fix(cursor): bake literal runtime env into container mcp.json (was ${env:}, broke in webterminal)

The container adapter's ~/.cursor/mcp.json forwarded ZCP_API_KEY +
serviceId/hostname/projectId via Cursor's ${env:NAME} substitution,
which resolves against cursor-agent's OWN launch environment. Some real
launch contexts lack the zembed vars: live-confirmed 2026-07-03 that the
Zerops webterminal launches cursor-agent without them, so
${env:ZCP_API_KEY} resolved empty and zcp serve closed the MCP
connection at startup — "MCP error -32000: Connection closed", 0 tools
in the interactive TUI. Earlier SSH-based verification passed only
because SSH shells DO carry the vars, masking the bug.

Fix (grok-parity): bake the resolved LITERAL values at init —
serviceId/hostname/projectId from runtime.Info, ZCP_API_KEY from the
init process env, each omitted when empty. This makes the MCP server
independent of cursor-agent's launch env. Cursor was the only adapter
depending on the agent's launch env for these vars (grok already bakes
literals).

Proven live: env -i HOME PATH cursor-agent mcp list-tools zerops →
literal-baked file enumerates 22 tools (incl. the three container-only
ones), the ${env:} file fails "Connection closed"; the real fixed
`zcp init` writes literals and works in the stripped env.

Pinned by TestCursor_MCPEntry_BakesLiteralRuntimeEnv (replaces
TestCursor_MCPEntry_EnvForwardsRuntimeDetectionVars) +
TestCursor_MCPEntry_OmitsEmptyEnvVars.

Author: krls2020

internal/init/adapters/cursor.go

@@ -2,9 +2,12 @@ package adapters
 
 import (
 	"fmt"
+	"os"
 	"path/filepath"
 	"strings"
 	"time"
+
+	"github.com/zeropsio/zcp/internal/runtime"
 )
 
