diff --git a/internal/generate/compose.go b/internal/generate/compose.go
index bad302e..267208c 100644
--- a/internal/generate/compose.go
+++ b/internal/generate/compose.go
@@ -97,6 +97,26 @@ func buildProjectService(res *graphResolver, m *config.Model, project, service s
 	if exp := exposeList(svc.Ports); len(exp) > 0 {
 		out["expose"] = exp
 	}
+
+	// spec 10 — a service-declared healthcheck overrides any template default and
+	// is lowered to a Compose-native healthcheck: block.
+	if svc.Healthcheck != nil {
+		hc, err := healthcheckBlock(svc.Healthcheck)
+		if err != nil {
+			return nil, fmt.Errorf("project %q service %q healthcheck: %w", project, service, err)
+		}
+		out["healthcheck"] = hc
+	}
+	// spec 10 — intra-project dependsOn → compose depends_on (cross-project edges
+	// are gated tool-side by the up saga, not expressible in compose).
+	dep, err := dependsOnBlock(m, project, svc.DependsOn)
+	if err != nil {
+		return nil, err
+	}
+	if len(dep) > 0 {
+		out["depends_on"] = dep
+	}
+
 	// NOTE: service-level compose `profiles:` are deliberately NOT emitted in M1.
 	// Compose disables a profiled service unless its profile is active, which would
 	// drop it from the generated document and from a plain `up`. Profile membership
diff --git a/internal/generate/health.go b/internal/generate/health.go
new file mode 100644
index 0000000..facb99f
--- /dev/null
+++ b/internal/generate/health.go
@@ -0,0 +1,169 @@
+package generate
+
+import (
+	"fmt"
+	"strconv"
+
+	"github.com/open-source-cloud/devstack/internal/config"
+)
+
+// This file lowers spec-10 readiness config into the generated compose document:
+// a service's `healthcheck:` block (the Compose-native, in-container probe) and
+// its intra-project `dependsOn` → compose `depends_on: { dep: { condition } }`.
+//
+// CROSS-project edges (shared services, or another project's service) are NOT
+// lowered here: compose `depends_on` cannot reference a service in a different
+// compose project, so those are gated tool-side by the up saga's health poll
+// (internal/health, spec 10 §two-enforcement-layers). The richer generate-time
+// validation ("condition: healthy ⇒ the target declares a healthcheck", with
+// file:line:col) is X2; here compose-go's own consistency check is the backstop.
+
+// healthcheckBlock lowers a config.Healthcheck into a Compose-native healthcheck
+// map. Timing fields are emitted only when set (compose applies its own defaults
+// otherwise); the result is deterministic for a given input.
+func healthcheckBlock(hc *config.Healthcheck) (map[string]any, error) {
+	test, err := healthcheckTest(hc)
+	if err != nil {
+		return nil, err
+	}
+	out := map[string]any{"test": test}
+	if hc.Interval != "" {
+		out["interval"] = hc.Interval
+	}
+	if hc.Timeout != "" {
+		out["timeout"] = hc.Timeout
+	}
+	if hc.Retries > 0 {
+		out["retries"] = hc.Retries
+	}
+	if hc.StartPeriod != "" {
+		out["start_period"] = hc.StartPeriod
+	}
+	return out, nil
+}
+
+// healthcheckTest lowers a healthcheck kind to a compose `test` directive (spec
+// 10 §kinds). The probe runs IN-CONTAINER (Compose owns it), so it relies on the
+// image carrying the relevant client (curl / pg_isready / redis-cli / nc).
