diff --git a/src/Serval.Client/Client.g.cs b/src/Serval.Client/Client.g.cs
index e1c408ee..029b275d 100644
--- a/src/Serval.Client/Client.g.cs
+++ b/src/Serval.Client/Client.g.cs
@@ -4426,6 +4426,9 @@ public partial class TranslationBuild
         [System.ComponentModel.DataAnnotations.Required]
         public ResourceLink Engine { get; set; } = new ResourceLink();
 
+        [Newtonsoft.Json.JsonProperty("trainOn", Required = Newtonsoft.Json.Required.Default, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
+        public System.Collections.Generic.IList<TrainingCorpus>? TrainOn { get; set; } = default!;
+
         [Newtonsoft.Json.JsonProperty("pretranslate", Required = Newtonsoft.Json.Required.Default, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
         public System.Collections.Generic.IList<PretranslateCorpus>? Pretranslate { get; set; } = default!;
 
@@ -4457,6 +4460,18 @@ public partial class TranslationBuild
 
     }
 
+    [System.CodeDom.Compiler.GeneratedCode("NJsonSchema", "13.18.2.0 (NJsonSchema v10.8.0.0 (Newtonsoft.Json v13.0.0.0))")]
+    public partial class TrainingCorpus
+    {
+        [Newtonsoft.Json.JsonProperty("corpus", Required = Newtonsoft.Json.Required.Always)]
+        [System.ComponentModel.DataAnnotations.Required]
+        public ResourceLink Corpus { get; set; } = new ResourceLink();
+
+        [Newtonsoft.Json.JsonProperty("textIds", Required = Newtonsoft.Json.Required.Default, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
+        public System.Collections.Generic.IList<string>? TextIds { get; set; } = default!;
+
+    }
+
     [System.CodeDom.Compiler.GeneratedCode("NJsonSchema", "13.18.2.0 (NJsonSchema v10.8.0.0 (Newtonsoft.Json v13.0.0.0))")]
     public partial class PretranslateCorpus
     {
@@ -4496,6 +4511,9 @@ public partial class TranslationBuildConfig
         [Newtonsoft.Json.JsonProperty("name", Required = Newtonsoft.Json.Required.Default, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
         public string? Name { get; set; } = default!;
 
+        [Newtonsoft.Json.JsonProperty("trainOn", Required = Newtonsoft.Json.Required.Default, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
+        public System.Collections.Generic.IList<TrainingCorpusConfig>? TrainOn { get; set; } = default!;
+
         [Newtonsoft.Json.JsonProperty("pretranslate", Required = Newtonsoft.Json.Required.Default, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
         public System.Collections.Generic.IList<PretranslateCorpusConfig>? Pretranslate { get; set; } = default!;
 
@@ -4504,6 +4522,18 @@ public partial class TranslationBuildConfig
 
     }
 
+    [System.CodeDom.Compiler.GeneratedCode("NJsonSchema", "13.18.2.0 (NJsonSchema v10.8.0.0 (Newtonsoft.Json v13.0.0.0))")]
+    public partial class TrainingCorpusConfig
+    {
+        [Newtonsoft.Json.JsonProperty("corpusId", Required = Newtonsoft.Json.Required.Always)]
+        [System.ComponentModel.DataAnnotations.Required(AllowEmptyStrings = true)]
+        public string CorpusId { get; set; } = default!;
+
+        [Newtonsoft.Json.JsonProperty("textIds", Required = Newtonsoft.Json.Required.Default, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
+        public System.Collections.Generic.IList<string>? TextIds { get; set; } = default!;
+
+    }
+
     [System.CodeDom.Compiler.GeneratedCode("NJsonSchema", "13.18.2.0 (NJsonSchema v10.8.0.0 (Newtonsoft.Json v13.0.0.0))")]
     public partial class PretranslateCorpusConfig
     {
diff --git a/src/Serval.Grpc/Protos/serval/translation/v1/engine.proto b/src/Serval.Grpc/Protos/serval/translation/v1/engine.proto
index f98478ca..89802f2a 100644
--- a/src/Serval.Grpc/Protos/serval/translation/v1/engine.proto
+++ b/src/Serval.Grpc/Protos/serval/translation/v1/engine.proto
@@ -126,10 +126,12 @@ message Corpus {
     string id = 1;
     string source_language = 2;
     string target_language = 3;
-    bool pretranslate_all = 4;
-    repeated string pretranslate_text_ids = 5;
-    repeated CorpusFile source_files = 6;
-    repeated CorpusFile target_files = 7;
+    bool train_on_all = 4;
+    bool pretranslate_all = 5;
+    repeated string train_on_text_ids = 6;
+    repeated string pretranslate_text_ids = 7;
+    repeated CorpusFile source_files = 8;
+    repeated CorpusFile target_files = 9;
 }
 
