diff --git a/tofhir-engine/src/main/scala/io/tofhir/engine/data/read/FileDataSourceReader.scala b/tofhir-engine/src/main/scala/io/tofhir/engine/data/read/FileDataSourceReader.scala
index 30b6bf09..a5e81650 100644
--- a/tofhir-engine/src/main/scala/io/tofhir/engine/data/read/FileDataSourceReader.scala
+++ b/tofhir-engine/src/main/scala/io/tofhir/engine/data/read/FileDataSourceReader.scala
@@ -92,7 +92,8 @@ class FileDataSourceReader(spark: SparkSession) extends BaseDataSourceReader[Fil
               .options(otherOptions)
               .schema(csvSchema.orNull)
               .csv(finalPath)
-        case SourceFileFormats.JSON =>
+        // assume that each line in the txt files contains a separate JSON object.
+        case SourceFileFormats.JSON | SourceFileFormats.TXT=>
           if(sourceSettings.asStream)
             spark.readStream.options(mappingSource.options).schema(schema.orNull).json(finalPath)
               // add a dummy column called 'filename' to print a log when the data reading is started for a file
diff --git a/tofhir-engine/src/main/scala/io/tofhir/engine/mapping/FhirMappingJobManager.scala b/tofhir-engine/src/main/scala/io/tofhir/engine/mapping/FhirMappingJobManager.scala
index 43714ed6..c8709acb 100644
--- a/tofhir-engine/src/main/scala/io/tofhir/engine/mapping/FhirMappingJobManager.scala
+++ b/tofhir-engine/src/main/scala/io/tofhir/engine/mapping/FhirMappingJobManager.scala
@@ -496,6 +496,34 @@ class FhirMappingJobManager(
           .toSeq // Convert to Seq[Resource]
       }
   }
+
+  override def executeMappingJobAndReturn(mappingJobExecution: FhirMappingJobExecution,
+                                          sourceSettings: Map[String, DataSourceSettings],
+                                          terminologyServiceSettings: Option[TerminologyServiceSettings],
+                                          identityServiceSettings: Option[IdentityServiceSettings],
+                                          taskCompletionCallback: () => Unit): Future[Dataset[FhirMappingResult]] = {
+    import spark.implicits._
+    // create an initial empty DataFrame
+    val initialDataFrame: Dataset[FhirMappingResult] = spark.emptyDataset[FhirMappingResult]
+    // fold over the mapping tasks to chain the futures sequentially
+    mappingJobExecution.mappingTasks.foldLeft(Future.successful(initialDataFrame)) { (accFuture, task) =>
+      accFuture.flatMap { accDataFrame =>
+        logger.info(s"Executing mapping task ${task.mappingRef} within mapping job: ${mappingJobExecution.job.id}")
+        readSourceAndExecuteTask(mappingJobExecution.job.id, task, sourceSettings, terminologyServiceSettings, identityServiceSettings, executionId = Some(mappingJobExecution.id), projectId = Some(mappingJobExecution.projectId))
+          .map { dataFrame =>
+            logger.info(s"Completed the execution of mapping task ${task.mappingRef} within mapping job: ${mappingJobExecution.job.id}")
+            // notify the caller that the mapping task execution is complete by invoking the taskCompletionCallback function
+            taskCompletionCallback()
+            // combine the accumulated DataFrame with the current task's DataFrame
+            accDataFrame.union(dataFrame)
+          }.recover {
+            case e: Throwable =>
+              logger.error(s"Failed to execute mapping task ${task.mappingRef} within mapping job: ${mappingJobExecution.job.id}",e)
+              throw e
+          }
+      }
+    }
+  }
 }
 
