diff --git a/examples/cpp/integer_programming.cc b/examples/cpp/integer_programming.cc
index cc433326ea..fc7e9f79a5 100644
--- a/examples/cpp/integer_programming.cc
+++ b/examples/cpp/integer_programming.cc
@@ -18,19 +18,21 @@
 #include "ortools/linear_solver/linear_solver.h"
 
 namespace operations_research {
-void RunIntegerProgrammingExample(
-    const std::string& optimization_problem_type) {
-  LOG(INFO) << "---- Integer programming example with "
-            << optimization_problem_type << " ----";
+void RunIntegerProgrammingExample(const std::string& solver_id) {
+  LOG(INFO) << "---- Integer programming example with " << solver_id << " ----";
 
-  if (!MPSolver::ParseAndCheckSupportForProblemType(
-          optimization_problem_type)) {
-    LOG(INFO) << "  support for solver not linked in.";
+  MPSolver::OptimizationProblemType problem_type;
+  if (!MPSolver::ParseSolverType(solver_id, &problem_type)) {
+    LOG(INFO) << "Solver id " << solver_id << " not recognized";
     return;
   }
 
-  MPSolver solver("IntegerProgrammingExample",
-                  MPSolver::ParseSolverTypeOrDie(optimization_problem_type));
+  if (!MPSolver::SupportsProblemType(problem_type)) {
+    LOG(INFO) << "Supports for solver " << solver_id << " not linked in.";
+    return;
+  }
+
+  MPSolver solver("IntegerProgrammingExample", problem_type);
 
   const double infinity = solver.infinity();
   // x and y are integer non-negative variables.
@@ -80,7 +82,6 @@ void RunAllExamples() {
   RunIntegerProgrammingExample("GUROBI");
   RunIntegerProgrammingExample("GLPK");
   RunIntegerProgrammingExample("CPLEX");
-  RunIntegerProgrammingExample("XPRESS");
 }
 }  // namespace operations_research
 
diff --git a/examples/cpp/linear_programming.cc b/examples/cpp/linear_programming.cc
index 54ea2ee4ed..fe7e6d2e90 100644
--- a/examples/cpp/linear_programming.cc
+++ b/examples/cpp/linear_programming.cc
@@ -19,17 +19,20 @@
 #include "ortools/linear_solver/linear_solver.pb.h"
 
 namespace operations_research {
-void RunLinearProgrammingExample(const std::string& optimization_problem_type) {
-  LOG(INFO) << "---- Linear programming example with "
-            << optimization_problem_type << " ----";
-  if (!MPSolver::ParseAndCheckSupportForProblemType(
-          optimization_problem_type)) {
-    LOG(INFO) << "  support for solver not linked in.";
+void RunLinearProgrammingExample(const std::string& solver_id) {
+  LOG(INFO) << "---- Linear programming example with " << solver_id << " ----";
+  MPSolver::OptimizationProblemType problem_type;
+  if (!MPSolver::ParseSolverType(solver_id, &problem_type)) {
+    LOG(INFO) << "Solver id " << solver_id << " not recognized";
     return;
   }
 
-  MPSolver solver("IntegerProgrammingExample",
-                  MPSolver::ParseSolverTypeOrDie(optimization_problem_type));
+  if (!MPSolver::SupportsProblemType(problem_type)) {
+    LOG(INFO) << "Supports for solver " << solver_id << " not linked in.";
+    return;
+  }
+
+  MPSolver solver("IntegerProgrammingExample", problem_type);
 
   const double infinity = solver.infinity();
   // x1, x2 and x3 are continuous non-negative variables.
diff --git a/examples/dotnet/csintegerprogramming.cs b/examples/dotnet/csintegerprogramming.cs
index 9db0b328d4..3c38fb4701 100644
--- a/examples/dotnet/csintegerprogramming.cs
+++ b/examples/dotnet/csintegerprogramming.cs
@@ -18,7 +18,7 @@ public class CsIntegerProgramming
 {
   private static void RunIntegerProgrammingExample(String solverType)
   {
-    Solver solver = Solver.CreateSolver("IntegerProgramming", solverType);
+    Solver solver = Solver.CreateSolver(solverType);
     if (solver == null)
     {
       Console.WriteLine("Could not create solver " + solverType);
@@ -65,7 +65,7 @@ public class CsIntegerProgramming
 
   private static void RunIntegerProgrammingExampleNaturalApi(String solverType)
   {
-    Solver solver = Solver.CreateSolver("IntegerProgramming", solverType);
+    Solver solver = Solver.CreateSolver(solverType);
     if (solver == null)
     {
       Console.WriteLine("Could not create solver " + solverType);
@@ -113,6 +113,8 @@ public class CsIntegerProgramming
     RunIntegerProgrammingExample("SCIP");
     Console.WriteLine("---- Linear programming example with SAT ----");
     RunIntegerProgrammingExample("SAT");
+    Console.WriteLine("---- Linear programming example with GUROBI ----");
+    RunIntegerProgrammingExample("GUROBI");
     Console.WriteLine(
         "---- Integer programming example (Natural API) with GLPK ----");
     RunIntegerProgrammingExampleNaturalApi("GLPK");
@@ -125,5 +127,8 @@ public class CsIntegerProgramming
     Console.WriteLine(
         "---- Linear programming example (Natural API) with SAT ----");
     RunIntegerProgrammingExampleNaturalApi("SAT");
+    Console.WriteLine(
+        "---- Linear programming example (Natural API) with GUROBI ----");
+    RunIntegerProgrammingExampleNaturalApi("GUROBI");
   }
 }
diff --git a/examples/dotnet/cslinearprogramming.cs b/examples/dotnet/cslinearprogramming.cs
index b58611f1bc..2b4a160ee7 100644
--- a/examples/dotnet/cslinearprogramming.cs
+++ b/examples/dotnet/cslinearprogramming.cs
@@ -20,7 +20,7 @@ public class CsLinearProgramming
   {
     Console.WriteLine($"---- Linear programming example with {solverType} ----");
 
