diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 0284c3e84..51b08a039 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -317,6 +317,48 @@ jobs:
             echo "::warning::Coverage is below 80% (current: ${coverage}%)"
           fi
 
+  mcp-build:
+    name: Build MCP (${{ matrix.os }})
+    runs-on: ${{ matrix.os }}
+    permissions:
+      contents: read
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - os: ubuntu-latest
+            binary_format: ELF
+          - os: macos-latest
+            binary_format: Mach-O
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5.0.1
+        with:
+          persist-credentials: false
+
+      - name: Set up Go
+        uses: actions/setup-go@4a3601121dd01d1626a1e23e37211e3254c1c06c # v6.4.0
+        with:
+          go-version: ${{ env.GO_VERSION }}
+          cache: true
+
+      - name: Assert MCP artifact is absent
+        run: test ! -e bin/cudly-mcp
+
+      - name: Build MCP
+        run: make build-mcp VERSION=v0.0.0-version-test
+
+      - name: Assert host-native binary format
+        run: file bin/cudly-mcp | grep -F '${{ matrix.binary_format }}'
+
+      - name: Verify Make-built MCP version
+        env:
+          CUDLY_MCP_TEST_BINARY: ${{ github.workspace }}/bin/cudly-mcp
+        run: go test ./cmd/cudly-mcp -run '^TestBuiltBinaryReportsInjectedVersion$' -count=1
+
+      - name: Assert clean target includes MCP artifact
+        run: make -n clean | grep -Fx 'rm -f cudly bootstrap bin/cudly-server bin/cudly-mcp'
+
   # Integration tests with real PostgreSQL
   integration-tests:
     name: Integration Tests
@@ -1023,6 +1065,7 @@ jobs:
       - lint
       - workflow-lint
       - unit-tests
+      - mcp-build
       - integration-tests
       - docker-build
       - terraform-validate
diff --git a/Makefile b/Makefile
index e34ce114e..fbc0d39c4 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,4 @@
-.PHONY: build clean test deploy help all build-server build-lambda test-unit test-integration \
+.PHONY: build clean test deploy help all build-server build-lambda build-mcp test-unit test-integration \
         test-coverage full-test security-scan terraform-validate docker-build \
         fmt vet lint complexity complexity-report security-scan-go security-scan-docker \
         security-scan-terraform terraform-fmt terraform-fmt-check iac-arm docker-test pre-commit \
@@ -30,6 +30,7 @@ help: ## Display available targets
 	@echo "  build              - Build the CLI"
 	@echo "  build-server       - Build the unified server"
 	@echo "  build-lambda       - Build for AWS Lambda"
+	@echo "  build-mcp          - Build the MCP server (cmd/cudly-mcp)"
 	@echo "  test               - Run all unit tests"
 	@echo "  test-unit          - Run unit tests only"
 	@echo "  test-integration   - Run integration tests with testcontainers"
@@ -59,6 +60,13 @@ build-server:
 build-lambda:
 	CGO_ENABLED=0 GOOS=linux GOARCH=arm64 go build -ldflags="-s -w" -o bootstrap ./cmd/lambda
 
+# Build the MCP server (see mcp/README.md). Uses the same $(LDFLAGS)/$(VERSION)
+# as build-server so a tagged release reports its version in the MCP
+# initialize response instead of "dev" (see cmd/cudly-mcp/main.go).
+build-mcp:
+	mkdir -p bin
+	CGO_ENABLED=0 go build $(LDFLAGS) -o bin/cudly-mcp ./cmd/cudly-mcp
+
 # Run unit tests
 test: test-unit
 
@@ -84,7 +92,7 @@ full-test: test-unit test-integration test-coverage
 
 # Clean build artifacts
 clean:
-	rm -f cudly bootstrap bin/cudly-server
+	rm -f cudly bootstrap bin/cudly-server bin/cudly-mcp
 	rm -f coverage.out coverage.html
 	rm -f gosec-report.json trivy-report.json tfsec-report.json
 	go clean
diff --git a/cmd/cudly-mcp/main.go b/cmd/cudly-mcp/main.go
index fde741f11..3d5a4d2c8 100644
--- a/cmd/cudly-mcp/main.go
+++ b/cmd/cudly-mcp/main.go
@@ -20,13 +20,17 @@ import (
 	_ "github.com/LeanerCloud/CUDly/providers/gcp"
 )
 
