diff --git a/pkl-commons-cli/src/main/kotlin/org/pkl/commons/cli/CliCommand.kt b/pkl-commons-cli/src/main/kotlin/org/pkl/commons/cli/CliCommand.kt
index bde2a0fa2..9d1db738c 100644
--- a/pkl-commons-cli/src/main/kotlin/org/pkl/commons/cli/CliCommand.kt
+++ b/pkl-commons-cli/src/main/kotlin/org/pkl/commons/cli/CliCommand.kt
@@ -21,7 +21,7 @@ import java.util.regex.Pattern
 import kotlin.io.path.isRegularFile
 import org.pkl.core.*
 import org.pkl.core.evaluatorSettings.PklEvaluatorSettings
-import org.pkl.core.externalreader.ExternalReaderProcess
+import org.pkl.core.externalreader.ReaderProcess
 import org.pkl.core.http.HttpClient
 import org.pkl.core.module.ModuleKeyFactories
 import org.pkl.core.module.ModuleKeyFactory
@@ -191,7 +191,7 @@ abstract class CliCommand(protected val cliOptions: CliBaseOptions) {
     // with the same spec. This avoids spawning multiple subprocesses if the same reader implements
     // both reader types and/or multiple schemes.
     (externalModuleReaders + externalResourceReaders).values.toSet().associateWith {
-      ExternalReaderProcess.of(it)
+      ReaderProcess.of(it)
     }
   }
 
diff --git a/pkl-core/src/main/java/org/pkl/core/EvaluatorBuilder.java b/pkl-core/src/main/java/org/pkl/core/EvaluatorBuilder.java
index 8b5ad5d43..9d402c9f7 100644
--- a/pkl-core/src/main/java/org/pkl/core/EvaluatorBuilder.java
+++ b/pkl-core/src/main/java/org/pkl/core/EvaluatorBuilder.java
@@ -21,7 +21,7 @@
 import java.util.regex.Pattern;
 import org.pkl.core.SecurityManagers.StandardBuilder;
 import org.pkl.core.evaluatorSettings.PklEvaluatorSettings.ExternalReader;
-import org.pkl.core.externalreader.ExternalReaderProcess;
+import org.pkl.core.externalreader.ReaderProcess;
 import org.pkl.core.http.HttpClient;
 import org.pkl.core.module.ModuleKeyFactories;
 import org.pkl.core.module.ModuleKeyFactory;
@@ -498,21 +498,19 @@ public EvaluatorBuilder applyFromProject(Project project) {
     }
 
     // this isn't ideal as project and non-project ExternalReaderProcess instances can be dupes
-    var procs = new HashMap<ExternalReader, ExternalReaderProcess>();
+    var procs = new HashMap<ExternalReader, ReaderProcess>();
     if (settings.externalModuleReaders() != null) {
       for (var entry : settings.externalModuleReaders().entrySet()) {
         addModuleKeyFactory(
             ModuleKeyFactories.externalProcess(
-                entry.getKey(),
-                procs.computeIfAbsent(entry.getValue(), ExternalReaderProcess::of)));
+                entry.getKey(), procs.computeIfAbsent(entry.getValue(), ReaderProcess::of)));
       }
     }
     if (settings.externalResourceReaders() != null) {
       for (var entry : settings.externalResourceReaders().entrySet()) {
         addResourceReader(
             ResourceReaders.externalProcess(
-                entry.getKey(),
-                procs.computeIfAbsent(entry.getValue(), ExternalReaderProcess::of)));
+                entry.getKey(), procs.computeIfAbsent(entry.getValue(), ReaderProcess::of)));
       }
     }
     return this;
diff --git a/pkl-core/src/main/java/org/pkl/core/ast/builder/AstBuilder.java b/pkl-core/src/main/java/org/pkl/core/ast/builder/AstBuilder.java
index 3b34d2c18..7d26a9756 100644
--- a/pkl-core/src/main/java/org/pkl/core/ast/builder/AstBuilder.java
+++ b/pkl-core/src/main/java/org/pkl/core/ast/builder/AstBuilder.java
@@ -55,7 +55,7 @@
 import org.pkl.core.ast.lambda.ApplyVmFunction1NodeGen;
 import org.pkl.core.ast.member.*;
 import org.pkl.core.ast.type.*;
-import org.pkl.core.externalreader.ExternalReaderProcessException;
+import org.pkl.core.externalreader.ReaderProcessException;
 import org.pkl.core.module.ModuleKey;
 import org.pkl.core.module.ModuleKeys;
 import org.pkl.core.module.ResolvedModuleKey;
@@ -1864,7 +1864,7 @@ private URI resolveImport(String importUri, StringConstantContext importUriCtx)
           .withHint(e.getHint())
           .withSourceSection(createSourceSection(importUriCtx))
           .build();
-    } catch (ExternalReaderProcessException e) {
+    } catch (ReaderProcessException e) {
       throw exceptionBuilder()
           .evalError("externalReaderFailure")
           .withCause(e.getCause())
diff --git a/pkl-core/src/main/java/org/pkl/core/ast/expression/unary/AbstractReadNode.java b/pkl-core/src/main/java/org/pkl/core/ast/expression/unary/AbstractReadNode.java
index 607e04189..d4abfeaad 100644
--- a/pkl-core/src/main/java/org/pkl/core/ast/expression/unary/AbstractReadNode.java
+++ b/pkl-core/src/main/java/org/pkl/core/ast/expression/unary/AbstractReadNode.java
@@ -23,7 +23,7 @@
 import java.net.URI;
 import java.net.URISyntaxException;
 import org.pkl.core.SecurityManagerException;
-import org.pkl.core.externalreader.ExternalReaderProcessException;
+import org.pkl.core.externalreader.ReaderProcessException;
 import org.pkl.core.module.ModuleKey;
 import org.pkl.core.packages.PackageLoadError;
 import org.pkl.core.runtime.VmContext;
@@ -76,7 +76,7 @@ private URI resolveResource(ModuleKey moduleKey, String resourceUri) {
           .build();
     } catch (PackageLoadError | SecurityManagerException e) {
       throw exceptionBuilder().withCause(e).build();
-    } catch (ExternalReaderProcessException e) {
+    } catch (ReaderProcessException e) {
       throw exceptionBuilder().evalError("externalReaderFailure").withCause(e).build();
     }
 
diff --git a/pkl-core/src/main/java/org/pkl/core/ast/expression/unary/ImportGlobNode.java b/pkl-core/src/main/java/org/pkl/core/ast/expression/unary/ImportGlobNode.java
index 66ae35934..fcaf7dc45 100644
--- a/pkl-core/src/main/java/org/pkl/core/ast/expression/unary/ImportGlobNode.java
+++ b/pkl-core/src/main/java/org/pkl/core/ast/expression/unary/ImportGlobNode.java
@@ -25,7 +25,7 @@
 import java.net.URI;
 import org.pkl.core.SecurityManagerException;
 import org.pkl.core.ast.member.SharedMemberNode;
-import org.pkl.core.externalreader.ExternalReaderProcessException;
+import org.pkl.core.externalreader.ReaderProcessException;
 import org.pkl.core.http.HttpClientInitException;
 import org.pkl.core.module.ResolvedModuleKey;
 import org.pkl.core.packages.PackageLoadError;
@@ -105,7 +105,7 @@ public Object executeGeneric(VirtualFrame frame) {
           .evalError("invalidGlobPattern", globPattern)
           .withHint(e.getMessage())
           .build();
-    } catch (ExternalReaderProcessException e) {
+    } catch (ReaderProcessException e) {
       throw exceptionBuilder().evalError("externalReaderFailure").withCause(e).build();
     }
   }
diff --git a/pkl-core/src/main/java/org/pkl/core/ast/expression/unary/ReadGlobNode.java b/pkl-core/src/main/java/org/pkl/core/ast/expression/unary/ReadGlobNode.java
index 9331629bc..a20483568 100644
--- a/pkl-core/src/main/java/org/pkl/core/ast/expression/unary/ReadGlobNode.java
+++ b/pkl-core/src/main/java/org/pkl/core/ast/expression/unary/ReadGlobNode.java
@@ -26,7 +26,7 @@
 import org.graalvm.collections.EconomicMap;
 import org.pkl.core.SecurityManagerException;
 import org.pkl.core.ast.member.SharedMemberNode;
-import org.pkl.core.externalreader.ExternalReaderProcessException;
+import org.pkl.core.externalreader.ReaderProcessException;
 import org.pkl.core.http.HttpClientInitException;
 import org.pkl.core.module.ModuleKey;
 import org.pkl.core.runtime.VmContext;
@@ -104,7 +104,7 @@ public Object read(String globPattern) {
           .evalError("invalidGlobPattern", globPattern)
           .withHint(e.getMessage())
           .build();
-    } catch (ExternalReaderProcessException e) {
+    } catch (ReaderProcessException e) {
       throw exceptionBuilder().evalError("externalReaderFailure").withCause(e).build();
     }
   }
diff --git a/pkl-core/src/main/java/org/pkl/core/externalreader/ExternalReaderMessagePackDecoder.java b/pkl-core/src/main/java/org/pkl/core/externalreader/MessagePackDecoder.java
similarity index 88%
rename from pkl-core/src/main/java/org/pkl/core/externalreader/ExternalReaderMessagePackDecoder.java
rename to pkl-core/src/main/java/org/pkl/core/externalreader/MessagePackDecoder.java
index 51bf6a122..3eaef692d 100644
--- a/pkl-core/src/main/java/org/pkl/core/externalreader/ExternalReaderMessagePackDecoder.java
+++ b/pkl-core/src/main/java/org/pkl/core/externalreader/MessagePackDecoder.java
@@ -21,20 +21,20 @@
 import org.msgpack.core.MessagePack;
 import org.msgpack.core.MessageUnpacker;
 import org.msgpack.value.Value;
-import org.pkl.core.externalreader.ExternalReaderMessages.*;
+import org.pkl.core.externalreader.ReaderMessages.*;
 import org.pkl.core.messaging.BaseMessagePackDecoder;
 import org.pkl.core.messaging.DecodeException;
 import org.pkl.core.messaging.Message;
 import org.pkl.core.messaging.Message.Type;
 import org.pkl.core.util.Nullable;
 
-final class ExternalReaderMessagePackDecoder extends BaseMessagePackDecoder {
+final class MessagePackDecoder extends BaseMessagePackDecoder {
 
-  public ExternalReaderMessagePackDecoder(MessageUnpacker unpacker) {
+  public MessagePackDecoder(MessageUnpacker unpacker) {
     super(unpacker);
   }
 
-  public ExternalReaderMessagePackDecoder(InputStream inputStream) {
+  public MessagePackDecoder(InputStream inputStream) {
     this(MessagePack.newDefaultUnpacker(inputStream));
   }
 
diff --git a/pkl-core/src/main/java/org/pkl/core/externalreader/ExternalReaderMessagePackEncoder.java b/pkl-core/src/main/java/org/pkl/core/externalreader/MessagePackEncoder.java
similarity index 89%
rename from pkl-core/src/main/java/org/pkl/core/externalreader/ExternalReaderMessagePackEncoder.java
rename to pkl-core/src/main/java/org/pkl/core/externalreader/MessagePackEncoder.java
index b383b4ac6..f5d6d5be1 100644
--- a/pkl-core/src/main/java/org/pkl/core/externalreader/ExternalReaderMessagePackEncoder.java
+++ b/pkl-core/src/main/java/org/pkl/core/externalreader/MessagePackEncoder.java
@@ -19,19 +19,19 @@
 import java.io.OutputStream;
 import org.msgpack.core.MessagePack;
 import org.msgpack.core.MessagePacker;
-import org.pkl.core.externalreader.ExternalReaderMessages.*;
+import org.pkl.core.externalreader.ReaderMessages.*;
 import org.pkl.core.messaging.BaseMessagePackEncoder;
 import org.pkl.core.messaging.Message;
 import org.pkl.core.messaging.ProtocolException;
 import org.pkl.core.util.Nullable;
 
