feat: change model notation from provider:model to provider/model

Switch the --model / -m flag format from colon-separated (provider:model)
to slash-separated (provider/model), e.g. anthropic/claude-sonnet-4-5-20250929
or ollama/qwen3:8b. The slash separator is cleaner since model names can
contain colons (ollama tags, bedrock ARNs).

Add centralized ParseModelString() in internal/models/providers.go that all
callers now use. The old colon format is still accepted with a deprecation
warning to stderr for backward compatibility.

Update default model to claude-sonnet-4-5-20250929.

Author: ezynda3

README.md

@@ -204,7 +204,7 @@ mcpServers:
       DEBUG: "${env://DEBUG:-false}"
       LOG_LEVEL: "${env://LOG_LEVEL:-info}"
 
-model: "${env://MODEL:-anthropic:claude-sonnet-4-20250514}"
+model: "${env://MODEL:-anthropic/claude-sonnet-4-5-20250929}"
 provider-api-key: "${env://OPENAI_API_KEY}"  # Required - will fail if not set
 ```
 
@@ -216,7 +216,7 @@ export OPENAI_API_KEY="your_openai_key"
 
 # Optionally override defaults
 export DEBUG="true"
-export MODEL="openai:gpt-4"
+export MODEL="openai/gpt-4"
 
 # Run mcphost
 mcphost
@@ -584,7 +584,7 @@ mcpServers:
     type: "local"
     command: ["npx", "-y", "@modelcontextprotocol/server-filesystem", "${env://WORK_DIR:-/tmp}"]
 
-model: "${env://MODEL:-anthropic:claude-sonnet-4-20250514}"
+model: "${env://MODEL:-anthropic/claude-sonnet-4-5-20250929}"
 ---
 Hello ${name:-World}! Please list ${repo_type:-public} repositories for user ${username}.
 Working directory is ${env://WORK_DIR:-/tmp}.
@@ -723,7 +723,7 @@ mcphost -p "What is the weather like today?"
 mcphost -p "What is 2+2?" --quiet
 
 # Use with different models
-mcphost -m ollama:qwen2.5:3b -p "Explain quantum computing" --quiet
+mcphost -m ollama/qwen2.5:3b -p "Explain quantum computing" --quiet
 ```
 
 ### Model Generation Parameters
@@ -751,24 +751,24 @@ These parameters work with all supported providers (OpenAI, Anthropic, Google, O
 
 ### Available Models
 Models can be specified using the `--model` (`-m`) flag:
-- **Anthropic Claude** (default): `anthropic:claude-sonnet-4-20250514`, `anthropic:claude-3-5-sonnet-latest`, `anthropic:claude-3-5-haiku-latest`
-- **OpenAI**: `openai:gpt-4`, `openai:gpt-4-turbo`, `openai:gpt-3.5-turbo`
-- **Google Gemini**: `google:gemini-2.0-flash`, `google:gemini-1.5-pro`
-- **Ollama models**: `ollama:llama3.2`, `ollama:qwen2.5:3b`, `ollama:mistral`
+- **Anthropic Claude** (default): `anthropic/claude-sonnet-4-5-20250929`, `anthropic/claude-3-5-sonnet-latest`, `anthropic/claude-3-5-haiku-latest`
+- **OpenAI**: `openai/gpt-4`, `openai/gpt-4-turbo`, `openai/gpt-3.5-turbo`
+- **Google Gemini**: `google/gemini-2.0-flash`, `google/gemini-1.5-pro`
+- **Ollama models**: `ollama/llama3.2`, `ollama/qwen2.5:3b`, `ollama/mistral`
 - **OpenAI-compatible**: Any model via custom endpoint with `--provider-url`
 
 ### Examples
 
 #### Interactive Mode
 ```bash
 # Use Ollama with Qwen model
-mcphost -m ollama:qwen2.5:3b
+mcphost -m ollama/qwen2.5:3b
 
 # Use OpenAI's GPT-4
-mcphost -m openai:gpt-4
+mcphost -m openai/gpt-4
 
 # Use OpenAI-compatible model with custom URL and API key
-mcphost --model openai:<your-model-name> \
+mcphost --model openai/<your-model-name> \
 --provider-url <your-base-url> \
 --provider-api-key <your-api-key>
 ```
@@ -800,7 +800,7 @@ mcphost -p "Generate a random UUID" --quiet | tr '[:lower:]' '[:upper:]'
 - `--system-prompt string`: system-prompt file location
 - `--debug`: Enable debug logging
 - `--max-steps int`: Maximum number of agent steps (0 for unlimited, default: 0)
-- `-m, --model string`: Model to use (format: provider:model) (default "anthropic:claude-sonnet-4-20250514")
+- `-m, --model string`: Model to use (format: provider/model) (default "anthropic/claude-sonnet-4-5-20250929")
 - `-p, --prompt string`: **Run in non-interactive mode with the given prompt**
 - `--quiet`: **Suppress all output except the AI response (only works with --prompt)**
 - `--compact`: **Enable compact output mode without fancy styling (ideal for scripting and automation)**
@@ -845,7 +845,7 @@ mcpServers:
     url: "https://api.example.com/mcp"
 