-// version is overridable at build time via:
+// Version is overridable at build time via:
 //
-//	go build -ldflags "-X main.version=1.2.3" ./cmd/cudly-mcp
-var version = "dev"
+//	go build -ldflags "-X main.Version=1.2.3" ./cmd/cudly-mcp
+//
+// `make build-mcp` sets it from the same $(LDFLAGS)/$(VERSION) the other
+// binaries (build-server, ...) use, so a release build's tag flows through to
+// the MCP initialize response's Implementation.Version.
+var Version = "dev"
 
 func main() {
-	server, err := cudlymcp.NewServer(version)
+	server, err := cudlymcp.NewServer(Version)
 	if err != nil {
 		log.Fatalf("cudly-mcp: failed to build server: %v", err)
 	}
diff --git a/cmd/cudly-mcp/version_test.go b/cmd/cudly-mcp/version_test.go
new file mode 100644
index 000000000..8f50688af
--- /dev/null
+++ b/cmd/cudly-mcp/version_test.go
@@ -0,0 +1,52 @@
+package main
+
+// Linker injection is exercised only by building and running a subprocess.
+
+import (
+	"context"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"testing"
+	"time"
+
+	gosdk "github.com/modelcontextprotocol/go-sdk/mcp"
+	"github.com/stretchr/testify/require"
+)
+
+const (
+	buildTimeout        = 5 * time.Minute
+	runTimeout          = 15 * time.Second
+	injectedTestVersion = "v0.0.0-version-test"
+)
+
+func TestBuiltBinaryReportsInjectedVersion(t *testing.T) {
+	binPath := os.Getenv("CUDLY_MCP_TEST_BINARY")
+	if binPath == "" {
+		binPath = filepath.Join(t.TempDir(), "cudly-mcp")
+		ctx, cancel := context.WithTimeout(context.Background(), buildTimeout)
+		defer cancel()
+
+		cmd := exec.CommandContext(ctx, "go", "build",
+			"-ldflags", "-X main.Version="+injectedTestVersion,
+			"-o", binPath, ".")
+		cmd.Dir = "."
+		out, err := cmd.CombinedOutput()
+		require.NoErrorf(t, err, "build cmd/cudly-mcp with version ldflags:\n%s", out)
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), runTimeout)
+	defer cancel()
+
+	transport := &gosdk.CommandTransport{Command: exec.CommandContext(ctx, binPath)}
+	client := gosdk.NewClient(&gosdk.Implementation{Name: "version-test-client"}, nil)
+	session, err := client.Connect(ctx, transport, nil)
+	require.NoError(t, err, "connect to the built binary over stdio")
+	defer session.Close()
+
+	result := session.InitializeResult()
+	require.NotNil(t, result, "InitializeResult")
+	require.NotNil(t, result.ServerInfo, "InitializeResult.ServerInfo")
+	require.Equal(t, injectedTestVersion, result.ServerInfo.Version,
+		"built binary must report the injected version")
+}
diff --git a/mcp/README.md b/mcp/README.md
index ea6fc3178..fedf5cf58 100644
--- a/mcp/README.md
+++ b/mcp/README.md
@@ -84,6 +84,22 @@ Add an entry to your client's MCP server config. For Claude Code, this is `~/.cl
 
 `env` is optional -- omit it entirely to rely on whatever ambient credentials are already active in the shell that launches the client, or set only the provider(s) you actually use.
 
+## Use with OpenAI Codex CLI
+
+Codex CLI reads MCP server definitions from `~/.codex/config.toml`, under a `[mcp_servers.<name>]` table -- same `command`/`args`/`env` shape as Claude Code's `mcpServers` JSON, different file format. A project-scoped `.codex/config.toml` works the same way, but only if you have marked that project directory as trusted in Codex CLI -- an untrusted project's `.codex/` layer is silently ignored, so if `cudly` doesn't show up, register it in `~/.codex/config.toml` instead (or trust the project).
+
+```toml
+[mcp_servers.cudly]
+command = "/absolute/path/to/cudly-mcp"
+args = []
+
+[mcp_servers.cudly.env]
+AWS_PROFILE = "my-aws-profile"
+AZURE_SUBSCRIPTION_ID = "00000000-0000-0000-0000-000000000000"
+```
+
+`CUDLY_MCP_ENABLE_REAL_PURCHASES` is deliberately omitted from this example -- leave it unset until you have exercised the dry-run path against this client and are ready to let it spend money; see [Safety model](#safety-model).
+
 ## Worked example
 
 A typical session searches for a recommendation, previews the purchase, then executes it: