diff --git a/edi_core_oca/models/edi_backend.py b/edi_core_oca/models/edi_backend.py
index d4af65ff6..937a143d5 100644
--- a/edi_core_oca/models/edi_backend.py
+++ b/edi_core_oca/models/edi_backend.py
@@ -370,6 +370,8 @@ def _output_new_records_domain(self, record_ids=None):
             ("backend_id", "=", self.id),
             ("type_id.exchange_file_auto_generate", "=", True),
             ("type_id.direction", "=", "output"),
+            ("type_id.generate_model_id", "!=", False),
+            ("type_id.send_model_id", "!=", False),
             ("edi_exchange_state", "=", "new"),
             ("exchange_file", "=", False),
         ]
@@ -388,6 +390,7 @@ def _output_pending_records_domain(self, skip_sent=True, record_ids=None):
             states += ("output_sent",)
         domain = [
             ("type_id.direction", "=", "output"),
+            ("type_id.send_model_id", "!=", False),
             ("backend_id", "=", self.id),
             ("edi_exchange_state", "in", states),
         ]
@@ -575,6 +578,7 @@ def _input_pending_records_domain(self, record_ids=None):
         domain = [
             ("backend_id", "=", self.id),
             ("type_id.direction", "=", "input"),
+            ("type_id.receive_model_id", "!=", False),
             ("edi_exchange_state", "=", "input_pending"),
             ("exchange_file", "=", False),
         ]
@@ -587,6 +591,7 @@ def _input_pending_process_records_domain(self, record_ids=None):
         domain = [
             ("backend_id", "=", self.id),
             ("type_id.direction", "=", "input"),
+            ("type_id.process_model_id", "!=", False),
             ("edi_exchange_state", "in", states),
         ]
         if record_ids:
diff --git a/edi_core_oca/models/edi_exchange_type.py b/edi_core_oca/models/edi_exchange_type.py
index d6a2cab96..2f602ac6a 100644
--- a/edi_core_oca/models/edi_exchange_type.py
+++ b/edi_core_oca/models/edi_exchange_type.py
@@ -240,6 +240,32 @@ def get_settings(self):
     def set_settings(self, val):
         self.advanced_settings_edit = val
 
+    @api.constrains(
+        "direction",
+        "send_model_id",
+        "process_model_id",
+        "generate_model_id",
+        "exchange_file_auto_generate",
+    )
+    def _check_direction_handlers(self):
+        for rec in self:
+            if rec.direction == "output":
+                if not rec.send_model_id:
+                    raise exceptions.ValidationError(
+                        self.env._("Output exchange types require a Sender handler.")
+                    )
+                if rec.exchange_file_auto_generate and not rec.generate_model_id:
+                    raise exceptions.ValidationError(
+                        self.env._(
+                            "Output exchange types with 'Auto Generate' enabled "
+                            "require a Generator handler."
+                        )
+                    )
+            elif rec.direction == "input" and not rec.process_model_id:
+                raise exceptions.ValidationError(
+                    self.env._("Input exchange types require a Processor handler.")
+                )
+
     @api.constrains("backend_id", "backend_type_id")
     def _check_backend(self):
         for rec in self:
diff --git a/edi_core_oca/tests/common.py b/edi_core_oca/tests/common.py
index fe9bdb9d1..0ed40d75a 100644
--- a/edi_core_oca/tests/common.py
+++ b/edi_core_oca/tests/common.py
@@ -5,6 +5,7 @@
 
 import os
 
+from odoo.orm.model_classes import add_to_registry
 from odoo.tests.common import TransactionCase
 