 message CorpusFile {
diff --git a/src/Serval.Translation/Contracts/TrainingCorpusConfigDto.cs b/src/Serval.Translation/Contracts/TrainingCorpusConfigDto.cs
new file mode 100644
index 00000000..a0071edc
--- /dev/null
+++ b/src/Serval.Translation/Contracts/TrainingCorpusConfigDto.cs
@@ -0,0 +1,7 @@
+namespace Serval.Translation.Contracts;
+
+public class TrainingCorpusConfigDto
+{
+    public string CorpusId { get; set; } = default!;
+    public IList<string>? TextIds { get; set; }
+}
diff --git a/src/Serval.Translation/Contracts/TrainingCorpusDto.cs b/src/Serval.Translation/Contracts/TrainingCorpusDto.cs
new file mode 100644
index 00000000..a6c3b05d
--- /dev/null
+++ b/src/Serval.Translation/Contracts/TrainingCorpusDto.cs
@@ -0,0 +1,8 @@
+namespace Serval.Translation.Contracts;
+
+public class TrainingCorpusDto
+{
+    public ResourceLinkDto Corpus { get; set; } = default!;
+
+    public IList<string>? TextIds { get; set; }
+}
diff --git a/src/Serval.Translation/Contracts/TranslationBuildConfigDto.cs b/src/Serval.Translation/Contracts/TranslationBuildConfigDto.cs
index 51297a9e..00265820 100644
--- a/src/Serval.Translation/Contracts/TranslationBuildConfigDto.cs
+++ b/src/Serval.Translation/Contracts/TranslationBuildConfigDto.cs
@@ -3,6 +3,7 @@
 public class TranslationBuildConfigDto
 {
     public string? Name { get; set; }
+    public IList<TrainingCorpusConfigDto>? TrainOn { get; set; }
     public IList<PretranslateCorpusConfigDto>? Pretranslate { get; set; }
 
     /// <example>
diff --git a/src/Serval.Translation/Contracts/TranslationBuildDto.cs b/src/Serval.Translation/Contracts/TranslationBuildDto.cs
index 9d9fa190..24f7cd34 100644
--- a/src/Serval.Translation/Contracts/TranslationBuildDto.cs
+++ b/src/Serval.Translation/Contracts/TranslationBuildDto.cs
@@ -7,6 +7,7 @@ public class TranslationBuildDto
     public int Revision { get; set; }
     public string? Name { get; set; }
     public ResourceLinkDto Engine { get; set; } = default!;
+    public IList<TrainingCorpusDto>? TrainOn { get; set; }
     public IList<PretranslateCorpusDto>? Pretranslate { get; set; }
     public int Step { get; set; }
     public double? PercentCompleted { get; set; }
diff --git a/src/Serval.Translation/Controllers/TranslationEnginesController.cs b/src/Serval.Translation/Controllers/TranslationEnginesController.cs
index 28f0c510..6547ffa3 100644
--- a/src/Serval.Translation/Controllers/TranslationEnginesController.cs
+++ b/src/Serval.Translation/Controllers/TranslationEnginesController.cs
@@ -1,4 +1,6 @@
-namespace Serval.Translation.Controllers;
+using System.Net.Sockets;
+
+namespace Serval.Translation.Controllers;
 
