API Reference

This section catalogs the primary interfaces exposed by the server.micro.bss platform.

gRPC Services (CRMServer)

The CRM Server (src/crm/crm_server.cpp) provides endpoints defined in the .proto schemas for backend-to-backend communication. The CRM frontend sends serialized requests, which are handled by the C++ CRMServiceImpl.

Core Management APIs

Endpoint	Request Message	Response Message	Description
AddSubscriber	billing::Subscriber	billing::CRMResponse	Provisions a new MSISDN with a default price plan and optional initial balance.
UpdateSubscriber	billing::Subscriber	billing::CRMResponse	Modifies an existing subscriber's status (e.g., active, suspended) or price plan assignment.
GetSubscriber	billing::QueryRequest	billing::Subscriber	Retrieves the full demographic, balance, and lifecycle state of a target MSISDN.
GenerateBill	billing::QueryRequest	billing::CRMResponse	Triggers an on-demand bill run for a specific MSISDN, forcing the rating of all pending CDRs up to the current timestamp.
TopUpVoucher	billing::VoucherRequest	billing::CRMResponse	Validates a 16-digit voucher PIN against the DB, credits the subscriber's balance, and marks the voucher as used.

Authentication Requirement

Every gRPC invocation must include a valid JSON Web Token (JWT) in the request metadata. The auth_interceptor.hpp middleware enforces this prior to routing to the implementation methods.

---

Internal C++ APIs

The following details the core C++ signatures responsible for business execution, adapted from their source Doxygen definitions.

Database Layer (db.hpp)

DB_layer implements the raw CRUD logic utilizing MySQL X DevAPI.

Method	Parameters	Returns	Description
insert(billing::CDR &cdr)	cdr: The deserialized CDR object	int: 0 on success, -1 on error	Inserts a new pending Call Detail Record into the ledger.
reserve_balance(billing::Subscriber &sub, float amount)	sub: Mutable subscriber passed by reference amount: Euro value to lock	int: 0 on success, -1 on DB lock/error	Locks funds during an active DIAMETER session to prevent double-spending.
debit_balance(billing::Subscriber &sub, float amount)	sub: Mutable subscriber passed by reference amount: Final Euro value to deduct	int: 0 on success, -1 on DB error	Finalizes a charge, permanently deducting the amount from the subscriber's main balance.

---

Credit Control (diameter_client.hpp)

The MockDiameterClient and DiameterClientConfig are utilities used for generating and handling test traffic simulating GGSN/PGW nodes.

Object	Type	Description
MockDiameterClient	Service Class	Sends dummy CCR-INITIAL, CCR-UPDATE, and CCR-TERMINATE requests to validate rating rules without needing a live telco switch.

---

Data Models (cdr.hpp, subscriber.hpp)

The domain entities support custom protocol buffer serialization interfaces.

Model	Method	Returns	Description
CDR / Subscriber	deserialize(const string &)	int: 1 on success, 0 on failure	Parses the target entity from a binary string. Fails gracefully by returning 0 allowing callers to handle bad input without crashing.
CDR / Subscriber	serialize(string &)	int: 1 on success, 0 on failure	Serializes the entity. Certain critical callers may perform a graceful shutdown (std::raise(SIGTERM)) on failure to avoid data consistency issues.