 
@@ -19,6 +20,24 @@ def _setup_context(cls, **kw):
     def _setup_env(cls, ctx=None):
         ctx = ctx or {}
         cls.env = cls.env(context=cls._setup_context(**ctx))
+        # Register EdiTestExecution early so _create_exchange_type can set default
+        # handler models — the new @api.constrains on edi.exchange.type requires
+        # send_model_id (output) and process_model_id (input) to be set.
+        # Guard prevents double-registration when individual test classes also call
+        # add_to_registry; pop() in cleanup is safe even if __delitem__ already ran.
+        if "edi.framework.test.execution" not in cls.registry:
+            from .fake_models import EdiTestExecution
+
+            add_to_registry(cls.registry, EdiTestExecution)
+            cls.registry._setup_models__(cls.env.cr, ["edi.framework.test.execution"])
+            cls.registry.init_models(
+                cls.env.cr, ["edi.framework.test.execution"], {"models_to_check": True}
+            )
+            cls.addClassCleanup(
+                lambda: cls.registry.__delitem__("edi.framework.test.execution")
+                if "edi.framework.test.execution" in cls.registry
+                else None
+            )
 
     @classmethod
     def _setup_records(cls):
@@ -84,6 +103,19 @@ def _get_backend(cls):
 
     @classmethod
     def _create_exchange_type(cls, **kw):
+        # Mirror the pattern in edi_component_oca/tests/common.py: provide default
+        # handler models so every test exchange type satisfies the new constraint.
+        # Callers can override individual fields by passing explicit values.
+        if "edi.framework.test.execution" in cls.registry:
+            handler_model = cls.env["ir.model"]._get("edi.framework.test.execution")
+            if handler_model:
+                kw.setdefault("receive_model_id", handler_model.id)
+                kw.setdefault("generate_model_id", handler_model.id)
+                kw.setdefault("input_validate_model_id", handler_model.id)
+                kw.setdefault("output_validate_model_id", handler_model.id)
+                kw.setdefault("send_model_id", handler_model.id)
+                kw.setdefault("process_model_id", handler_model.id)
+                kw.setdefault("check_model_id", handler_model.id)
         model = cls.env["edi.exchange.type"]
         vals = {
             "name": "Test CSV exchange",
diff --git a/edi_core_oca/tests/fake_models.py b/edi_core_oca/tests/fake_models.py
index df7d5e25c..badea718a 100644
--- a/edi_core_oca/tests/fake_models.py
+++ b/edi_core_oca/tests/fake_models.py
@@ -33,6 +33,7 @@ def _get_edi_exchange_record_name(self, exchange_record):
 class EdiTestExecution(models.AbstractModel):
     _name = "edi.framework.test.execution"
     _inherit = [
+        "edi.oca.handler.generate",
         "edi.oca.handler.process",
         "edi.oca.handler.check",
         "edi.oca.handler.send",
diff --git a/edi_core_oca/tests/test_backend_base.py b/edi_core_oca/tests/test_backend_base.py
index 87219bea0..dc401f7c0 100644
--- a/edi_core_oca/tests/test_backend_base.py
+++ b/edi_core_oca/tests/test_backend_base.py
@@ -85,9 +85,15 @@ def test_get_handler_avg_user(self):
         self._test_get_handler(user=user)
 
     def test_get_handler_no_handler(self):
-        self.exchange_type_in.process_model_id = False
-        self.exchange_type_in.input_validate_model_id = False
-        self.exchange_type_in.receive_model_id = False
+        self.env.cr.execute(
+            """UPDATE edi_exchange_type
+               SET process_model_id = NULL,
+                   input_validate_model_id = NULL,
+                   receive_model_id = NULL
+               WHERE id = %s""",
+            [self.exchange_type_in.id],
+        )
+        self.exchange_type_in.invalidate_recordset()
         vals = {
             "model": self.partner._name,
             "res_id": self.partner.id,
diff --git a/edi_core_oca/views/edi_exchange_type_views.xml b/edi_core_oca/views/edi_exchange_type_views.xml
index e7f0be5e1..549494b30 100644
--- a/edi_core_oca/views/edi_exchange_type_views.xml
+++ b/edi_core_oca/views/edi_exchange_type_views.xml
@@ -63,6 +63,7 @@
                                 <field
                                     name="process_model_id"
                                     options="{'no_create': True}"
+                                    required="direction == 'input'"
                                 />
                                 <field
                                     name="input_validate_model_id"
@@ -76,10 +77,12 @@
                                 <field
                                     name="generate_model_id"
                                     options="{'no_create': True}"
+                                    required="direction == 'output' and exchange_file_auto_generate"
                                 />
                                 <field
                                     name="send_model_id"
                                     options="{'no_create': True}"
+                                    required="direction == 'output'"
                                 />
                                 <field
                                     name="output_validate_model_id"
diff --git a/edi_endpoint_oca/tests/common.py b/edi_endpoint_oca/tests/common.py
index 606f2890f..e0d87099f 100644
--- a/edi_endpoint_oca/tests/common.py
+++ b/edi_endpoint_oca/tests/common.py
@@ -1,6 +1,7 @@
 # Copyright 2026 Camptocamp SA
 # License LGPL-3.0 or later (http://www.gnu.org/licenses/lgpl).
 