+func healthcheckTest(hc *config.Healthcheck) ([]any, error) {
+	switch hc.Kind {
+	case "tcp":
+		if hc.Port == 0 {
+			return nil, fmt.Errorf("kind tcp requires a port")
+		}
+		return cmdShell(fmt.Sprintf("nc -z localhost %d", hc.Port)), nil
+	case "http", "https":
+		host := hc.Host
+		if host == "" {
+			host = "localhost"
+		}
+		path := hc.Path
+		if path == "" {
+			path = "/"
+		}
+		url := hc.Kind + "://" + host
+		if hc.Port != 0 {
+			url = fmt.Sprintf("%s://%s:%d", hc.Kind, host, hc.Port)
+		}
+		url += path
+		args := []any{"CMD", "curl", "-fsS"}
+		if hc.Kind == "https" {
+			args = append(args, "-k") // local CA: skip-verify (spec 10)
+		}
+		args = append(args, "-o", "/dev/null", url)
+		return args, nil
+	case "exec":
+		if len(hc.Command) == 0 {
+			return nil, fmt.Errorf("kind exec requires a command")
+		}
+		out := make([]any, 0, len(hc.Command)+1)
+		out = append(out, "CMD")
+		for _, c := range hc.Command {
+			out = append(out, c)
+		}
+		return out, nil
+	case "pg_isready":
+		port := hc.Port
+		if port == 0 {
+			port = 5432
+		}
+		user := hc.User
+		if user == "" {
+			user = "postgres"
+		}
+		cmd := fmt.Sprintf("pg_isready -p %d -U %s", port, user)
+		if hc.DB != "" {
+			cmd += " -d " + hc.DB
+		}
+		return cmdShell(cmd), nil
+	case "redis":
+		port := hc.Port
+		if port == 0 {
+			port = 6379
+		}
+		cmd := "redis-cli -p " + strconv.Itoa(port)
+		// A secret:// auth ref must never be written to the generated file (§7.5):
+		// redis-cli reads $REDISCLI_AUTH from the container env, so we omit -a and
+		// rely on that. Only a plain (already-committed) literal is embedded.
+		if hc.Auth != "" && !isSecretRef(hc.Auth) {
+			cmd += " -a " + hc.Auth
+		}
+		cmd += " PING"
+		return cmdShell(cmd), nil
+	default:
+		// config validation restricts kind to the oneof set; defensive only.
+		return nil, fmt.Errorf("unknown healthcheck kind %q", hc.Kind)
+	}
+}
+
+func cmdShell(s string) []any { return []any{"CMD-SHELL", s} }
+
+// isSecretRef reports whether a value is a secret:// reference (resolved later by
+// internal/secrets, never embedded in a generated file).
+func isSecretRef(s string) bool { return len(s) >= 9 && s[:9] == "secret://" }
+
+// dependsOnBlock lowers a service's INTRA-project dependsOn edges to a compose
+// `depends_on` map. Cross-project edges (shared, or another project) are skipped
+// (the saga's tool-side poll handles them). An intra-project target that does not
+// exist in the project is a generate error with context.
+func dependsOnBlock(m *config.Model, project string, deps []config.DependsOn) (map[string]any, error) {
+	if len(deps) == 0 {
+		return nil, nil
+	}
+	proj := m.Projects[project]
+	out := map[string]any{}
+	for _, d := range deps {
+		target, intra := intraProjectTarget(project, d.Service)
+		if !intra {
+			continue // cross-project: gated tool-side, not via compose
+		}
+		if _, ok := proj.Services[target]; !ok {
+			return nil, fmt.Errorf("project %q: dependsOn target %q is not a service in this project", project, d.Service)
+		}
+		cond := "service_healthy"
+		if d.Condition == "started" {
+			cond = "service_started"
+		}
+		out[target] = map[string]any{"condition": cond}
+	}
+	if len(out) == 0 {
+		return nil, nil
+	}
+	return out, nil
+}
+
+// intraProjectTarget classifies a dependsOn target. It returns the bare service
+// name and true when the target is in THIS compose project: a bare service name,
+// or workspace.<project>.<service> with project == current. Shared refs and other
+// projects' services return intra=false.
+func intraProjectTarget(project, target string) (string, bool) {
+	ref, ok := config.ParseRef(target)
+	if !ok {
+		// Not a dotted reference → a bare intra-project service name.