 [ApiVersion(1.0)]
 [Route("api/v{version:apiVersion}/translation/engines")]
@@ -998,10 +1000,10 @@ private Engine Map(TranslationEngineConfigDto source)
     private static Build Map(Engine engine, TranslationBuildConfigDto source)
     {
         var build = new Build { EngineRef = engine.Id, Name = source.Name };
+        var corpusIds = new HashSet<string>(engine.Corpora.Select(c => c.Id));
         if (source.Pretranslate != null)
         {
             var pretranslateCorpora = new List<PretranslateCorpus>();
-            var corpusIds = new HashSet<string>(engine.Corpora.Select(c => c.Id));
             foreach (PretranslateCorpusConfigDto ptcc in source.Pretranslate)
             {
                 if (!corpusIds.Contains(ptcc.CorpusId))
@@ -1013,6 +1015,17 @@ private static Build Map(Engine engine, TranslationBuildConfigDto source)
             }
             build.Pretranslate = pretranslateCorpora;
         }
+        if (source.TrainOn != null)
+        {
+            var trainOnCorpora = new List<TrainingCorpus>();
+            foreach (TrainingCorpusConfigDto tcc in source.TrainOn)
+            {
+                if (!corpusIds.Contains(tcc.CorpusId))
+                    throw new InvalidOperationException($"The corpus {tcc.CorpusId} is not valid.");
+                trainOnCorpora.Add(new TrainingCorpus { CorpusRef = tcc.CorpusId, TextIds = tcc.TextIds?.ToList() });
+            }
+            build.TrainOn = trainOnCorpora;
+        }
         try
         {
             var jsonSerializerOptions = new JsonSerializerOptions();
@@ -1061,6 +1074,7 @@ private TranslationBuildDto Map(Build source)
                 Id = source.EngineRef,
                 Url = _urlService.GetUrl("GetTranslationEngine", new { id = source.EngineRef })
             },
+            TrainOn = source.TrainOn?.Select(s => Map(source.EngineRef, s)).ToList(),
             Pretranslate = source.Pretranslate?.Select(s => Map(source.EngineRef, s)).ToList(),
             Step = source.Step,
             PercentCompleted = source.PercentCompleted,
@@ -1085,6 +1099,19 @@ private PretranslateCorpusDto Map(string engineId, PretranslateCorpus source)
         };
     }
 
