Add Cursor Cloud Agent integration

.gitignore

@@ -28,6 +28,8 @@ web/src/sample/
 .mcp.json
 opencode.json
 AGENTS.md
+.worktrees/
+.superpowers/
 
 # Release artifacts
 dist/

cmd/antares/main.go

@@ -763,10 +763,19 @@ func cmdModel(args []string) error {
 		return nil
 	}
 	prevProvider := cfg.Model.Provider
-	cfg.Model.Default = args[0]
+	resultProvider := prevProvider
 	if len(args) > 1 {
-		cfg.Model.Provider = args[1]
+		resultProvider = args[1]
+	}
+	// An agent integration can never become the active chat model — refused
+	// here before any mutation, exactly as /model, the API, and the TUI do.
+	if providers.CapabilityOf(cfg, resultProvider) == providers.CapabilityAgent {
+		return fmt.Errorf(
+			"%s is an agent integration, not a chat model provider; use the cursor_agent tool",
+			resultProvider)
 	}
+	cfg.Model.Default = args[0]
+	cfg.Model.Provider = resultProvider
 	if cfg.Model.Provider != prevProvider {
 		cfg.ClearInlineModelCredentials()
 	} else if p, ok := cfg.Providers[cfg.Model.Provider]; ok &&
@@ -821,6 +830,9 @@ func cmdProvider(args []string) error {
 			return fmt.Errorf("usage: antares provider use <id>")
 		}
 		id := args[1]
+		if providers.CapabilityOf(cfg, id) == providers.CapabilityAgent {
+			return fmt.Errorf("%s is an agent integration, not a chat model provider; use the cursor_agent tool", id)
+		}
 		if !providers.Connected(cfg, id) {
 			return fmt.Errorf("%s is not connected — run `antares provider add %s <api-key>`", id, id)
 		}
@@ -844,6 +856,15 @@ func cmdProvider(args []string) error {
 		if known && info.NeedsKey && key == "" && !providers.Connected(cfg, id) {
 			return fmt.Errorf("%s needs an API key: antares provider add %s <api-key>", info.Label, id)
 		}
+		if providers.CapabilityOf(cfg, id) == providers.CapabilityAgent {
+			providers.Connect(cfg, id, key)
+			if err := config.Save(cfg); err != nil {
+				return err
+			}
+			fmt.Printf("connected %s agent integration; active model remains %s (%s)\n",
+				id, cfg.Model.Default, cfg.Model.Provider)
+			return nil
+		}
 		providers.Activate(cfg, id, key)
 		if err := config.Save(cfg); err != nil {
 			return err

cmd/antares/model_test.go

@@ -0,0 +1,57 @@
+package main
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/enowdev/antares/internal/config"
+)
+
+// `antares model <id> cursor` used to persist an agent integration as the
+// active chat provider, which every other selector already refuses.
+func TestModelCommandRejectsAgentProvider(t *testing.T) {
+	t.Setenv("ANTARES_HOME", t.TempDir())
+	cfg := config.Default()
+	beforeProvider, beforeModel := cfg.Model.Provider, cfg.Model.Default
+	if err := config.Save(cfg); err != nil {
+		t.Fatal(err)
+	}
+
+	err := cmdModel([]string{"claude-sonnet-5", "cursor"})
+	if err == nil || !strings.Contains(err.Error(), "cursor_agent") {
+		t.Fatalf("model set to cursor error = %v, want an agent-integration refusal", err)
+	}
+
+	after, err := config.Reload()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if after.Model.Provider != beforeProvider || after.Model.Default != beforeModel {
+		t.Fatalf("active model changed to %s (%s), want %s (%s)",
+			after.Model.Default, after.Model.Provider, beforeModel, beforeProvider)
+	}
+}
+
+func TestModelCommandStillSwitchesLLMProvider(t *testing.T) {
+	t.Setenv("ANTARES_HOME", t.TempDir())
+	if err := config.Save(config.Default()); err != nil {
+		t.Fatal(err)
+	}
+
+	output := captureProviderStdout(t, func() {
+		if err := cmdModel([]string{"gpt-5", "openai"}); err != nil {
+			t.Fatal(err)
+		}
+	})
+	if !strings.Contains(output, "active model: gpt-5 (openai)") {
+		t.Fatalf("model set output = %q", output)
+	}
+
+	after, err := config.Reload()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if after.Model.Provider != "openai" || after.Model.Default != "gpt-5" {
+		t.Fatalf("active model = %s (%s), want gpt-5 (openai)", after.Model.Default, after.Model.Provider)
+	}
+}