-final class ExternalReaderMessagePackEncoder extends BaseMessagePackEncoder {
+final class MessagePackEncoder extends BaseMessagePackEncoder {
 
-  public ExternalReaderMessagePackEncoder(MessagePacker packer) {
+  public MessagePackEncoder(MessagePacker packer) {
     super(packer);
   }
 
-  public ExternalReaderMessagePackEncoder(OutputStream outputStream) {
+  public MessagePackEncoder(OutputStream outputStream) {
     this(MessagePack.newDefaultPacker(outputStream));
   }
 
diff --git a/pkl-core/src/main/java/org/pkl/core/externalreader/ExternalModuleReaderSpec.java b/pkl-core/src/main/java/org/pkl/core/externalreader/ModuleReaderSpec.java
similarity index 95%
rename from pkl-core/src/main/java/org/pkl/core/externalreader/ExternalModuleReaderSpec.java
rename to pkl-core/src/main/java/org/pkl/core/externalreader/ModuleReaderSpec.java
index fd199cdbc..0e0770fc4 100644
--- a/pkl-core/src/main/java/org/pkl/core/externalreader/ExternalModuleReaderSpec.java
+++ b/pkl-core/src/main/java/org/pkl/core/externalreader/ModuleReaderSpec.java
@@ -15,5 +15,5 @@
  */
 package org.pkl.core.externalreader;
 
-public record ExternalModuleReaderSpec(
+public record ModuleReaderSpec(
     String scheme, boolean hasHierarchicalUris, boolean isLocal, boolean isGlobbable) {}
diff --git a/pkl-core/src/main/java/org/pkl/core/externalreader/ExternalModuleResolver.java b/pkl-core/src/main/java/org/pkl/core/externalreader/ModuleResolver.java
similarity index 87%
rename from pkl-core/src/main/java/org/pkl/core/externalreader/ExternalModuleResolver.java
rename to pkl-core/src/main/java/org/pkl/core/externalreader/ModuleResolver.java
index a962a3867..0b830ae1a 100644
--- a/pkl-core/src/main/java/org/pkl/core/externalreader/ExternalModuleResolver.java
+++ b/pkl-core/src/main/java/org/pkl/core/externalreader/ModuleResolver.java
@@ -23,9 +23,9 @@
 import org.pkl.core.messaging.MessageTransport;
 import org.pkl.core.module.PathElement;
 
-public interface ExternalModuleResolver {
-  static ExternalModuleResolver of(MessageTransport transport, long evaluatorId) {
-    return new ExternalModuleResolverImpl(transport, evaluatorId);
+public interface ModuleResolver {
+  static ModuleResolver of(MessageTransport transport, long evaluatorId) {
+    return new ModuleResolverImpl(transport, evaluatorId);
   }
 
   String resolveModule(SecurityManager securityManager, URI uri)
diff --git a/pkl-core/src/main/java/org/pkl/core/externalreader/ExternalModuleResolverImpl.java b/pkl-core/src/main/java/org/pkl/core/externalreader/ModuleResolverImpl.java
similarity index 97%
rename from pkl-core/src/main/java/org/pkl/core/externalreader/ExternalModuleResolverImpl.java
rename to pkl-core/src/main/java/org/pkl/core/externalreader/ModuleResolverImpl.java
index 4338eafc7..1a16519a5 100644
--- a/pkl-core/src/main/java/org/pkl/core/externalreader/ExternalModuleResolverImpl.java
+++ b/pkl-core/src/main/java/org/pkl/core/externalreader/ModuleResolverImpl.java
@@ -35,14 +35,14 @@
 import org.pkl.core.messaging.ProtocolException;
 import org.pkl.core.module.PathElement;
 
-final class ExternalModuleResolverImpl implements ExternalModuleResolver {
+final class ModuleResolverImpl implements ModuleResolver {
   private final MessageTransport transport;
   private final long evaluatorId;
   private final Map<URI, Future<String>> readResponses = new ConcurrentHashMap<>();
   private final Map<URI, Future<List<PathElement>>> listResponses = new ConcurrentHashMap<>();
   private final Random requestIdGenerator = new Random();
 
-  ExternalModuleResolverImpl(MessageTransport transport, long evaluatorId) {
+  ModuleResolverImpl(MessageTransport transport, long evaluatorId) {
     this.transport = transport;
     this.evaluatorId = evaluatorId;
   }
diff --git a/pkl-core/src/main/java/org/pkl/core/externalreader/ExternalReaderMessages.java b/pkl-core/src/main/java/org/pkl/core/externalreader/ReaderMessages.java
similarity index 96%
rename from pkl-core/src/main/java/org/pkl/core/externalreader/ExternalReaderMessages.java
rename to pkl-core/src/main/java/org/pkl/core/externalreader/ReaderMessages.java
index cd89f87ce..afcf97f91 100644
--- a/pkl-core/src/main/java/org/pkl/core/externalreader/ExternalReaderMessages.java
+++ b/pkl-core/src/main/java/org/pkl/core/externalreader/ReaderMessages.java
@@ -20,8 +20,8 @@
 import org.pkl.core.messaging.Messages.ResourceReaderSpec;
 import org.pkl.core.util.Nullable;
 
-final class ExternalReaderMessages {
-  private ExternalReaderMessages() {}
+final class ReaderMessages {
+  private ReaderMessages() {}
 
   record InitializeModuleReaderRequest(long requestId, String scheme) implements Server.Request {
     public Type type() {
diff --git a/pkl-core/src/main/java/org/pkl/core/externalreader/ExternalReaderProcess.java b/pkl-core/src/main/java/org/pkl/core/externalreader/ReaderProcess.java
similarity index 73%
rename from pkl-core/src/main/java/org/pkl/core/externalreader/ExternalReaderProcess.java
rename to pkl-core/src/main/java/org/pkl/core/externalreader/ReaderProcess.java
index 7f7caca70..200faf8ff 100644
--- a/pkl-core/src/main/java/org/pkl/core/externalreader/ExternalReaderProcess.java
+++ b/pkl-core/src/main/java/org/pkl/core/externalreader/ReaderProcess.java
@@ -20,13 +20,13 @@
 import org.pkl.core.util.Nullable;
 
 /** An external process that reads Pkl modules and resources. */
-public interface ExternalReaderProcess extends AutoCloseable {
+public interface ReaderProcess extends AutoCloseable {
   /**
-   * Creates a new {@link ExternalReaderProcess} from the given spec. No resources are allocated at
-   * this time.
+   * Creates a new {@link ReaderProcess} from the given spec. No resources are allocated at this
+   * time.
    */
-  static ExternalReaderProcess of(ExternalReader spec) {
-    return new ExternalReaderProcessImpl(spec);
+  static ReaderProcess of(ExternalReader spec) {
+    return new ReaderProcessImpl(spec);
   }
 
   /**
@@ -36,7 +36,7 @@ static ExternalReaderProcess of(ExternalReader spec) {
    *
    * @throws IllegalStateException if this process has already been closed
    */
-  ExternalModuleResolver getModuleResolver(long evaluatorId) throws ExternalReaderProcessException;
+  ModuleResolver getModuleResolver(long evaluatorId) throws ReaderProcessException;
 
   /**
    * Returns a resolver for resources provided via this reader.
@@ -45,8 +45,7 @@ static ExternalReaderProcess of(ExternalReader spec) {
    *
    * @throws IllegalStateException if this process has already been closed
    */
-  ExternalResourceResolver getResourceResolver(long evaluatorId)
-      throws ExternalReaderProcessException;
+  ResourceResolver getResourceResolver(long evaluatorId) throws ReaderProcessException;
 
   /**
    * Returns the spec, if available, of this process's module reader with the given scheme.
@@ -55,7 +54,7 @@ ExternalResourceResolver getResourceResolver(long evaluatorId)
    * @throws IOException if an I/O error occurs
    */
   @Nullable
-  ExternalModuleReaderSpec getModuleReaderSpec(String scheme) throws IOException;
+  ModuleReaderSpec getModuleReaderSpec(String scheme) throws IOException;
 
   /**
    * Returns the spec, if available, of this process's resource reader with the given scheme.
@@ -64,7 +63,7 @@ ExternalResourceResolver getResourceResolver(long evaluatorId)
    * @throws IOException if an I/O error occurs
    */
   @Nullable
-  ExternalResourceReaderSpec getResourceReaderSpec(String scheme) throws IOException;
+  ResourceReaderSpec getResourceReaderSpec(String scheme) throws IOException;
 
   /**
    * Closes this process, releasing any associated resources.
@@ -72,8 +71,8 @@ ExternalResourceResolver getResourceResolver(long evaluatorId)
    * <p>This method can be safely called multiple times. Subsequent calls have no effect.
    *
    * @implNote Implementers should request a graceful termination by sending a {@link
-   *     ExternalReaderMessages.CloseExternalProcess CloseExternalProcess} message to the process
-   *     before terminating it forcibly.
+   *     ReaderMessages.CloseExternalProcess CloseExternalProcess} message to the process before
+   *     terminating it forcibly.
    */
   @Override
   void close();
diff --git a/pkl-core/src/main/java/org/pkl/core/externalreader/ExternalReaderProcessException.java b/pkl-core/src/main/java/org/pkl/core/externalreader/ReaderProcessException.java
similarity index 79%
rename from pkl-core/src/main/java/org/pkl/core/externalreader/ExternalReaderProcessException.java
rename to pkl-core/src/main/java/org/pkl/core/externalreader/ReaderProcessException.java
index 6dbf4bf5d..9b830e413 100644
--- a/pkl-core/src/main/java/org/pkl/core/externalreader/ExternalReaderProcessException.java
+++ b/pkl-core/src/main/java/org/pkl/core/externalreader/ReaderProcessException.java
@@ -15,12 +15,12 @@
  */
 package org.pkl.core.externalreader;
 
-public final class ExternalReaderProcessException extends Exception {
-  public ExternalReaderProcessException(String msg) {
+public final class ReaderProcessException extends Exception {
+  public ReaderProcessException(String msg) {
     super(msg);
   }
 
-  public ExternalReaderProcessException(Throwable cause) {
+  public ReaderProcessException(Throwable cause) {
     super(cause);
   }
 }
diff --git a/pkl-core/src/main/java/org/pkl/core/externalreader/ExternalReaderProcessImpl.java b/pkl-core/src/main/java/org/pkl/core/externalreader/ReaderProcessImpl.java
similarity index 79%
rename from pkl-core/src/main/java/org/pkl/core/externalreader/ExternalReaderProcessImpl.java
rename to pkl-core/src/main/java/org/pkl/core/externalreader/ReaderProcessImpl.java
index ab206dbdd..5d8b69f18 100644
--- a/pkl-core/src/main/java/org/pkl/core/externalreader/ExternalReaderProcessImpl.java
+++ b/pkl-core/src/main/java/org/pkl/core/externalreader/ReaderProcessImpl.java
@@ -28,7 +28,7 @@
 import java.util.concurrent.TimeUnit;
 import javax.annotation.concurrent.GuardedBy;
 import org.pkl.core.evaluatorSettings.PklEvaluatorSettings.ExternalReader;
-import org.pkl.core.externalreader.ExternalReaderMessages.*;
+import org.pkl.core.externalreader.ReaderMessages.*;
 import org.pkl.core.messaging.MessageTransport;
 import org.pkl.core.messaging.MessageTransports;
 import org.pkl.core.messaging.ProtocolException;
@@ -36,15 +36,15 @@
 import org.pkl.core.util.LateInit;
 import org.pkl.core.util.Nullable;
 