-    Solver solver = Solver.CreateSolver("IntegerProgramming", solverType);
+    Solver solver = Solver.CreateSolver(solverType);
     if (solver == null)
     {
       Console.WriteLine("Could not create solver " + solverType);
@@ -101,7 +101,7 @@ public class CsLinearProgramming
     Console.WriteLine(
         $"---- Linear programming example (Natural API) with {solverType} ----");
 
-    Solver solver = Solver.CreateSolver("IntegerProgramming", solverType);
+    Solver solver = Solver.CreateSolver(solverType);
     if (solver == null)
     {
       Console.WriteLine("Could not create solver " + solverType);
diff --git a/examples/java/IntegerProgramming.java b/examples/java/IntegerProgramming.java
index 353cd50ee1..aec090ccb9 100644
--- a/examples/java/IntegerProgramming.java
+++ b/examples/java/IntegerProgramming.java
@@ -29,7 +29,7 @@ public class IntegerProgramming {
   }
 
   private static void runIntegerProgrammingExample(String solverType) {
-    MPSolver solver = MPSolver.createSolver("IntegerProgramming", solverType);
+    MPSolver solver = MPSolver.createSolver(solverType);
     if (solver == null) {
       System.out.println("Could not create solver " + solverType);
       return;
diff --git a/examples/java/LinearProgramming.java b/examples/java/LinearProgramming.java
index 271674d75e..d190f4a390 100644
--- a/examples/java/LinearProgramming.java
+++ b/examples/java/LinearProgramming.java
@@ -29,7 +29,7 @@ public class LinearProgramming {
   }
 
   private static void runLinearProgrammingExample(String solverType, boolean printModel) {
-    MPSolver solver = MPSolver.createSolver("IntegerProgramming", solverType);
+    MPSolver solver = MPSolver.createSolver(solverType);
     if (solver == null) {
       System.out.println("Could not create solver " + solverType);
       return;
diff --git a/examples/python/integer_programming.py b/examples/python/integer_programming.py
index e1693eac48..9f40381439 100644
--- a/examples/python/integer_programming.py
+++ b/examples/python/integer_programming.py
@@ -25,8 +25,7 @@ def Announce(solver, api_type):
 def RunIntegerExampleNaturalLanguageAPI(optimization_problem_type):
     """Example of simple integer program with natural language API."""
 
-    solver = pywraplp.Solver.CreateSolver('RunIntegerExampleNaturalLanguageAPI',
-                                          optimization_problem_type)
+    solver = pywraplp.Solver.CreateSolver(optimization_problem_type)
     if not solver:
         return
 
@@ -45,8 +44,7 @@ def RunIntegerExampleNaturalLanguageAPI(optimization_problem_type):
 
 def RunIntegerExampleCppStyleAPI(optimization_problem_type):
     """Example of simple integer program with the C++ style API."""
-    solver = pywraplp.Solver.CreateSolver('RunIntegerExampleCppStyleAPI',
-                                          optimization_problem_type)
+    solver = pywraplp.Solver.CreateSolver(optimization_problem_type)
     if not solver:
         return
 
diff --git a/examples/python/linear_programming.py b/examples/python/linear_programming.py
index 62da7bc23e..0a8d16b698 100644
--- a/examples/python/linear_programming.py
+++ b/examples/python/linear_programming.py
@@ -24,8 +24,7 @@ def Announce(solver, api_type):
 
 def RunLinearExampleNaturalLanguageAPI(optimization_problem_type):
     """Example of simple linear program with natural language API."""
-    solver = pywraplp.Solver.CreateSolver('RunLinearExampleNaturalLanguageAPI',
-                                          optimization_problem_type)
+    solver = pywraplp.Solver.CreateSolver(optimization_problem_type)
 
     if not solver:
         return
@@ -51,8 +50,7 @@ def RunLinearExampleNaturalLanguageAPI(optimization_problem_type):
 
 def RunLinearExampleCppStyleAPI(optimization_problem_type):
     """Example of simple linear program with the C++ style API."""
-    solver = pywraplp.Solver.CreateSolver('RunLinearExampleCppStyle',
-                                          optimization_problem_type)
+    solver = pywraplp.Solver.CreateSolver(optimization_problem_type)
     if not solver:
         return
 
diff --git a/examples/tests/lp_test.py b/examples/tests/lp_test.py
index c373fd395d..512140c8d3 100644
--- a/examples/tests/lp_test.py
+++ b/examples/tests/lp_test.py
@@ -228,6 +228,10 @@ class PyWrapLpTest(unittest.TestCase):
         result_status = solver.Solve()
         print(result_status) # outputs: 0
 
+    def testSolveFromProto(self):
+        solver = pywraplp.Solver('', pywraplp.Solver.GLOP_LINEAR_PROGRAMMING)
+        solver.LoadSolutionFromProto(linear_solver_pb2.MPSolutionResponse())
+
 
 if __name__ == '__main__':
     unittest.main()
diff --git a/ortools/linear_solver/csharp/SolverHelper.cs b/ortools/linear_solver/csharp/SolverHelper.cs
index 85b654b820..9746b39070 100644
--- a/ortools/linear_solver/csharp/SolverHelper.cs
+++ b/ortools/linear_solver/csharp/SolverHelper.cs
@@ -180,16 +180,6 @@ public partial class Solver {
     return matrix;
   }
 
