fix: use SHA-256 for container fingerprints instead of DefaultHasher

DefaultHasher is not stable across Rust compiler versions or binary
rebuilds, causing unnecessary container recreations on every app update.
Replace with SHA-256 for deterministic, cross-build-stable fingerprints.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/src-tauri/Cargo.lock

@@ -4681,6 +4681,7 @@ dependencies = [
  "reqwest 0.12.28",
  "serde",
  "serde_json",
+ "sha2",
  "tar",
  "tauri",
  "tauri-build",

app/src-tauri/Cargo.toml

@@ -30,6 +30,7 @@ fern = { version = "0.7", features = ["date-based"] }
 tar = "0.4"
 reqwest = { version = "0.12", default-features = false, features = ["json", "rustls-tls"] }
 iana-time-zone = "0.1"
+sha2 = "0.10"
 
 [build-dependencies]
 tauri-build = { version = "2", features = [] }

app/src-tauri/src/commands/project_commands.rs

@@ -53,6 +53,19 @@ fn load_secrets_for_project(project: &mut Project) {
     }
 }
 
+/// Resolve enabled MCP servers and filter to Docker-only ones.
+fn resolve_mcp_servers(project: &Project, state: &AppState) -> (Vec<McpServer>, Vec<McpServer>) {
+    let all_mcp_servers = state.mcp_store.list();
+    let enabled_mcp: Vec<McpServer> = project.enabled_mcp_servers.iter()
+        .filter_map(|id| all_mcp_servers.iter().find(|s| &s.id == id).cloned())
+        .collect();
+    let docker_mcp: Vec<McpServer> = enabled_mcp.iter()
+        .filter(|s| s.is_docker())
+        .cloned()
+        .collect();
+    (enabled_mcp, docker_mcp)
+}
+
 #[tauri::command]
 pub async fn list_projects(state: State<'_, AppState>) -> Result<Vec<Project>, String> {
     Ok(state.projects_store.list())
@@ -97,6 +110,18 @@ pub async fn remove_project(
             let _ = docker::stop_container(container_id).await;
             let _ = docker::remove_container(container_id).await;
         }
+
+        // Remove MCP containers and network
+        let (_enabled_mcp, docker_mcp) = resolve_mcp_servers(project, &state);
+        if !docker_mcp.is_empty() {
+            if let Err(e) = docker::remove_mcp_containers(&docker_mcp).await {
+                log::warn!("Failed to remove MCP containers for project {}: {}", project_id, e);
+            }
+        }
+        if let Err(e) = docker::remove_project_network(&project.id).await {
+            log::warn!("Failed to remove project network for project {}: {}", project_id, e);
+        }
+
         // Clean up the snapshot image + volumes
         if let Err(e) = docker::remove_snapshot_image(project).await {
             log::warn!("Failed to remove snapshot image for project {}: {}", project_id, e);
@@ -143,10 +168,7 @@ pub async fn start_project_container(
     let image_name = container_config::resolve_image_name(&settings.image_source, &settings.custom_image_name);
 
     // Resolve enabled MCP servers for this project
-    let all_mcp_servers = state.mcp_store.list();
+    let (enabled_mcp, docker_mcp) = resolve_mcp_servers(&project, &state);
-    let enabled_mcp: Vec<McpServer> = project.enabled_mcp_servers.iter()
-        .filter_map(|id| all_mcp_servers.iter().find(|s| &s.id == id).cloned())
-        .collect();
 
     // Validate auth mode requirements
     if project.auth_mode == AuthMode::Bedrock {
@@ -178,6 +200,17 @@ pub async fn start_project_container(
         // AWS config path from global settings
         let aws_config_path = settings.global_aws.aws_config_path.clone();
 
