diff --git a/endpoint_spec/README.rst b/endpoint_spec/README.rst
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+++ b/endpoint_spec/README.rst
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+waiting the bot :)
diff --git a/endpoint_spec/__init__.py b/endpoint_spec/__init__.py
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index 00000000..e69de29b
diff --git a/endpoint_spec/__manifest__.py b/endpoint_spec/__manifest__.py
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+++ b/endpoint_spec/__manifest__.py
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+# Copyright 2026 Camptocamp SA
+# License LGPL-3.0 or later (http://www.gnu.org/licenses/lgpl).
+
+{
+    "name": "Endpoint spec",
+    "summary": "Declare endpoints on any class: metadata for routes generators.",
+    "version": "18.0.1.0.0",
+    "license": "LGPL-3",
+    "development_status": "Alpha",
+    "author": "Camptocamp,Odoo Community Association (OCA)",
+    "maintainers": ["simahawk"],
+    "website": "https://github.com/OCA/web-api",
+    "depends": ["base"],
+}
diff --git a/endpoint_spec/endpoint.py b/endpoint_spec/endpoint.py
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+++ b/endpoint_spec/endpoint.py
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+# Copyright 2026 Camptocamp SA
+# @author: Simone Orsi <simone.orsi@camptocamp.com>
+# License LGPL-3.0 or later (http://www.gnu.org/licenses/lgpl).
+"""Declare endpoints on classes that are not controllers.
+
+Controllers declare their routes w/ `odoo.http.route`.
+This module is for service-like classes whose methods are turned into
+routes by a generator (see `endpoint_route_handler` generators):
+
+    class MyService:
+
+        @endpoint("GET", path="/<int:id>")
+        def get(self, id):
+            ...
+
+        @endpoint(input=MyParam(), output=MyParam())
+        def scan(self, barcode):
+            ...
+
+    specs = collect_endpoints(MyService)
+
+The decorator only declares metadata: it never wraps the method.
+Validation happens in the dispatcher, at the HTTP boundary.
+Hence, methods can call each other and tests can call them directly.
+"""
+
+import dataclasses
+import inspect
+from collections.abc import Mapping
+from typing import Any
+
+ENDPOINT_ATTR = "_endpoint_spec"
+ENDPOINT_EXTEND_ATTR = "_endpoint_spec_extend"
+
+
+@dataclasses.dataclass(frozen=True)
+class EndpointRoute:
+    """Paths served with the same HTTP methods."""
+
+    paths: tuple
+    methods: tuple
+
+
+@dataclasses.dataclass(frozen=True)
+class EndpointSpec:
+    """Metadata of an endpoint.
+
+    :param routes: tuple of `EndpointRoute`.
+        Paths are relative to the root of the generator.
+        When no route is given, conventions provide the default one.
+    :param methods: HTTP methods to use for the default route
+    :param input: param object for request params (eg: an `http_api_dispatcher` param)
+    :param output: param object for the result
+    :param routing: any other routing key (auth, cors, csrf, api_doc, ...)
+    """
+
+    routes: tuple = ()
+    methods: tuple = ()
+    input: Any = None
+    output: Any = None
+    routing: Mapping = dataclasses.field(default_factory=dict)
+
+    def merge(self, **values):
+        """Return a new spec updated with given values.
+
+        `routing` values are merged, other values are replaced.
+        """
+        if "routing" in values:
+            values["routing"] = dict(self.routing, **values["routing"])
+        return dataclasses.replace(self, **values)
+
+
+def _as_tuple(value):
+    """Normalize a single value or an iterable to a tuple."""
+    if value is None:
+        return ()
+    if isinstance(value, str):
+        return (value,)
+    return tuple(value)
+
+
+def endpoint(methods="POST", path=None, input=None, output=None, **routing):
+    """Declare a method as endpoint.
+
+    :param methods: HTTP method(s)
+    :param path: path(s) relative to the root of the generator.
