Honor PI_CODING_AGENT_DIR for Pi MCP and skills

pkg/client/config.go

@@ -236,6 +236,12 @@ type clientAppConfig struct {
 	YAMLDefaults        map[string]any  // Default values to add to entries
 	// TOML-specific configuration (only used when Extension == TOML)
 	TOMLStorageType TOMLStorageType // How servers are stored in TOML (map or array)
+	// ConfigDirEnvVar names an environment variable that, when set, relocates
+	// the client's config directory. It replaces the home-relative directory
+	// holding SettingsFile and LLMSettingsFile, and the global skills directory
+	// becomes <dir>/skills. A leading "~" expands to the home directory and a
+	// relative value resolves against the working directory.
+	ConfigDirEnvVar string
 	// Skill-specific configuration
 	SupportsSkills    bool     // Whether this client supports skills
 	SkillsGlobalPath  []string // Path segments for global skills dir (from home dir)
@@ -1052,6 +1058,7 @@ var supportedClientIntegrations = []clientAppConfig{
 			types.TransportTypeSSE:            defaultURLFieldName,
 			types.TransportTypeStreamableHTTP: defaultURLFieldName,
 		},
+		ConfigDirEnvVar:    "PI_CODING_AGENT_DIR",
 		SupportsSkills:     true,
 		SkillsGlobalPath:   []string{".pi", "agent", skillsDirName},
 		SkillsProjectPath:  []string{".pi", skillsDirName},
@@ -1286,7 +1293,7 @@ func (cm *ClientManager) CreateClientConfig(clientType ClientApp) (*ConfigFile,
 	}
 
 	// Build the path to the configuration file
-	path := buildConfigFilePath(clientCfg.SettingsFile, clientCfg.RelPath, clientCfg.PlatformPrefix, []string{cm.homeDir})
+	path := cm.buildMCPConfigPath(clientCfg)
 
 	// Validate that the file does not already exist
 	if _, err := os.Stat(path); !os.IsNotExist(err) {
@@ -1392,7 +1399,7 @@ func (cm *ClientManager) retrieveConfigFileMetadata(clientType ClientApp) (*Conf
 	}
 
 	// Build the path to the configuration file
-	path := buildConfigFilePath(clientCfg.SettingsFile, clientCfg.RelPath, clientCfg.PlatformPrefix, []string{cm.homeDir})
+	path := cm.buildMCPConfigPath(clientCfg)
 
 	// Validate that the file exists
 	if err := validateConfigFileExists(path); err != nil {
@@ -1446,6 +1453,38 @@ func (cm *ClientManager) retrieveConfigFileMetadata(clientType ClientApp) (*Conf
 	}, nil
 }
 
+// buildMCPConfigPath resolves the absolute path to the client's MCP settings
+// file, honoring cfg.ConfigDirEnvVar when it is set.
+func (cm *ClientManager) buildMCPConfigPath(cfg *clientAppConfig) string {
+	if dir := cm.configDirOverride(cfg); dir != "" {
+		return filepath.Join(dir, cfg.SettingsFile)
+	}
+	return buildConfigFilePath(cfg.SettingsFile, cfg.RelPath, cfg.PlatformPrefix, []string{cm.homeDir})
+}
+
+// configDirOverride returns the absolute directory named by cfg.ConfigDirEnvVar,
+// or "" when the client has no override variable or it is unset.
+func (cm *ClientManager) configDirOverride(cfg *clientAppConfig) string {
+	if cfg.ConfigDirEnvVar == "" {
+		return ""
+	}
+	dir := os.Getenv(cfg.ConfigDirEnvVar)
+	switch {
+	case dir == "":
+		return ""
+	case dir == "~":
+		dir = cm.homeDir
+	case strings.HasPrefix(dir, "~/"):
+		dir = filepath.Join(cm.homeDir, dir[2:])
+	}
+	if !filepath.IsAbs(dir) {
+		if absolute, err := filepath.Abs(dir); err == nil {
+			dir = absolute
+		}
+	}
+	return dir
+}
+
 func buildConfigFilePath(settingsFile string, relPath []string, platformPrefix map[Platform][]string, path []string) string {
 	if prefix, ok := platformPrefix[Platform(runtime.GOOS)]; ok {
 		path = append(path, prefix...)

pkg/client/discovery.go

@@ -113,12 +113,15 @@ func (cm *ClientManager) IsClientInstalled(clientType ClientApp) bool {
 	if cfg == nil || cfg.LLMGatewayOnly {
 		return false
 	}
-	var pathToCheck string
-	if len(cfg.RelPath) == 0 && len(cfg.PlatformPrefix) == 0 {
-		pathToCheck = filepath.Join(cm.homeDir, cfg.SettingsFile)
-	} else {
-		pathToCheck = buildConfigDirectoryPath(cfg.RelPath, cfg.PlatformPrefix, []string{cm.homeDir})
-	}
+	pathToCheck := func() string {
+		if dir := cm.configDirOverride(cfg); dir != "" {
+			return dir
+		}
+		if len(cfg.RelPath) == 0 && len(cfg.PlatformPrefix) == 0 {
+			return filepath.Join(cm.homeDir, cfg.SettingsFile)
+		}
+		return buildConfigDirectoryPath(cfg.RelPath, cfg.PlatformPrefix, []string{cm.homeDir})
+	}()
 	_, err := os.Stat(pathToCheck)
 	return err == nil
 }

pkg/client/llm_gateway.go

@@ -547,22 +547,11 @@ func (cm *ClientManager) LLMClientDetectionHint(clientType ClientApp) string {
 }
 