+        // Set up Docker network and MCP containers if needed
+        let network_name = if !docker_mcp.is_empty() {
+            emit_progress(&app_handle, &project_id, "Setting up MCP network...");
+            let net = docker::ensure_project_network(&project.id).await?;
+            emit_progress(&app_handle, &project_id, "Starting MCP containers...");
+            docker::start_mcp_containers(&docker_mcp, &net).await?;
+            Some(net)
+        } else {
+            None
+        };
+
         let container_id = if let Some(existing_id) = docker::find_existing_container(&project).await? {
             // Check if config changed — if so, snapshot + recreate
             let needs_recreate = docker::container_needs_recreation(
@@ -218,6 +251,7 @@ pub async fn start_project_container(
                     &settings.global_custom_env_vars,
                     settings.timezone.as_deref(),
                     &enabled_mcp,
+                    network_name.as_deref(),
                 ).await?;
                 emit_progress(&app_handle, &project_id, "Starting container...");
                 docker::start_container(&new_id).await?;
@@ -250,6 +284,7 @@ pub async fn start_project_container(
                 &settings.global_custom_env_vars,
                 settings.timezone.as_deref(),
                 &enabled_mcp,
+                network_name.as_deref(),
             ).await?;
             emit_progress(&app_handle, &project_id, "Starting container...");
             docker::start_container(&new_id).await?;
@@ -299,6 +334,15 @@ pub async fn stop_project_container(
         }
     }
 
+    // Stop MCP containers (best-effort)
+    let (_enabled_mcp, docker_mcp) = resolve_mcp_servers(&project, &state);
+    if !docker_mcp.is_empty() {
+        emit_progress(&app_handle, &project_id, "Stopping MCP containers...");
+        if let Err(e) = docker::stop_mcp_containers(&docker_mcp).await {
+            log::warn!("Failed to stop MCP containers for project {}: {}", project_id, e);
+        }
+    }
+
     state.projects_store.update_status(&project_id, ProjectStatus::Stopped)?;
     Ok(())
 }
@@ -322,6 +366,14 @@ pub async fn rebuild_project_container(
         state.projects_store.set_container_id(&project_id, None)?;
     }
 
+    // Remove MCP containers before rebuild
+    let (_enabled_mcp, docker_mcp) = resolve_mcp_servers(&project, &state);
+    if !docker_mcp.is_empty() {
+        if let Err(e) = docker::remove_mcp_containers(&docker_mcp).await {
+            log::warn!("Failed to remove MCP containers for project {}: {}", project_id, e);
+        }
+    }
+
     // Remove snapshot image + volumes so Reset creates from the clean base image
     if let Err(e) = docker::remove_snapshot_image(&project).await {
         log::warn!("Failed to remove snapshot image for project {}: {}", project_id, e);

app/src-tauri/src/docker/container.rs

@@ -5,8 +5,7 @@ use bollard::container::{
 use bollard::image::{CommitContainerOptions, RemoveImageOptions};
 use bollard::models::{ContainerSummary, HostConfig, Mount, MountTypeEnum, PortBinding};
 use std::collections::HashMap;
-use std::collections::hash_map::DefaultHasher;
+use sha2::{Sha256, Digest};
-use std::hash::{Hash, Hasher};
 
 use super::client::get_docker;
 use crate::models::{AuthMode, BedrockAuthMethod, ContainerInfo, EnvVar, GlobalAwsSettings, McpServer, McpTransportType, PortMapping, Project, ProjectPath};
@@ -129,20 +128,28 @@ fn merge_claude_instructions(
     }
 }
 
