fix: add Commands (receiver) to CPO version details for all OCPI versions

[alfonsosastre]

Summary

• Adds ModuleID.commands with InterfaceRole.receiver to CPO ENDPOINTS_LIST for OCPI 2.1.1, 2.2.1, and 2.3.0 so that Payter and other eMSP/PTP partners can discover the Commands endpoint via GET /ocpi/{version}/details
• Adds credentials SENDER role to CPO endpoints for 2.2.1 and 2.3.0 as recommended by Payter
• Adds payments SENDER role to CPO endpoints for 2.3.0 as recommended by Payter
• Converts ENDPOINTS_LIST from dict[ModuleID, Endpoint] to list[Endpoint] in all 6 endpoint files (CPO + eMSP × 3 versions) to support multiple interface roles per module; updates main.py to iterate the list instead of calling .get(module)

Context

Payter reported:

"Invalid states for chargeSession CHARGE_SESSION_IS_ERROR No commands Module found for platform ELU Mobility CREATED"

The command handler in elu_ocpi/crud.py was fully implemented but not discoverable because ModuleID.commands was missing from the CPO ENDPOINTS_LIST in the ocpi-python library.

Test plan

• All existing tests pass (pytest tests/ — 43 tests passing)
• After deploying elu-ocpi, GET /ocpi/2.2.1/details includes a commands entry with role RECEIVER
• GET /ocpi/2.2.1/details includes credentials with both SENDER and RECEIVER
• Payter can successfully issue START_SESSION via POST /ocpi/cpo/2.2.1/commands/START_SESSION

Made with Cursor

[alfonsosastre]

Code Review

The fix is correct and well-scoped. The root cause (missing commands RECEIVER entry for CPO) directly matches the Payter error, and the dict → list refactor is the right structural change to support multiple interface roles per module. The main.py two-pass logic (collect modules with routers, then iterate all endpoints filtering by that set) handles the multi-role case cleanly.

Verified

• elu_ocpi/main.py already passes ModuleID.commands in the modules list (line 280), so the endpoint will be advertised after this library is updated.
• All 6 endpoint files (CPO + eMSP × 3 versions) are updated consistently.
• OCPI spec compliance looks correct: Commands RECEIVER for CPO (CPO receives START_SESSION/STOP_SESSION from eMSP), Credentials SENDER for CPO (proactive token push), Payments SENDER for CPO (DirectPayment data push to eMSPs).

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Issues

Moderate — missing test for the core behaviour

The test plan items are manual checkboxes. There is no automated test that verifies GET /ocpi/{version}/details actually returns commands with role=RECEIVER for a CPO app. The existing test_get_versions_v_2_2_1 test passes modules=[], so it exercises none of the new filtering logic; the assertion len(response.json()["data"]) == 2 is checking keys in VersionDetail (version + endpoints), not the number of endpoints.

Suggest adding a test like:

def test_version_details_includes_commands_for_cpo():
    app = get_application(
        version_numbers=[VersionNumber.v_2_2_1],
        roles=[enums.RoleEnum.cpo],
        modules=[enums.ModuleID.commands],
        crud=MockCrud,
        authenticator=ClientAuthenticator,
    )
    client = TestClient(app)
    response = client.get("/ocpi/2.2.1/details", headers=AUTH_HEADERS)
    assert response.status_code == 200
    endpoints = response.json()["data"]["endpoints"]
    commands_endpoints = [e for e in endpoints if e["identifier"] == "commands"]
    assert len(commands_endpoints) == 1
    assert commands_endpoints[0]["role"] == "RECEIVER"

This would also serve as a regression guard for the Payter bug.

Minor — CREDENTIALS_SENDER omitted for OCPI 2.1.1, silently

credentials SENDER is added for 2.2.1 and 2.3.0 but not 2.1.1. This is correct because the 2.1.1 Endpoint schema has no role field (InterfaceRole is a 2.2.1+ concept), but there is nothing in the code to signal this to future maintainers. A short comment in v_2_1_1/cpo.py would help:

# OCPI 2.1.1 Endpoint schema has no InterfaceRole field;
# credentials SENDER role is implicit and not separately advertised.

Minor — no type annotation on ENDPOINTS_LIST

The variable changed from dict[ModuleID, Endpoint] to list[Endpoint]. Adding an explicit annotation makes the change self-documenting and helps mypy catch any future accidental reversion:

ENDPOINTS_LIST: list[Endpoint] = [...]

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Summary

Approve with suggestions — the fix is correct and unblocks Payter's START_SESSION flow. The moderate item (automated test) is worth doing before merging so the fix is regression-guarded; the minor items are optional cleanup.