+		return target, true
+	}
+	if ref.Kind == config.RefService && ref.Project == project {
+		return ref.Name, true
+	}
+	return "", false
+}
diff --git a/internal/generate/health_test.go b/internal/generate/health_test.go
new file mode 100644
index 0000000..5774560
--- /dev/null
+++ b/internal/generate/health_test.go
@@ -0,0 +1,163 @@
+package generate
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/open-source-cloud/devstack/internal/config"
+	"github.com/open-source-cloud/devstack/internal/template"
+	"github.com/open-source-cloud/devstack/templates"
+)
+
+func TestHealthcheckTestKinds(t *testing.T) {
+	cases := []struct {
+		name string
+		hc   config.Healthcheck
+		want []any
+	}{
+		{"tcp", config.Healthcheck{Kind: "tcp", Port: 5432},
+			[]any{"CMD-SHELL", "nc -z localhost 5432"}},
+		{"http", config.Healthcheck{Kind: "http", Port: 8080, Path: "/healthz"},
+			[]any{"CMD", "curl", "-fsS", "-o", "/dev/null", "http://localhost:8080/healthz"}},
+		{"https-skipverify", config.Healthcheck{Kind: "https", Port: 443, Path: "/"},
+			[]any{"CMD", "curl", "-fsS", "-k", "-o", "/dev/null", "https://localhost:443/"}},
+		{"exec", config.Healthcheck{Kind: "exec", Command: []string{"mysqladmin", "ping"}},
+			[]any{"CMD", "mysqladmin", "ping"}},
+		{"pg_isready", config.Healthcheck{Kind: "pg_isready", User: "app", DB: "appdb"},
+			[]any{"CMD-SHELL", "pg_isready -p 5432 -U app -d appdb"}},
+		{"redis-default", config.Healthcheck{Kind: "redis"},
+			[]any{"CMD-SHELL", "redis-cli -p 6379 PING"}},
+		{"redis-literal-auth", config.Healthcheck{Kind: "redis", Auth: "devpass"},
+			[]any{"CMD-SHELL", "redis-cli -p 6379 -a devpass PING"}},
+		{"redis-secret-auth-omitted", config.Healthcheck{Kind: "redis", Auth: "secret://vault/redis#pw"},
+			[]any{"CMD-SHELL", "redis-cli -p 6379 PING"}},
+	}
+	for _, c := range cases {
+		t.Run(c.name, func(t *testing.T) {
+			got, err := healthcheckTest(&c.hc)
+			if err != nil {
+				t.Fatal(err)
+			}
+			if fmt.Sprint(got) != fmt.Sprint(c.want) {
+				t.Errorf("test = %v, want %v", got, c.want)
+			}
+		})
+	}
+}
+
+func TestHealthcheckTestErrors(t *testing.T) {
+	for _, hc := range []config.Healthcheck{
+		{Kind: "tcp"},  // no port
+		{Kind: "exec"}, // no command
+	} {
+		if _, err := healthcheckTest(&hc); err == nil {
+			t.Errorf("kind %q with missing params should error", hc.Kind)
+		}
+	}
+}
+
+func TestHealthcheckBlockTimingOnlyWhenSet(t *testing.T) {
+	// Only the test is present when timing is unset.