cmd/antares/provider_test.go

@@ -0,0 +1,70 @@
+package main
+
+import (
+	"io"
+	"os"
+	"strings"
+	"testing"
+
+	"github.com/enowdev/antares/internal/config"
+)
+
+func TestProviderAddAndUseCursorPreserveActiveModel(t *testing.T) {
+	t.Setenv("ANTARES_HOME", t.TempDir())
+	cfg := config.Default()
+	beforeProvider, beforeModel := cfg.Model.Provider, cfg.Model.Default
+	if err := config.Save(cfg); err != nil {
+		t.Fatal(err)
+	}
+
+	output := captureProviderStdout(t, func() {
+		if err := cmdProvider([]string{"add", "cursor", "synthetic-key"}); err != nil {
+			t.Fatal(err)
+		}
+	})
+	if !strings.Contains(output, "connected cursor agent integration") {
+		t.Fatalf("add output = %q", output)
+	}
+	connected, err := config.Reload()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if connected.Model.Provider != beforeProvider || connected.Model.Default != beforeModel {
+		t.Fatalf("model changed to %s/%s", connected.Model.Provider, connected.Model.Default)
+	}
+	if p := connected.Providers["cursor"]; !p.Enabled || p.APIKey != "synthetic-key" || p.Kind != "cursor-agent" {
+		t.Fatalf("cursor provider = %+v", p)
+	}
+
+	err = cmdProvider([]string{"use", "cursor"})
+	if err == nil || !strings.Contains(err.Error(), "cursor_agent") {
+		t.Fatalf("use cursor error = %v", err)
+	}
+	afterUse, err := config.Reload()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if afterUse.Model.Provider != beforeProvider || afterUse.Model.Default != beforeModel {
+		t.Fatalf("model changed to %s/%s", afterUse.Model.Provider, afterUse.Model.Default)
+	}
+}
+
+func captureProviderStdout(t *testing.T, f func()) string {
+	t.Helper()
+	old := os.Stdout
+	r, w, err := os.Pipe()
+	if err != nil {
+		t.Fatal(err)
+	}
+	os.Stdout = w
+	t.Cleanup(func() { os.Stdout = old })
+	f()
+	if err := w.Close(); err != nil {
+		t.Fatal(err)
+	}
+	out, err := io.ReadAll(r)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return string(out)
+}

docs/configuration.md

@@ -88,6 +88,29 @@ release. A model family Antares does not recognise defaults to the OpenAI
 format, which is correct for the GLM, Kimi, DeepSeek, MiMo, GPT, Grok and
 Hunyuan families it currently serves.
 
+### Cursor Cloud Agents
+
+Cursor is an agent integration, not a primary Antares model provider. Configure
+the deployment-owned key through the environment:
+
+```yaml
+providers:
+  cursor:
+    kind: cursor-agent
+    base_url: https://api.cursor.com
+    api_key_env: CURSOR_API_KEY
+    enabled: true
+    timeout_seconds: 900
+```
+
+Cursor is a built-in cloud-only agent integration. Existing configuration and
+providers need no migration and retain their current LLM behavior. The default
+Cursor entry is enabled but disconnected; it becomes usable only when Antares
+resolves its key. `CURSOR_API_KEY` works with that entry without writing a key
+to YAML. One deployment key and its quota are shared by every user who can
+invoke the Cursor tools. Repository-backed runs use the repository state
+available to Cursor, so unpushed local changes are not included.
+
 `model.auxiliary` is worth setting. Titles, compaction summaries, verification,
 and goal judging all use it, and a small model does those as well as a large one
 for a fraction of the cost.
@@ -100,6 +123,7 @@ OPENAI_API_KEY=…
 OPENROUTER_API_KEY=…
 OPENCODE_API_KEY=…
 GEMINI_API_KEY=…
+CURSOR_API_KEY=…
 ```
 
 ## Storage