-  public static int GetSolverEnum(String solverType) {
-    System.Reflection.FieldInfo fieldInfo =
-      typeof(Solver).GetField(solverType);
-    if (fieldInfo != null) {
-      return (int)fieldInfo.GetValue(null);
-    } else {
-      throw new System.ApplicationException("Solver not supported");
-    }
-  }
-
   public Constraint Add(LinearConstraint constraint) {
     return constraint.Extract(this);
   }
diff --git a/ortools/linear_solver/csharp/linear_solver.i b/ortools/linear_solver/csharp/linear_solver.i
index 8ee9c7e7ac..4601a0180b 100644
--- a/ortools/linear_solver/csharp/linear_solver.i
+++ b/ortools/linear_solver/csharp/linear_solver.i
@@ -126,7 +126,6 @@ CONVERT_VECTOR(operations_research::MPVariable, MPVariable)
 %unignore operations_research::MPSolver::~MPSolver;
 %newobject operations_research::MPSolver::CreateSolver;
 %unignore operations_research::MPSolver::CreateSolver;
-%unignore operations_research::MPSolver::ParseAndCheckSupportForProblemType;
 %unignore operations_research::MPSolver::MakeBoolVar;
 %unignore operations_research::MPSolver::MakeIntVar;
 %unignore operations_research::MPSolver::MakeNumVar;
diff --git a/ortools/linear_solver/gurobi_interface.cc b/ortools/linear_solver/gurobi_interface.cc
index add7d51f2d..191ed9fb20 100644
--- a/ortools/linear_solver/gurobi_interface.cc
+++ b/ortools/linear_solver/gurobi_interface.cc
@@ -27,6 +27,7 @@
 #include "ortools/base/integral_types.h"
 #include "ortools/base/logging.h"
 #include "ortools/base/map_util.h"
+#include "ortools/base/statusor.h"
 #include "ortools/base/timer.h"
 #include "ortools/linear_solver/gurobi_environment.h"
 #include "ortools/linear_solver/gurobi_proto_solver.h"
@@ -1218,4 +1219,3 @@ void GurobiInterface::SetCallback(MPCallback* mp_callback) {
 }
 
 }  // namespace operations_research
-
diff --git a/ortools/linear_solver/java/linear_solver.i b/ortools/linear_solver/java/linear_solver.i
index 469e30ed74..9820ae0642 100644
--- a/ortools/linear_solver/java/linear_solver.i
+++ b/ortools/linear_solver/java/linear_solver.i
@@ -287,8 +287,6 @@ PROTO2_RETURN(
 %unignore operations_research::MPSolver::~MPSolver;
 %newobject operations_research::MPSolver::CreateSolver;
 %rename (createSolver) operations_research::MPSolver::CreateSolver;
-%rename (parseAndCheckSupportForProblemType)
-    operations_research::MPSolver::ParseAndCheckSupportForProblemType;
 
 %unignore operations_research::MPConstraint;
 %unignore operations_research::MPVariable;
diff --git a/ortools/linear_solver/linear_solver.cc b/ortools/linear_solver/linear_solver.cc
index b608992e42..67ffb068f0 100644
--- a/ortools/linear_solver/linear_solver.cc
+++ b/ortools/linear_solver/linear_solver.cc
@@ -35,6 +35,7 @@
 #include "ortools/base/logging.h"
 #include "ortools/base/map_util.h"
 #include "ortools/base/status_macros.h"
+#include "ortools/base/statusor.h"
 #include "ortools/base/stl_util.h"
 #include "ortools/linear_solver/linear_solver.pb.h"
 #include "ortools/linear_solver/model_exporter.h"
@@ -207,7 +208,7 @@ void MPObjective::OptimizeLinearExpr(const LinearExpr& linear_expr,
   CheckLinearExpr(*interface_->solver_, linear_expr);
   interface_->ClearObjective();
   coefficients_.clear();
-  offset_ = linear_expr.offset();
+  SetOffset(linear_expr.offset());
   for (const auto& kv : linear_expr.terms()) {
     SetCoefficient(kv.first, kv.second);
   }
@@ -216,7 +217,7 @@ void MPObjective::OptimizeLinearExpr(const LinearExpr& linear_expr,
 
 void MPObjective::AddLinearExpr(const LinearExpr& linear_expr) {
   CheckLinearExpr(*interface_->solver_, linear_expr);
-  offset_ += linear_expr.offset();
+  SetOffset(offset_ + linear_expr.offset());
   for (const auto& kv : linear_expr.terms()) {
     SetCoefficient(kv.first, GetCoefficient(kv.first) + kv.second);
   }
@@ -519,11 +520,11 @@ constexpr
         {MPSolver::CBC_MIXED_INTEGER_PROGRAMMING, "cbc"},
         {MPSolver::SAT_INTEGER_PROGRAMMING, "sat"},
         {MPSolver::BOP_INTEGER_PROGRAMMING, "bop"},
-        {MPSolver::GUROBI_MIXED_INTEGER_PROGRAMMING, "gurobi_mip"},
-        {MPSolver::GLPK_MIXED_INTEGER_PROGRAMMING, "glpk_mip"},
+        {MPSolver::GUROBI_MIXED_INTEGER_PROGRAMMING, "gurobi"},
+        {MPSolver::GLPK_MIXED_INTEGER_PROGRAMMING, "glpk"},
         {MPSolver::KNAPSACK_MIXED_INTEGER_PROGRAMMING, "knapsack"},
-        {MPSolver::CPLEX_MIXED_INTEGER_PROGRAMMING, "cplex_mip"},
-        {MPSolver::XPRESS_MIXED_INTEGER_PROGRAMMING, "xpress_mip"},
+        {MPSolver::CPLEX_MIXED_INTEGER_PROGRAMMING, "cplex"},
+        {MPSolver::XPRESS_MIXED_INTEGER_PROGRAMMING, "xpress"},
 
 };
 // static
@@ -533,59 +534,35 @@ bool MPSolver::ParseSolverType(absl::string_view solver_id,
   const std::string id =
       absl::StrReplaceAll(absl::AsciiStrToUpper(solver_id), {{"-", "_"}});
 
