import datadog.trace.api.naming.v0.NamingSchemaV0
 import datadog.trace.api.naming.v1.NamingSchemaV1
@@ -13,10 +14,12 @@ class PeerServiceCalculatorTest extends DDSpecification {
     setup:
     def calculator = new PeerServiceCalculator(new NamingSchemaV0().peerService(), Collections.emptyMap())
     when:
-    def enrichedTags = calculator.processTags(tags, null, [])
+    def unsafeTags = TagMap.fromMap(tags)
+    calculator.processTags(unsafeTags, null, {link ->})
+
     then:
     // tags are not modified
-    assert enrichedTags == tags
+    assert unsafeTags == tags
 
     where:
     tags                                                 | _
@@ -31,13 +34,16 @@ class PeerServiceCalculatorTest extends DDSpecification {
   def "schema v1: test peer service default logic and precursors"() {
     setup:
     def calculator = new PeerServiceCalculator(new NamingSchemaV1().peerService(), Collections.emptyMap())
+
     when:
     tags.put(Tags.SPAN_KIND, Tags.SPAN_KIND_CLIENT)
-    def calculated = calculator.processTags(tags, null, [])
+
+    def unsafeTags = TagMap.fromMap(tags)
+    calculator.processTags(unsafeTags, null, {link ->})
 
     then:
-    calculated.get(DDTags.PEER_SERVICE_SOURCE) == provenance
-    calculated.get(Tags.PEER_SERVICE) == peerService
+    unsafeTags.get(DDTags.PEER_SERVICE_SOURCE) == provenance
+    unsafeTags.get(Tags.PEER_SERVICE) == peerService
 
     where:
     tags                                                                          | provenance         | peerService
@@ -55,10 +61,13 @@ class PeerServiceCalculatorTest extends DDSpecification {
     setup:
     injectSysConfig(TracerConfig.TRACE_PEER_SERVICE_DEFAULTS_ENABLED, "true")
     def calculator = new PeerServiceCalculator(new NamingSchemaV0().peerService(), Collections.emptyMap())
+
     when:
-    def calculated = calculator.processTags(["span.kind": "client", "peer.hostname": "test"], null, [])
+    def unsafeTags = TagMap.fromMap(["span.kind": "client", "peer.hostname": "test"])
+    calculator.processTags(unsafeTags, null, {link ->})
+
     then:
-    assert calculated.get(Tags.PEER_SERVICE) == "test"
+    assert unsafeTags.get(Tags.PEER_SERVICE) == "test"
   }
 
 
@@ -68,9 +77,12 @@ class PeerServiceCalculatorTest extends DDSpecification {
 
     when:
     def tags = ["span.kind": kind, "peer.hostname": "test"]
+    def unsafeTags = TagMap.fromMap(tags)
+
+    calculator.processTags(unsafeTags, null, {link -> })
 
     then:
-    assert calculator.processTags(tags, null, []).containsKey(Tags.PEER_SERVICE) == calculate
+    assert unsafeTags.containsKey(Tags.PEER_SERVICE) == calculate
 
     where:
     kind       | calculate
@@ -87,11 +99,12 @@ class PeerServiceCalculatorTest extends DDSpecification {
     def calculator = new PeerServiceCalculator(new NamingSchemaV0().peerService(), Config.get().getPeerServiceMapping())
 
     when:
-    def calculated = calculator.processTags(tags, null, [])
+    def unsafeTags = TagMap.fromMap(tags)
+    calculator.processTags(unsafeTags, null, {link ->})
 
     then:
-    assert calculated.get(Tags.PEER_SERVICE) == expected
-    assert calculated.get(DDTags.PEER_SERVICE_REMAPPED_FROM) == original
+    assert unsafeTags.get(Tags.PEER_SERVICE) == expected
+    assert unsafeTags.get(DDTags.PEER_SERVICE_REMAPPED_FROM) == original
 
     where:
     tags                                                                    | expected            | original
@@ -108,11 +121,12 @@ class PeerServiceCalculatorTest extends DDSpecification {
     def calculator = new PeerServiceCalculator(new NamingSchemaV0().peerService(), Config.get().getPeerServiceComponentOverrides())
 
     when:
-    def calculated = calculator.processTags(tags, null, [])
+    def unsafeTags = TagMap.fromMap(tags)
+    calculator.processTags(unsafeTags, null, {link -> })
 
