Add xAI Grok as a provider (#46)

Co-authored-by: dev_agent <dev_agent@cubecraftlabs.com>
Co-committed-by: dev_agent <dev_agent@cubecraftlabs.com>

internal/ai/llm/presets/presets.go

@@ -145,6 +145,15 @@ var all = map[string]Preset{
 		StructuredOutputs:        []openai.StructuredOutput{openai.JSONSchema, openai.JSONObject},
 		OmitTemperature:          []*regexp.Regexp{openRouterReasoningModels},
 	},
+	"xai": {
+		Name:                     "xai",
+		Adapter:                  AdapterOpenAI,
+		BaseURL:                  "https://api.x.ai/v1",
+		Key:                      KeyRequired,
+		StructuredOutput:         openai.JSONSchema,
+		FallbackStructuredOutput: openai.JSONObject,
+		StructuredOutputs:        []openai.StructuredOutput{openai.JSONSchema, openai.JSONObject},
+	},
 	"ollama": {
 		Name:    "ollama",
 		Adapter: AdapterOllama,

internal/ai/llm/presets/presets_test.go

@@ -180,6 +180,43 @@ func TestOpenRouterFallbackModeIsJSONObject(t *testing.T) {
 	}
 }
 
+func TestXAIPreset(t *testing.T) {
+	c := generate(t, llm.Settings{Provider: "xai", Model: "grok-4", Temperature: 0.6}, testKey, schemaRequest())
+	if c.url != "https://api.x.ai/v1/chat/completions" {
+		t.Fatalf("URL = %q", c.url)
+	}
+	if got := c.header.Get("Authorization"); got != "Bearer "+testKey {
+		t.Fatalf("Authorization = %q", got)
+	}
+	for _, h := range []string{"X-Api-Key", "HTTP-Referer", "X-Title"} {
+		if got := c.header.Get(h); got != "" {
+			t.Fatalf("%s = %q, want none", h, got)
+		}
+	}
+	if got := responseFormatType(t, c); got != "json_schema" {
+		t.Fatalf("default response_format type = %q, want json_schema", got)
+	}
+	if got, ok := temperature(t, c); !ok || got != 0.6 {
+		t.Fatalf("temperature = %v, %v; want 0.6", got, ok)
+	}
+}
+
+func TestXAIFallbackModeIsJSONObject(t *testing.T) {
+	p, _ := Lookup("xai")
+	s := llm.Settings{Provider: "xai", Model: "grok-4", StructuredOutput: string(p.FallbackStructuredOutput)}
+	c := generate(t, s, testKey, schemaRequest())
+	if got := responseFormatType(t, c); got != "json_object" {
+		t.Fatalf("response_format type = %q, want json_object", got)
+	}
+}
+
+func TestXAIPresetAcceptsItsOwnBaseURL(t *testing.T) {
+	c := generate(t, llm.Settings{Provider: "xai", BaseURL: "https://api.x.ai/v1", Model: "grok-4"}, testKey, plainRequest())
+	if c.url != "https://api.x.ai/v1/chat/completions" {
+		t.Fatalf("URL = %q", c.url)
+	}
+}
+
 func TestOllamaPreset(t *testing.T) {
 	s := llm.Settings{Provider: "ollama", BaseURL: "http://ollama.lan:11434", Model: "llama3.2", Temperature: 0.5}
 	c := generate(t, s, "", plainRequest())
@@ -318,6 +355,7 @@ func TestPresetTable(t *testing.T) {
 		{"anthropic", AdapterAnthropic, "https://api.anthropic.com", KeyRequired},
 		{"openai", AdapterOpenAI, "https://api.openai.com/v1", KeyRequired},
 		{"openrouter", AdapterOpenAI, "https://openrouter.ai/api/v1", KeyRequired},
+		{"xai", AdapterOpenAI, "https://api.x.ai/v1", KeyRequired},
 		{"ollama", AdapterOllama, "", KeyNone},
 		{"openai_compatible", AdapterOpenAI, "", KeyOptional},
 	}
@@ -350,10 +388,12 @@ func TestConfigErrors(t *testing.T) {
 		{"anthropic no key", llm.Settings{Provider: "anthropic", Model: "m"}, "", llm.ErrMissingKey},
 		{"openai no key", llm.Settings{Provider: "openai", Model: "m"}, "", llm.ErrMissingKey},
 		{"openrouter no key", llm.Settings{Provider: "openrouter", Model: "m", PublicURL: "https://x.example"}, "", llm.ErrMissingKey},
+		{"xai no key", llm.Settings{Provider: "xai", Model: "grok-4"}, "", llm.ErrMissingKey},
 		{"ollama with key", llm.Settings{Provider: "ollama", BaseURL: "http://o:11434", Model: "m"}, testKey, llm.ErrUnexpectedKey},
 		{"anthropic key with newline", llm.Settings{Provider: "anthropic", Model: "m"}, testKey + "\n", llm.ErrInvalidKey},