-final class ExternalReaderProcessImpl implements ExternalReaderProcess {
+final class ReaderProcessImpl implements ReaderProcess {
 
   private static final Duration CLOSE_TIMEOUT = Duration.ofSeconds(3);
 
   private final ExternalReader spec;
   private final @Nullable String logPrefix;
-  private final Map<String, Future<@Nullable ExternalModuleReaderSpec>>
-      initializeModuleReaderResponses = new ConcurrentHashMap<>();
-  private final Map<String, Future<@Nullable ExternalResourceReaderSpec>>
+  private final Map<String, Future<@Nullable ModuleReaderSpec>> initializeModuleReaderResponses =
+      new ConcurrentHashMap<>();
+  private final Map<String, Future<@Nullable ResourceReaderSpec>>
       initializeResourceReaderResponses = new ConcurrentHashMap<>();
   private final Random requestIdGenerator = new Random();
 
@@ -65,7 +65,7 @@ private void log(String msg) {
     }
   }
 
-  ExternalReaderProcessImpl(ExternalReader spec) {
+  ReaderProcessImpl(ExternalReader spec) {
     this.spec = spec;
     logPrefix =
         Objects.equals(System.getenv("PKL_DEBUG"), "1")
@@ -74,26 +74,23 @@ private void log(String msg) {
   }
 
   @Override
-  public ExternalModuleResolver getModuleResolver(long evaluatorId)
-      throws ExternalReaderProcessException {
-    return ExternalModuleResolver.of(getTransport(), evaluatorId);
+  public ModuleResolver getModuleResolver(long evaluatorId) throws ReaderProcessException {
+    return ModuleResolver.of(getTransport(), evaluatorId);
   }
 
   @Override
-  public ExternalResourceResolver getResourceResolver(long evaluatorId)
-      throws ExternalReaderProcessException {
-    return ExternalResourceResolver.of(getTransport(), evaluatorId);
+  public ResourceResolver getResourceResolver(long evaluatorId) throws ReaderProcessException {
+    return ResourceResolver.of(getTransport(), evaluatorId);
   }
 
-  private MessageTransport getTransport() throws ExternalReaderProcessException {
+  private MessageTransport getTransport() throws ReaderProcessException {
     synchronized (lock) {
       if (closed) {
         throw new IllegalStateException("External reader process has already been closed.");
       }
       if (process != null) {
         if (!process.isAlive()) {
-          throw new ExternalReaderProcessException(
-              ErrorMessages.create("externalReaderAlreadyTerminated"));
+          throw new ReaderProcessException(ErrorMessages.create("externalReaderAlreadyTerminated"));
         }
 
         return transport;
@@ -110,12 +107,12 @@ private MessageTransport getTransport() throws ExternalReaderProcessException {
     try {
       process = builder.start();
     } catch (IOException e) {
-      throw new ExternalReaderProcessException(e);
+      throw new ReaderProcessException(e);
     }
     transport =
         MessageTransports.stream(
-            new ExternalReaderMessagePackDecoder(process.getInputStream()),
-            new ExternalReaderMessagePackEncoder(process.getOutputStream()),
+            new MessagePackDecoder(process.getInputStream()),
+            new MessagePackEncoder(process.getOutputStream()),
             this::log);
 
     var rxThread = new Thread(this::runTransport, "ExternalReaderProcessImpl rxThread for " + spec);
@@ -169,12 +166,12 @@ public void close() {
   }
 
   @Override
-  public ExternalModuleReaderSpec getModuleReaderSpec(String uriScheme) throws IOException {
+  public ModuleReaderSpec getModuleReaderSpec(String uriScheme) throws IOException {
     return MessageTransports.resolveFuture(
         initializeModuleReaderResponses.computeIfAbsent(
             uriScheme,
             (scheme) -> {
-              var future = new CompletableFuture<@Nullable ExternalModuleReaderSpec>();
+              var future = new CompletableFuture<@Nullable ModuleReaderSpec>();
               var request =
                   new InitializeModuleReaderRequest(requestIdGenerator.nextLong(), scheme);
               try {
@@ -186,7 +183,7 @@ public ExternalModuleReaderSpec getModuleReaderSpec(String uriScheme) throws IOE
                             var spec =
                                 resp.spec() == null
                                     ? null
-                                    : new ExternalModuleReaderSpec(
+                                    : new ModuleReaderSpec(
                                         resp.spec().scheme(),
                                         resp.spec().hasHierarchicalUris(),
                                         resp.spec().isLocal(),
@@ -197,7 +194,7 @@ public ExternalModuleReaderSpec getModuleReaderSpec(String uriScheme) throws IOE
                                 new ProtocolException("unexpected response"));
                           }
                         });
-              } catch (ProtocolException | IOException | ExternalReaderProcessException e) {
+              } catch (ProtocolException | IOException | ReaderProcessException e) {
                 future.completeExceptionally(e);
               }
               return future;
@@ -205,12 +202,12 @@ public ExternalModuleReaderSpec getModuleReaderSpec(String uriScheme) throws IOE
   }
 
   @Override
-  public ExternalResourceReaderSpec getResourceReaderSpec(String uriScheme) throws IOException {
+  public ResourceReaderSpec getResourceReaderSpec(String uriScheme) throws IOException {
     return MessageTransports.resolveFuture(
         initializeResourceReaderResponses.computeIfAbsent(
             uriScheme,
             (scheme) -> {
-              var future = new CompletableFuture<@Nullable ExternalResourceReaderSpec>();
+              var future = new CompletableFuture<@Nullable ResourceReaderSpec>();
               var request =
                   new InitializeResourceReaderRequest(requestIdGenerator.nextLong(), scheme);
               try {
@@ -223,7 +220,7 @@ public ExternalResourceReaderSpec getResourceReaderSpec(String uriScheme) throws
                             var spec =
                                 resp.spec() == null
                                     ? null
-                                    : new ExternalResourceReaderSpec(
+                                    : new ResourceReaderSpec(
                                         resp.spec().scheme(),
                                         resp.spec().hasHierarchicalUris(),
                                         resp.spec().isGlobbable());
@@ -233,7 +230,7 @@ public ExternalResourceReaderSpec getResourceReaderSpec(String uriScheme) throws
                                 new ProtocolException("unexpected response"));
                           }
                         });
-              } catch (ProtocolException | IOException | ExternalReaderProcessException e) {
+              } catch (ProtocolException | IOException | ReaderProcessException e) {
                 future.completeExceptionally(e);
               }
               return future;
diff --git a/pkl-core/src/main/java/org/pkl/core/externalreader/ExternalResourceReaderSpec.java b/pkl-core/src/main/java/org/pkl/core/externalreader/ResourceReaderSpec.java
similarity index 85%
rename from pkl-core/src/main/java/org/pkl/core/externalreader/ExternalResourceReaderSpec.java
rename to pkl-core/src/main/java/org/pkl/core/externalreader/ResourceReaderSpec.java
index fdade079e..0436d3322 100644
--- a/pkl-core/src/main/java/org/pkl/core/externalreader/ExternalResourceReaderSpec.java
+++ b/pkl-core/src/main/java/org/pkl/core/externalreader/ResourceReaderSpec.java
@@ -15,5 +15,4 @@
  */
 package org.pkl.core.externalreader;
 
-public record ExternalResourceReaderSpec(
-    String scheme, boolean hasHierarchicalUris, boolean isGlobbable) {}
+public record ResourceReaderSpec(String scheme, boolean hasHierarchicalUris, boolean isGlobbable) {}
diff --git a/pkl-core/src/main/java/org/pkl/core/externalreader/ExternalResourceResolver.java b/pkl-core/src/main/java/org/pkl/core/externalreader/ResourceResolver.java
similarity index 86%
rename from pkl-core/src/main/java/org/pkl/core/externalreader/ExternalResourceResolver.java
rename to pkl-core/src/main/java/org/pkl/core/externalreader/ResourceResolver.java
index 12712bfd7..7a4aeb008 100644
--- a/pkl-core/src/main/java/org/pkl/core/externalreader/ExternalResourceResolver.java
+++ b/pkl-core/src/main/java/org/pkl/core/externalreader/ResourceResolver.java
@@ -24,9 +24,9 @@
 import org.pkl.core.messaging.MessageTransport;
 import org.pkl.core.module.PathElement;
 
-public interface ExternalResourceResolver {
-  static ExternalResourceResolver of(MessageTransport transport, long evaluatorId) {
-    return new ExternalResourceResolverImpl(transport, evaluatorId);
+public interface ResourceResolver {
+  static ResourceResolver of(MessageTransport transport, long evaluatorId) {
+    return new ResourceResolverImpl(transport, evaluatorId);
   }
 
   Optional<Object> read(URI uri) throws IOException;
diff --git a/pkl-core/src/main/java/org/pkl/core/externalreader/ExternalResourceResolverImpl.java b/pkl-core/src/main/java/org/pkl/core/externalreader/ResourceResolverImpl.java
similarity index 96%
rename from pkl-core/src/main/java/org/pkl/core/externalreader/ExternalResourceResolverImpl.java
rename to pkl-core/src/main/java/org/pkl/core/externalreader/ResourceResolverImpl.java
index de9e50e5d..aa006fa78 100644
--- a/pkl-core/src/main/java/org/pkl/core/externalreader/ExternalResourceResolverImpl.java
+++ b/pkl-core/src/main/java/org/pkl/core/externalreader/ResourceResolverImpl.java
@@ -34,14 +34,14 @@
 import org.pkl.core.module.PathElement;
 import org.pkl.core.resource.Resource;
 
-final class ExternalResourceResolverImpl implements ExternalResourceResolver {
+final class ResourceResolverImpl implements ResourceResolver {
   private final MessageTransport transport;
   private final long evaluatorId;
   private final Map<URI, Future<byte[]>> readResponses = new ConcurrentHashMap<>();
   private final Map<URI, Future<List<PathElement>>> listResponses = new ConcurrentHashMap<>();
   private final Random requestIdGenerator = new Random();
 
-  ExternalResourceResolverImpl(MessageTransport transport, long evaluatorId) {
+  ResourceResolverImpl(MessageTransport transport, long evaluatorId) {
     this.transport = transport;
     this.evaluatorId = evaluatorId;
   }
diff --git a/pkl-core/src/main/java/org/pkl/core/module/ModuleKeyFactories.java b/pkl-core/src/main/java/org/pkl/core/module/ModuleKeyFactories.java
index eae4e7e66..7038a1224 100644
--- a/pkl-core/src/main/java/org/pkl/core/module/ModuleKeyFactories.java
+++ b/pkl-core/src/main/java/org/pkl/core/module/ModuleKeyFactories.java
@@ -28,9 +28,9 @@
 import java.util.ServiceLoader;
 import javax.annotation.concurrent.GuardedBy;
 import org.pkl.core.Closeables;
-import org.pkl.core.externalreader.ExternalModuleResolver;
-import org.pkl.core.externalreader.ExternalReaderProcess;
-import org.pkl.core.externalreader.ExternalReaderProcessException;
+import org.pkl.core.externalreader.ModuleResolver;
+import org.pkl.core.externalreader.ReaderProcess;
+import org.pkl.core.externalreader.ReaderProcessException;
 import org.pkl.core.util.ErrorMessages;
 import org.pkl.core.util.IoUtils;
 