 // Cursor implements Adapter for the Cursor IDE's headless CLI
@@ -135,7 +138,7 @@ func (Cursor) ContainerInit(env Env) error {
 	if err != nil {
 		return fmt.Errorf("load %s: %w", configPath, err)
 	}
-	UpsertPath(data, cursorMCPServerEntry(), "mcpServers", "zerops")
+	UpsertPath(data, cursorMCPServerEntry(env.RT), "mcpServers", "zerops")
 	if err := SaveJSONFile(configPath, data); err != nil {
 		return fmt.Errorf("write %s: %w", configPath, err)
 	}
@@ -176,35 +179,49 @@ func cursorWorkspaceDir(workspacePath string) string {
 //   - type=stdio is required by Cursor's schema (distinguishes from
 //     SSE / streamable HTTP transports).
 //   - command + args invoke `zcp serve` via the stdio transport.
-//   - env uses Cursor's "${env:NAME}" substitution syntax to forward
-//     the four vars the zcp serve subprocess needs from the Cursor
-//     process env. This is REQUIRED because Cursor spawns the MCP
-//     subprocess with a STRIPPED env (verified empirically 2026-05-24
-//     by wrapping zcp serve with a logger — Cursor passed only
-//     HOME/USER/PATH to the subprocess).
+//   - env forwards the four vars the zcp serve subprocess needs. This is
+//     REQUIRED because Cursor spawns the MCP subprocess with a STRIPPED
+//     env (verified 2026-05-24 by wrapping zcp serve with a logger —
+//     Cursor passed only HOME/USER/PATH). Without them, zcp serve sees
+//     runtime.Detect returning InContainer=false (skipping the three
+//     container-only tools) and, worse, a missing ZCP_API_KEY makes
+//     zcp serve close the connection at startup ("MCP error -32000:
+//     Connection closed").
 //
-// Without this env block, zcp serve sees serviceId="" → runtime.Detect
-// returns InContainer=false → server.go skips three container-only
-// tools (zerops_browser gated on InContainer, zerops_dev_server and
-// zerops_deploy_batch gated on sshDeployer != nil which only initializes
-// in container mode). Plus ZCP_API_KEY is missing → API calls fail
-// auth.
+// The values are baked as RESOLVED LITERALS (grok-parity), NOT Cursor's
+// "${env:NAME}" substitution. "${env:NAME}" resolves against
+// CURSOR-AGENT's OWN launch env at spawn time — which some real launch
+// contexts lack: live-confirmed 2026-07-03 that the Zerops webterminal
+// launches cursor-agent WITHOUT the zembed vars, so
+// "${env:ZCP_API_KEY}" resolved empty and every MCP call failed with
+// "Connection closed" (while an SSH shell, which does carry the vars,
+// worked — masking the bug in earlier verification). Baking the value
+// the init process already holds makes the server independent of the
+// launch env, exactly as grokMCPServerEntry does.
 //
-// Same bug class as Codex (commit 07a2044a) — restrictive env
-// pass-through requires explicit enumeration. Cursor's mechanism
-// (env-value substitution via "${env:NAME}") differs from Codex's
-// (env_vars allowlist) but the structural fix is the same: name every
-// var zcp serve reads at startup.
-func cursorMCPServerEntry() map[string]any {
+// serviceId/hostname/projectId come from rt (resolved by runtime.Detect
+// at init); ZCP_API_KEY from the init process env (same pattern as
+// grok's os.Getenv read). Each is omitted when empty so no phantom blank
+// value lands in the config.
+func cursorMCPServerEntry(rt runtime.Info) map[string]any {
+	serverEnv := map[string]any{}
+	if rt.ServiceID != "" {
+		serverEnv["serviceId"] = rt.ServiceID
+	}
+	if rt.ServiceName != "" {
+		serverEnv["hostname"] = rt.ServiceName
+	}
+	if rt.ProjectID != "" {
+		serverEnv["projectId"] = rt.ProjectID
+	}
+	if key := strings.TrimSpace(os.Getenv("ZCP_API_KEY")); key != "" {
+		serverEnv["ZCP_API_KEY"] = key
+	}
+
 	return map[string]any{
 		"type":    "stdio",
 		"command": "zcp",
 		"args":    []any{"serve"},
-		"env": map[string]any{
-			"ZCP_API_KEY": "${env:ZCP_API_KEY}",
-			"serviceId":   "${env:serviceId}",
-			"hostname":    "${env:hostname}",
-			"projectId":   "${env:projectId}",
-		},
+		"env":     serverEnv,
 	}
 }

internal/init/adapters/cursor_test.go

@@ -365,23 +365,29 @@ func TestCursor_ContainerInit_EmptyHomeReturnsError(t *testing.T) {
 	}
 }
 