+from odoo.orm.model_classes import add_to_registry
 from odoo.tests.common import TransactionCase
 
 
@@ -13,6 +14,21 @@ def _setup_context(cls, **kw):
     def _setup_env(cls, ctx=None):
         ctx = ctx or {}
         cls.env = cls.env(context=cls._setup_context(**ctx))
+        # Register EdiTestExecution so _get_exchange_type can satisfy the
+        # _check_direction_handlers constraint (input types need process_model_id).
+        if "edi.framework.test.execution" not in cls.registry:
+            from odoo.addons.edi_core_oca.tests.fake_models import EdiTestExecution
+
+            add_to_registry(cls.registry, EdiTestExecution)
+            cls.registry._setup_models__(cls.env.cr, ["edi.framework.test.execution"])
+            cls.registry.init_models(
+                cls.env.cr, ["edi.framework.test.execution"], {"models_to_check": True}
+            )
+            cls.addClassCleanup(
+                lambda: cls.registry.__delitem__("edi.framework.test.execution")
+                if "edi.framework.test.execution" in cls.registry
+                else None
+            )
 
     @classmethod
     def _setup_records(cls):
@@ -75,12 +91,14 @@ def _get_backend(cls):
 
     @classmethod
     def _get_exchange_type(cls):
+        handler_model = cls.env["ir.model"]._get("edi.framework.test.execution")
         return cls.env["edi.exchange.type"].create(
             {
                 "name": "EDI exchange demo",
                 "code": "demo_endpoint",
                 "backend_type_id": cls.backend_type.id,
                 "direction": "input",
+                "process_model_id": handler_model.id,
             }
         )
 
diff --git a/edi_queue_oca/tests/test_backend_output_jobs.py b/edi_queue_oca/tests/test_backend_output_jobs.py
index b600a0d9b..7c611d4a2 100644
--- a/edi_queue_oca/tests/test_backend_output_jobs.py
+++ b/edi_queue_oca/tests/test_backend_output_jobs.py
@@ -4,6 +4,7 @@
 # License LGPL-3.0 or later (http://www.gnu.org/licenses/lgpl).
 
 
+from odoo.orm.model_classes import add_to_registry
 from odoo.tests import tagged
 
 from odoo.addons.edi_core_oca.tests.common import EDIBackendCommonTestCase
@@ -12,6 +13,21 @@
 
 @tagged("-at_install", "post_install")
 class EDIBackendTestOutputJobsCase(EDIBackendCommonTestCase):
+    @classmethod
+    def _setup_records(cls):  # pylint:disable=missing-return
+        super()._setup_records()
+        from odoo.addons.edi_core_oca.tests.fake_models import EdiTestExecution
+
+        add_to_registry(cls.registry, EdiTestExecution)
+        cls.registry._setup_models__(cls.env.cr, ["edi.framework.test.execution"])
+        cls.registry.init_models(
+            cls.env.cr, ["edi.framework.test.execution"], {"models_to_check": True}
+        )
+        cls.addClassCleanup(cls.registry.__delitem__, "edi.framework.test.execution")
+        model = cls.env["ir.model"]._get("edi.framework.test.execution")
+        cls.exchange_type_out.generate_model_id = model
+        cls.exchange_type_out.send_model_id = model
+
     @classmethod
     def setUpClass(cls):
         super().setUpClass()