 
diff --git a/tofhir-engine/src/main/scala/io/tofhir/engine/mapping/IFhirMappingJobManager.scala b/tofhir-engine/src/main/scala/io/tofhir/engine/mapping/IFhirMappingJobManager.scala
index dcd6d642..f3a58f95 100644
--- a/tofhir-engine/src/main/scala/io/tofhir/engine/mapping/IFhirMappingJobManager.scala
+++ b/tofhir-engine/src/main/scala/io/tofhir/engine/mapping/IFhirMappingJobManager.scala
@@ -3,6 +3,7 @@ package io.tofhir.engine.mapping
 import java.time.LocalDateTime
 
 import io.tofhir.engine.model._
+import org.apache.spark.sql.Dataset
 import org.apache.spark.sql.streaming.StreamingQuery
 
 import scala.concurrent.Future
@@ -97,4 +98,22 @@ trait IFhirMappingJobManager {
                                   terminologyServiceSettings: Option[TerminologyServiceSettings] = None,
                                   identityServiceSettings: Option[IdentityServiceSettings] = None
                                  ): Future[Seq[FhirMappingResult]]
+
+  /**
+   * Executes the specified FHIR mapping job and returns the resulting FhirMappingResult dataset.
+   *
+   * @param mappingJobExecution        The FHIR Mapping Job execution details.
+   * @param sourceSettings             A map containing settings for the source system(s).
+   * @param terminologyServiceSettings Optional settings for the terminology service to use within mappings (e.g., for lookupDisplay).
+   * @param identityServiceSettings    Optional settings for the identity service to use within mappings (e.g., for resolveIdentifier).
+   * @param taskCompletionCallback     A callback function to be invoked when a mapping task execution is completed.
+   * @return A Future containing a Dataset of FhirMappingResult representing the outcome of the mapping job.
+   */
+  def executeMappingJobAndReturn(mappingJobExecution: FhirMappingJobExecution,
+                                 sourceSettings: Map[String, DataSourceSettings],
+                                 terminologyServiceSettings: Option[TerminologyServiceSettings] = None,
+                                 identityServiceSettings: Option[IdentityServiceSettings] = None,
+                                 taskCompletionCallback: () => Unit
+                                ): Future[Dataset[FhirMappingResult]]
+
 }
diff --git a/tofhir-engine/src/main/scala/io/tofhir/engine/model/FhirMappingJobExecution.scala b/tofhir-engine/src/main/scala/io/tofhir/engine/model/FhirMappingJobExecution.scala
index a88aa844..4fe18279 100644
--- a/tofhir-engine/src/main/scala/io/tofhir/engine/model/FhirMappingJobExecution.scala
+++ b/tofhir-engine/src/main/scala/io/tofhir/engine/model/FhirMappingJobExecution.scala
@@ -17,6 +17,8 @@ import java.util.regex.Pattern
  * @param mappingTasks               List of mapping tasks to be executed (as a subset of the mapping tasks defined in the job)
  * @param jobGroupIdOrStreamingQuery Keeps Spark job group id for batch jobs and StreamingQuery for streaming jobs
  */
+// TODO: The FhirMappingJobExecution model currently includes the entire FhirMappingJob ('job' field), which is unnecessary.
+//  We should remove the 'job' field from the model. Instead, add only the necessary fields to the model.
 case class FhirMappingJobExecution(id: String = UUID.randomUUID().toString,
                                    projectId: String = "",
                                    job: FhirMappingJob,
diff --git a/tofhir-engine/src/main/scala/io/tofhir/engine/model/FhirMappingTask.scala b/tofhir-engine/src/main/scala/io/tofhir/engine/model/FhirMappingTask.scala
index 02cc7d84..99144acb 100644
--- a/tofhir-engine/src/main/scala/io/tofhir/engine/model/FhirMappingTask.scala
+++ b/tofhir-engine/src/main/scala/io/tofhir/engine/model/FhirMappingTask.scala
@@ -126,5 +126,6 @@ object SourceFileFormats {
   final val PARQUET = "parquet"
   final val JSON = "json"
   final val AVRO = "avro"
+  final val TXT = "txt"
 }