 # Application settings
-model: "anthropic:claude-sonnet-4-20250514"
+model: "anthropic/claude-sonnet-4-5-20250929"
 max-steps: 20
 debug: false
 system-prompt: "/path/to/system-prompt.txt"

cmd/root.go

@@ -96,16 +96,16 @@ through a unified interface. It supports various tools through MCP servers
 and provides streaming responses.
 
 Available models can be specified using the --model flag:
-- Anthropic Claude (default): anthropic:claude-sonnet-4-20250514
-- OpenAI: openai:gpt-4
-- Ollama models: ollama:modelname
-- Google: google:modelname
+- Anthropic Claude (default): anthropic/claude-sonnet-4-5-20250929
+- OpenAI: openai/gpt-4
+- Ollama models: ollama/modelname
+- Google: google/modelname
 
 Examples:
   # Interactive mode
-  mcphost -m ollama:qwen2.5:3b
-  mcphost -m openai:gpt-4
-  mcphost -m google:gemini-2.0-flash
+  mcphost -m ollama/qwen2.5:3b
+  mcphost -m openai/gpt-4
+  mcphost -m google/gemini-2.0-flash
   
   # Non-interactive mode
   mcphost -p "What is the weather like today?"
@@ -284,8 +284,8 @@ func init() {
 		StringVar(&systemPromptFile, "system-prompt", "", "system prompt text or path to text file")
 
 	rootCmd.PersistentFlags().
-		StringVarP(&modelFlag, "model", "m", "anthropic:claude-sonnet-4-20250514",
-			"model to use (format: provider:model)")
+		StringVarP(&modelFlag, "model", "m", "anthropic/claude-sonnet-4-5-20250929",
+			"model to use (format: provider/model)")
 	rootCmd.PersistentFlags().
 		BoolVar(&debugMode, "debug", false, "enable debug logging")
 	rootCmd.PersistentFlags().
@@ -467,10 +467,9 @@ func runNormalMode(ctx context.Context) error {
 	// Initialize hook executor if hooks are configured
 	// Get model name for display
 	modelString := viper.GetString("model")
-	parts := strings.SplitN(modelString, ":", 2)
-	modelName := "Unknown"
-	if len(parts) == 2 {
-		modelName = parts[1]
+	parsedProvider, modelName, _ := models.ParseModelString(modelString)
+	if modelName == "" {
+		modelName = "Unknown"
 	}
 
 	var hookExecutor *hooks.Executor
@@ -533,7 +532,7 @@ func runNormalMode(ctx context.Context) error {
 		}
 
 		// Add Ollama-specific parameters if using Ollama
-		if strings.HasPrefix(viper.GetString("model"), "ollama:") {
+		if parsedProvider == "ollama" {
 			debugConfig["num-gpu-layers"] = viper.GetInt("num-gpu-layers")
 			debugConfig["main-gpu"] = viper.GetInt("main-gpu")
 		}
@@ -733,7 +732,7 @@ func runNormalMode(ctx context.Context) error {
 		// Set metadata
 		sessionManager.SetMetadata(session.Metadata{
 			MCPHostVersion: "dev", // TODO: Get actual version
-			Provider:       parts[0],
+			Provider:       parsedProvider,
 			Model:          modelName,
 		})
 	}

cmd/script.go

@@ -17,6 +17,7 @@ import (
 	"github.com/mark3labs/mcphost/internal/models"
 	"github.com/mark3labs/mcphost/internal/tools"
 	"github.com/mark3labs/mcphost/internal/ui"
+
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
 )
@@ -34,7 +35,7 @@ model settings, and other options.
 