+        If not given, conventions provide the default path.
+    :param input: param object for request params
+    :param output: param object for the result
+    :param routing: any other routing key (auth, cors, csrf, api_doc, ...)
+    """
+    methods = _as_tuple(methods)
+    routes = ()
+    if path:
+        routes = (EndpointRoute(paths=_as_tuple(path), methods=methods),)
+    spec = EndpointSpec(
+        routes=routes, methods=methods, input=input, output=output, routing=routing
+    )
+
+    def deco(func):
+        """Store the spec on the function, untouched."""
+        setattr(func, ENDPOINT_ATTR, spec)
+        return func
+
+    return deco
+
+
+def extend(**values):
+    """Update the spec inherited from parent classes.
+
+    Use it on overrides to change only some values:
+
+        @endpoint.extend(routing={"api_doc": {"tags": ["new"]}})
+        def scan(self, barcode):
+            return super().scan(barcode)
+    """
+
+    def deco(func):
+        """Store the values to merge into the inherited spec."""
+        setattr(func, ENDPOINT_EXTEND_ATTR, values)
+        return func
+
+    return deco
+
+
+endpoint.extend = extend
+
+
+def find_spec(cls, name):
+    """Return the spec of method `name` looking up the class hierarchy.
+
+    An override without decorator keeps the spec of its parent.
+    `endpoint.extend` updates on overrides are applied
+    from the parent to the child.
+    """
+    extensions = []
+    for klass in cls.__mro__:
+        func = klass.__dict__.get(name)
+        if func is None:
+            continue
+        func = getattr(func, "__func__", func)
+        ext = getattr(func, ENDPOINT_EXTEND_ATTR, None)
+        if ext:
+            extensions.append(ext)
+        spec = getattr(func, ENDPOINT_ATTR, None)
+        if spec is not None:
+            for ext in reversed(extensions):
+                spec = spec.merge(**ext)
+            return spec
+    return None
+
+
+def public_methods(cls):
+    """Return `(name, func)` of public methods without triggering properties."""
+    res = []
+    for attr in inspect.classify_class_attrs(cls):
+        if attr.kind != "method" or attr.name.startswith("_"):
+            continue
+        res.append((attr.name, getattr(cls, attr.name)))
+    return sorted(res)
+
+
+class Conventions:
+    """Provide defaults for endpoint specs.
+
+    The base class exposes only decorated methods
+    and uses `/<method name>` as default path.
+    This is the recommended behavior: endpoints are declared explicitly.
+
+    Subclasses can expose non decorated methods via `guess`.
+    This is meant only as a transition, eg: to migrate services from `base_rest`
+    (see `ShopfloorConventions` in `shopfloor_base`).
+    """
+
+    def guess(self, cls, name, func):
+        """Return a spec for a non decorated method or None to skip it."""
+        return None
+
+    def default_routes(self, cls, name, func, methods=None):
+        """Default route: POST (or given methods) on `/<method name>`."""
+        methods = _as_tuple(methods) or ("POST",)
+        return (EndpointRoute(paths=(f"/{name}",), methods=methods),)
+
+    def complete(self, cls, name, func, spec):
+        """Fill the missing values of a spec."""
+        if not spec.routes:
+            routes = self.default_routes(cls, name, func, spec.methods or None)
+            spec = spec.merge(routes=routes)
+        return spec
+
+
+def collect_endpoints(cls, conventions=None):
+    """Return `{method name: EndpointSpec}` for the endpoints of `cls`.
+
+    Decorated methods (on the class or its parents) are always collected.
+    Non decorated public methods are passed to `conventions.guess`.