+    private TrainingCorpusDto Map(string engineId, TrainingCorpus source)
+    {
+        return new TrainingCorpusDto
+        {
+            Corpus = new ResourceLinkDto
+            {
+                Id = source.CorpusRef,
+                Url = _urlService.GetUrl("GetTranslationCorpus", new { id = engineId, corpusId = source.CorpusRef })
+            },
+            TextIds = source.TextIds
+        };
+    }
+
     private TranslationResultDto Map(TranslationResult source)
     {
         return new TranslationResultDto
diff --git a/src/Serval.Translation/Models/Build.cs b/src/Serval.Translation/Models/Build.cs
index fbfe2b3f..0a4f6a8c 100644
--- a/src/Serval.Translation/Models/Build.cs
+++ b/src/Serval.Translation/Models/Build.cs
@@ -6,6 +6,7 @@ public class Build : IEntity
     public int Revision { get; set; } = 1;
     public string? Name { get; set; }
     public string EngineRef { get; set; } = default!;
+    public IList<TrainingCorpus>? TrainOn { get; set; }
     public List<PretranslateCorpus>? Pretranslate { get; set; }
     public int Step { get; set; }
     public double? PercentCompleted { get; set; }
diff --git a/src/Serval.Translation/Models/TrainingCorpus.cs b/src/Serval.Translation/Models/TrainingCorpus.cs
new file mode 100644
index 00000000..cc5dc71c
--- /dev/null
+++ b/src/Serval.Translation/Models/TrainingCorpus.cs
@@ -0,0 +1,7 @@
+namespace Serval.Translation.Models;
+
+public class TrainingCorpus
+{
+    public string CorpusRef { get; set; } = default!;
+    public IList<string>? TextIds { get; set; }
+}
diff --git a/src/Serval.Translation/Services/EngineService.cs b/src/Serval.Translation/Services/EngineService.cs
index be39dbed..6888ac3a 100644
--- a/src/Serval.Translation/Services/EngineService.cs
+++ b/src/Serval.Translation/Services/EngineService.cs
@@ -191,6 +191,7 @@ public async Task<bool> StartBuildAsync(Build build, CancellationToken cancellat
         try
         {
             Dictionary<string, PretranslateCorpus>? pretranslate = build.Pretranslate?.ToDictionary(c => c.CorpusRef);
+            Dictionary<string, TrainingCorpus>? trainOn = build.TrainOn?.ToDictionary(c => c.CorpusRef);
             var client = _grpcClientFactory.CreateClient<TranslationEngineApi.TranslationEngineApiClient>(engine.Type);
             var request = new StartBuildRequest
             {
@@ -210,6 +211,12 @@ public async Task<bool> StartBuildAsync(Build build, CancellationToken cancellat
                             if (pretranslateCorpus.TextIds is not null)
                                 corpus.PretranslateTextIds.Add(pretranslateCorpus.TextIds);
                         }
+                        if (trainOn?.TryGetValue(c.Id, out TrainingCorpus? trainingCorpus) ?? false)
+                        {
+                            corpus.TrainOnAll = trainingCorpus.TextIds is null || trainingCorpus.TextIds.Count == 0;
+                            if (trainingCorpus.TextIds is not null)
+                                corpus.TrainOnTextIds.Add(trainingCorpus.TextIds);
+                        }
                         return corpus;
                     })
                 }
diff --git a/tests/Serval.E2ETests/ServalApiTests.cs b/tests/Serval.E2ETests/ServalApiTests.cs
index 833c8c83..8f28dc3c 100644
--- a/tests/Serval.E2ETests/ServalApiTests.cs
+++ b/tests/Serval.E2ETests/ServalApiTests.cs
@@ -110,13 +110,16 @@ public async Task NmtBatch()
         await _helperClient!.ClearEngines();
         string engineId = await _helperClient.CreateNewEngine("Nmt", "es", "en", "NMT1");
         var books = new string[] { "MAT.txt", "1JN.txt", "2JN.txt" };
-        await _helperClient.AddTextCorpusToEngine(engineId, books, "es", "en", false);
-        var cId = await _helperClient.AddTextCorpusToEngine(engineId, new string[] { "3JN.txt" }, "es", "en", true);
+        var cId1 = await _helperClient.AddTextCorpusToEngine(engineId, books, "es", "en", false);
+        _helperClient.TranslationBuildConfig.TrainOn!.Add(
+            new TrainingCorpusConfig { CorpusId = cId1, TextIds = new string[] { "1JN.txt" } }
+        );
+        var cId2 = await _helperClient.AddTextCorpusToEngine(engineId, new string[] { "3JN.txt" }, "es", "en", true);
         await _helperClient.BuildEngine(engineId);
         await Task.Delay(1000);
         IList<Pretranslation> lTrans = await _helperClient.translationEnginesClient.GetAllPretranslationsAsync(
             engineId,
-            cId
+            cId2
         );
         Assert.IsTrue(lTrans[0].Translation.Contains("dearly beloved Gaius"));
     }
diff --git a/tests/Serval.E2ETests/ServalClientHelper.cs b/tests/Serval.E2ETests/ServalClientHelper.cs
index df1b209f..bc983641 100644
--- a/tests/Serval.E2ETests/ServalClientHelper.cs
+++ b/tests/Serval.E2ETests/ServalClientHelper.cs
@@ -32,7 +32,8 @@ public ServalClientHelper(string audience, string prefix = "SCE_", bool ignoreSS
         TranslationBuildConfig = new TranslationBuildConfig
         {
             Pretranslate = new List<PretranslateCorpusConfig>(),
-            Options = "{\"max_steps\":10}"
+            Options = "{\"max_steps\":10}",
+            TrainOn = new List<TrainingCorpusConfig>()
         };
     }
 
@@ -86,6 +87,7 @@ public async Task ClearEngines(string name = "")
             }
         }
         TranslationBuildConfig.Pretranslate = new List<PretranslateCorpusConfig>();
+        TranslationBuildConfig.TrainOn = new List<TrainingCorpusConfig>();
         EnginePerUser.Clear();
     }