 Example script file:
 ---
-model: "anthropic:claude-sonnet-4-20250514"
+model: "anthropic/claude-sonnet-4-5-20250929"
 max-steps: 10
 mcpServers:
   filesystem:
@@ -520,7 +521,7 @@ func runScriptMode(ctx context.Context, mcpConfig *config.Config, prompt string,
 		finalModel = mcpConfig.Model
 	}
 	if finalModel == "" {
-		finalModel = "anthropic:claude-sonnet-4-20250514" // default
+		finalModel = "anthropic/claude-sonnet-4-5-20250929" // default
 	}
 
 	finalSystemPrompt := viper.GetString("system-prompt")
@@ -626,10 +627,9 @@ func runScriptMode(ctx context.Context, mcpConfig *config.Config, prompt string,
 	defer mcpAgent.Close()
 
 	// Get model name for display
-	parts := strings.SplitN(finalModel, ":", 2)
-	modelName := "Unknown"
-	if len(parts) == 2 {
-		modelName = parts[1]
+	_, modelName, _ := models.ParseModelString(finalModel)
+	if modelName == "" {
+		modelName = "Unknown"
 	}
 
 	// Create an adapter for the agent to match the UI interface

cmd/script_deepseek_test.go

@@ -20,7 +20,7 @@ func TestDeepSeekChatScriptMode(t *testing.T) {
 
 	scriptContent := `#!/usr/bin/env -S mcphost script
 ---
-model: "openai:deepseek-chat"
+model: "openai/deepseek-chat"
 provider-url: "https://api.deepseek.com/v1"
 provider-api-key: "${env://DEEPSEEK_API_KEY}"
 ---
@@ -44,8 +44,8 @@ Calculate 3 times 4 equal to?
 	}
 
 	// Verify the script config has the correct values
-	if scriptConfig.Model != "openai:deepseek-chat" {
-		t.Errorf("Expected model=openai:deepseek-chat, got %s", scriptConfig.Model)
+	if scriptConfig.Model != "openai/deepseek-chat" {
+		t.Errorf("Expected model=openai/deepseek-chat, got %s", scriptConfig.Model)
 	}
 	if scriptConfig.ProviderURL != "https://api.deepseek.com/v1" {
 		t.Errorf("Expected provider-url=https://api.deepseek.com/v1, got %s", scriptConfig.ProviderURL)
@@ -87,7 +87,7 @@ Calculate 3 times 4 equal to?
 func TestDeepSeekChatCLIMode(t *testing.T) {
 	// Test the CLI mode behavior - this should work
 	providerConfig := &models.ProviderConfig{
-		ModelString:    "openai:deepseek-chat",
+		ModelString:    "openai/deepseek-chat",
 		ProviderAPIKey: "sk-test-key",
 		ProviderURL:    "https://api.deepseek.com/v1", // This should skip validation
 		MaxTokens:      0,
@@ -119,25 +119,25 @@ func TestProviderURLValidationSkip(t *testing.T) {
 	}{
 		{
 			name:        "OpenAI with custom URL should skip validation",
-			model:       "openai:custom-model",
+			model:       "openai/custom-model",
 			providerURL: "https://api.custom.com/v1",
 			shouldSkip:  true,
 		},
 		{
 			name:        "OpenAI without custom URL should validate",
-			model:       "openai:custom-model",
+			model:       "openai/custom-model",
 			providerURL: "",
 			shouldSkip:  false,
 		},
 		{
 			name:        "Ollama should always skip validation",
-			model:       "ollama:custom-model",
+			model:       "ollama/custom-model",
 			providerURL: "",
 			shouldSkip:  true,
 		},
 		{
 			name:        "Anthropic with custom URL should skip validation",
-			model:       "anthropic:custom-model",
+			model:       "anthropic/custom-model",
 			providerURL: "https://api.custom.com/v1",
 			shouldSkip:  true,
 		},

cmd/script_integration_test.go

@@ -28,7 +28,7 @@ mcpServers:
     options:
       allowed_directories: ["${env://WORK_DIR:-/tmp}"]
 
-model: "${env://MODEL:-anthropic:claude-sonnet-4-20250514}"
+model: "${env://MODEL:-anthropic/claude-sonnet-4-5-20250929}"
 debug: ${env://DEBUG:-false}
 ---
 List ${repo_type:-public} repositories for user ${username}.
@@ -91,8 +91,8 @@ Working directory is ${env://WORK_DIR:-/tmp}.
 	}
 