-  if (id == "CLP_LINEAR_PROGRAMMING" || id == "CLP") {
-    *type = MPSolver::CLP_LINEAR_PROGRAMMING;
+  // Support the full enum name
+  MPModelRequest::SolverType solver_type;
+  if (MPModelRequest::SolverType_Parse(id, &solver_type)) {
+    *type = static_cast<MPSolver::OptimizationProblemType>(solver_type);
     return true;
-  } else if (id == "CBC_MIXED_INTEGER_PROGRAMMING" || id == "CBC") {
-    *type = MPSolver::CBC_MIXED_INTEGER_PROGRAMMING;
-    return true;
-  } else if (id == "GLOP_LINEAR_PROGRAMMING" || id == "GLOP") {
-    *type = MPSolver::GLOP_LINEAR_PROGRAMMING;
-    return true;
-  } else if (id == "BOP_INTEGER_PROGRAMMING" || id == "BOP") {
-    *type = MPSolver::BOP_INTEGER_PROGRAMMING;
-    return true;
-  } else if (id == "SAT_INTEGER_PROGRAMMING" || id == "SAT" || id == "CP_SAT") {
-    *type = MPSolver::SAT_INTEGER_PROGRAMMING;
-    return true;
-  } else if (id == "SCIP_MIXED_INTEGER_PROGRAMMING" || id == "SCIP") {
-    *type = MPSolver::SCIP_MIXED_INTEGER_PROGRAMMING;
-    return true;
-  } else if (id == "GUROBI_LINEAR_PROGRAMMING" || id == "GUROBI_LP") {
-    *type = MPSolver::GUROBI_LINEAR_PROGRAMMING;
-    return true;
-  } else if (id == "GUROBI_MIXED_INTEGER_PROGRAMMING" || id == "GUROBI_MIP" ||
-             id == "GUROBI") {
-    *type = MPSolver::GUROBI_MIXED_INTEGER_PROGRAMMING;
-    return true;
-  } else if (id == "CPLEX_MIXED_INTEGER_PROGRAMMING" || id == "CPLEX_MIP" ||
-             id == "CPLEX") {
-    *type = MPSolver::CPLEX_MIXED_INTEGER_PROGRAMMING;
-    return true;
-  } else if (id == "CPLEX_LINEAR_PROGRAMMING" || id == "CPLEX_LP") {
-    *type = MPSolver::CPLEX_LINEAR_PROGRAMMING;
-    return true;
-  } else if (id == "XPRESS_MIXED_INTEGER_PROGRAMMING" || id == "XPRESS" ||
-             id == "XPRESS_MIP") {
-    *type = MPSolver::XPRESS_MIXED_INTEGER_PROGRAMMING;
-    return true;
-  } else if (id == "XPRESS_LINEAR_PROGRAMMING" || id == "XPRESS_LP") {
-    *type = MPSolver::XPRESS_LINEAR_PROGRAMMING;
-    return true;
-
-  } else if (id == "GLPK_MIXED_INTEGER_PROGRAMMING" || id == "GLPK_MIP" ||
-             id == "GLPK") {
-    *type = MPSolver::GLPK_MIXED_INTEGER_PROGRAMMING;
-    return true;
-  } else if (id == "GLPK_LINEAR_PROGRAMMING" || id == "GLPK_LP") {
-    *type = MPSolver::GLPK_LINEAR_PROGRAMMING;
-    return true;
-  } else if (id == "KNAPSACK_MIXED_INTEGER_PROGRAMMING" || id == "KNAPSACK") {
-    *type = MPSolver::KNAPSACK_MIXED_INTEGER_PROGRAMMING;
-    return true;
-  } else {
-    return false;
   }
+
+  // Names are stored in lower case.
+  std::string lower_id = absl::AsciiStrToLower(id);
+
+  // Remove any "_mip" suffix, since they are optional.
+  if (absl::EndsWith(lower_id, "_mip")) {
+    lower_id = lower_id.substr(0, lower_id.size() - 4);
+  }
+
+  // Rewrite CP-SAT into SAT.
+  if (lower_id == "cp_sat") {
+    lower_id = "sat";
+  }
+
+  // Reverse lookup in the kOptimizationProblemTypeNames[] array.
+  for (auto& named_solver : kOptimizationProblemTypeNames) {
+    if (named_solver.name == lower_id) {
+      *type = named_solver.problem_type;
+      return true;
+    }
+  }
+
+  return false;
 }
 
 const absl::string_view ToString(
@@ -612,25 +589,16 @@ bool AbslParseFlag(const absl::string_view text,
   return result;
 }
 
-/* static */
-bool MPSolver::ParseAndCheckSupportForProblemType(
-    const std::string& solver_id) {
-  MPSolver::OptimizationProblemType problem_type;
-  return MPSolver::ParseSolverType(solver_id, &problem_type) &&
-         MPSolver::SupportsProblemType(problem_type);
-}
-
 /* static */
 MPSolver::OptimizationProblemType MPSolver::ParseSolverTypeOrDie(
     const std::string& solver_id) {
   MPSolver::OptimizationProblemType problem_type;
-  CHECK(MPSolver::ParseSolverType(solver_id, &problem_type));
+  CHECK(MPSolver::ParseSolverType(solver_id, &problem_type)) << solver_id;
   return problem_type;
 }
 
 /* static */
-MPSolver* MPSolver::CreateSolver(const std::string& name,
-                                 const std::string& solver_id) {
+MPSolver* MPSolver::CreateSolver(const std::string& solver_id) {
   MPSolver::OptimizationProblemType problem_type;
   if (!MPSolver::ParseSolverType(solver_id, &problem_type)) {
     LOG(WARNING) << "Unrecognized solver type: " << solver_id;
@@ -641,7 +609,7 @@ MPSolver* MPSolver::CreateSolver(const std::string& name,
                  << " not linked in, or the license was not found.";
     return nullptr;
   }
-  return new MPSolver(name, problem_type);
+  return new MPSolver("", problem_type);
 }
 