@@ -82,21 +82,21 @@ public static ModuleKeyFactory classPath(ClassLoader classLoader) {
   /**
    * Returns a factory for external reader module keys.
    *
-   * <p>NOTE: {@code process} needs to be {@link ExternalReaderProcess#close closed} to avoid
-   * resource leaks.
+   * <p>NOTE: {@code process} needs to be {@link ReaderProcess#close closed} to avoid resource
+   * leaks.
    */
-  public static ModuleKeyFactory externalProcess(String scheme, ExternalReaderProcess process) {
+  public static ModuleKeyFactory externalProcess(String scheme, ReaderProcess process) {
     return new ExternalProcess(scheme, process, 0);
   }
 
   /**
    * Returns a factory for external reader module keys.
    *
-   * <p>NOTE: {@code process} needs to be {@link ExternalReaderProcess#close closed} to avoid
-   * resource leaks.
+   * <p>NOTE: {@code process} needs to be {@link ReaderProcess#close closed} to avoid resource
+   * leaks.
    */
   public static ModuleKeyFactory externalProcess(
-      String scheme, ExternalReaderProcess process, long evaluatorId) {
+      String scheme, ReaderProcess process, long evaluatorId) {
     return new ExternalProcess(scheme, process, evaluatorId);
   }
 
@@ -262,20 +262,19 @@ private static class FromServiceProviders {
   /** Represents a module from an external reader process. */
   private static final class ExternalProcess implements ModuleKeyFactory {
     private final String scheme;
-    private final ExternalReaderProcess process;
+    private final ReaderProcess process;
     private final long evaluatorId;
 
     @GuardedBy("this")
-    private ExternalModuleResolver resolver;
+    private ModuleResolver resolver;
 
-    ExternalProcess(String scheme, ExternalReaderProcess process, long evaluatorId) {
+    ExternalProcess(String scheme, ReaderProcess process, long evaluatorId) {
       this.scheme = scheme;
       this.process = process;
       this.evaluatorId = evaluatorId;
     }
 
-    private synchronized ExternalModuleResolver getResolver()
-        throws ExternalReaderProcessException {
+    private synchronized ModuleResolver getResolver() throws ReaderProcessException {
       if (resolver != null) {
         return resolver;
       }
@@ -284,12 +283,12 @@ private synchronized ExternalModuleResolver getResolver()
       return resolver;
     }
 
-    public Optional<ModuleKey> create(URI uri) throws ExternalReaderProcessException, IOException {
+    public Optional<ModuleKey> create(URI uri) throws ReaderProcessException, IOException {
       if (!scheme.equalsIgnoreCase(uri.getScheme())) return Optional.empty();
 
       var spec = process.getModuleReaderSpec(scheme);
       if (spec == null) {
-        throw new ExternalReaderProcessException(
+        throw new ReaderProcessException(
             ErrorMessages.create("externalReaderDoesNotSupportScheme", "module", scheme));
       }
 
diff --git a/pkl-core/src/main/java/org/pkl/core/module/ModuleKeyFactory.java b/pkl-core/src/main/java/org/pkl/core/module/ModuleKeyFactory.java
index 7bc17cc98..85b085f85 100644
--- a/pkl-core/src/main/java/org/pkl/core/module/ModuleKeyFactory.java
+++ b/pkl-core/src/main/java/org/pkl/core/module/ModuleKeyFactory.java
@@ -19,7 +19,7 @@
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.util.Optional;
-import org.pkl.core.externalreader.ExternalReaderProcessException;
+import org.pkl.core.externalreader.ReaderProcessException;
 
 /** A factory for {@link ModuleKey}s. */
 public interface ModuleKeyFactory extends AutoCloseable {
@@ -38,7 +38,7 @@ public interface ModuleKeyFactory extends AutoCloseable {
    * @return a module key for the given URI
    */
   Optional<ModuleKey> create(URI uri)
-      throws URISyntaxException, ExternalReaderProcessException, IOException;
+      throws URISyntaxException, ReaderProcessException, IOException;
 
   /**
    * Closes this factory, releasing any resources held. See the documentation of factory methods in
diff --git a/pkl-core/src/main/java/org/pkl/core/module/ModuleKeys.java b/pkl-core/src/main/java/org/pkl/core/module/ModuleKeys.java
index 7cc1d916e..afac9147e 100644
--- a/pkl-core/src/main/java/org/pkl/core/module/ModuleKeys.java
+++ b/pkl-core/src/main/java/org/pkl/core/module/ModuleKeys.java
@@ -29,9 +29,9 @@
 import java.util.Map;
 import org.pkl.core.SecurityManager;
 import org.pkl.core.SecurityManagerException;
-import org.pkl.core.externalreader.ExternalModuleReaderSpec;
-import org.pkl.core.externalreader.ExternalModuleResolver;
-import org.pkl.core.externalreader.ExternalReaderProcessException;
+import org.pkl.core.externalreader.ModuleReaderSpec;
+import org.pkl.core.externalreader.ModuleResolver;
+import org.pkl.core.externalreader.ReaderProcessException;
 import org.pkl.core.packages.Dependency;
 import org.pkl.core.packages.Dependency.LocalDependency;
 import org.pkl.core.packages.PackageAssetUri;
@@ -132,7 +132,7 @@ public static ModuleKey projectpackage(URI uri) throws URISyntaxException {
 
   /** Creates a module key for an externally read module. */
   public static ModuleKey externalResolver(
-      URI uri, ExternalModuleReaderSpec spec, ExternalModuleResolver resolver) {
+      URI uri, ModuleReaderSpec spec, ModuleResolver resolver) {
     return new ExternalResolver(uri, spec, resolver);
   }
 
@@ -174,7 +174,7 @@ public ResolvedModuleKey resolve(SecurityManager securityManager) {
     }
 
     @Override
-    public boolean hasHierarchicalUris() throws IOException, ExternalReaderProcessException {
+    public boolean hasHierarchicalUris() throws IOException, ReaderProcessException {
       return delegate.hasHierarchicalUris();
     }
 
@@ -184,19 +184,19 @@ public boolean isLocal() {
     }
 
     @Override
-    public boolean isGlobbable() throws IOException, ExternalReaderProcessException {
+    public boolean isGlobbable() throws IOException, ReaderProcessException {
       return delegate.isGlobbable();
     }
 
     @Override
     public boolean hasElement(SecurityManager securityManager, URI uri)
-        throws IOException, SecurityManagerException, ExternalReaderProcessException {
+        throws IOException, SecurityManagerException, ReaderProcessException {
       return delegate.hasElement(securityManager, uri);
     }
 
     @Override
     public List<PathElement> listElements(SecurityManager securityManager, URI baseUri)
-        throws IOException, SecurityManagerException, ExternalReaderProcessException {
+        throws IOException, SecurityManagerException, ReaderProcessException {
       return delegate.listElements(securityManager, baseUri);
     }
   }
@@ -719,7 +719,7 @@ public ResolvedModuleKey resolve(SecurityManager securityManager)
 
     @Override
     public List<PathElement> listElements(SecurityManager securityManager, URI baseUri)
-        throws IOException, SecurityManagerException, ExternalReaderProcessException {
+        throws IOException, SecurityManagerException, ReaderProcessException {
       securityManager.checkResolveModule(baseUri);
       var packageAssetUri = PackageAssetUri.create(baseUri);
       var dependency =
@@ -740,7 +740,7 @@ public List<PathElement> listElements(SecurityManager securityManager, URI baseU
 
     @Override
     public boolean hasElement(SecurityManager securityManager, URI elementUri)
-        throws IOException, SecurityManagerException, ExternalReaderProcessException {
+        throws IOException, SecurityManagerException, ReaderProcessException {
       securityManager.checkResolveModule(elementUri);
       var packageAssetUri = PackageAssetUri.create(elementUri);
       var dependency =
@@ -780,10 +780,10 @@ public boolean hasElement(SecurityManager securityManager, URI elementUri)
   public static class ExternalResolver implements ModuleKey {
 
     private final URI uri;
-    private final ExternalModuleReaderSpec spec;
-    private final ExternalModuleResolver resolver;
+    private final ModuleReaderSpec spec;
+    private final ModuleResolver resolver;
 
-    ExternalResolver(URI uri, ExternalModuleReaderSpec spec, ExternalModuleResolver resolver) {
+    ExternalResolver(URI uri, ModuleReaderSpec spec, ModuleResolver resolver) {
       this.uri = uri;
       this.spec = spec;
       this.resolver = resolver;
diff --git a/pkl-core/src/main/java/org/pkl/core/resource/ResourceReader.java b/pkl-core/src/main/java/org/pkl/core/resource/ResourceReader.java
index 40e3f39eb..ad1801a3f 100644
--- a/pkl-core/src/main/java/org/pkl/core/resource/ResourceReader.java
+++ b/pkl-core/src/main/java/org/pkl/core/resource/ResourceReader.java
@@ -20,7 +20,7 @@
 import java.net.URISyntaxException;
 import java.util.Optional;
 import org.pkl.core.SecurityManagerException;
-import org.pkl.core.externalreader.ExternalReaderProcessException;
+import org.pkl.core.externalreader.ReaderProcessException;
 import org.pkl.core.runtime.ReaderBase;
 
 /**
@@ -56,10 +56,7 @@ public interface ResourceReader extends ReaderBase, AutoCloseable {
    * </ul>
    */
   Optional<Object> read(URI uri)
-      throws IOException,
-          URISyntaxException,
-          SecurityManagerException,
-          ExternalReaderProcessException;
+      throws IOException, URISyntaxException, SecurityManagerException, ReaderProcessException;
 
   /**
    * Closes this reader, releasing any resources held. See the documentation of factory methods in
diff --git a/pkl-core/src/main/java/org/pkl/core/resource/ResourceReaders.java b/pkl-core/src/main/java/org/pkl/core/resource/ResourceReaders.java
index 68361c526..8ec026b79 100644
--- a/pkl-core/src/main/java/org/pkl/core/resource/ResourceReaders.java
+++ b/pkl-core/src/main/java/org/pkl/core/resource/ResourceReaders.java
@@ -29,10 +29,10 @@
 import java.util.ServiceLoader;
 import org.pkl.core.SecurityManager;
 import org.pkl.core.SecurityManagerException;
-import org.pkl.core.externalreader.ExternalReaderProcess;
-import org.pkl.core.externalreader.ExternalReaderProcessException;
-import org.pkl.core.externalreader.ExternalResourceReaderSpec;
-import org.pkl.core.externalreader.ExternalResourceResolver;
+import org.pkl.core.externalreader.ReaderProcess;
+import org.pkl.core.externalreader.ReaderProcessException;
+import org.pkl.core.externalreader.ResourceReaderSpec;
+import org.pkl.core.externalreader.ResourceResolver;
 import org.pkl.core.module.FileResolver;
 import org.pkl.core.module.ModulePathResolver;
 import org.pkl.core.module.PathElement;
@@ -144,27 +144,27 @@ public static List<ResourceReader> fromServiceProviders() {
   /**
    * Returns a reader for external reader resources.
    *
-   * <p>NOTE: {@code process} needs to be {@link ExternalReaderProcess#close closed} to avoid
-   * resource leaks.
+   * <p>NOTE: {@code process} needs to be {@link ReaderProcess#close closed} to avoid resource
+   * leaks.
    */
-  public static ResourceReader externalProcess(String scheme, ExternalReaderProcess process) {
+  public static ResourceReader externalProcess(String scheme, ReaderProcess process) {
     return new ExternalProcess(scheme, process, 0);
   }
 
