gRPC Client

pkg/grpc/client establishes a gRPC connection and registers a typed client in DI via WithClient.

Setup

Pass WithClient a proto-generated constructor (func(*grpc.ClientConn) T). The typed client is registered directly in DI — no need to ever handle the raw connection.

lakta.NewRuntime(
    config.NewModule(
        config.WithConfigDirs(".", "./config"),
        config.WithArgs(os.Args[1:]),
    ),
    tint.NewModule(),
    slog.NewModule(),
    otel.NewModule(),
    grpcclient.NewModule(
        grpcclient.WithName("data"),
        grpcclient.WithClient(v1.NewDataServiceClient),
    ),
    grpcclient.NewModule(
        grpcclient.WithName("orchestrator"),
        grpcclient.WithClient(v1.NewWorkflowServiceClient),
    ),
    myapp.NewModule(),
)

Consuming the client

Use lakta.Invoke[T](ctx) in any handler. The typed interface is what was registered — not the raw *grpc.ClientConn.

// gRPC handler
func (s *MyServer) PlaceOrder(ctx context.Context, req *pb.PlaceOrderRequest) (*pb.PlaceOrderResponse, error) {
    dataClient, err := lakta.Invoke[v1.DataServiceClient](ctx)
    if err != nil {
        return nil, err
    }
    return dataClient.CreateOrder(ctx, &v1.CreateOrderRequest{...})
}

// HTTP handler (Fiber)
func handlePost(c fiber.Ctx) error {
    client, err := lakta.Invoke[v1.DataServiceClient](c.Context())
    if err != nil {
        return err
    }
    resp, err := client.GetThing(c.Context(), &v1.GetThingRequest{Id: c.Params("id")})
    ...
}

Multiple connections

Each instance needs a name and its own config block:

grpcclient.NewModule(
    grpcclient.WithName("data"),
    grpcclient.WithClient(v1.NewDataServiceClient),
),
grpcclient.NewModule(
    grpcclient.WithName("orchestrator"),
    grpcclient.WithClient(v1.NewWorkflowServiceClient),
),

modules:
  grpc:
    client:
      data:
        target: "data-svc:50051"
        insecure: true
      orchestrator:
        target: "orchestrator-svc:50052"
        insecure: true

See Multi-instance Modules for the full pattern.

Configuration Reference

Config path: modules.grpc.client.<name>

target string default: localhost:50051

target specifies the target address for the gRPC client connection

env LAKTA_MODULES_GRPC_CLIENT_<NAME>_TARGET

insecure bool

insecure determines whether transport credentials should use an insecure configuration

env LAKTA_MODULES_GRPC_CLIENT_<NAME>_INSECURE

Code-only options

These options can only be set in Go code via With*() functions, not via config files or environment variables.

Option	Type	Description
Credentials(...)	credentials.TransportCredentials
WithClient(...)	[]client.ClientRegistrar	registers a typed client constructor (code-only)