+    """
+    conventions = conventions or Conventions()
+    res = {}
+    for name, func in public_methods(cls):
+        spec = find_spec(cls, name)
+        if spec is None:
+            spec = conventions.guess(cls, name, func)
+        if spec is None:
+            continue
+        res[name] = conventions.complete(cls, name, func, spec)
+    return res
diff --git a/endpoint_spec/pyproject.toml b/endpoint_spec/pyproject.toml
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index 00000000..4231d0cc
--- /dev/null
+++ b/endpoint_spec/pyproject.toml
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+[build-system]
+requires = ["whool"]
+build-backend = "whool.buildapi"
diff --git a/endpoint_spec/readme/CONTRIBUTORS.md b/endpoint_spec/readme/CONTRIBUTORS.md
new file mode 100644
index 00000000..2b66303a
--- /dev/null
+++ b/endpoint_spec/readme/CONTRIBUTORS.md
@@ -0,0 +1 @@
+- Simone Orsi \<<simone.orsi@camptocamp.com>\>
diff --git a/endpoint_spec/readme/DESCRIPTION.md b/endpoint_spec/readme/DESCRIPTION.md
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+++ b/endpoint_spec/readme/DESCRIPTION.md
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+Declare endpoints on any class (eg: services), not only on controllers.
+
+Provides the metadata that routes generators (see `endpoint_route_handler`)
+read to build routes: HTTP methods, paths, input/output params and any routing key.
+
+- `endpoint` decorator: declares metadata only, it never wraps the method
+- `EndpointSpec`: the metadata of an endpoint
+- `collect_endpoints`: collect the specs of a class, following inheritance
+- conventions: defaults for non decorated methods
+
+It does not depend on any dispatcher: generated routes can use
+any route type (eg: `http_api`, `restapi` from `base_rest`).
diff --git a/endpoint_spec/readme/USAGE.md b/endpoint_spec/readme/USAGE.md
new file mode 100644
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+++ b/endpoint_spec/readme/USAGE.md
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+## Declare endpoints
+
+    from odoo.addons.endpoint_spec.endpoint import collect_endpoints, endpoint
+
+    class MyService:
+
+        @endpoint("GET", path="/<int:id>")
+        def get(self, id):
+            ...
+
+        @endpoint(input=MyParam(), output=MyParam())
+        def scan(self, barcode):
+            ...
+
+    specs = collect_endpoints(MyService)
+    # {"get": EndpointSpec(...), "scan": EndpointSpec(...)}
+
+The decorator only declares metadata: it does not wrap the method.
+Methods can call each other and tests can call them directly.
+
+Specs are inherited: an override w/o decorator keeps the spec of its parent.
+Use `@endpoint.extend(...)` on an override to change only some values.
+
+Decorated methods w/o path get `/<method name>` as default path.
+Non decorated methods are not exposed.
+
+Use the specs in a routes generator: one route per path of each `EndpointRoute`,
+w/ the HTTP methods, the `input` / `output` params and the `routing` keys of the spec.
+
+## Conventions
+
+By default only decorated methods are exposed: this is the recommended behavior.
+
+To expose non decorated methods, pass your own `Conventions` subclass
+to `collect_endpoints` and implement `guess`. Use it only as a transition,
+eg: to migrate services from `base_rest` w/o declaring every endpoint at once
+(see `ShopfloorConventions` in `shopfloor_base`). With implicit exposure,
+any new public method becomes an endpoint by mistake.
diff --git a/endpoint_spec/static/description/icon.png b/endpoint_spec/static/description/icon.png
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diff --git a/endpoint_spec/tests/__init__.py b/endpoint_spec/tests/__init__.py
new file mode 100644
index 00000000..c3f07a7d
--- /dev/null
+++ b/endpoint_spec/tests/__init__.py
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+from . import test_endpoint
diff --git a/endpoint_spec/tests/test_endpoint.py b/endpoint_spec/tests/test_endpoint.py
new file mode 100644
index 00000000..b988aa1d
--- /dev/null
+++ b/endpoint_spec/tests/test_endpoint.py
@@ -0,0 +1,104 @@
+# Copyright 2026 Camptocamp SA
+# @author: Simone Orsi <simone.orsi@camptocamp.com>
+# License LGPL-3.0 or later (http://www.gnu.org/licenses/lgpl).