 		{"openai key with newline", llm.Settings{Provider: "openai", Model: "m"}, testKey + "\n", llm.ErrInvalidKey},
 		{"openrouter key with CR LF", llm.Settings{Provider: "openrouter", Model: "m", PublicURL: "https://x.example"}, testKey + "\r\nX-Injected: 1", llm.ErrInvalidKey},
+		{"xai key with newline", llm.Settings{Provider: "xai", Model: "grok-4"}, testKey + "\n", llm.ErrInvalidKey},
 		{"openai_compatible key with NUL", llm.Settings{Provider: "openai_compatible", BaseURL: "http://l/v1", Model: "m"}, "\x00" + testKey, llm.ErrInvalidKey},
 		{"ollama no base URL", llm.Settings{Provider: "ollama", Model: "m"}, "", llm.ErrMissingBaseURL},
 		{"openai_compatible no base URL", llm.Settings{Provider: "openai_compatible", Model: "m"}, "", llm.ErrMissingBaseURL},
@@ -362,8 +402,11 @@ func TestConfigErrors(t *testing.T) {
 		{"openrouter no model", llm.Settings{Provider: "openrouter", PublicURL: "https://x.example"}, testKey, llm.ErrMissingModel},
 		{"ollama no model", llm.Settings{Provider: "ollama", BaseURL: "http://o:11434"}, "", llm.ErrMissingModel},
 		{"openai_compatible no model", llm.Settings{Provider: "openai_compatible", BaseURL: "http://l/v1"}, "", llm.ErrMissingModel},
+		{"xai no model", llm.Settings{Provider: "xai"}, testKey, llm.ErrMissingModel},
 		{"openrouter no public URL", llm.Settings{Provider: "openrouter", Model: "m"}, testKey, llm.ErrMissingPublicURL},
 		{"fixed base URL overridden", llm.Settings{Provider: "openai", BaseURL: "https://evil.example/v1", Model: "m"}, testKey, llm.ErrInvalidSetting},
+		{"xai base URL overridden", llm.Settings{Provider: "xai", BaseURL: "https://api.openai.com/v1", Model: "grok-4"}, testKey, llm.ErrInvalidSetting},
+		{"xai prompt_only", llm.Settings{Provider: "xai", Model: "grok-4", StructuredOutput: "prompt_only"}, testKey, llm.ErrInvalidSetting},
 		{"openai json_object", llm.Settings{Provider: "openai", Model: "m", StructuredOutput: "json_object"}, testKey, llm.ErrInvalidSetting},
 		{"anthropic mode", llm.Settings{Provider: "anthropic", Model: "m", StructuredOutput: "json_schema"}, testKey, llm.ErrInvalidSetting},
 		{"unknown mode", llm.Settings{Provider: "openai_compatible", BaseURL: "http://l/v1", Model: "m", StructuredOutput: "xml"}, "", llm.ErrInvalidSetting},
@@ -396,6 +439,7 @@ func TestReadyProviderForEveryPreset(t *testing.T) {
 		{llm.Settings{Provider: "anthropic", Model: "m"}, testKey},
 		{llm.Settings{Provider: "openai", Model: "m"}, testKey},
 		{llm.Settings{Provider: "openrouter", Model: "m", PublicURL: "https://x.example"}, testKey},
+		{llm.Settings{Provider: "xai", Model: "m"}, testKey},
 		{llm.Settings{Provider: "ollama", BaseURL: "http://o:11434", Model: "m"}, ""},
 		{llm.Settings{Provider: "openai_compatible", BaseURL: "http://l/v1", Model: "m"}, ""},
 	} {
@@ -454,6 +498,10 @@ func TestConfigErrorsNeverLeakKey(t *testing.T) {
 		{"key in bad base URL", llm.Settings{Provider: "openai_compatible", BaseURL: "ftp://k3y", Model: "m"}, "k3y", llm.ErrInvalidSetting},
 		{"ollama with key", llm.Settings{Provider: "ollama", BaseURL: "http://o:11434", Model: "m"}, "key", llm.ErrUnexpectedKey},
 		{"key with newline", llm.Settings{Provider: "openai", Model: "m"}, "sk-test\n", llm.ErrInvalidKey},
+		{"xai key as preset name", llm.Settings{Provider: "xai"}, "xai", llm.ErrMissingModel},
+		{"xai key as missing-model text", llm.Settings{Provider: "xai"}, "model is required", llm.ErrMissingModel},
+		{"xai key as fixed-URL text", llm.Settings{Provider: "xai", BaseURL: "https://x.example/v1", Model: "m"}, "fixed", llm.ErrInvalidSetting},
+		{"xai key as structured-output text", llm.Settings{Provider: "xai", Model: "m", StructuredOutput: "prompt_only"}, "structured output", llm.ErrInvalidSetting},
 		{"key with newline as text", llm.Settings{Provider: "openai", Model: "m"}, "header\n", llm.ErrInvalidKey},
 	}
 	for _, c := range cases {

