framework-grpc

# AI Skill: gRPC Engineering and Architecture (framework-grpc) This skill guides the AI to act as a specialist in the high-performance RPC framework **gRPC** and the **Protocol Buffers (proto3)** IDL, aligned with the official CNCF and gRPC.io documentation ([grpc.io](https://grpc.io/)). It covers service contract modeling, bidirectional streaming, HTTP/2 transport, interceptors, error handling, and inter-service integration. --- ## 🧭 Contract Specification with Protocol Buffers (proto3) ### 1. `.proto` File Definition Standards - Use the `syntax = "proto3";` syntax. - Organize packages logically to avoid collisions (`package company.service.v1;`). - Assign a unique, sequential numeric tag to fields (`1` through `15` consume only 1 byte in the varint field encoding). ```protobuf syntax = "proto3"; package billing.v1; import "google/protobuf/timestamp.proto"; option go_package = "github.com/empresa/billing/v1;billingv1"; service PaymentService { // Unary RPC rpc ProcessPayment (ProcessPaymentRequest) returns (ProcessPaymentResponse); // Server Streaming RPC rpc StreamTransactions (StreamTransactionsRequest) returns (stream TransactionEvent); } message ProcessPaymentRequest { string account_id = 1; int64 amount_cents = 2; string currency = 3; PaymentMethod method = 4; } enum PaymentMethod { PAYMENT_METHOD_UNSPECIFIED = 0; PAYMENT_METHOD_CREDIT_CARD = 1; PAYMENT_METHOD_PIX = 2; } message ProcessPaymentResponse { string transaction_id = 1; string status = 2; google.protobuf.Timestamp processed_at = 3; } message StreamTransactionsRequest { string account_id = 1; } message TransactionEvent { string transaction_id = 1; int64 amount_cents = 2; google.protobuf.Timestamp timestamp = 3; } ``` --- ## 🛠️ Communication Patterns and HTTP/2 Transport ### 1. RPC Operating Modes 1. **Unary RPC**: The client sends a single request and receives a response. 2. **Server Streaming RPC**: The client sends a request and receives a continuous stream of messages. 3. **Client Streaming RPC**: The client sends a stream of messages and awaits a single final response from the server. 4. **Bidirectional Streaming RPC**: Client and server exchange independent streams of messages over the same multiplexed HTTP/2 connection. ### 2. Interceptors (Middlewares) Use unary and streaming interceptors to: - Authenticate and extract credentials via metadata headers (`metadata.MD`). - Collect metrics and distributed tracing (OpenTelemetry / Jaeger). - Recover from panics (*panic recovery*) and provide centralized call logging. --- ## 🚨 Rich Error Handling (`google.rpc.Status`) Avoid using only raw gRPC codes (`codes.Internal`, `codes.InvalidArgument`). Return rich error payloads using the `google.rpc.Status` model: ```json { "code": 3, "message": "Invalid arguments provided for the transaction", "details": [ { "@type": "type.googleapis.com/google.rpc.BadRequest", "field_violations": [ { "field": "amount_cents", "description": "The value must be greater than zero" } ] } ] } ``` --- ## 🔗 Integration with Other Skills - For high-performance inter-microservice communication architecture, see [backend-developer](../../roles/backend-developer/SKILL.md) and [software-architect](../../roles/software-architect/SKILL.md). - To implement gRPC clients/servers in Go, Rust, or Python, see [lang-go](../../languages/lang-go/SKILL.md), [lang-rust](../../languages/lang-rust/SKILL.md), and [lang-python](../../languages/lang-python/SKILL.md). - For transport-layer security and mTLS authentication in gRPC, see [network-security-onprem-cloud](../../security/operations/network-security-onprem-cloud/SKILL.md) and [auth-protocols-mfa](../../security/operations/auth-protocols-mfa/SKILL.md).