     then:
-    assert calculated.get(Tags.PEER_SERVICE) == expected
-    assert calculated.get(DDTags.PEER_SERVICE_SOURCE) == source
+    assert unsafeTags.get(Tags.PEER_SERVICE) == expected
+    assert unsafeTags.get(DDTags.PEER_SERVICE_SOURCE) == source
 
     where:
     tags                                                                                   | expected       | source
diff --git a/dd-trace-core/src/test/groovy/datadog/trace/core/tagprocessor/PostProcessorChainTest.groovy b/dd-trace-core/src/test/groovy/datadog/trace/core/tagprocessor/PostProcessorChainTest.groovy
index 8961c8d41f8..3d62f0b29da 100644
--- a/dd-trace-core/src/test/groovy/datadog/trace/core/tagprocessor/PostProcessorChainTest.groovy
+++ b/dd-trace-core/src/test/groovy/datadog/trace/core/tagprocessor/PostProcessorChainTest.groovy
@@ -1,7 +1,7 @@
 package datadog.trace.core.tagprocessor
 
 import datadog.trace.api.TagMap
-import datadog.trace.bootstrap.instrumentation.api.AgentSpanLink
+import datadog.trace.bootstrap.instrumentation.api.AppendableSpanLinks
 import datadog.trace.core.DDSpanContext
 import datadog.trace.test.util.DDSpecification
 
@@ -10,40 +10,43 @@ class PostProcessorChainTest extends DDSpecification {
     setup:
     def processor1 = new TagsPostProcessor() {
         @Override
-        void processTags(TagMap unsafeTags, DDSpanContext spanContext, List<AgentSpanLink> spanLinks) {
+        void processTags(TagMap unsafeTags, DDSpanContext spanContext, AppendableSpanLinks spanLinks) {
           unsafeTags.put("key1", "processor1")
           unsafeTags.put("key2", "processor1")
         }
       }
     def processor2 = new TagsPostProcessor() {
         @Override
-        void processTags(TagMap unsafeTags, DDSpanContext spanContext, List<AgentSpanLink> spanLinks) {
+        void processTags(TagMap unsafeTags, DDSpanContext spanContext, AppendableSpanLinks spanLinks) {
           unsafeTags.put("key1", "processor2")
         }
       }
 
     def chain = new PostProcessorChain(processor1, processor2)
-    def tags = TagMap.fromMap(["key1": "root", "key3": "root"])
+
+    def links = []
+    def tags = TagMap.fromMap(["key1": "overwrite", "key3": "unchanged"])
 
     when:
-    chain.processTags(tags, null, [])
+    chain.processTags(tags, null, {link -> links.add(link)})
 
     then:
-    assert tags == ["key1": "processor2", "key2": "processor1", "key3": "root"]
+    assert tags == ["key1": "processor2", "key2": "processor1", "key3": "unchanged"]
+    assert links == []
   }
 
   def "processor can hide tags to next one()"() {
     setup:
     def processor1 = new TagsPostProcessor() {
         @Override
-        void processTags(TagMap unsafeTags, DDSpanContext spanContext, List<AgentSpanLink> spanLinks) {
+        void processTags(TagMap unsafeTags, DDSpanContext spanContext, AppendableSpanLinks spanLinks) {
           unsafeTags.clear()
           unsafeTags.put("my", "tag")
         }
       }
     def processor2 = new TagsPostProcessor() {
         @Override
-        void processTags(TagMap unsafeTags, DDSpanContext spanContext, List<AgentSpanLink> spanLinks) {
+        void processTags(TagMap unsafeTags, DDSpanContext spanContext, AppendableSpanLinks spanLinks) {
           if (unsafeTags.containsKey("test")) {
             unsafeTags.put("found", "true")
           }
@@ -51,12 +54,15 @@ class PostProcessorChainTest extends DDSpecification {
       }
 
     def chain = new PostProcessorChain(processor1, processor2)
+
+    def links = []
     def tags = TagMap.fromMap(["test": "test"])
 
     when:
-    chain.processTags(tags, null, [])
+    chain.processTags(tags, null, {link -> links.add(link)})
 