 MPVariable* MPSolver::LookupVariableOrNull(const std::string& var_name) const {
@@ -983,7 +951,7 @@ void MPSolver::ExportModelToProto(MPModelProto* output_model) const {
     // few terms.
     std::sort(linear_term.begin(), linear_term.end());
     // Now use linear term.
-    for (const std::pair<int, double> var_and_coeff : linear_term) {
+    for (const std::pair<int, double>& var_and_coeff : linear_term) {
       constraint_proto->add_var_index(var_and_coeff.first);
       constraint_proto->add_coefficient(var_and_coeff.second);
     }
diff --git a/ortools/linear_solver/linear_solver.h b/ortools/linear_solver/linear_solver.h
index c11b712978..fc80d36ebd 100644
--- a/ortools/linear_solver/linear_solver.h
+++ b/ortools/linear_solver/linear_solver.h
@@ -248,8 +248,7 @@ class MPSolver {
    *   - GLPK_LINEAR_PROGRAMMING or GLPK_LP
    *   - GLPK_MIXED_INTEGER_PROGRAMMING or GLPK or GLPK_MIP
    */
-  static MPSolver* CreateSolver(const std::string& name,
-                                const std::string& solver_id);
+  static MPSolver* CreateSolver(const std::string& solver_id);
 
   /**
    * Whether the given problem type is supported (this will depend on the
@@ -260,6 +259,7 @@ class MPSolver {
   /**
    * Parses the name of the solver. Returns true if the solver type is
    * successfully parsed as one of the OptimizationProblemType.
+   * See the documentation of CreateSolver() for the list of supported names.
    */
   static bool ParseSolverType(absl::string_view solver_id,
                               OptimizationProblemType* type);
@@ -271,12 +271,6 @@ class MPSolver {
   static OptimizationProblemType ParseSolverTypeOrDie(
       const std::string& solver_id);
 
-  /**
-   * Parses the name of the solver. Returns true if the solver type is
-   * recognized and support for the solver is actually linked in.
-   */
-  static bool ParseAndCheckSupportForProblemType(const std::string& solver_id);
-
   bool IsMIP() const;
 
   /// Returns the name of the model set at construction.
@@ -534,6 +528,12 @@ class MPSolver {
    * If you want to keep the MPSolver alive (for debugging, or for incremental
    * solving), you should write another version of this function that creates
    * the MPSolver object on the heap and returns it.
+   *
+   * Note(user): This attempts to first use `DirectlySolveProto()` (if
+   * implemented). Consequently, this most likely does *not* override any of
+   * the default parameters of the underlying solver. This behavior *differs*
+   * from `MPSolver::Solve()` which by default sets the feasibility tolerance
+   * and the gap limit (as of 2020/02/11, to 1e-7 and 0.0001, respectively).
    */
   static void SolveWithProto(const MPModelRequest& model_request,
                              MPSolutionResponse* response);
@@ -1107,8 +1107,6 @@ class MPVariable {
    */
   MPSolver::BasisStatus basis_status() const;
 
-  /** Returns the branching priority, or 0 if it was not set. */
-  int branching_priority() const { return branching_priority_; }
   /**
    * Advanced usage: Certain MIP solvers (e.g. Gurobi or SCIP) allow you to set
    * a per-variable priority for determining which variable to branch on.
@@ -1119,6 +1117,7 @@ class MPVariable {
    * support setting branching priority; all other solvers will simply ignore
    * this annotation.
    */
+  int branching_priority() const { return branching_priority_; }
   void SetBranchingPriority(int priority);
 
  protected:
diff --git a/ortools/linear_solver/samples/AssignmentMip.cs b/ortools/linear_solver/samples/AssignmentMip.cs
index 52606a1e06..777d2fe684 100644
--- a/ortools/linear_solver/samples/AssignmentMip.cs
+++ b/ortools/linear_solver/samples/AssignmentMip.cs
@@ -36,7 +36,7 @@ public class AssignmentMip
 
     // Model.
     // [START model]
-    Solver solver = Solver.CreateSolver("AssignmentMip", "CBC");
+    Solver solver = Solver.CreateSolver("SCIP");
     // [END model]
 
     // Variables.
diff --git a/ortools/linear_solver/samples/AssignmentMip.java b/ortools/linear_solver/samples/AssignmentMip.java
index 364526ae45..9668a6ee55 100644
--- a/ortools/linear_solver/samples/AssignmentMip.java
+++ b/ortools/linear_solver/samples/AssignmentMip.java
@@ -42,8 +42,8 @@ public class AssignmentMip {
 
     // Solver
     // [START solver]
-    // Create the linear solver with the CBC backend.
-    MPSolver solver = MPSolver.createSolver("AssignmentMip", "CBC");
+    // Create the linear solver with the SCIP backend.
+    MPSolver solver = MPSolver.createSolver("SCIP");
     // [END solver]
 
     // Variables
diff --git a/ortools/linear_solver/samples/BinPackingMip.cs b/ortools/linear_solver/samples/BinPackingMip.cs
index 3eaee73fe5..073926d776 100644
--- a/ortools/linear_solver/samples/BinPackingMip.cs
+++ b/ortools/linear_solver/samples/BinPackingMip.cs
@@ -37,8 +37,8 @@ public class BinPackingMip
     // [END program_part1]
 
     // [START solver]
-    // Create the linear solver with the CBC backend.
-    Solver solver = Solver.CreateSolver("BinPackingMip", "CBC");
+    // Create the linear solver with the SCIP backend.
+    Solver solver = Solver.CreateSolver("SCIP");
     // [END solver]
 
     // [START program_part2]
diff --git a/ortools/linear_solver/samples/BinPackingMip.java b/ortools/linear_solver/samples/BinPackingMip.java
index 1574ae9c0e..0e148f972f 100644
--- a/ortools/linear_solver/samples/BinPackingMip.java
+++ b/ortools/linear_solver/samples/BinPackingMip.java
@@ -44,8 +44,8 @@ public class BinPackingMip {
     // [END program_part1]
 
     // [START solver]
-    // Create the linear solver with the CBC backend.
-    MPSolver solver = MPSolver.createSolver("BinPackingMip", "CBC");
+    // Create the linear solver with the SCIP backend.
+    MPSolver solver = MPSolver.createSolver("SCIP");
     // [END solver]
 
