Support Pi in LLM gateway setup

cmd/thv/app/llm.go

@@ -289,7 +289,7 @@ func newLLMSetupCommand() *cobra.Command {
 	cmd := &cobra.Command{
 		Use:   "setup",
 		Short: "Configure detected AI tools to use the LLM gateway",
-		Long: `Detect installed AI tools (Claude Code, Gemini CLI, Cursor, VS Code, Xcode,
+		Long: `Detect installed AI tools (Claude Code, Gemini CLI, Pi, Cursor, VS Code, Xcode,
 Claude Desktop, Codex) and patch each tool's configuration to route through the
 LLM gateway.
 
@@ -309,6 +309,20 @@ untouched. Desktop app detection is supported on macOS and Windows; the canonica
 --client target remains "codex". If the desktop app is running, fully quit and
 reopen it after setup.
 
+Pi is configured with OpenAI-compatible and Anthropic providers in
+~/.pi/agent/models.json (or $PI_CODING_AGENT_DIR/models.json). It runs
+"thv llm token" for each request; authenticated setup discovers models and
+context sizes from both gateway APIs and Anthropic thinking support when
+advertised. --models filters the discovered models. Pi does not support --lazy
+because model discovery determines each model's API.
+Pi defaults to short prompt caching: start Pi with PI_CACHE_RETENTION=long
+in its environment for long retention (Anthropic: 1h; OpenAI: 24h).
+This cannot be persisted in models.json. The gateway does not currently provide
+image-input or max-output metadata, so Pi defaults to text-only input and 16K
+max output tokens. OpenAI models without reasoning metadata default to no reasoning.
+If Pi cannot refresh its gateway token, run "thv llm token" in a terminal to
+log in again.
+
 Proxy-mode tools (Cursor, VS Code, Xcode) are configured to send requests to
 the localhost reverse proxy started by "thv llm proxy start".
 
@@ -358,8 +372,8 @@ Run "thv llm teardown" to revert all changes.`,
 		"Use Claude Code's five-minute prompt cache instead of ToolHive's one-hour default. Persisted, so a later "+
 			"plain \"thv llm setup\" keeps it; use --short-prompt-cache=false to restore one-hour caching.")
 	cmd.Flags().StringVar(&anthropicPathPrefix, "anthropic-path-prefix", "",
-		"Path prefix appended to the gateway URL when writing ANTHROPIC_BASE_URL for direct-mode tools "+
-			"(e.g. /anthropic). When omitted, the gateway is probed automatically.")
+		"Path prefix appended to the gateway URL for Anthropic API tools (e.g. /anthropic). "+
+			"Also used for Pi model discovery. When omitted, the gateway is probed automatically.")
 	cmd.Flags().StringVar(&targetClient, "client", "",
 		"Configure only this AI tool by name (e.g. claude-code, cursor, codex). Omit to configure all detected tools.")
 	cmd.Flags().BoolVar(&lazy, "lazy", false,
@@ -370,6 +384,7 @@ Run "thv llm teardown" to revert all changes.`,
 	cmd.Flags().StringSliceVar(&models, "models", nil,
 		"Model IDs to configure, comma-separated or by repeating the flag, e.g. "+
 			"--models=us.anthropic.claude-opus-4-8,us.anthropic.claude-sonnet-5. "+
+			"For Pi these filter its discovered models (Pi does not support --lazy). "+
 			"For credential-helper clients (Claude Desktop) these become inferenceModels. "+
 			"With --bedrock-compat, each ID is also mapped to a Claude Code tier by matching "+
 			"'haiku', 'opus', or 'sonnet' in the ID (IDs matching no tier are ignored with a "+

pkg/client/config.go

@@ -1052,9 +1052,13 @@ var supportedClientIntegrations = []clientAppConfig{
 			types.TransportTypeSSE:            defaultURLFieldName,
 			types.TransportTypeStreamableHTTP: defaultURLFieldName,
 		},
-		SupportsSkills:    true,
-		SkillsGlobalPath:  []string{".pi", "agent", skillsDirName},
-		SkillsProjectPath: []string{".pi", skillsDirName},
+		SupportsSkills:     true,
+		SkillsGlobalPath:   []string{".pi", "agent", skillsDirName},
+		SkillsProjectPath:  []string{".pi", skillsDirName},
+		LLMGatewayMode:     llmgateway.ModePi,
+		LLMBinaryName:      "pi",
+		LLMSettingsFile:    "models.json",
+		LLMSettingsRelPath: []string{".pi", "agent"},
 	},
 	{
 		// Xcode does not support MCP; it is an LLM-gateway-only entry.

pkg/client/llm_gateway.go

@@ -53,6 +53,9 @@ func (cm *ClientManager) ConfigureLLMGateway(clientType ClientApp, cfg llmgatewa
 	if appCfg.LLMGatewayMode == llmgateway.ModeCodexAuth {
 		return cm.configureCodexAuth(appCfg, cfg)
 	}
+	if appCfg.LLMGatewayMode == llmgateway.ModePi {
+		return cm.configurePi(appCfg, cfg)
+	}
 	if appCfg.LLMGatewayMode == llmgateway.ModeVSCode {
 		return cm.configureVSCode(appCfg, cfg)
 	}
@@ -192,6 +195,9 @@ func (cm *ClientManager) RevertLLMGateway(clientType ClientApp, configPath strin
 	if appCfg.LLMGatewayMode == llmgateway.ModeCodexAuth {
 		return cm.revertCodexAuth(appCfg, configPath)
 	}
+	if appCfg.LLMGatewayMode == llmgateway.ModePi {
+		return cm.revertPi(appCfg, configPath)
+	}
 	if appCfg.LLMGatewayMode == llmgateway.ModeVSCode {
 		return cm.revertVSCode(appCfg, configPath)
 	}
@@ -543,6 +549,21 @@ 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.
 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)
+		}
+	}
 	return buildConfigFilePath(
 		cfg.LLMSettingsFile,
 		cfg.LLMSettingsRelPath,