     then:
     assert tags == ["my": "tag"]
+    assert links == []
   }
 }
diff --git a/dd-trace-core/src/test/groovy/datadog/trace/core/tagprocessor/QueryObfuscatorTest.groovy b/dd-trace-core/src/test/groovy/datadog/trace/core/tagprocessor/QueryObfuscatorTest.groovy
index 655a1a720fb..1e4332477ed 100644
--- a/dd-trace-core/src/test/groovy/datadog/trace/core/tagprocessor/QueryObfuscatorTest.groovy
+++ b/dd-trace-core/src/test/groovy/datadog/trace/core/tagprocessor/QueryObfuscatorTest.groovy
@@ -1,6 +1,7 @@
 package datadog.trace.core.tagprocessor
 
 import datadog.trace.api.DDTags
+import datadog.trace.api.TagMap
 import datadog.trace.bootstrap.instrumentation.api.Tags
 import datadog.trace.test.util.DDSpecification
 
@@ -14,11 +15,12 @@ class QueryObfuscatorTest extends DDSpecification {
     ]
 
     when:
-    def result = obfuscator.processTags(tags, null, [])
+    def unsafeTags = TagMap.fromMap(tags)
+    obfuscator.processTags(unsafeTags, null, {link ->})
 
     then:
-    assert result.get(DDTags.HTTP_QUERY) == expectedQuery
-    assert result.get(Tags.HTTP_URL) == 'http://site.com/index?' + expectedQuery
+    assert unsafeTags.get(DDTags.HTTP_QUERY) == expectedQuery
+    assert unsafeTags.get(Tags.HTTP_URL) == 'http://site.com/index?' + expectedQuery
 
     where:
     query                                                               | expectedQuery
@@ -36,11 +38,12 @@ class QueryObfuscatorTest extends DDSpecification {
     ]
 
     when:
-    def result = obfuscator.processTags(tags, null, [])
+    def unsafeTags = TagMap.fromMap(tags)
+    obfuscator.processTags(unsafeTags, null, {link ->})
 
     then:
-    assert result.get(DDTags.HTTP_QUERY) == expectedQuery
-    assert result.get(Tags.HTTP_URL) == 'http://site.com/index?' + expectedQuery
+    assert unsafeTags.get(DDTags.HTTP_QUERY) == expectedQuery
+    assert unsafeTags.get(Tags.HTTP_URL) == 'http://site.com/index?' + expectedQuery
 
     where:
     query                                                               | expectedQuery
diff --git a/dd-trace-core/src/test/groovy/datadog/trace/core/tagprocessor/SpanPointersProcessorTest.groovy b/dd-trace-core/src/test/groovy/datadog/trace/core/tagprocessor/SpanPointersProcessorTest.groovy
index 09bae762eff..a3407e30a02 100644
--- a/dd-trace-core/src/test/groovy/datadog/trace/core/tagprocessor/SpanPointersProcessorTest.groovy
+++ b/dd-trace-core/src/test/groovy/datadog/trace/core/tagprocessor/SpanPointersProcessorTest.groovy
@@ -2,6 +2,7 @@ package datadog.trace.core.tagprocessor
 
 import datadog.trace.api.DDSpanId
 import datadog.trace.api.DDTraceId
+import datadog.trace.api.TagMap
 import datadog.trace.bootstrap.instrumentation.api.InstrumentationTags
 import datadog.trace.bootstrap.instrumentation.api.SpanLink
 import datadog.trace.core.DDSpanContext
@@ -11,22 +12,22 @@ class SpanPointersProcessorTest extends DDSpecification{
   def "SpanPointersProcessor adds correct link with basic values"() {
     given:
     def processor = new SpanPointersProcessor()
-    def unsafeTags = [
+    def unsafeTags = TagMap.fromMap([
       (InstrumentationTags.AWS_BUCKET_NAME): "some-bucket",
       (InstrumentationTags.AWS_OBJECT_KEY) : "some-key.data",
       "s3.eTag"                            : "ab12ef34"
-    ]
+    ])
     def spanContext = Mock(DDSpanContext)
     def spanLinks = []
     def expectedHash = "e721375466d4116ab551213fdea08413"
 
     when:
     // Process the tags; the processor should remove 's3.eTag' and add one link
-    def returnedTags = processor.processTags(unsafeTags, spanContext, spanLinks)
+    processor.processTags(unsafeTags, spanContext, {link -> spanLinks.add(link)})
 