 	// Verify global config values
-	if scriptConfig.Model != "anthropic:claude-sonnet-4-20250514" {
-		t.Errorf("Expected model=anthropic:claude-sonnet-4-20250514, got %s", scriptConfig.Model)
+	if scriptConfig.Model != "anthropic/claude-sonnet-4-5-20250929" {
+		t.Errorf("Expected model=anthropic/claude-sonnet-4-5-20250929, got %s", scriptConfig.Model)
 	}
 	if !scriptConfig.Debug {
 		t.Error("Expected debug=true")
@@ -250,7 +250,7 @@ mcpServers:
     options:
       allowed_directories: ["/tmp"]
 
-model: "anthropic:claude-sonnet-4-20250514"
+model: "anthropic/claude-sonnet-4-5-20250929"
 ---
 List files in ${directory:-/tmp} for user ${username}.
 `
@@ -278,7 +278,7 @@ List files in ${directory:-/tmp} for user ${username}.
 	}
 
 	// Verify that config is unchanged
-	if scriptConfig.Model != "anthropic:claude-sonnet-4-20250514" {
+	if scriptConfig.Model != "anthropic/claude-sonnet-4-5-20250929" {
 		t.Errorf("Expected model unchanged, got %s", scriptConfig.Model)
 	}
 }

cmd/script_test.go

@@ -244,7 +244,7 @@ func TestSubstituteVariables(t *testing.T) {
 func TestBackwardCompatibility(t *testing.T) {
 	// Test that existing scripts without default syntax continue to work
 	content := `---
-model: "anthropic:claude-sonnet-4-20250514"
+model: "anthropic/claude-sonnet-4-5-20250929"
 ---
 Hello ${name}! Please analyze ${directory}.`
 
@@ -262,7 +262,7 @@ Hello ${name}! Please analyze ${directory}.`
 	// Should substitute correctly
 	result := substituteVariables(content, variables)
 	expected := `---
-model: "anthropic:claude-sonnet-4-20250514"
+model: "anthropic/claude-sonnet-4-5-20250929"
 ---
 Hello John! Please analyze /tmp.`
 
@@ -302,7 +302,7 @@ Test prompt with compact mode`
 
 func TestParseScriptContentMCPServersNewFormat(t *testing.T) {
 	content := `---
-model: "anthropic:claude-sonnet-4-20250514"
+model: "anthropic/claude-sonnet-4-5-20250929"
 mcpServers:
   filesystem:
     type: "local"
@@ -379,7 +379,7 @@ Test prompt with new format MCP servers`
 
 func TestParseScriptContentMCPServersLegacyFormat(t *testing.T) {
 	content := `---
-model: "anthropic:claude-sonnet-4-20250514"
+model: "anthropic/claude-sonnet-4-5-20250929"
 mcpServers:
   legacy-stdio:
     transport: "stdio"

examples/scripts/default-values-demo.sh

@@ -1,7 +1,7 @@
 #!/usr/bin/env -S mcphost script
 ---
 # Demo script showcasing default values in MCPHost scripts
-model: "anthropic:claude-sonnet-4-20250514"
+model: "anthropic/claude-sonnet-4-5-20250929"
 mcpServers:
   filesystem:
     type: "builtin"

examples/scripts/env-substitution-script.sh

@@ -17,7 +17,7 @@ mcpServers:
     options:
       allowed_directories: ["${env://WORK_DIR:-/tmp}"]
 
-model: "${env://MODEL:-anthropic:claude-sonnet-4-20250514}"
+model: "${env://MODEL:-anthropic/claude-sonnet-4-5-20250929}"
 debug: ${env://DEBUG:-false}
 ---
 List ${repo_type:-public} repositories for user ${username}.

examples/scripts/tls-test-script.sh

@@ -1,7 +1,7 @@
 #!/usr/bin/env -S mcphost script
 ---
 # Example script demonstrating TLS skip verify for self-signed certificates
-model: "ollama:llama3.2"
+model: "ollama/llama3.2"
 provider-url: "https://localhost:8443"
 tls-skip-verify: true
 max-tokens: 1000

internal/agent/agent.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	"strings"
 	"time"
 
 	tea "charm.land/bubbletea/v2"
@@ -115,9 +114,8 @@ func NewAgent(ctx context.Context, agentConfig *AgentConfig) (*Agent, error) {
 	// Determine provider type from model string
 	providerType := "default"
 	if agentConfig.ModelConfig != nil && agentConfig.ModelConfig.ModelString != "" {
-		parts := strings.SplitN(agentConfig.ModelConfig.ModelString, ":", 2)
-		if len(parts) >= 1 {
-			providerType = parts[0]
+		if p, _, err := models.ParseModelString(agentConfig.ModelConfig.ModelString); err == nil {
+			providerType = p
 		}
 	}