-// TestCursor_MCPEntry_EnvForwardsRuntimeDetectionVars pins the env
-// block contract — Cursor RESTRICTS the spawned MCP subprocess's env
-// (verified 2026-05-24 by wrapping zcp serve with a logger; Cursor
-// passed only HOME/USER/PATH). Without explicit forwarding of
-// ZCP_API_KEY + serviceId + hostname + projectId, zcp serve sees
-// runtime.Detect returning InContainer=false and 3 tools fail to
-// register (zerops_browser, zerops_dev_server, zerops_deploy_batch).
-// Pin guards against well-meaning "drop the env block, it's redundant"
-// edits — same bug class as Codex commit 07a2044a's env_vars fix.
+// TestCursor_MCPEntry_BakesLiteralRuntimeEnv pins the env block
+// contract — Cursor RESTRICTS the spawned MCP subprocess's env (verified
+// 2026-05-24 by wrapping zcp serve with a logger; Cursor passed only
+// HOME/USER/PATH). Without explicit forwarding of ZCP_API_KEY +
+// serviceId + hostname + projectId, zcp serve sees runtime.Detect
+// returning InContainer=false / loses API auth.
 //
-// "${env:NAME}" is Cursor's documented substitution syntax — value
-// resolves to the named var from Cursor's calling-process env at
-// subprocess spawn time.
-func TestCursor_MCPEntry_EnvForwardsRuntimeDetectionVars(t *testing.T) {
-	t.Parallel()
+// The values are baked as RESOLVED LITERALS (grok-parity), NOT Cursor's
+// "${env:NAME}" substitution. "${env:NAME}" resolves against
+// CURSOR-AGENT's own launch env — which some real launch contexts lack
+// (live-confirmed 2026-07-03: the Zerops webterminal launches
+// cursor-agent without the zembed vars, so "${env:ZCP_API_KEY}"
+// resolved empty and zcp serve closed the MCP connection — "MCP error
+// -32000: Connection closed"). Baking the value the init process already
+// holds makes the server independent of the launch env. Pin guards
+// against a regression back to "${env:...}".
+func TestCursor_MCPEntry_BakesLiteralRuntimeEnv(t *testing.T) {
+	// Not parallel — sets ZCP_API_KEY so the literal assertion is deterministic.
 	home := t.TempDir()
 	env := newCursorEnv(t, home)
+	env.RT = runtime.Info{InContainer: true, ServiceID: "svc-123", ServiceName: "appdev", ProjectID: "proj-456"}
+	t.Setenv("ZCP_API_KEY", "secret-key-value")
+
 	if err := adapters.NewCursor().ContainerInit(env); err != nil {
 		t.Fatal(err)
 	}
@@ -392,18 +398,15 @@ func TestCursor_MCPEntry_EnvForwardsRuntimeDetectionVars(t *testing.T) {
 	if !ok {
 		t.Fatalf("mcpServers.zerops.env missing or wrong shape; got %v (type %T)", zerops["env"], zerops["env"])
 	}
-
-	required := []string{"ZCP_API_KEY", "serviceId", "hostname", "projectId"}
-	for _, name := range required {
-		v, has := envMap[name]
-		if !has {
-			t.Errorf("env.%s missing — without it Cursor's restrictive subprocess env strips this var and zcp serve loses runtime detection / auth", name)
-			continue
-		}
-		s, _ := v.(string)
-		want := "${env:" + name + "}"
-		if s != want {
-			t.Errorf("env.%s = %q, want %q (Cursor's documented substitution syntax)", name, s, want)
+	want := map[string]string{
+		"serviceId":   "svc-123",
+		"hostname":    "appdev",
+		"projectId":   "proj-456",
+		"ZCP_API_KEY": "secret-key-value",
+	}
+	for k, v := range want {
+		if envMap[k] != v {
+			t.Errorf("env.%s = %v, want %q (literal value — must not interpolate: launch env may lack the var)", k, envMap[k], v)
 		}
 	}
 
@@ -415,6 +418,30 @@ func TestCursor_MCPEntry_EnvForwardsRuntimeDetectionVars(t *testing.T) {
 	}
 }
 
+// TestCursor_MCPEntry_OmitsEmptyEnvVars pins that env keys are omitted
+// (not written blank) when unresolved — a blank ZCP_API_KEY/serviceId is
+// worse than absent (it shadows nothing but reads as a phantom value).
+// Grok-parity (TestGrok_MCPEntry_OmitsAPIKeyWhenUnset).
+func TestCursor_MCPEntry_OmitsEmptyEnvVars(t *testing.T) {
+	// Not parallel — clears ZCP_API_KEY.
+	home := t.TempDir()
+	env := newCursorEnv(t, home)
+	env.RT = runtime.Info{InContainer: true} // no ServiceID/Name/ProjectID
+	t.Setenv("ZCP_API_KEY", "")
+
+	if err := adapters.NewCursor().ContainerInit(env); err != nil {
+		t.Fatal(err)
+	}
+	config := loadCursorJSON(t, home)
+	zerops := config["mcpServers"].(map[string]any)["zerops"].(map[string]any)
+	envMap, _ := zerops["env"].(map[string]any)
+	for _, k := range []string{"ZCP_API_KEY", "serviceId", "hostname", "projectId"} {
+		if _, present := envMap[k]; present {
+			t.Errorf("env.%s present but should be omitted when unresolved; got %v", k, envMap[k])
+		}
+	}
+}
+
 // TestCursor_MCPEntry_TypeStdioRequired pins the `type=stdio` field —
 // Cursor's schema requires explicit transport type to distinguish from
 // SSE / Streamable HTTP. Omitting type would either default to remote