+/// Hash a string with SHA-256 and return the hex digest.
+fn sha256_hex(input: &str) -> String {
+    let mut hasher = Sha256::new();
+    hasher.update(input.as_bytes());
+    format!("{:x}", hasher.finalize())
+}
+
 /// Compute a fingerprint for the Bedrock configuration so we can detect changes.
 fn compute_bedrock_fingerprint(project: &Project) -> String {
     if let Some(ref bedrock) = project.bedrock_config {
-        let mut hasher = DefaultHasher::new();
+        let parts = vec![
-        format!("{:?}", bedrock.auth_method).hash(&mut hasher);
+            format!("{:?}", bedrock.auth_method),
-        bedrock.aws_region.hash(&mut hasher);
+            bedrock.aws_region.clone(),
-        bedrock.aws_access_key_id.hash(&mut hasher);
+            bedrock.aws_access_key_id.as_deref().unwrap_or("").to_string(),
-        bedrock.aws_secret_access_key.hash(&mut hasher);
+            bedrock.aws_secret_access_key.as_deref().unwrap_or("").to_string(),
-        bedrock.aws_session_token.hash(&mut hasher);
+            bedrock.aws_session_token.as_deref().unwrap_or("").to_string(),
-        bedrock.aws_profile.hash(&mut hasher);
+            bedrock.aws_profile.as_deref().unwrap_or("").to_string(),
-        bedrock.aws_bearer_token.hash(&mut hasher);
+            bedrock.aws_bearer_token.as_deref().unwrap_or("").to_string(),
-        bedrock.model_id.hash(&mut hasher);
+            bedrock.model_id.as_deref().unwrap_or("").to_string(),
-        bedrock.disable_prompt_caching.hash(&mut hasher);
+            format!("{}", bedrock.disable_prompt_caching),
-        format!("{:x}", hasher.finish())
+        ];
+        sha256_hex(&parts.join("|"))
     } else {
         String::new()
     }
@@ -157,9 +164,7 @@ fn compute_paths_fingerprint(paths: &[ProjectPath]) -> String {
         .collect();
     parts.sort();
     let joined = parts.join(",");
-    let mut hasher = DefaultHasher::new();
+    sha256_hex(&joined)
-    joined.hash(&mut hasher);
-    format!("{:x}", hasher.finish())
 }
 
 /// Compute a fingerprint for port mappings so we can detect changes.
@@ -171,13 +176,17 @@ fn compute_ports_fingerprint(port_mappings: &[PortMapping]) -> String {
         .collect();
     parts.sort();
     let joined = parts.join(",");
-    let mut hasher = DefaultHasher::new();
+    sha256_hex(&joined)
-    joined.hash(&mut hasher);
-    format!("{:x}", hasher.finish())
 }
 
 /// Build the JSON value for MCP servers config to be injected into ~/.claude.json.
 /// Produces `{"mcpServers": {"name": {"type": "stdio", ...}, ...}}`.
+///
+/// Handles 4 modes:
+/// - Stdio+Docker: `docker exec -i <mcp-container-name> <command> ...args`
+/// - Stdio+Manual: `<command> ...args` (existing behavior)
+/// - HTTP+Docker: `streamableHttp` URL pointing to `http://<mcp-container-name>:<port>/mcp`
+/// - HTTP+Manual: `streamableHttp` with user-provided URL + headers
 fn build_mcp_servers_json(servers: &[McpServer]) -> String {
     let mut mcp_map = serde_json::Map::new();
     for server in servers {
@@ -185,18 +194,44 @@ fn build_mcp_servers_json(servers: &[McpServer]) -> String {
         match server.transport_type {
             McpTransportType::Stdio => {
                 entry.insert("type".to_string(), serde_json::json!("stdio"));
+                if server.is_docker() {
+                    // Stdio+Docker: use `docker exec` to communicate with MCP container
+                    entry.insert("command".to_string(), serde_json::json!("docker"));
+                    let mut args = vec![
+                        "exec".to_string(),
+                        "-i".to_string(),
+                        server.mcp_container_name(),
+                    ];
+                    if let Some(ref cmd) = server.command {
+                        args.push(cmd.clone());
+                    }
+                    args.extend(server.args.iter().cloned());
+                    entry.insert("args".to_string(), serde_json::json!(args));
+                } else {
+                    // Stdio+Manual: existing behavior
                     if let Some(ref cmd) = server.command {
                         entry.insert("command".to_string(), serde_json::json!(cmd));
                     }
                     if !server.args.is_empty() {
                         entry.insert("args".to_string(), serde_json::json!(server.args));
                     }
+                }
                 if !server.env.is_empty() {
                     entry.insert("env".to_string(), serde_json::json!(server.env));
                 }
             }
             McpTransportType::Http => {
-                entry.insert("type".to_string(), serde_json::json!("http"));
+                entry.insert("type".to_string(), serde_json::json!("streamableHttp"));
+                if server.is_docker() {
+                    // HTTP+Docker: point to MCP container by name on the shared network
+                    let url = format!(
+                        "http://{}:{}/mcp",
+                        server.mcp_container_name(),
+                        server.effective_container_port()
+                    );
+                    entry.insert("url".to_string(), serde_json::json!(url));
+                } else {
+                    // HTTP+Manual: user-provided URL + headers
                     if let Some(ref url) = server.url {
                         entry.insert("url".to_string(), serde_json::json!(url));
                     }
@@ -204,14 +239,6 @@ fn build_mcp_servers_json(servers: &[McpServer]) -> String {
                         entry.insert("headers".to_string(), serde_json::json!(server.headers));
                     }
                 }
-            McpTransportType::Sse => {
-                entry.insert("type".to_string(), serde_json::json!("sse"));
-                if let Some(ref url) = server.url {
-                    entry.insert("url".to_string(), serde_json::json!(url));
-                }
-                if !server.headers.is_empty() {
-                    entry.insert("headers".to_string(), serde_json::json!(server.headers));
-                }
             }
         }
         mcp_map.insert(server.name.clone(), serde_json::Value::Object(entry));
@@ -226,9 +253,7 @@ fn compute_mcp_fingerprint(servers: &[McpServer]) -> String {
         return String::new();
     }
     let json = build_mcp_servers_json(servers);
-    let mut hasher = DefaultHasher::new();
+    sha256_hex(&json)
-    json.hash(&mut hasher);
-    format!("{:x}", hasher.finish())
 }
 