   /**
    * Returns a reader for external reader resources.
    *
-   * <p>NOTE: {@code process} needs to be {@link ExternalReaderProcess#close closed} to avoid
-   * resource leaks.
+   * <p>NOTE: {@code process} needs to be {@link ReaderProcess#close closed} to avoid resource
+   * leaks.
    */
   public static ResourceReader externalProcess(
-      String scheme, ExternalReaderProcess process, long evaluatorId) {
+      String scheme, ReaderProcess process, long evaluatorId) {
     return new ExternalProcess(scheme, process, evaluatorId);
   }
 
   /** Returns a reader for external and client reader resources. */
   public static ResourceReader externalResolver(
-      ExternalResourceReaderSpec spec, ExternalResourceResolver resolver) {
+      ResourceReaderSpec spec, ResourceResolver resolver) {
     return new ExternalResolver(spec, resolver);
   }
 
@@ -552,7 +552,7 @@ public boolean hasFragmentPaths() {
 
     @Override
     public List<PathElement> listElements(SecurityManager securityManager, URI baseUri)
-        throws IOException, SecurityManagerException, ExternalReaderProcessException {
+        throws IOException, SecurityManagerException, ReaderProcessException {
       securityManager.checkResolveResource(baseUri);
       var packageAssetUri = PackageAssetUri.create(baseUri);
       var dependency =
@@ -574,7 +574,7 @@ public List<PathElement> listElements(SecurityManager securityManager, URI baseU
 
     @Override
     public boolean hasElement(SecurityManager securityManager, URI elementUri)
-        throws IOException, SecurityManagerException, ExternalReaderProcessException {
+        throws IOException, SecurityManagerException, ReaderProcessException {
       securityManager.checkResolveResource(elementUri);
       var packageAssetUri = PackageAssetUri.create(elementUri);
       var dependency =
@@ -629,25 +629,24 @@ private static class FromServiceProviders {
 
   private static final class ExternalProcess implements ResourceReader {
     private final String scheme;
-    private final ExternalReaderProcess process;
+    private final ReaderProcess process;
     private final long evaluatorId;
     private ExternalResolver underlying;
 
-    public ExternalProcess(String scheme, ExternalReaderProcess process, long evaluatorId) {
+    public ExternalProcess(String scheme, ReaderProcess process, long evaluatorId) {
       this.scheme = scheme;
       this.process = process;
       this.evaluatorId = evaluatorId;
     }
 
-    private ExternalResolver getUnderlyingReader()
-        throws ExternalReaderProcessException, IOException {
+    private ExternalResolver getUnderlyingReader() throws ReaderProcessException, IOException {
       if (underlying != null) {
         return underlying;
       }
 
       var spec = process.getResourceReaderSpec(scheme);
       if (spec == null) {
-        throw new ExternalReaderProcessException(
+        throw new ReaderProcessException(
             ErrorMessages.create("externalReaderDoesNotSupportScheme", "resource", scheme));
       }
       underlying = new ExternalResolver(spec, process.getResourceResolver(evaluatorId));
@@ -660,29 +659,29 @@ public String getUriScheme() {
     }
 
     @Override
-    public boolean hasHierarchicalUris() throws ExternalReaderProcessException, IOException {
+    public boolean hasHierarchicalUris() throws ReaderProcessException, IOException {
       return getUnderlyingReader().hasHierarchicalUris();
     }
 
     @Override
-    public boolean isGlobbable() throws ExternalReaderProcessException, IOException {
+    public boolean isGlobbable() throws ReaderProcessException, IOException {
       return getUnderlyingReader().isGlobbable();
     }
 
     @Override
-    public Optional<Object> read(URI uri) throws IOException, ExternalReaderProcessException {
+    public Optional<Object> read(URI uri) throws IOException, ReaderProcessException {
       return getUnderlyingReader().read(uri);
     }
 
     @Override
     public boolean hasElement(SecurityManager securityManager, URI elementUri)
-        throws IOException, SecurityManagerException, ExternalReaderProcessException {
+        throws IOException, SecurityManagerException, ReaderProcessException {
       return getUnderlyingReader().hasElement(securityManager, elementUri);
     }
 
     @Override
     public List<PathElement> listElements(SecurityManager securityManager, URI baseUri)
-        throws IOException, SecurityManagerException, ExternalReaderProcessException {
+        throws IOException, SecurityManagerException, ReaderProcessException {
       return getUnderlyingReader().listElements(securityManager, baseUri);
     }
 
@@ -693,11 +692,10 @@ public void close() {
   }
 
   private static final class ExternalResolver implements ResourceReader {
-    private final ExternalResourceReaderSpec readerSpec;
-    private final ExternalResourceResolver resolver;
+    private final ResourceReaderSpec readerSpec;
+    private final ResourceResolver resolver;
 
-    public ExternalResolver(
-        ExternalResourceReaderSpec readerSpec, ExternalResourceResolver resolver) {
+    public ExternalResolver(ResourceReaderSpec readerSpec, ResourceResolver resolver) {
       this.readerSpec = readerSpec;
       this.resolver = resolver;
     }
diff --git a/pkl-core/src/main/java/org/pkl/core/runtime/ModuleResolver.java b/pkl-core/src/main/java/org/pkl/core/runtime/ModuleResolver.java
index e90719f18..179882bd6 100644
--- a/pkl-core/src/main/java/org/pkl/core/runtime/ModuleResolver.java
+++ b/pkl-core/src/main/java/org/pkl/core/runtime/ModuleResolver.java
@@ -22,7 +22,7 @@
 import java.util.Collection;
 import java.util.Optional;
 import org.pkl.core.ModuleSource;
-import org.pkl.core.externalreader.ExternalReaderProcessException;
+import org.pkl.core.externalreader.ReaderProcessException;
 import org.pkl.core.module.ModuleKey;
 import org.pkl.core.module.ModuleKeyFactory;
 import org.pkl.core.module.ModuleKeys;
@@ -84,7 +84,7 @@ public ModuleKey resolve(URI moduleUri, @Nullable Node importNode) {
             .evalError("invalidModuleUri", moduleUri)
             .withHint(e.getReason())
             .build();
-      } catch (ExternalReaderProcessException e) {
+      } catch (ReaderProcessException e) {
         throw new VmExceptionBuilder()
             .withOptionalLocation(importNode)
             .evalError("externalReaderFailure")
diff --git a/pkl-core/src/main/java/org/pkl/core/runtime/ReaderBase.java b/pkl-core/src/main/java/org/pkl/core/runtime/ReaderBase.java
index e1f461d25..cfd934633 100644
--- a/pkl-core/src/main/java/org/pkl/core/runtime/ReaderBase.java
+++ b/pkl-core/src/main/java/org/pkl/core/runtime/ReaderBase.java
@@ -20,7 +20,7 @@
 import java.util.List;
 import org.pkl.core.SecurityManager;
 import org.pkl.core.SecurityManagerException;
-import org.pkl.core.externalreader.ExternalReaderProcessException;
+import org.pkl.core.externalreader.ReaderProcessException;
 import org.pkl.core.module.ModuleKey;
 import org.pkl.core.module.PathElement;
 import org.pkl.core.util.IoUtils;
@@ -30,10 +30,10 @@ public interface ReaderBase {
    * Tells if the URIs represented by this module key or resource reader should be interpreted as <a
    * href="https://www.rfc-editor.org/rfc/rfc3986#section-1.2.3">hierarchical</a>.
    */
-  boolean hasHierarchicalUris() throws ExternalReaderProcessException, IOException;
+  boolean hasHierarchicalUris() throws ReaderProcessException, IOException;
 
   /** Tells if this module key or resource reader supports globbing. */
-  boolean isGlobbable() throws ExternalReaderProcessException, IOException;
+  boolean isGlobbable() throws ReaderProcessException, IOException;
 
   /**
    * Tells if relative paths of this URI should be resolved from {@link URI#getFragment()}, rather
@@ -50,7 +50,7 @@ default boolean hasFragmentPaths() {
    * if either {@link #isGlobbable()} or {@link ModuleKey#isLocal()} returns true.
    */
   default boolean hasElement(SecurityManager securityManager, URI elementUri)
-      throws IOException, SecurityManagerException, ExternalReaderProcessException {
+      throws IOException, SecurityManagerException, ReaderProcessException {
     throw new UnsupportedOperationException();
   }
 
@@ -67,7 +67,7 @@ default boolean hasElement(SecurityManager securityManager, URI elementUri)
    * this reader.
    */
   default List<PathElement> listElements(SecurityManager securityManager, URI baseUri)
-      throws IOException, SecurityManagerException, ExternalReaderProcessException {
+      throws IOException, SecurityManagerException, ReaderProcessException {
     throw new UnsupportedOperationException();
   }
 
diff --git a/pkl-core/src/main/java/org/pkl/core/runtime/ResourceManager.java b/pkl-core/src/main/java/org/pkl/core/runtime/ResourceManager.java
index 17f2cbdf4..1353163fa 100644
--- a/pkl-core/src/main/java/org/pkl/core/runtime/ResourceManager.java
+++ b/pkl-core/src/main/java/org/pkl/core/runtime/ResourceManager.java
@@ -26,7 +26,7 @@
 import java.util.Optional;
 import org.pkl.core.SecurityManager;
 import org.pkl.core.SecurityManagerException;
-import org.pkl.core.externalreader.ExternalReaderProcessException;
+import org.pkl.core.externalreader.ReaderProcessException;
 import org.pkl.core.http.HttpClientInitException;
 import org.pkl.core.packages.PackageLoadError;
 import org.pkl.core.resource.Resource;
@@ -87,7 +87,7 @@ public Optional<Object> doRead(ResourceReader reader, URI uri, @Nullable Node re
     } catch (SecurityManagerException
         | PackageLoadError
         | HttpClientInitException
-        | ExternalReaderProcessException e) {
+        | ReaderProcessException e) {
       throw new VmExceptionBuilder().withCause(e).withOptionalLocation(readNode).build();
     }
     return resource;
diff --git a/pkl-core/src/main/java/org/pkl/core/runtime/VmImportAnalyzer.java b/pkl-core/src/main/java/org/pkl/core/runtime/VmImportAnalyzer.java
index 7a239a4a7..732db9034 100644
--- a/pkl-core/src/main/java/org/pkl/core/runtime/VmImportAnalyzer.java
+++ b/pkl-core/src/main/java/org/pkl/core/runtime/VmImportAnalyzer.java
@@ -30,7 +30,7 @@
 import org.pkl.core.SecurityManagerException;
 import org.pkl.core.ast.builder.ImportsAndReadsParser;
 import org.pkl.core.ast.builder.ImportsAndReadsParser.Entry;
-import org.pkl.core.externalreader.ExternalReaderProcessException;
+import org.pkl.core.externalreader.ReaderProcessException;
 import org.pkl.core.util.GlobResolver;
 import org.pkl.core.util.GlobResolver.InvalidGlobPatternException;
 import org.pkl.core.util.GlobResolver.ResolvedGlobElement;
@@ -39,10 +39,7 @@
 public class VmImportAnalyzer {
   @TruffleBoundary
   public static ImportGraph analyze(URI[] moduleUris, VmContext context)
-      throws IOException,
-          URISyntaxException,
-          SecurityManagerException,
-          ExternalReaderProcessException {
+      throws IOException, URISyntaxException, SecurityManagerException, ReaderProcessException {
     var imports = new TreeMap<URI, Set<ImportGraph.Import>>();
     var resolvedImports = new TreeMap<URI, URI>();
     for (var moduleUri : moduleUris) {
@@ -57,10 +54,7 @@ private static void analyzeSingle(
       VmContext context,
       Map<URI, Set<ImportGraph.Import>> imports,
       Map<URI, URI> resolvedImports)
-      throws IOException,
-          URISyntaxException,
-          SecurityManagerException,
-          ExternalReaderProcessException {
+      throws IOException, URISyntaxException, SecurityManagerException, ReaderProcessException {
     var moduleResolver = context.getModuleResolver();
     var securityManager = context.getSecurityManager();
     var importsInModule = collectImports(moduleUri, moduleResolver, securityManager);
@@ -78,10 +72,7 @@ private static void analyzeSingle(
 