 // buildLLMSettingsPath resolves the absolute path to the LLM settings file
-// for the given client using the same PlatformPrefix logic as MCP config paths.
+// for the given client using the same PlatformPrefix logic as MCP config paths,
+// honoring cfg.ConfigDirEnvVar when it is set.
 func (cm *ClientManager) buildLLMSettingsPath(cfg *clientAppConfig) string {
-	if cfg.ClientType == ClientApp(Pi) {
-		if dir := os.Getenv("PI_CODING_AGENT_DIR"); dir != "" {
-			if dir == "~" {
-				dir = cm.homeDir
-			} else if strings.HasPrefix(dir, "~/") {
-				dir = filepath.Join(cm.homeDir, dir[2:])
-			}
-			if !filepath.IsAbs(dir) {
-				if absolute, err := filepath.Abs(dir); err == nil {
-					dir = absolute
-				}
-			}
-			return filepath.Join(dir, cfg.LLMSettingsFile)
-		}
+	if dir := cm.configDirOverride(cfg); dir != "" {
+		return filepath.Join(dir, cfg.LLMSettingsFile)
 	}
 	return buildConfigFilePath(
 		cfg.LLMSettingsFile,

pkg/client/llm_gateway_pi_test.go

@@ -13,6 +13,7 @@ import (
 	"github.com/stretchr/testify/require"
 
 	"github.com/stacklok/toolhive/pkg/llmgateway"
+	"github.com/stacklok/toolhive/pkg/skills"
 )
 
 func TestPiGatewaySetupAndTeardown(t *testing.T) {
@@ -169,6 +170,33 @@ func TestPiGatewayAgentDirOverride(t *testing.T) {
 	require.Equal(t, relativePath, cm.buildLLMSettingsPath(cm.lookupClientAppConfig(ClientApp(Pi))))
 }
 
+// TestPiAgentDirOverrideAppliesToMCPAndSkills pins that PI_CODING_AGENT_DIR
+// relocates Pi's MCP config and global skills alongside models.json, so
+// `thv client register` and `thv skill install` land in the same directory as
+// `thv llm setup`.
+func TestPiAgentDirOverrideAppliesToMCPAndSkills(t *testing.T) {
+	home, agentDir := t.TempDir(), filepath.Join(t.TempDir(), "agent")
+	t.Setenv("PI_CODING_AGENT_DIR", agentDir)
+	cm := NewTestClientManager(home, nil, supportedClientIntegrations, nil)
+
+	mcpPath, err := cm.GetConfigPath(ClientApp(Pi))
+	require.NoError(t, err)
+	require.Equal(t, filepath.Join(agentDir, "mcp.json"), mcpPath)
+
+	skillPath, err := cm.GetSkillPath(ClientApp(Pi), "my-skill", skills.ScopeUser, "")
+	require.NoError(t, err)
+	require.Equal(t, filepath.Join(agentDir, "skills", "my-skill"), skillPath)
+
+	require.False(t, cm.IsClientInstalled(ClientApp(Pi)))
+	require.NoError(t, os.MkdirAll(agentDir, 0o700))
+	require.True(t, cm.IsClientInstalled(ClientApp(Pi)))
+
+	_, err = cm.CreateClientConfig(ClientApp(Pi))
+	require.NoError(t, err)
+	require.FileExists(t, mcpPath)
+	require.NoFileExists(t, filepath.Join(home, ".pi", "agent", "mcp.json"))
+}
+
 func TestPiGatewayAnthropicOnly(t *testing.T) {
 	t.Parallel()
 	home := t.TempDir()

pkg/client/plugins.go

@@ -112,5 +112,5 @@ func (cm *ClientManager) GetConfigPath(clientType ClientApp) (string, error) {
 	if cfg == nil {
 		return "", fmt.Errorf("%w: %s", ErrUnsupportedClientType, clientType)
 	}
-	return buildConfigFilePath(cfg.SettingsFile, cfg.RelPath, cfg.PlatformPrefix, []string{cm.homeDir}), nil
+	return cm.buildMCPConfigPath(cfg), nil
 }

pkg/client/skills.go

@@ -49,7 +49,8 @@ func (cm *ClientManager) ListSkillSupportingClients() []ClientApp {
 
 // GetSkillPath resolves the filesystem path for a skill installation.
 //
-// For [skills.ScopeUser], it returns ~/<SkillsGlobalPath>/<skillName>.
+// For [skills.ScopeUser], it returns ~/<SkillsGlobalPath>/<skillName>, or
+// <dir>/skills/<skillName> when the client's ConfigDirEnvVar is set.
 // For [skills.ScopeProject], it returns <projectRoot>/<SkillsProjectPath>/<skillName>.
 //
 // Returns an error if the client doesn't support skills, the scope has no
@@ -125,6 +126,10 @@ func (cm *ClientManager) buildSkillsGlobalPath(cfg *clientAppConfig, skillName s
 		return "", fmt.Errorf("%w: %s has no global skill path", ErrNoSkillPath, cfg.ClientType)
 	}
 
+	if dir := cm.configDirOverride(cfg); dir != "" {
+		return filepath.Join(dir, skillsDirName, skillName), nil
+	}
+
 	parts := []string{cm.homeDir}
 	if prefix, ok := cfg.SkillsPlatformPrefix[Platform(runtime.GOOS)]; ok {
 		parts = append(parts, prefix...)