internal/ai/llm/settings.go

@@ -18,7 +18,7 @@ import "errors"
 // to presets.FromSettings separately.
 type Settings struct {
 	// Provider names the preset: "anthropic", "openai", "openrouter",
-	// "ollama" or "openai_compatible".
+	// "xai", "ollama" or "openai_compatible".
 	Provider string
 	// BaseURL is the API root. It is required for ollama and
 	// openai_compatible; the other presets fix their own, and a non-empty

internal/store/migrate_test.go

@@ -175,8 +175,8 @@ func TestMigrateEmbeddedMigrations(t *testing.T) {
 	if err := Migrate(context.Background(), s.Writer, migrations.FS); err != nil {
 		t.Fatal(err)
 	}
-	if got := versions(migrationRows(t, s)); got != "0000_bootstrap,0001_init,0002_household_settings_updated_by,0003_jobs_status,0004_ai_provider_presets" {
+	if got := versions(migrationRows(t, s)); got != "0000_bootstrap,0001_init,0002_household_settings_updated_by,0003_jobs_status,0004_ai_provider_presets,0005_ai_provider_xai" {
-		t.Errorf("versions = %q, want 0000_bootstrap,0001_init,0002_household_settings_updated_by,0003_jobs_status,0004_ai_provider_presets", got)
+		t.Errorf("versions = %q, want 0000_bootstrap,0001_init,0002_household_settings_updated_by,0003_jobs_status,0004_ai_provider_presets,0005_ai_provider_xai", got)
 	}
 }
 
