gRPC

Expose gRPC services (server) or call external gRPC endpoints (client). Uses Protocol Buffers for schema definition and supports TLS, load balancing, and all standard gRPC patterns.

Server Configuration

connector "grpc_api" {
  type   = "grpc"
  driver = "server"
  port   = 50051

  proto_path  = "./proto"
  proto_files = ["service.proto"]
  reflection  = true

  tls {
    cert = "/path/to/cert.pem"
    key  = "/path/to/key.pem"
  }
}

Client Configuration

connector "grpc_service" {
  type   = "grpc"
  driver = "client"
  target = "localhost:50051"

  proto_path  = "./proto"
  proto_files = ["service.proto"]
}

Common Options

Option	Type	Description
driver	string	server or client
port	int	Listen port (server)
target	string	Target address host:port (client)
proto_path	string	Directory containing .proto files
proto_files	list	Specific .proto files to load
reflection	bool	Enable gRPC reflection (default: true)
insecure	bool	Disable TLS (client, default: false)
tls.cert	string	Certificate this connector presents
tls.key	string	Private key for tls.cert
tls.ca_cert	string	CA used to verify the other side
tls.server_name	string	Expected server name, overriding the address (SNI)
tls.insecure_skip_verify	bool	Skip certificate verification. Development only

See TLS for the shared block, including the older cert_file / key_file / ca_file / skip_verify names, which are still accepted.

Operations

Server (source): RPC method names as defined in the proto file — e.g., GetUser, ListUsers.

Client (target): Same RPC method names, resolved against the target service.

Example

flow "get_user" {
  from {
    connector = "grpc_api"
    operation = "GetUser"
  }

  step "user" {
    connector = "db"
    query     = "SELECT * FROM users WHERE id = :id"
    params = {
      id = "input.id"
    }
  }

  response {
    user = "step.user"
  }
}

See the grpc example and grpc-loadbalancing example for complete setups.

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Full configuration reference: See gRPC in the Configuration Reference.