     // [START program_part2]
diff --git a/ortools/linear_solver/samples/LinearProgrammingExample.cs b/ortools/linear_solver/samples/LinearProgrammingExample.cs
index dee9d58e80..9b84ea3647 100644
--- a/ortools/linear_solver/samples/LinearProgrammingExample.cs
+++ b/ortools/linear_solver/samples/LinearProgrammingExample.cs
@@ -20,7 +20,7 @@ public class LinearProgrammingExample
   static void Main()
   {
       // [START solver]
-      Solver solver = Solver.CreateSolver("LinearProgrammingExample", "GLOP");
+      Solver solver = Solver.CreateSolver("GLOP");
       // [END solver]
       // x and y are continuous non-negative variables.
       // [START variables]
diff --git a/ortools/linear_solver/samples/LinearProgrammingExample.java b/ortools/linear_solver/samples/LinearProgrammingExample.java
index a280ade296..82fdd817c9 100644
--- a/ortools/linear_solver/samples/LinearProgrammingExample.java
+++ b/ortools/linear_solver/samples/LinearProgrammingExample.java
@@ -27,7 +27,7 @@ public class LinearProgrammingExample {
 
   public static void main(String[] args) throws Exception {
     // [START solver]
-    MPSolver solver = MPSolver.createSolver("LinearProgrammingExample", "GLOP");
+    MPSolver solver = MPSolver.createSolver("GLOP");
     // [END solver]
 
     // [START variables]
diff --git a/ortools/linear_solver/samples/MipVarArray.cs b/ortools/linear_solver/samples/MipVarArray.cs
index 2518a96887..c854c2c3c9 100644
--- a/ortools/linear_solver/samples/MipVarArray.cs
+++ b/ortools/linear_solver/samples/MipVarArray.cs
@@ -43,8 +43,8 @@ public class MipVarArray
     // [END program_part1]
 
     // [START solver]
-    // Create the linear solver with the CBC backend.
-    Solver solver = Solver.CreateSolver("MipVarArray", "CBC");
+    // Create the linear solver with the SCIP backend.
+    Solver solver = Solver.CreateSolver("SCIP");
     // [END solver]
 
     // [START program_part2]
diff --git a/ortools/linear_solver/samples/MipVarArray.java b/ortools/linear_solver/samples/MipVarArray.java
index c6f287edb2..bf84f8a5f4 100644
--- a/ortools/linear_solver/samples/MipVarArray.java
+++ b/ortools/linear_solver/samples/MipVarArray.java
@@ -49,8 +49,8 @@ public class MipVarArray {
     // [END program_part1]
 
     // [START solver]
-    // Create the linear solver with the CBC backend.
-    MPSolver solver = MPSolver.createSolver("MipVarArray", "CBC");
+    // Create the linear solver with the SCIP backend.
+    MPSolver solver = MPSolver.createSolver("SCIP");
     // [END solver]
 
     // [START program_part2]
diff --git a/ortools/linear_solver/samples/MultipleKnapsackMip.cs b/ortools/linear_solver/samples/MultipleKnapsackMip.cs
index 509bf66b5f..bbd9fe3930 100644
--- a/ortools/linear_solver/samples/MultipleKnapsackMip.cs
+++ b/ortools/linear_solver/samples/MultipleKnapsackMip.cs
@@ -40,8 +40,8 @@ public class MultipleKnapsackMip
     // [END program_part1]
 
     // [START solver]
-    // Create the linear solver with the CBC backend.
-    Solver solver = Solver.CreateSolver("MultipleKnapsackMip", "CBC");
+    // Create the linear solver with the SCIP backend.
+    Solver solver = Solver.CreateSolver("SCIP");
     // [END solver]
 
     // [START program_part2]
diff --git a/ortools/linear_solver/samples/MultipleKnapsackMip.java b/ortools/linear_solver/samples/MultipleKnapsackMip.java
index cca0ecd76c..6ad9bb58db 100644
--- a/ortools/linear_solver/samples/MultipleKnapsackMip.java
+++ b/ortools/linear_solver/samples/MultipleKnapsackMip.java
@@ -45,8 +45,8 @@ public class MultipleKnapsackMip {
     // [END program_part1]
 
     // [START solver]
-    // Create the linear solver with the CBC backend.
-    MPSolver solver = MPSolver.createSolver("MultipleKnapsackMip", "CBC");
+    // Create the linear solver with the SCIP backend.
+    MPSolver solver = MPSolver.createSolver("SCIP");
     // [END solver]
 
     // [START program_part2]
diff --git a/ortools/linear_solver/samples/SimpleLpProgram.cs b/ortools/linear_solver/samples/SimpleLpProgram.cs
index 80ab61ffd1..8711896a35 100644
--- a/ortools/linear_solver/samples/SimpleLpProgram.cs
+++ b/ortools/linear_solver/samples/SimpleLpProgram.cs
@@ -22,7 +22,7 @@ public class SimpleLpProgram
   {
     // [START solver]
     // Create the linear solver with the GLOP backend.
-    Solver solver = Solver.CreateSolver("SimpleLpProgram", "GLOP");
+    Solver solver = Solver.CreateSolver("GLOP");
     // [END solver]
 
     // [START variables]
diff --git a/ortools/linear_solver/samples/SimpleLpProgram.java b/ortools/linear_solver/samples/SimpleLpProgram.java
index ff4c340f4f..6dbba1acbb 100644
--- a/ortools/linear_solver/samples/SimpleLpProgram.java
+++ b/ortools/linear_solver/samples/SimpleLpProgram.java
@@ -30,7 +30,7 @@ public class SimpleLpProgram {
   public static void main(String[] args) throws Exception {
     // [START solver]
     // Create the linear solver with the GLOP backend.
-    MPSolver solver = MPSolver.createSolver("SimpleLpProgram", "GLOP");
+    MPSolver solver = MPSolver.createSolver("GLOP");
     // [END solver]
 