   private static Set<ImportGraph.Import> collectImports(
       URI moduleUri, ModuleResolver moduleResolver, SecurityManager securityManager)
-      throws IOException,
-          URISyntaxException,
-          SecurityManagerException,
-          ExternalReaderProcessException {
+      throws IOException, URISyntaxException, SecurityManagerException, ReaderProcessException {
     var moduleKey = moduleResolver.resolve(moduleUri);
     var resolvedModuleKey = moduleKey.resolve(securityManager);
     List<Entry> importsAndReads;
diff --git a/pkl-core/src/main/java/org/pkl/core/stdlib/analyze/AnalyzeNodes.java b/pkl-core/src/main/java/org/pkl/core/stdlib/analyze/AnalyzeNodes.java
index fdfaad1cc..025c6a397 100644
--- a/pkl-core/src/main/java/org/pkl/core/stdlib/analyze/AnalyzeNodes.java
+++ b/pkl-core/src/main/java/org/pkl/core/stdlib/analyze/AnalyzeNodes.java
@@ -23,7 +23,7 @@
 import org.pkl.core.ImportGraph;
 import org.pkl.core.ImportGraph.Import;
 import org.pkl.core.SecurityManagerException;
-import org.pkl.core.externalreader.ExternalReaderProcessException;
+import org.pkl.core.externalreader.ReaderProcessException;
 import org.pkl.core.packages.PackageLoadError;
 import org.pkl.core.runtime.AnalyzeModule;
 import org.pkl.core.runtime.VmContext;
@@ -96,7 +96,7 @@ protected Object eval(@SuppressWarnings("unused") VmTyped self, VmSet moduleUris
           | URISyntaxException
           | SecurityManagerException
           | PackageLoadError
-          | ExternalReaderProcessException e) {
+          | ReaderProcessException e) {
         throw exceptionBuilder().withCause(e).build();
       }
     }
diff --git a/pkl-core/src/main/java/org/pkl/core/stdlib/benchmark/OutputBenchmarkNodes.java b/pkl-core/src/main/java/org/pkl/core/stdlib/benchmark/OutputBenchmarkNodes.java
index 1bce83c1a..91fbe50a6 100644
--- a/pkl-core/src/main/java/org/pkl/core/stdlib/benchmark/OutputBenchmarkNodes.java
+++ b/pkl-core/src/main/java/org/pkl/core/stdlib/benchmark/OutputBenchmarkNodes.java
@@ -25,7 +25,7 @@
 import java.util.List;
 import org.pkl.core.SecurityManager;
 import org.pkl.core.SecurityManagerException;
-import org.pkl.core.externalreader.ExternalReaderProcessException;
+import org.pkl.core.externalreader.ReaderProcessException;
 import org.pkl.core.module.ModuleKey;
 import org.pkl.core.module.PathElement;
 import org.pkl.core.module.ResolvedModuleKey;
@@ -109,7 +109,7 @@ public boolean isCached() {
     }
 
     @Override
-    public boolean hasHierarchicalUris() throws IOException, ExternalReaderProcessException {
+    public boolean hasHierarchicalUris() throws IOException, ReaderProcessException {
       return delegate.hasHierarchicalUris();
     }
 
@@ -119,19 +119,19 @@ public boolean isLocal() {
     }
 
     @Override
-    public boolean isGlobbable() throws IOException, ExternalReaderProcessException {
+    public boolean isGlobbable() throws IOException, ReaderProcessException {
       return delegate.isGlobbable();
     }
 
     @Override
     public boolean hasElement(SecurityManager securityManager, URI uri)
-        throws IOException, SecurityManagerException, ExternalReaderProcessException {
+        throws IOException, SecurityManagerException, ReaderProcessException {
       return delegate.hasElement(securityManager, uri);
     }
 
     @Override
     public List<PathElement> listElements(SecurityManager securityManager, URI baseUri)
-        throws IOException, SecurityManagerException, ExternalReaderProcessException {
+        throws IOException, SecurityManagerException, ReaderProcessException {
       return delegate.listElements(securityManager, baseUri);
     }
   }
diff --git a/pkl-core/src/main/java/org/pkl/core/util/GlobResolver.java b/pkl-core/src/main/java/org/pkl/core/util/GlobResolver.java
index eca25f358..1789eabcd 100644
--- a/pkl-core/src/main/java/org/pkl/core/util/GlobResolver.java
+++ b/pkl-core/src/main/java/org/pkl/core/util/GlobResolver.java
@@ -31,7 +31,7 @@
 import org.pkl.core.PklBugException;
 import org.pkl.core.SecurityManager;
 import org.pkl.core.SecurityManagerException;
-import org.pkl.core.externalreader.ExternalReaderProcessException;
+import org.pkl.core.externalreader.ReaderProcessException;
 import org.pkl.core.module.ModuleKey;
 import org.pkl.core.module.PathElement;
 import org.pkl.core.runtime.ReaderBase;
@@ -244,7 +244,7 @@ private static void resolveOpaqueGlob(
       URI globUri,
       Pattern pattern,
       Map<String, ResolvedGlobElement> result)
-      throws IOException, SecurityManagerException, ExternalReaderProcessException {
+      throws IOException, SecurityManagerException, ReaderProcessException {
     var elements = reader.listElements(securityManager, globUri);
     for (var elem : sorted(elements)) {
       URI resolvedUri;
@@ -305,7 +305,7 @@ private static List<ResolvedGlobElement> expandHierarchicalGlobPart(
       throws IOException,
           SecurityManagerException,
           InvalidGlobPatternException,
-          ExternalReaderProcessException {
+          ReaderProcessException {
     var result = new ArrayList<ResolvedGlobElement>();
     doExpandHierarchicalGlobPart(
         securityManager,
@@ -333,7 +333,7 @@ private static void doExpandHierarchicalGlobPart(
       throws IOException,
           SecurityManagerException,
           InvalidGlobPatternException,
-          ExternalReaderProcessException {
+          ReaderProcessException {
 
     if (listElementCallCount.getAndIncrement() > maxListElements()) {
       throw new InvalidGlobPatternException(ErrorMessages.create("invalidGlobTooComplex"));
@@ -377,7 +377,7 @@ private static void resolveHierarchicalGlob(
       throws IOException,
           SecurityManagerException,
           InvalidGlobPatternException,
-          ExternalReaderProcessException {
+          ReaderProcessException {
     var isLeaf = idx == globPatternParts.length - 1;
     var patternPart = globPatternParts[idx];
     if (isRegularPathPart(patternPart)) {
@@ -477,7 +477,7 @@ public static Map<String, ResolvedGlobElement> resolveGlob(
       throws IOException,
           SecurityManagerException,
           InvalidGlobPatternException,
-          ExternalReaderProcessException {
+          ReaderProcessException {
 
     var result = new LinkedHashMap<String, ResolvedGlobElement>();
     var hasAbsoluteGlob = globPattern.matches("\\w+:.*");
diff --git a/pkl-core/src/main/java/org/pkl/core/util/IoUtils.java b/pkl-core/src/main/java/org/pkl/core/util/IoUtils.java
index f7a8bbd79..8f885d571 100644
--- a/pkl-core/src/main/java/org/pkl/core/util/IoUtils.java
+++ b/pkl-core/src/main/java/org/pkl/core/util/IoUtils.java
@@ -38,7 +38,7 @@
 import org.pkl.core.Platform;
 import org.pkl.core.SecurityManager;
 import org.pkl.core.SecurityManagerException;
-import org.pkl.core.externalreader.ExternalReaderProcessException;
+import org.pkl.core.externalreader.ReaderProcessException;
 import org.pkl.core.module.ModuleKey;
 import org.pkl.core.packages.PackageLoadError;
 import org.pkl.core.runtime.ReaderBase;
@@ -318,7 +318,7 @@ public static URI resolve(ReaderBase reader, URI baseUri, URI importUri) {
 
   private static URI resolveTripleDotImport(
       SecurityManager securityManager, ModuleKey moduleKey, String tripleDotPath)
-      throws IOException, SecurityManagerException, ExternalReaderProcessException {
+      throws IOException, SecurityManagerException, ReaderProcessException {
     var moduleKeyUri = moduleKey.getUri();
     if (!moduleKey.isLocal() || !moduleKey.hasHierarchicalUris()) {
       throw new VmExceptionBuilder()
@@ -365,7 +365,7 @@ public static Pair<String, String> parseDependencyNotation(String importPath) {
   }
 
   private static URI resolveProjectDependency(ModuleKey moduleKey, String notation)
-      throws IOException, ExternalReaderProcessException {
+      throws IOException, ReaderProcessException {
     var parsed = parseDependencyNotation(notation);
     var name = parsed.getFirst();
     var path = parsed.getSecond();
@@ -397,10 +397,7 @@ private static URI resolveProjectDependency(ModuleKey moduleKey, String notation
    * dependency notation ()
    */
   public static URI resolve(SecurityManager securityManager, ModuleKey moduleKey, URI importUri)
-      throws URISyntaxException,
-          IOException,
-          SecurityManagerException,
-          ExternalReaderProcessException {
+      throws URISyntaxException, IOException, SecurityManagerException, ReaderProcessException {
     if (importUri.isAbsolute()) {
       return moduleKey.resolveUri(importUri);
     }
diff --git a/pkl-core/src/test/kotlin/org/pkl/core/externalreader/ExternalProcessProcessReaderMessagePackCodecTest.kt b/pkl-core/src/test/kotlin/org/pkl/core/externalreader/MessagePackCodecTest.kt
similarity index 87%
rename from pkl-core/src/test/kotlin/org/pkl/core/externalreader/ExternalProcessProcessReaderMessagePackCodecTest.kt
rename to pkl-core/src/test/kotlin/org/pkl/core/externalreader/MessagePackCodecTest.kt
index 235524fdc..ac04db2f8 100644
--- a/pkl-core/src/test/kotlin/org/pkl/core/externalreader/ExternalProcessProcessReaderMessagePackCodecTest.kt
+++ b/pkl-core/src/test/kotlin/org/pkl/core/externalreader/MessagePackCodecTest.kt
@@ -20,18 +20,18 @@ import java.io.PipedOutputStream
 import org.assertj.core.api.Assertions.assertThat
 import org.junit.jupiter.api.Test
 import org.msgpack.core.MessagePack
-import org.pkl.core.externalreader.ExternalReaderMessages.*
+import org.pkl.core.externalreader.ReaderMessages.*
 import org.pkl.core.messaging.*
 