@@ -196,8 +196,8 @@ func TestMigrateBootstrapThenEmbeddedInitApplies(t *testing.T) {
 	if err := Migrate(ctx, s.Writer, migrations.FS); err != nil {
 		t.Fatal(err)
 	}
-	if got := versions(migrationRows(t, s)); got != "0000_bootstrap,0001_init,0002_household_settings_updated_by,0003_jobs_status,0004_ai_provider_presets" {
+	if got := versions(migrationRows(t, s)); got != "0000_bootstrap,0001_init,0002_household_settings_updated_by,0003_jobs_status,0004_ai_provider_presets,0005_ai_provider_xai" {
-		t.Errorf("versions = %q, want 0000_bootstrap,0001_init,0002_household_settings_updated_by,0003_jobs_status,0004_ai_provider_presets", got)
+		t.Errorf("versions = %q, want 0000_bootstrap,0001_init,0002_household_settings_updated_by,0003_jobs_status,0004_ai_provider_presets,0005_ai_provider_xai", got)
 	}
 	if !tableExists(t, s, "dinners") {
 		t.Error("table from 0001_init was not created")
@@ -396,3 +396,93 @@ func TestMigrateAIProviderPresetsKeepsRowsAndReferences(t *testing.T) {
 		}
 	}
 }
+
+// TestMigrateAIProviderXAIKeepsRowsAndReferences upgrades a database at 0004
+// holding ai_settings and ai_runs rows with 0004's providers, with
+// suggestion_batches and week_plans referencing the run, and checks 0005
+// carries every row over, keeps the references enforced, accepts xai and
+// still rejects an unknown provider.
+func TestMigrateAIProviderXAIKeepsRowsAndReferences(t *testing.T) {
+	ctx := context.Background()
+	s := openTestStore(t)
+	before := fstest.MapFS{}
+	for _, name := range []string{"0000_bootstrap.sql", "0001_init.sql", "0002_household_settings_updated_by.sql", "0003_jobs_status.sql", "0004_ai_provider_presets.sql"} {
+		body, err := fs.ReadFile(migrations.FS, name)
+		if err != nil {
+			t.Fatal(err)
+		}
+		before[name] = &fstest.MapFile{Data: body}
+	}
+	if err := Migrate(ctx, s.Writer, before); err != nil {
+		t.Fatal(err)
+	}
+	for _, stmt := range []string{
+		`INSERT INTO ai_settings (id, provider, base_url, model, temperature, system_prompt, api_key_ct, api_key_last4, key_verified_at, created_at, updated_at)
+			VALUES (1, 'openrouter', 'https://openrouter.ai/api/v1', 'openai/gpt-4o', 0.7, 'sp', x'0102', 'abcd', 'v', 'c', 'u')`,
+		`INSERT INTO ai_runs (id, skill, skill_version, provider, model, temperature, status, latency_ms, tokens_in, tokens_out, error, request_redacted, response_redacted, created_at, updated_at)
+			VALUES ('run-1', 'suggest', '1', 'openai', 'gpt-4o', 0.5, 'ok', 10, 20, 30, 'e', 'req', 'resp', 'c', 'u')`,
+		`INSERT INTO suggestion_batches (id, trigger, status, ai_run_id, created_at, updated_at)
+			VALUES ('batch-1', 'manual', 'done', 'run-1', 'c', 'u')`,
+		`INSERT INTO week_plans (id, week_start, status, ai_run_id, created_at, updated_at)
+			VALUES ('plan-1', '2026-10-04', 'draft', 'run-1', 'c', 'u')`,
+	} {
+		if _, err := s.Writer.Exec(stmt); err != nil {
+			t.Fatalf("seed: %v", err)
+		}
+	}
+
+	if err := Migrate(ctx, s.Writer, migrations.FS); err != nil {
+		t.Fatal(err)
+	}
+
+	var provider, baseURL, model, systemPrompt, last4, verifiedAt, createdAt, updatedAt string
+	var temperature float64
+	var keyCT []byte
+	if err := s.Reader.QueryRow(`SELECT provider, base_url, model, temperature, system_prompt, api_key_ct, api_key_last4, key_verified_at, created_at, updated_at FROM ai_settings WHERE id = 1`).
+		Scan(&provider, &baseURL, &model, &temperature, &systemPrompt, &keyCT, &last4, &verifiedAt, &createdAt, &updatedAt); err != nil {
+		t.Fatalf("read ai_settings: %v", err)
+	}
+	settings := []any{provider, baseURL, model, temperature, systemPrompt, string(keyCT), last4, verifiedAt, createdAt, updatedAt}
+	if want := []any{"openrouter", "https://openrouter.ai/api/v1", "openai/gpt-4o", 0.7, "sp", "\x01\x02", "abcd", "v", "c", "u"}; !slices.Equal(settings, want) {
+		t.Errorf("ai_settings = %v, want %v", settings, want)
+	}
+
+	var skill, skillVersion, status, errText, request, response string
+	var latency, tokensIn, tokensOut int
+	if err := s.Reader.QueryRow(`SELECT skill, skill_version, provider, model, temperature, status, latency_ms, tokens_in, tokens_out, error, request_redacted, response_redacted, created_at, updated_at FROM ai_runs WHERE id = 'run-1'`).
+		Scan(&skill, &skillVersion, &provider, &model, &temperature, &status, &latency, &tokensIn, &tokensOut, &errText, &request, &response, &createdAt, &updatedAt); err != nil {
+		t.Fatalf("read ai_runs: %v", err)
+	}
+	run := []any{skill, skillVersion, provider, model, temperature, status, latency, tokensIn, tokensOut, errText, request, response, createdAt, updatedAt}
+	if want := []any{"suggest", "1", "openai", "gpt-4o", 0.5, "ok", 10, 20, 30, "e", "req", "resp", "c", "u"}; !slices.Equal(run, want) {
+		t.Errorf("ai_runs = %v, want %v", run, want)
+	}
+
+	rows, err := s.Reader.Query("PRAGMA foreign_key_check")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if rows.Next() {
+		t.Error("foreign_key_check reported violations after 0005")
+	}
+	if err := rows.Close(); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := s.Writer.Exec(`DELETE FROM ai_runs WHERE id = 'run-1'`); err == nil || !strings.Contains(err.Error(), "FOREIGN KEY constraint failed") {
+		t.Errorf("deleting a referenced ai_run: error %v, want FOREIGN KEY constraint failure", err)
+	}
+
+	for _, table := range []string{"ai_settings", "ai_runs"} {
+		if _, err := s.Writer.Exec(`UPDATE ` + table + ` SET provider = 'xai'`); err != nil {
+			t.Errorf("%s.provider xai rejected: %v", table, err)
+		}
+		if _, err := s.Writer.Exec(`UPDATE ` + table + ` SET provider = 'grok'`); err == nil || !strings.Contains(err.Error(), "CHECK constraint failed") {
+			t.Errorf("%s.provider grok: error %v, want CHECK constraint failure", table, err)
+		}
+	}
+	for _, table := range []string{"ai_settings_copy", "ai_runs_copy"} {
+		if tableExists(t, s, table) {
+			t.Errorf("%s left behind", table)
+		}
+	}
+}