     // [START variables]
diff --git a/ortools/linear_solver/samples/SimpleMipProgram.cs b/ortools/linear_solver/samples/SimpleMipProgram.cs
index b39e9d08af..2b3fd2d2a3 100644
--- a/ortools/linear_solver/samples/SimpleMipProgram.cs
+++ b/ortools/linear_solver/samples/SimpleMipProgram.cs
@@ -22,8 +22,8 @@ public class SimpleMipProgram
   static void Main()
   {
     // [START solver]
-    // Create the linear solver with the CBC backend.
-    Solver solver = Solver.CreateSolver("SimpleMipProgram", "CBC");
+    // Create the linear solver with the SCIP backend.
+    Solver solver = Solver.CreateSolver("SCIP");
     // [END solver]
 
     // [START variables]
diff --git a/ortools/linear_solver/samples/SimpleMipProgram.java b/ortools/linear_solver/samples/SimpleMipProgram.java
index 7dd394b716..188adb8d39 100644
--- a/ortools/linear_solver/samples/SimpleMipProgram.java
+++ b/ortools/linear_solver/samples/SimpleMipProgram.java
@@ -29,8 +29,8 @@ public class SimpleMipProgram {
 
   public static void main(String[] args) throws Exception {
     // [START solver]
-    // Create the linear solver with the CBC backend.
-    MPSolver solver = MPSolver.createSolver("SimpleMipProgram", "CBC");
+    // Create the linear solver with the SCIP backend.
+    MPSolver solver = MPSolver.createSolver("SCIP");
     // [END solver]
 
     // [START variables]
diff --git a/ortools/linear_solver/samples/assignment_mip.cc b/ortools/linear_solver/samples/assignment_mip.cc
index f48bf9a567..0fb00e1908 100644
--- a/ortools/linear_solver/samples/assignment_mip.cc
+++ b/ortools/linear_solver/samples/assignment_mip.cc
@@ -33,9 +33,8 @@ void AssignmentMip() {
 
   // Solver
   // [START solver]
-  // Create the mip solver with the CBC backend.
-  MPSolver solver("AssignmentMip",
-                  MPSolver::CBC_MIXED_INTEGER_PROGRAMMING);
+  // Create the mip solver with the SCIP backend.
+  MPSolver solver("assignment_mip", MPSolver::SCIP_MIXED_INTEGER_PROGRAMMING);
   // [END solver]
 
   // Variables
diff --git a/ortools/linear_solver/samples/assignment_mip.py b/ortools/linear_solver/samples/assignment_mip.py
index 3115b7e234..8b1f17d51b 100644
--- a/ortools/linear_solver/samples/assignment_mip.py
+++ b/ortools/linear_solver/samples/assignment_mip.py
@@ -33,8 +33,8 @@ def main():
 
     # Solver
     # [START solver]
-    # Create the mip solver with the CBC backend.
-    solver = pywraplp.Solver.CreateSolver('assignment_mip', 'CBC')
+    # Create the mip solver with the SCIP backend.
+    solver = pywraplp.Solver.CreateSolver('SCIP')
 
     # [END solver]
 
diff --git a/ortools/linear_solver/samples/bin_packing_mip.py b/ortools/linear_solver/samples/bin_packing_mip.py
index 42674b8738..676d2a3c4c 100644
--- a/ortools/linear_solver/samples/bin_packing_mip.py
+++ b/ortools/linear_solver/samples/bin_packing_mip.py
@@ -42,8 +42,8 @@ def main():
     # [END program_part1]
 
     # [START solver]
-    # Create the mip solver with the CBC backend.
-    solver = pywraplp.Solver.CreateSolver('bin_packing_mip', 'CBC')
+    # Create the mip solver with the SCIP backend.
+    solver = pywraplp.Solver.CreateSolver('SCIP')
 
     # [END solver]
 
diff --git a/ortools/linear_solver/samples/integer_programming_example.cc b/ortools/linear_solver/samples/integer_programming_example.cc
index 4e4deab999..8ffe27e851 100644
--- a/ortools/linear_solver/samples/integer_programming_example.cc
+++ b/ortools/linear_solver/samples/integer_programming_example.cc
@@ -20,9 +20,9 @@
 namespace operations_research {
 void IntegerProgrammingExample() {
   // [START solver]
-  // Create the mip solver with the CBC backend.
+  // Create the mip solver with the SCIP backend.
   MPSolver solver("integer_programming_example",
-                  MPSolver::CBC_MIXED_INTEGER_PROGRAMMING);
+                  MPSolver::SCIP_MIXED_INTEGER_PROGRAMMING);
   // [END solver]
 
   // [START variables]
diff --git a/ortools/linear_solver/samples/integer_programming_example.py b/ortools/linear_solver/samples/integer_programming_example.py
index 0c219bc011..66b3a593f2 100644
--- a/ortools/linear_solver/samples/integer_programming_example.py
+++ b/ortools/linear_solver/samples/integer_programming_example.py
@@ -21,8 +21,8 @@ from ortools.linear_solver import pywraplp
 def IntegerProgrammingExample():
     """Integer programming sample."""
     # [START solver]
-    # Create the mip solver with the CBC backend.
-    solver = pywraplp.Solver.CreateSolver('integer_programming_example', 'CBC')
+    # Create the mip solver with the SCIP backend.
+    solver = pywraplp.Solver.CreateSolver('SCIP')
 
     # [END solver]
 
diff --git a/ortools/linear_solver/samples/linear_programming_example.py b/ortools/linear_solver/samples/linear_programming_example.py
index 9508c6414a..ba17cdab27 100644
--- a/ortools/linear_solver/samples/linear_programming_example.py
+++ b/ortools/linear_solver/samples/linear_programming_example.py
@@ -23,7 +23,7 @@ def LinearProgrammingExample():
     """Linear programming sample."""
     # Instantiate a Glop solver, naming it LinearExample.
     # [START solver]
-    solver = pywraplp.Solver.CreateSolver('linear_programming_examples', 'GLOP')
+    solver = pywraplp.Solver.CreateSolver('GLOP')
     # [END solver]
 