-class ExternalProcessProcessReaderMessagePackCodecTest {
+class MessagePackCodecTest {
   private val encoder: MessageEncoder
   private val decoder: MessageDecoder
 
   init {
     val inputStream = PipedInputStream()
     val outputStream = PipedOutputStream(inputStream)
-    encoder = ExternalReaderMessagePackEncoder(MessagePack.newDefaultPacker(outputStream))
-    decoder = ExternalReaderMessagePackDecoder(MessagePack.newDefaultUnpacker(inputStream))
+    encoder = MessagePackEncoder(MessagePack.newDefaultPacker(outputStream))
+    decoder = MessagePackDecoder(MessagePack.newDefaultUnpacker(inputStream))
   }
 
   private fun roundtrip(message: Message) {
diff --git a/pkl-core/src/test/kotlin/org/pkl/core/externalreader/ExternalModuleReader.kt b/pkl-core/src/test/kotlin/org/pkl/core/externalreader/ModuleReader.kt
similarity index 87%
rename from pkl-core/src/test/kotlin/org/pkl/core/externalreader/ExternalModuleReader.kt
rename to pkl-core/src/test/kotlin/org/pkl/core/externalreader/ModuleReader.kt
index e9be21d6f..34a639de3 100644
--- a/pkl-core/src/test/kotlin/org/pkl/core/externalreader/ExternalModuleReader.kt
+++ b/pkl-core/src/test/kotlin/org/pkl/core/externalreader/ModuleReader.kt
@@ -18,8 +18,8 @@ package org.pkl.core.externalreader
 import java.net.URI
 import org.pkl.core.messaging.Messages.ModuleReaderSpec
 
-/** An external module reader, to be used with [ExternalReaderRuntime]. */
-interface ExternalModuleReader : ExternalReaderBase {
+/** An external module reader, to be used with [ReaderRuntime]. */
+interface ModuleReader : ExternalReaderBase {
   val isLocal: Boolean
 
   fun read(uri: URI): String
diff --git a/pkl-core/src/test/kotlin/org/pkl/core/externalreader/ExternalReaderRuntime.kt b/pkl-core/src/test/kotlin/org/pkl/core/externalreader/ReaderRuntime.kt
similarity index 92%
rename from pkl-core/src/test/kotlin/org/pkl/core/externalreader/ExternalReaderRuntime.kt
rename to pkl-core/src/test/kotlin/org/pkl/core/externalreader/ReaderRuntime.kt
index 95b7dba32..0e87a1db2 100644
--- a/pkl-core/src/test/kotlin/org/pkl/core/externalreader/ExternalReaderRuntime.kt
+++ b/pkl-core/src/test/kotlin/org/pkl/core/externalreader/ReaderRuntime.kt
@@ -16,17 +16,18 @@
 package org.pkl.core.externalreader
 
 import java.io.IOException
-import org.pkl.core.externalreader.ExternalReaderMessages.*
+import org.pkl.core.externalreader.ReaderMessages.*
 import org.pkl.core.messaging.Message
 import org.pkl.core.messaging.MessageTransport
+import org.pkl.core.messaging.Messages
 import org.pkl.core.messaging.Messages.*
 import org.pkl.core.messaging.ProtocolException
 import org.pkl.core.util.Nullable
 
 /** An implementation of the client side of the external reader flow */
-class ExternalReaderRuntime(
-  private val moduleReaders: List<ExternalModuleReader>,
-  private val resourceReaders: List<ExternalResourceReader>,
+class ReaderRuntime(
+  private val moduleReaders: List<ModuleReader>,
+  private val resourceReaders: List<ResourceReader>,
   private val transport: MessageTransport
 ) {
   /** Close the runtime and its transport. */
@@ -34,7 +35,7 @@ class ExternalReaderRuntime(
     transport.close()
   }
 
-  private fun findModuleReader(scheme: String): @Nullable ExternalModuleReader? {
+  private fun findModuleReader(scheme: String): @Nullable ModuleReader? {
     for (moduleReader in moduleReaders) {
       if (moduleReader.scheme.equals(scheme, ignoreCase = true)) {
         return moduleReader
@@ -43,7 +44,7 @@ class ExternalReaderRuntime(
     return null
   }
 
-  private fun findResourceReader(scheme: String): @Nullable ExternalResourceReader? {
+  private fun findResourceReader(scheme: String): @Nullable ResourceReader? {
     for (resourceReader in resourceReaders) {
       if (resourceReader.scheme.equals(scheme, ignoreCase = true)) {
         return resourceReader
@@ -72,7 +73,7 @@ class ExternalReaderRuntime(
           Message.Type.INITIALIZE_MODULE_READER_REQUEST -> {
             val req = msg as InitializeModuleReaderRequest
             val reader = findModuleReader(req.scheme)
-            var spec: @Nullable ModuleReaderSpec? = null
+            var spec: Messages.ModuleReaderSpec? = null
             if (reader != null) {
               spec = reader.spec
             }
@@ -81,7 +82,7 @@ class ExternalReaderRuntime(
           Message.Type.INITIALIZE_RESOURCE_READER_REQUEST -> {
             val req = msg as InitializeResourceReaderRequest
             val reader = findResourceReader(req.scheme)
-            var spec: @Nullable ResourceReaderSpec? = null
+            var spec: Messages.ResourceReaderSpec? = null
             if (reader != null) {
               spec = reader.spec
             }
diff --git a/pkl-core/src/test/kotlin/org/pkl/core/externalreader/ExternalResourceReader.kt b/pkl-core/src/test/kotlin/org/pkl/core/externalreader/ResourceReader.kt
similarity index 87%
rename from pkl-core/src/test/kotlin/org/pkl/core/externalreader/ExternalResourceReader.kt
rename to pkl-core/src/test/kotlin/org/pkl/core/externalreader/ResourceReader.kt
index bf5ab46f3..d209e545e 100644
--- a/pkl-core/src/test/kotlin/org/pkl/core/externalreader/ExternalResourceReader.kt
+++ b/pkl-core/src/test/kotlin/org/pkl/core/externalreader/ResourceReader.kt
@@ -18,8 +18,8 @@ package org.pkl.core.externalreader
 import java.net.URI
 import org.pkl.core.messaging.Messages.ResourceReaderSpec
 
-/** An external resource reader, to be used with [ExternalReaderRuntime]. */
-interface ExternalResourceReader : ExternalReaderBase {
+/** An external resource reader, to be used with [ReaderRuntime]. */
+interface ResourceReader : ExternalReaderBase {
   fun read(uri: URI): ByteArray
 
   val spec: ResourceReaderSpec
diff --git a/pkl-core/src/test/kotlin/org/pkl/core/externalreader/TestExternalModuleReader.kt b/pkl-core/src/test/kotlin/org/pkl/core/externalreader/TestModuleReader.kt
similarity index 95%
rename from pkl-core/src/test/kotlin/org/pkl/core/externalreader/TestExternalModuleReader.kt
rename to pkl-core/src/test/kotlin/org/pkl/core/externalreader/TestModuleReader.kt
index 12b543cec..f826b7e98 100644
--- a/pkl-core/src/test/kotlin/org/pkl/core/externalreader/TestExternalModuleReader.kt
+++ b/pkl-core/src/test/kotlin/org/pkl/core/externalreader/TestModuleReader.kt
@@ -18,7 +18,7 @@ package org.pkl.core.externalreader
 import java.net.URI
 import org.pkl.core.module.PathElement
 
-class TestExternalModuleReader : ExternalModuleReader {
+class TestModuleReader : ModuleReader {
   override val scheme: String = "test"
 
   override val hasHierarchicalUris: Boolean = false
diff --git a/pkl-core/src/test/kotlin/org/pkl/core/externalreader/TestExternalReaderProcess.kt b/pkl-core/src/test/kotlin/org/pkl/core/externalreader/TestReaderProcess.kt
similarity index 63%
rename from pkl-core/src/test/kotlin/org/pkl/core/externalreader/TestExternalReaderProcess.kt
rename to pkl-core/src/test/kotlin/org/pkl/core/externalreader/TestReaderProcess.kt
index cccbf83f7..75d52a95c 100644
--- a/pkl-core/src/test/kotlin/org/pkl/core/externalreader/TestExternalReaderProcess.kt
+++ b/pkl-core/src/test/kotlin/org/pkl/core/externalreader/TestReaderProcess.kt
@@ -23,17 +23,15 @@ import java.util.concurrent.ConcurrentHashMap
 import java.util.concurrent.ExecutionException
 import java.util.concurrent.Future
 import kotlin.random.Random
-import org.pkl.core.externalreader.ExternalReaderMessages.*
+import org.pkl.core.externalreader.ReaderMessages.*
 import org.pkl.core.messaging.MessageTransport
 import org.pkl.core.messaging.MessageTransports
 import org.pkl.core.messaging.ProtocolException
 
-class TestExternalReaderProcess(private val transport: MessageTransport) : ExternalReaderProcess {
-  private val initializeModuleReaderResponses:
-    MutableMap<String, Future<ExternalModuleReaderSpec?>> =
+class TestReaderProcess(private val transport: MessageTransport) : ReaderProcess {
+  private val initializeModuleReaderResponses: MutableMap<String, Future<ModuleReaderSpec?>> =
     ConcurrentHashMap()
-  private val initializeResourceReaderResponses:
-    MutableMap<String, Future<ExternalResourceReaderSpec?>> =
+  private val initializeResourceReaderResponses: MutableMap<String, Future<ResourceReaderSpec?>> =
     ConcurrentHashMap()
 
   override fun close() {
@@ -41,11 +39,11 @@ class TestExternalReaderProcess(private val transport: MessageTransport) : Exter
     transport.close()
   }
 
-  override fun getModuleResolver(evaluatorId: Long): ExternalModuleResolver =
-    ExternalModuleResolver.of(transport, evaluatorId)
+  override fun getModuleResolver(evaluatorId: Long): ModuleResolver =
+    ModuleResolver.of(transport, evaluatorId)
 
-  override fun getResourceResolver(evaluatorId: Long): ExternalResourceResolver =
-    ExternalResourceResolver.of(transport, evaluatorId)
+  override fun getResourceResolver(evaluatorId: Long): ResourceResolver =
+    ResourceResolver.of(transport, evaluatorId)
 
   fun run() {
     try {
@@ -60,22 +58,17 @@ class TestExternalReaderProcess(private val transport: MessageTransport) : Exter
     }
   }
 
-  override fun getModuleReaderSpec(scheme: String): ExternalModuleReaderSpec? =
+  override fun getModuleReaderSpec(scheme: String): ModuleReaderSpec? =
     initializeModuleReaderResponses
       .computeIfAbsent(scheme) {
-        CompletableFuture<ExternalModuleReaderSpec?>().apply {
+        CompletableFuture<ModuleReaderSpec?>().apply {
           val request = InitializeModuleReaderRequest(Random.nextLong(), scheme)
           transport.send(request) { response ->
             when (response) {
               is InitializeModuleReaderResponse -> {
                 val spec =
                   response.spec?.let {
-                    ExternalModuleReaderSpec(
-                      it.scheme,
-                      it.hasHierarchicalUris,
-                      it.isLocal,
-                      it.isGlobbable
-                    )
+                    ModuleReaderSpec(it.scheme, it.hasHierarchicalUris, it.isLocal, it.isGlobbable)
                   }
                 complete(spec)
               }
@@ -86,17 +79,17 @@ class TestExternalReaderProcess(private val transport: MessageTransport) : Exter
       }
       .getUnderlying()
 