     then:
     // 1. s3.eTag was removed
-    !returnedTags.containsKey("s3.eTag")
+    !unsafeTags.containsKey("s3.eTag")
     // 2. Exactly one link was added
     spanLinks.size() == 1
     // 3. Check link
@@ -43,11 +44,11 @@ class SpanPointersProcessorTest extends DDSpecification{
   def "SpanPointersProcessor adds correct link with non-ascii key"() {
     given:
     def processor = new SpanPointersProcessor()
-    def unsafeTags = [
+    def unsafeTags = TagMap.fromMap([
       (InstrumentationTags.AWS_BUCKET_NAME): "some-bucket",
       (InstrumentationTags.AWS_OBJECT_KEY)  : "some-key.你好",
       "s3.eTag"                             : "ab12ef34"
-    ]
+    ])
     def spanContext = Mock(DDSpanContext)
     def spanLinks = []
 
@@ -55,10 +56,10 @@ class SpanPointersProcessorTest extends DDSpecification{
     def expectedHash = "d1333a04b9928ab462b5c6cadfa401f4"
 
     when:
-    def returnedTags = processor.processTags(unsafeTags, spanContext, spanLinks)
+    processor.processTags(unsafeTags, spanContext, {link -> spanLinks.add(link)})
 
     then:
-    !returnedTags.containsKey("s3.eTag")
+    !unsafeTags.containsKey("s3.eTag")
     spanLinks.size() == 1
     def link = spanLinks[0]
     link.traceId() == DDTraceId.ZERO
@@ -72,11 +73,11 @@ class SpanPointersProcessorTest extends DDSpecification{
   def "SpanPointersProcessor adds correct link with multipart-upload ETag"() {
     given:
     def processor = new SpanPointersProcessor()
-    def unsafeTags = [
+    def unsafeTags = TagMap.fromMap([
       (InstrumentationTags.AWS_BUCKET_NAME): "some-bucket",
       (InstrumentationTags.AWS_OBJECT_KEY)  : "some-key.data",
       "s3.eTag"                             : "ab12ef34-5"
-    ]
+    ])
     def spanContext = Mock(DDSpanContext)
     def spanLinks = []
 
@@ -84,10 +85,10 @@ class SpanPointersProcessorTest extends DDSpecification{
     def expectedHash = "2b90dffc37ebc7bc610152c3dc72af9f"
 
     when:
-    def returnedTags = processor.processTags(unsafeTags, spanContext, spanLinks)
+    processor.processTags(unsafeTags, spanContext, {link -> spanLinks.add(link)})
 
     then:
-    !returnedTags.containsKey("s3.eTag")
+    !unsafeTags.containsKey("s3.eTag")
     spanLinks.size() == 1
     def link = spanLinks[0]
     link.traceId() == DDTraceId.ZERO
diff --git a/internal-api/src/main/java/datadog/trace/bootstrap/instrumentation/api/AgentSpan.java b/internal-api/src/main/java/datadog/trace/bootstrap/instrumentation/api/AgentSpan.java
index af2ccfedc8d..99c90b53b30 100644
--- a/internal-api/src/main/java/datadog/trace/bootstrap/instrumentation/api/AgentSpan.java
+++ b/internal-api/src/main/java/datadog/trace/bootstrap/instrumentation/api/AgentSpan.java
@@ -18,7 +18,12 @@
 import javax.annotation.Nullable;
 
 public interface AgentSpan
-    extends MutableSpan, ImplicitContextKeyed, Context, IGSpanInfo, WithAgentSpan {
+    extends MutableSpan,
+        AppendableSpanLinks,
+        ImplicitContextKeyed,
+        Context,
+        IGSpanInfo,
+        WithAgentSpan {
 
   /**
    * Extracts the span from context.
diff --git a/internal-api/src/main/java/datadog/trace/bootstrap/instrumentation/api/AppendableSpanLinks.java b/internal-api/src/main/java/datadog/trace/bootstrap/instrumentation/api/AppendableSpanLinks.java
new file mode 100644
index 00000000000..f1cc5325695
--- /dev/null
+++ b/internal-api/src/main/java/datadog/trace/bootstrap/instrumentation/api/AppendableSpanLinks.java
@@ -0,0 +1,7 @@
+package datadog.trace.bootstrap.instrumentation.api;
+
+/** Interface that provides the ability to append a span link */
+@FunctionalInterface
+public interface AppendableSpanLinks {
+  void addLink(AgentSpanLink link);
+}