feat: Add LOCALAI_DISABLE_MCP environment variable to disable MCP support (#8816)

* feat: Add LOCALAI_DISABLE_MCP environment variable to disable MCP support

- Added DisableMCP field to RunCMD struct in core/cli/run.go
- Added LOCALAI_DISABLE_MCP environment variable support
- Added DisableMCP field to ApplicationConfig struct
- Added DisableMCP AppOption function
- Updated MCP endpoint routing to check appConfig.DisableMCP
- When LOCALAI_DISABLE_MCP is set to true/1/yes, MCP endpoints are not registered

When set, all MCP functionality is disabled and appropriate error messages
are returned to users.

Use Cases:
- Security-conscious deployments where MCP is not needed
- Reducing attack surface
- Compliance requirements that prohibit certain protocol support

Environment variable: LOCALAI_DISABLE_MCP=true

Signed-off-by: localai-bot <localai-bot@users.noreply.github.com>

* docs: Add documentation for LOCALAI_DISABLE_MCP environment variable

- Add section explaining how to disable MCP support using environment variable
- Document use cases for disabling MCP
- Provide examples for CLI and Docker usage

Signed-off-by: localai-bot <localai-bot@users.noreply.github.com>

---------

Signed-off-by: localai-bot <localai-bot@users.noreply.github.com>
Co-authored-by: localai-bot <localai-bot@users.noreply.github.com>

core/cli/run.go

@@ -79,6 +79,7 @@ type RunCMD struct {
 	LRUEvictionRetryInterval           string   `env:"LOCALAI_LRU_EVICTION_RETRY_INTERVAL,LRU_EVICTION_RETRY_INTERVAL" default:"1s" help:"Interval between retries when waiting for busy models to become idle (e.g., 1s, 2s) (default: 1s)" group:"backends"`
 	Federated                          bool     `env:"LOCALAI_FEDERATED,FEDERATED" help:"Enable federated instance" group:"federated"`
 	DisableGalleryEndpoint             bool     `env:"LOCALAI_DISABLE_GALLERY_ENDPOINT,DISABLE_GALLERY_ENDPOINT" help:"Disable the gallery endpoints" group:"api"`
+	DisableMCP                         bool     `env:"LOCALAI_DISABLE_MCP,DISABLE_MCP" help:"Disable MCP (Model Context Protocol) support" group:"api" default:"false"`
 	MachineTag                         string   `env:"LOCALAI_MACHINE_TAG,MACHINE_TAG" help:"Add Machine-Tag header to each response which is useful to track the machine in the P2P network" group:"api"`
 	LoadToMemory                       []string `env:"LOCALAI_LOAD_TO_MEMORY,LOAD_TO_MEMORY" help:"A list of models to load into memory at startup" group:"models"`
 	EnableTracing                      bool     `env:"LOCALAI_ENABLE_TRACING,ENABLE_TRACING" help:"Enable API tracing" group:"api"`
@@ -198,6 +199,10 @@ func (r *RunCMD) Run(ctx *cliContext.Context) error {
 		opts = append(opts, config.DisableGalleryEndpoint)
 	}
 
+	if r.DisableMCP {
+		opts = append(opts, config.DisableMCP)
+	}
+
 	if idleWatchDog || busyWatchDog {
 		opts = append(opts, config.EnableWatchDog)
 		if idleWatchDog {

core/config/application_config.go

@@ -45,6 +45,7 @@ type ApplicationConfig struct {
 	DisableMetrics                     bool
 	HttpGetExemptedEndpoints           []*regexp.Regexp
 	DisableGalleryEndpoint             bool
+	DisableMCP                         bool
 	LoadToMemory                       []string
 
 	Galleries        []Gallery
@@ -184,6 +185,10 @@ var DisableGalleryEndpoint = func(o *ApplicationConfig) {
 	o.DisableGalleryEndpoint = true
 }
 
+var DisableMCP = func(o *ApplicationConfig) {
+	o.DisableMCP = true
+}
+
 var EnableWatchDogBusyCheck = func(o *ApplicationConfig) {
 	o.WatchDog = true
 	o.WatchDogBusy = true

core/http/routes/localai.go

@@ -140,7 +140,7 @@ func RegisterLocalAIRoutes(router *echo.Echo,
 
 	// MCP endpoint - supports both streaming and non-streaming modes
 	// Note: streaming mode is NOT compatible with the OpenAI apis. We have a set which streams more states.
-	if evaluator != nil {
+	if evaluator != nil && !appConfig.DisableMCP {
 		mcpStreamHandler := localai.MCPEndpoint(cl, ml, evaluator, appConfig)
 		mcpStreamMiddleware := []echo.MiddlewareFunc{
 			requestExtractor.BuildFilteredFirstAvailableDefaultModel(config.BuildUsecaseFilterFn(config.FLAG_CHAT)),

docs/content/features/mcp.md

@@ -365,3 +365,33 @@ mcp:
 
 - [Awesome MCPs](https://github.com/punkpeye/awesome-mcp-servers)
 - [A list of MCPs by mudler](https://github.com/mudler/MCPs)
+
+## Disabling MCP Support
+
+You can completely disable MCP functionality in LocalAI by setting the `LOCALAI_DISABLE_MCP` environment variable to `true`, `1`, or `yes`:
+
+```bash
+export LOCALAI_DISABLE_MCP=true
+```
+
+When this environment variable is set, all MCP-related features will be disabled, including:
+- MCP server connections (both remote and stdio)
+- Agent tool execution
+- The `/mcp/v1/chat/completions` endpoint
+
+This is useful when you want to:
+- Run LocalAI without MCP capabilities for security reasons
+- Reduce the attack surface by disabling unnecessary features
+- Troubleshoot MCP-related issues
+
+### Example
+
+```bash
+# Disable MCP completely
+LOCALAI_DISABLE_MCP=true localai run
+
+# Or in Docker
+docker run -e LOCALAI_DISABLE_MCP=true localai/localai:latest
+```
+
+When MCP is disabled, any model configuration with `mcp` sections will be ignored, and attempts to use the MCP endpoint will return an error indicating that MCP support is disabled.