+
+from odoo.tests.common import BaseCase
+
+from ..endpoint import (
+    Conventions,
+    EndpointRoute,
+    EndpointSpec,
+    collect_endpoints,
+    endpoint,
+    find_spec,
+)
+
+
+class Base:
+    def helper(self):
+        """Public method of the base class: never exposed by conventions."""
+
+    @property
+    def boom(self):
+        raise AssertionError("Properties must not be evaluated")
+
+
+class Service(Base):
+    @endpoint("GET", path=["/<int:id>", "/<int:id>/get"], auth="public")
+    def get(self, id):
+        return id
+
+    @endpoint(input="in", output="out")
+    def scan(self, barcode):
+        return barcode
+
+    @endpoint(["GET", "POST"])
+    def multi(self):
+        return True
+
+    def not_decorated(self):
+        return True
+
+    def _private(self):
+        return True
+
+
+class ServiceChild(Service):
+    def scan(self, barcode):
+        return super().scan(barcode)
+
+    @endpoint.extend(routing={"api_doc": {"tags": ["child"]}}, output="out2")
+    def multi(self):
+        return super().multi()
+
+
+def _routes(*pairs):
+    return tuple(EndpointRoute(paths=tuple(p), methods=tuple(m)) for p, m in pairs)
+
+
+class TestEndpoint(BaseCase):
+    def test_decorator_does_not_wrap(self):
+        """The decorator only attaches metadata: the method is left as is."""
+        self.assertEqual(Service().scan("abc"), "abc")
+        self.assertEqual(Service.scan.__name__, "scan")
+
+    def test_collect_explicit_only(self):
+        """Only decorated methods are collected, w/ their routes and routing."""
+        specs = collect_endpoints(Service)
+        self.assertEqual(sorted(specs), ["get", "multi", "scan"])
+        self.assertEqual(
+            specs["get"].routes, _routes((("/<int:id>", "/<int:id>/get"), ("GET",)))
+        )
+        self.assertEqual(specs["get"].routing, {"auth": "public"})
+        self.assertEqual(specs["scan"].routes, _routes((("/scan",), ("POST",))))
+        self.assertEqual(specs["scan"].input, "in")
+        self.assertEqual(specs["multi"].routes, _routes((("/multi",), ("GET", "POST"))))
+
+    def test_inherited_spec(self):
+        """Child classes inherit the specs of their parents and extend them."""
+        specs = collect_endpoints(ServiceChild)
+        self.assertEqual(specs["scan"].input, "in")
+        self.assertEqual(specs["multi"].output, "out2")
+        self.assertEqual(specs["multi"].routing, {"api_doc": {"tags": ["child"]}})
+        self.assertEqual(specs["multi"].routes, _routes((("/multi",), ("GET", "POST"))))
+        self.assertIsNone(find_spec(ServiceChild, "not_decorated"))
+
+    def test_custom_conventions(self):
+        """Conventions can expose undecorated methods; explicit specs win."""
+
+        class ExposeAll(Conventions):
+            """Expose every public method not inherited from `Base`."""
+
+            def guess(self, cls, name, func):
+                if hasattr(Base, name):
+                    return None
+                return EndpointSpec(methods=("PUT",))
+
+        specs = collect_endpoints(Service, conventions=ExposeAll())
+        self.assertEqual(sorted(specs), ["get", "multi", "not_decorated", "scan"])
+        self.assertNotIn("helper", specs)
+        self.assertEqual(
+            specs["not_decorated"].routes, _routes((("/not_decorated",), ("PUT",)))
+        )
+        # Explicit specs are not affected by conventions
+        self.assertEqual(specs["scan"].routes, _routes((("/scan",), ("POST",))))