Add system Nexus WIT operation metadata

Makefile

@@ -8,7 +8,7 @@ ci-build: install proto http-api-docs
 install: grpc-install api-linter-install buf-install
 
 # Run all linters and compile proto files.
-proto: grpc http-api-docs nexus-rpc-yaml
+proto: grpc http-api-docs system-nexus-wit
 ########################################################################
 
 ##### Variables ######
@@ -17,7 +17,9 @@ GOPATH := $(shell go env GOPATH)
 endif
 
 GOBIN := $(if $(shell go env GOBIN),$(shell go env GOBIN),$(GOPATH)/bin)
-PATH := $(GOBIN):$(PATH)
+CARGO_HOME ?= $(HOME)/.cargo
+CARGO_BIN := $(CARGO_HOME)/bin
+PATH := $(GOBIN):$(CARGO_BIN):$(PATH)
 STAMPDIR := .stamp
 
 COLOR := "\e[1;36m%s\e[0m\n"
@@ -33,6 +35,10 @@ PROTO_PATHS = paths=source_relative:$(PROTO_OUT)
 OAPI_OUT := openapi
 OAPI3_PATH := .components.schemas.Payload
 
+SYSTEM_NEXUS_WIT := nexus/temporal-system.wit
+SYSTEM_NEXUS_SERVICE_PROTO_FILES := $(shell find temporal/api -name "service.proto" | sort)
+NEXUS_API_GEN ?= nexus-api-gen
+
 $(PROTO_OUT):
 	mkdir $(PROTO_OUT)
 
@@ -121,21 +127,22 @@ buf-breaking:
 	@printf $(COLOR) "Run buf breaking changes check against master branch..."	
 	@(cd $(PROTO_ROOT) && buf breaking --against 'https://github.com/temporalio/api.git#branch=master')
 
-nexus-rpc-yaml: nexus-rpc-yaml-install
-	printf $(COLOR) "Generate nexus/temporal-proto-models-nexusrpc.yaml..."
-	mkdir -p nexus
+##### Compile system Nexus WIT files #####
+system-nexus-wit: system-nexus-wit-install nexus-api-gen-install
+	printf $(COLOR) "Generate system Nexus WIT..."
 	protoc -I $(PROTO_ROOT) \
-		--nexus-rpc-yaml_opt=nexus-rpc_langs_out=nexus/temporal-proto-models-nexusrpc.yaml \
-		--nexus-rpc-yaml_opt=python_package_prefix=temporalio.api \
-		--nexus-rpc-yaml_opt=typescript_package_prefix=@temporalio/api \
-		--nexus-rpc-yaml_opt=include_operation_tags=exposed \
-		--nexus-rpc-yaml_out=. \
-		temporal/api/workflowservice/v1/* \
-		temporal/api/operatorservice/v1/*
-
-nexus-rpc-yaml-install:
-	printf $(COLOR) "Build and install protoc-gen-nexus-rpc-yaml..."
-	@cd cmd/protoc-gen-nexus-rpc-yaml && go install .
+		--system-nexus-wit_opt=output=$(SYSTEM_NEXUS_WIT) \
+		--system-nexus-wit_opt=nexus_api_gen=$(NEXUS_API_GEN) \
+		--system-nexus-wit_out=. \
+		$(SYSTEM_NEXUS_SERVICE_PROTO_FILES)
+
+system-nexus-wit-install:
+	printf $(COLOR) "Build and install protoc-gen-system-nexus-wit..."
+	@cd cmd/protoc-gen-system-nexus-wit && go install .
+
+nexus-api-gen-install:
+	printf $(COLOR) "Install nexus-api-gen if missing..."
+	command -v $(NEXUS_API_GEN) >/dev/null || CARGO_NET_GIT_FETCH_WITH_CLI=true cargo install --git https://github.com/temporalio/nexus-api-gen
 
 ##### Clean #####
 clean:

README.md

@@ -9,6 +9,7 @@ Install as git submodule to the project.
 ## Contribution
 
 Make your change to the temporal/proto files, and run `make` to update the openapi definitions.
+Rust is also required because `make` installs and runs `nexus-api-gen` when regenerating system Nexus WIT files.
 
 ## Breaking changes