+	bare, _ := healthcheckBlock(&config.Healthcheck{Kind: "tcp", Port: 1})
+	if len(bare) != 1 {
+		t.Errorf("bare block = %v, want only test", bare)
+	}
+	full, _ := healthcheckBlock(&config.Healthcheck{
+		Kind: "tcp", Port: 1, Interval: "5s", Timeout: "3s", Retries: 7, StartPeriod: "20s",
+	})
+	for _, k := range []string{"test", "interval", "timeout", "retries", "start_period"} {
+		if _, ok := full[k]; !ok {
+			t.Errorf("full block missing %q: %v", k, full)
+		}
+	}
+}
+
+func TestDependsOnBlockClassification(t *testing.T) {
+	m := &config.Model{Projects: map[string]config.Project{
+		"api": {Services: map[string]config.Service{
+			"web":   {Template: "t"},
+			"cache": {Template: "t"},
+		}},
+	}}
+	deps := []config.DependsOn{
+		{Service: "cache", Condition: "healthy"},                     // intra (bare)
+		{Service: "workspace.api.web", Condition: "started"},         // intra (qualified)
+		{Service: "workspace.shared.postgres", Condition: "healthy"}, // shared → skip
+		{Service: "workspace.other.svc", Condition: "healthy"},       // other project → skip
+	}
+	got, err := dependsOnBlock(m, "api", deps)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(got) != 2 {
+		t.Fatalf("depends_on = %v, want 2 intra-project edges", got)
+	}
+	if got["cache"].(map[string]any)["condition"] != "service_healthy" {
+		t.Errorf("cache condition = %v, want service_healthy", got["cache"])
+	}
+	if got["web"].(map[string]any)["condition"] != "service_started" {
+		t.Errorf("web condition = %v, want service_started", got["web"])
+	}
+}
+
+func TestDependsOnBlockMissingTarget(t *testing.T) {
+	m := &config.Model{Projects: map[string]config.Project{
+		"api": {Services: map[string]config.Service{"web": {Template: "t"}}},
+	}}
+	_, err := dependsOnBlock(m, "api", []config.DependsOn{{Service: "ghost"}})
+	if err == nil || !strings.Contains(err.Error(), "ghost") {
+		t.Fatalf("want a missing-target error naming ghost, got %v", err)
+	}
+}
+
+// TestIntraProjectDependsOn_EndToEnd generates a real project where one service
+// depends on a sibling (condition healthy) and the sibling declares a
+// healthcheck, asserting the lowering reaches compose AND compose-go accepts the
+// service_healthy edge.
+func TestIntraProjectDependsOn_EndToEnd(t *testing.T) {
+	root := t.TempDir()
+	write := func(rel, body string) {
+		p := filepath.Join(root, rel)
+		if err := os.MkdirAll(filepath.Dir(p), 0o755); err != nil {
+			t.Fatal(err)
+		}
+		if err := os.WriteFile(p, []byte(body), 0o644); err != nil {
+			t.Fatal(err)
+		}
+	}
+	write("workspace.yaml", "apiVersion: devstack/v1\nkind: Workspace\nname: demo\nprojects:\n  - { name: app, path: app }\n")
+	write("app/devstack.yaml", `apiVersion: devstack/v1
+kind: Project
+name: app
+services:
+  cache:
+    template: node.vite
+    healthcheck: { kind: tcp, port: 6379, interval: 2s }
+  web:
+    template: node.vite
+    dependsOn:
+      - { service: cache, condition: healthy }
+`)
+	m, err := config.LoadAt(root)
+	if err != nil {
+		t.Fatalf("load: %v", err)
+	}
+	g, err := New(m, template.NewFSSource(templates.FS), WithEnv(map[string]string{}))
+	if err != nil {
+		t.Fatalf("New: %v", err)
+	}
+	st, err := g.GenerateProject("app")
+	if err != nil {
+		t.Fatalf("GenerateProject: %v", err)
+	}
+	compose := string(st.Compose)
+	if !strings.Contains(compose, "depends_on:") || !strings.Contains(compose, "condition: service_healthy") {
+		t.Errorf("compose missing lowered depends_on:\n%s", compose)
+	}
+	if !strings.Contains(compose, "cache") {
+		t.Errorf("compose should reference the cache dependency:\n%s", compose)
+	}
+}
diff --git a/internal/generate/testdata/golden/devstack-api.docker-compose.yaml b/internal/generate/testdata/golden/devstack-api.docker-compose.yaml
index 44c8283..db375d3 100644
--- a/internal/generate/testdata/golden/devstack-api.docker-compose.yaml
+++ b/internal/generate/testdata/golden/devstack-api.docker-compose.yaml
@@ -23,6 +23,18 @@ services:
       XDEBUG_MODE: "off"
     expose:
       - "8080"
+    healthcheck:
+      test:
+        - CMD
+        - curl
+        - -fsS
+        - -o
+        - /dev/null
+        - http://localhost:8080/healthz
+      timeout: 3s
+      interval: 5s
+      retries: 12
+      start_period: 20s
     labels:
       com.devstack.managed: "true"
       com.devstack.project: api