internal/store/schema_test.go

@@ -364,7 +364,7 @@ func TestSchemaRotationReviewEventAllowed(t *testing.T) {
 // both ai_settings and ai_runs.
 func TestSchemaAIProvidersAllowed(t *testing.T) {
 	s := seededStore(t)
-	for _, provider := range []string{"openai_compatible", "anthropic", "ollama", "openai", "openrouter"} {
+	for _, provider := range []string{"openai_compatible", "anthropic", "ollama", "openai", "openrouter", "xai"} {
 		for _, table := range []string{"ai_settings", "ai_runs"} {
 			inRolledBackTx(t, s, func(tx *sql.Tx) {
 				row := testRow(table, 1)

migrations/0005_ai_provider_xai.sql

@@ -0,0 +1,64 @@
+-- 0005_ai_provider_xai: ai_settings.provider and ai_runs.provider also
+-- accept xai, the xAI Grok preset in internal/ai/llm/presets. Every 0004
+-- value is kept, so existing rows copy unchanged. The rebuild is 0004's:
+-- copy the rows aside, drop the table, create it again with the wider CHECK,
+-- copy the rows back and drop the copy. Neither table has indexes or
+-- triggers.
+--
+-- suggestion_batches.ai_run_id and week_plans.ai_run_id reference ai_runs,
+-- so foreign keys are deferred until commit, after the ai_runs rows are
+-- back. The pragma lasts only for this migration's transaction.
+
+PRAGMA defer_foreign_keys = ON;
+
+CREATE TABLE ai_settings_copy AS SELECT * FROM ai_settings;
+
+DROP TABLE ai_settings;
+
+CREATE TABLE ai_settings (
+	id              INTEGER PRIMARY KEY CHECK (id = 1),
+	provider        TEXT    NOT NULL CHECK (provider IN ('openai_compatible', 'anthropic', 'ollama', 'openai', 'openrouter', 'xai')),
+	base_url        TEXT    NOT NULL,
+	model           TEXT    NOT NULL,
+	temperature     REAL    NOT NULL,
+	system_prompt   TEXT,
+	api_key_ct      BLOB,
+	api_key_last4   TEXT,
+	key_verified_at TEXT,
+	created_at      TEXT    NOT NULL,
+	updated_at      TEXT    NOT NULL
+);
+
+INSERT INTO ai_settings (id, provider, base_url, model, temperature, system_prompt, api_key_ct, api_key_last4, key_verified_at, created_at, updated_at)
+SELECT id, provider, base_url, model, temperature, system_prompt, api_key_ct, api_key_last4, key_verified_at, created_at, updated_at
+FROM ai_settings_copy;
+
+DROP TABLE ai_settings_copy;
+
+CREATE TABLE ai_runs_copy AS SELECT * FROM ai_runs;
+
+DROP TABLE ai_runs;
+
+CREATE TABLE ai_runs (
+	id                 TEXT    NOT NULL PRIMARY KEY,
+	skill              TEXT    NOT NULL,
+	skill_version      TEXT    NOT NULL,
+	provider           TEXT    NOT NULL CHECK (provider IN ('openai_compatible', 'anthropic', 'ollama', 'openai', 'openrouter', 'xai')),
+	model              TEXT    NOT NULL,
+	temperature        REAL    NOT NULL,
+	status             TEXT    NOT NULL CHECK (status IN ('running', 'ok', 'error')),
+	latency_ms         INTEGER,
+	tokens_in          INTEGER,
+	tokens_out         INTEGER,
+	error              TEXT,
+	request_redacted   TEXT    NOT NULL,
+	response_redacted  TEXT,
+	created_at         TEXT    NOT NULL,
+	updated_at         TEXT    NOT NULL
+);
+
+INSERT INTO ai_runs (id, skill, skill_version, provider, model, temperature, status, latency_ms, tokens_in, tokens_out, error, request_redacted, response_redacted, created_at, updated_at)
+SELECT id, skill, skill_version, provider, model, temperature, status, latency_ms, tokens_in, tokens_out, error, request_redacted, response_redacted, created_at, updated_at
+FROM ai_runs_copy;
+
+DROP TABLE ai_runs_copy;