-  override fun getResourceReaderSpec(scheme: String): ExternalResourceReaderSpec? =
+  override fun getResourceReaderSpec(scheme: String): ResourceReaderSpec? =
     initializeResourceReaderResponses
       .computeIfAbsent(scheme) {
-        CompletableFuture<ExternalResourceReaderSpec?>().apply {
+        CompletableFuture<ResourceReaderSpec?>().apply {
           val request = InitializeResourceReaderRequest(Random.nextLong(), scheme)
           transport.send(request) { response ->
             when (response) {
               is InitializeResourceReaderResponse -> {
                 val spec =
                   response.spec?.let {
-                    ExternalResourceReaderSpec(it.scheme, it.hasHierarchicalUris, it.isGlobbable)
+                    ResourceReaderSpec(it.scheme, it.hasHierarchicalUris, it.isGlobbable)
                   }
                 complete(spec)
               }
@@ -109,26 +102,20 @@ class TestExternalReaderProcess(private val transport: MessageTransport) : Exter
 
   companion object {
     fun initializeTestHarness(
-      moduleReaders: List<ExternalModuleReader>,
-      resourceReaders: List<ExternalResourceReader>
-    ): Pair<TestExternalReaderProcess, ExternalReaderRuntime> {
+      moduleReaders: List<ModuleReader>,
+      resourceReaders: List<ResourceReader>
+    ): Pair<TestReaderProcess, ReaderRuntime> {
       val rxIn = PipedInputStream(10240)
       val rxOut = PipedOutputStream(rxIn)
       val txIn = PipedInputStream(10240)
       val txOut = PipedOutputStream(txIn)
       val serverTransport =
-        MessageTransports.stream(
-          ExternalReaderMessagePackDecoder(rxIn),
-          ExternalReaderMessagePackEncoder(txOut)
-        ) {}
+        MessageTransports.stream(MessagePackDecoder(rxIn), MessagePackEncoder(txOut)) {}
       val clientTransport =
-        MessageTransports.stream(
-          ExternalReaderMessagePackDecoder(txIn),
-          ExternalReaderMessagePackEncoder(rxOut)
-        ) {}
+        MessageTransports.stream(MessagePackDecoder(txIn), MessagePackEncoder(rxOut)) {}
 
-      val runtime = ExternalReaderRuntime(moduleReaders, resourceReaders, clientTransport)
-      val proc = TestExternalReaderProcess(serverTransport)
+      val runtime = ReaderRuntime(moduleReaders, resourceReaders, clientTransport)
+      val proc = TestReaderProcess(serverTransport)
 
       Thread(runtime::run).start()
       Thread(proc::run).start()
diff --git a/pkl-core/src/test/kotlin/org/pkl/core/externalreader/TestExternalResourceReader.kt b/pkl-core/src/test/kotlin/org/pkl/core/externalreader/TestResourceReader.kt
similarity index 94%
rename from pkl-core/src/test/kotlin/org/pkl/core/externalreader/TestExternalResourceReader.kt
rename to pkl-core/src/test/kotlin/org/pkl/core/externalreader/TestResourceReader.kt
index 6cabf362b..434dd4754 100644
--- a/pkl-core/src/test/kotlin/org/pkl/core/externalreader/TestExternalResourceReader.kt
+++ b/pkl-core/src/test/kotlin/org/pkl/core/externalreader/TestResourceReader.kt
@@ -18,7 +18,7 @@ package org.pkl.core.externalreader
 import java.net.URI
 import org.pkl.core.module.PathElement
 
-class TestExternalResourceReader : ExternalResourceReader {
+class TestResourceReader : ResourceReader {
   override val scheme: String = "test"
 
   override val hasHierarchicalUris: Boolean = false
diff --git a/pkl-core/src/test/kotlin/org/pkl/core/module/ModuleKeyFactoriesTest.kt b/pkl-core/src/test/kotlin/org/pkl/core/module/ModuleKeyFactoriesTest.kt
index 032fc5fe6..7f1b370b2 100644
--- a/pkl-core/src/test/kotlin/org/pkl/core/module/ModuleKeyFactoriesTest.kt
+++ b/pkl-core/src/test/kotlin/org/pkl/core/module/ModuleKeyFactoriesTest.kt
@@ -130,9 +130,8 @@ class ModuleKeyFactoriesTest {
 
   @Test
   fun externalProcess() {
-    val extReader = TestExternalModuleReader()
-    val (proc, runtime) =
-      TestExternalReaderProcess.initializeTestHarness(listOf(extReader), emptyList())
+    val extReader = TestModuleReader()
+    val (proc, runtime) = TestReaderProcess.initializeTestHarness(listOf(extReader), emptyList())
 
     val factory = ModuleKeyFactories.externalProcess(extReader.scheme, proc)
 
diff --git a/pkl-core/src/test/kotlin/org/pkl/core/resource/ResourceReadersTest.kt b/pkl-core/src/test/kotlin/org/pkl/core/resource/ResourceReadersTest.kt
index 58c34b469..24f63e080 100644
--- a/pkl-core/src/test/kotlin/org/pkl/core/resource/ResourceReadersTest.kt
+++ b/pkl-core/src/test/kotlin/org/pkl/core/resource/ResourceReadersTest.kt
@@ -23,8 +23,8 @@ import org.assertj.core.api.Assertions.assertThat
 import org.junit.jupiter.api.Test
 import org.junit.jupiter.api.assertThrows
 import org.junit.jupiter.api.io.TempDir
-import org.pkl.core.externalreader.TestExternalReaderProcess
-import org.pkl.core.externalreader.TestExternalResourceReader
+import org.pkl.core.externalreader.TestReaderProcess
+import org.pkl.core.externalreader.TestResourceReader
 import org.pkl.core.module.ModulePathResolver
 
 class ResourceReadersTest {
@@ -137,9 +137,8 @@ class ResourceReadersTest {
 
   @Test
   fun externalProcess() {
-    val extReader = TestExternalResourceReader()
-    val (proc, runtime) =
-      TestExternalReaderProcess.initializeTestHarness(emptyList(), listOf(extReader))
+    val extReader = TestResourceReader()
+    val (proc, runtime) = TestReaderProcess.initializeTestHarness(emptyList(), listOf(extReader))
 
     val reader = ResourceReaders.externalProcess(extReader.scheme, proc)
     val resource = reader.read(URI("test:foo"))
diff --git a/pkl-server/src/main/kotlin/org/pkl/server/ClientModuleKeyFactory.kt b/pkl-server/src/main/kotlin/org/pkl/server/ClientModuleKeyFactory.kt
index 84c9f7800..abe5d67a5 100644
--- a/pkl-server/src/main/kotlin/org/pkl/server/ClientModuleKeyFactory.kt
+++ b/pkl-server/src/main/kotlin/org/pkl/server/ClientModuleKeyFactory.kt
@@ -17,19 +17,19 @@ package org.pkl.server
 
 import java.net.URI
 import java.util.Optional
-import org.pkl.core.externalreader.ExternalModuleReaderSpec
-import org.pkl.core.externalreader.ExternalModuleResolver
+import org.pkl.core.externalreader.ModuleReaderSpec
+import org.pkl.core.externalreader.ModuleResolver
 import org.pkl.core.messaging.*
 import org.pkl.core.module.*
 
 internal class ClientModuleKeyFactory(
-  private val readerSpecs: Collection<ExternalModuleReaderSpec>,
+  private val readerSpecs: Collection<ModuleReaderSpec>,
   transport: MessageTransport,
   evaluatorId: Long
 ) : ModuleKeyFactory {
   private val schemes = readerSpecs.map { it.scheme }
 
-  private val resolver: ExternalModuleResolver = ExternalModuleResolver.of(transport, evaluatorId)
+  private val resolver: ModuleResolver = ModuleResolver.of(transport, evaluatorId)
 
   override fun create(uri: URI): Optional<ModuleKey> =
     when (uri.scheme) {
diff --git a/pkl-server/src/main/kotlin/org/pkl/server/Server.kt b/pkl-server/src/main/kotlin/org/pkl/server/Server.kt
index 6b10e9e00..b108f2254 100644
--- a/pkl-server/src/main/kotlin/org/pkl/server/Server.kt
+++ b/pkl-server/src/main/kotlin/org/pkl/server/Server.kt
@@ -25,10 +25,10 @@ import java.util.regex.Pattern
 import kotlin.random.Random
 import org.pkl.core.*
 import org.pkl.core.evaluatorSettings.PklEvaluatorSettings
-import org.pkl.core.externalreader.ExternalModuleReaderSpec
-import org.pkl.core.externalreader.ExternalReaderProcess
-import org.pkl.core.externalreader.ExternalResourceReaderSpec
-import org.pkl.core.externalreader.ExternalResourceResolver
+import org.pkl.core.externalreader.ModuleReaderSpec
+import org.pkl.core.externalreader.ReaderProcess
+import org.pkl.core.externalreader.ResourceReaderSpec
+import org.pkl.core.externalreader.ResourceResolver
 import org.pkl.core.http.HttpClient
 import org.pkl.core.messaging.MessageTransport
 import org.pkl.core.messaging.MessageTransports
@@ -49,8 +49,7 @@ class Server(private val transport: MessageTransport) : AutoCloseable {
   private val executor: ExecutorService = Executors.newSingleThreadExecutor()
 
   // ExternalProcess instances with the same ExternalReader spec are shared per evaluator
-  private val externalReaderProcesses:
-    MutableMap<Long, MutableMap<ExternalReader, ExternalReaderProcess>> =
+  private val readerProcesses: MutableMap<Long, MutableMap<ExternalReader, ReaderProcess>> =
     ConcurrentHashMap()
 
   companion object {
@@ -144,7 +143,7 @@ class Server(private val transport: MessageTransport) : AutoCloseable {
     evaluator.close()
 
     // close any running ExternalProcess instances for the closed evaluator
-    externalReaderProcesses[message.evaluatorId]?.values?.forEach { it.close() }
+    readerProcesses[message.evaluatorId]?.values?.forEach { it.close() }
   }
 
   private fun buildDeclaredDependencies(
@@ -250,12 +249,12 @@ class Server(private val transport: MessageTransport) : AutoCloseable {
     for (readerSpec in message.clientResourceReaders ?: emptyList()) {
       add(
         ResourceReaders.externalResolver(
-          ExternalResourceReaderSpec(
+          ResourceReaderSpec(
             readerSpec.scheme,
             readerSpec.hasHierarchicalUris,
             readerSpec.isGlobbable
           ),
-          ExternalResourceResolver.of(transport, evaluatorId)
+          ResourceResolver.of(transport, evaluatorId)
         )
       )
     }
@@ -270,7 +269,7 @@ class Server(private val transport: MessageTransport) : AutoCloseable {
     if (message.clientModuleReaders?.isNotEmpty() == true) {
       val readerSpecs =
         message.clientModuleReaders.map {
-          ExternalModuleReaderSpec(it.scheme, it.hasHierarchicalUris, it.isLocal, it.isGlobbable)
+          ModuleReaderSpec(it.scheme, it.hasHierarchicalUris, it.isLocal, it.isGlobbable)
         }
       add(ClientModuleKeyFactory(readerSpecs, transport, evaluatorId))
     }
@@ -293,10 +292,10 @@ class Server(private val transport: MessageTransport) : AutoCloseable {
     add(ModuleKeyFactories.genericUrl)
   }
 
-  private fun getExternalProcess(evaluatorId: Long, spec: ExternalReader): ExternalReaderProcess =
-    externalReaderProcesses
+  private fun getExternalProcess(evaluatorId: Long, spec: ExternalReader): ReaderProcess =
+    readerProcesses
       .computeIfAbsent(evaluatorId) { ConcurrentHashMap() }
       .computeIfAbsent(spec) {
-        ExternalReaderProcess.of(PklEvaluatorSettings.ExternalReader(it.executable, it.arguments))
+        ReaderProcess.of(PklEvaluatorSettings.ExternalReader(it.executable, it.arguments))
       }
 }