     # Create the two variables and let them take on any non-negative value.
diff --git a/ortools/linear_solver/samples/mip_var_array.cc b/ortools/linear_solver/samples/mip_var_array.cc
index 05fdad057e..d60a63efef 100644
--- a/ortools/linear_solver/samples/mip_var_array.cc
+++ b/ortools/linear_solver/samples/mip_var_array.cc
@@ -40,8 +40,8 @@ void MipVarArray() {
   // [END program_part1]
 
   // [START solver]
-  // Create the mip solver with the CBC backend.
-  MPSolver solver("mip_var_array", MPSolver::CBC_MIXED_INTEGER_PROGRAMMING);
+  // Create the mip solver with the SCIP backend.
+  MPSolver solver("mip_var_array", MPSolver::SCIP_MIXED_INTEGER_PROGRAMMING);
   // [END solver]
 
   // [START program_part2]
diff --git a/ortools/linear_solver/samples/mip_var_array.py b/ortools/linear_solver/samples/mip_var_array.py
index 549a782a06..ad1cc729e5 100644
--- a/ortools/linear_solver/samples/mip_var_array.py
+++ b/ortools/linear_solver/samples/mip_var_array.py
@@ -46,9 +46,8 @@ def main():
     # [END data]
     # [END program_part1]
     # [START solver]
-    # Create the mip solver with the CBC backend.
-    solver = pywraplp.Solver.CreateSolver('mip_var_array', 'CBC')
-    # [END solver]
+    # Create the mip solver with the SCIP backend.
+    solver = pywraplp.Solver.CreateSolver('SCIP')
 
     # [START program_part2]
     # [START variables]
diff --git a/ortools/linear_solver/samples/multiple_knapsack_mip.py b/ortools/linear_solver/samples/multiple_knapsack_mip.py
index 6fb868a467..f660840a76 100644
--- a/ortools/linear_solver/samples/multiple_knapsack_mip.py
+++ b/ortools/linear_solver/samples/multiple_knapsack_mip.py
@@ -46,8 +46,8 @@ def main():
     # [END program_part1]
 
     # [START solver]
-    # Create the mip solver with the CBC backend.
-    solver = pywraplp.Solver.CreateSolver('multiple_knapsack_mip', 'CBC')
+    # Create the mip solver with the SCIP backend.
+    solver = pywraplp.Solver.CreateSolver('SCIP')
     # [END solver]
 
     # [START program_part2]
diff --git a/ortools/linear_solver/samples/simple_lp_program.py b/ortools/linear_solver/samples/simple_lp_program.py
index c112e8a96a..010ba7e959 100644
--- a/ortools/linear_solver/samples/simple_lp_program.py
+++ b/ortools/linear_solver/samples/simple_lp_program.py
@@ -21,7 +21,7 @@ from ortools.linear_solver import pywraplp
 def main():
     # [START solver]
     # Create the linear solver with the GLOP backend.
-    solver = pywraplp.Solver.CreateSolver('simple_lp_program', 'GLOP')
+    solver = pywraplp.Solver.CreateSolver('GLOP')
     # [END solver]
 
     # [START variables]
diff --git a/ortools/linear_solver/samples/simple_mip_program.cc b/ortools/linear_solver/samples/simple_mip_program.cc
index 52e730ae00..dbfc2cab34 100644
--- a/ortools/linear_solver/samples/simple_mip_program.cc
+++ b/ortools/linear_solver/samples/simple_mip_program.cc
@@ -20,9 +20,9 @@
 namespace operations_research {
 void SimpleMipProgram() {
   // [START solver]
-  // Create the mip solver with the CBC backend.
+  // Create the mip solver with the SCIP backend.
   MPSolver solver("simple_mip_program",
-                  MPSolver::CBC_MIXED_INTEGER_PROGRAMMING);
+                  MPSolver::SCIP_MIXED_INTEGER_PROGRAMMING);
   // [END solver]
 
   // [START variables]
diff --git a/ortools/linear_solver/samples/simple_mip_program.py b/ortools/linear_solver/samples/simple_mip_program.py
index 28cd43d806..e2a31d5bc9 100644
--- a/ortools/linear_solver/samples/simple_mip_program.py
+++ b/ortools/linear_solver/samples/simple_mip_program.py
@@ -20,8 +20,8 @@ from ortools.linear_solver import pywraplp
 
 def main():
     # [START solver]
-    # Create the mip solver with the CBC backend.
-    solver = pywraplp.Solver.CreateSolver('simple_mip_program', 'CBC')
+    # Create the mip solver with the SCIP backend.
+    solver = pywraplp.Solver.CreateSolver('SCIP')
     # [END solver]
 
     # [START variables]
diff --git a/ortools/linear_solver/sat_interface.cc b/ortools/linear_solver/sat_interface.cc
index 720e62ea51..d26b81289b 100644
--- a/ortools/linear_solver/sat_interface.cc
+++ b/ortools/linear_solver/sat_interface.cc
@@ -19,6 +19,7 @@
 #include "ortools/base/hash.h"
 #include "ortools/base/integral_types.h"
 #include "ortools/base/logging.h"
+#include "ortools/base/statusor.h"
 #include "ortools/linear_solver/linear_solver.h"
 #include "ortools/linear_solver/linear_solver.pb.h"
 #include "ortools/linear_solver/sat_proto_solver.h"
diff --git a/ortools/linear_solver/sat_proto_solver.cc b/ortools/linear_solver/sat_proto_solver.cc
index 58f5d01acf..00c9292f59 100644
--- a/ortools/linear_solver/sat_proto_solver.cc
+++ b/ortools/linear_solver/sat_proto_solver.cc
@@ -15,6 +15,7 @@
 
 #include <vector>
 
+#include "ortools/base/statusor.h"
 #include "ortools/linear_solver/linear_solver.pb.h"
 #include "ortools/linear_solver/model_validator.h"
 #include "ortools/linear_solver/sat_solver_utils.h"