 pub async fn find_existing_container(project: &Project) -> Result<Option<String>, String> {
@@ -271,6 +296,7 @@ pub async fn create_container(
     global_custom_env_vars: &[EnvVar],
     timezone: Option<&str>,
     mcp_servers: &[McpServer],
+    network_name: Option<&str>,
 ) -> Result<String, String> {
     let docker = get_docker()?;
     let container_name = project.container_name();
@@ -492,8 +518,12 @@ pub async fn create_container(
         }
     }
 
-    // Docker socket (only if allowed)
+    // Docker socket (if allowed, or auto-enabled for stdio+Docker MCP servers)
-    if project.allow_docker_access {
+    let needs_docker_for_mcp = any_stdio_docker_mcp(mcp_servers);
+    if project.allow_docker_access || needs_docker_for_mcp {
+        if needs_docker_for_mcp && !project.allow_docker_access {
+            log::info!("Auto-enabling Docker socket access for stdio+Docker MCP servers");
+        }
         // On Windows, the named pipe (//./pipe/docker_engine) cannot be
         // bind-mounted into a Linux container. Docker Desktop exposes the
         // daemon socket as /var/run/docker.sock for container mounts.
@@ -542,6 +572,8 @@ pub async fn create_container(
         mounts: Some(mounts),
         port_bindings: if port_bindings.is_empty() { None } else { Some(port_bindings) },
         init: Some(true),
+        // Connect to project network if specified (for MCP container communication)
+        network_mode: network_name.map(|n| n.to_string()),
         ..Default::default()
     };
 
@@ -931,3 +963,178 @@ pub async fn list_sibling_containers() -> Result<Vec<ContainerSummary>, String>
 
     Ok(siblings)
 }
+
+// ── MCP Container Lifecycle ─────────────────────────────────────────────
+
+/// Returns true if any MCP server uses stdio transport with Docker.
+pub fn any_stdio_docker_mcp(servers: &[McpServer]) -> bool {
+    servers.iter().any(|s| s.is_docker() && s.transport_type == McpTransportType::Stdio)
+}
+
+/// Returns true if any MCP server uses Docker.
+pub fn any_docker_mcp(servers: &[McpServer]) -> bool {
+    servers.iter().any(|s| s.is_docker())
+}
+
+/// Find an existing MCP container by its expected name.
+pub async fn find_mcp_container(server: &McpServer) -> Result<Option<String>, String> {
+    let docker = get_docker()?;
+    let container_name = server.mcp_container_name();
+
+    let filters: HashMap<String, Vec<String>> = HashMap::from([
+        ("name".to_string(), vec![container_name.clone()]),
+    ]);
+
+    let containers: Vec<ContainerSummary> = docker
+        .list_containers(Some(ListContainersOptions {
+            all: true,
+            filters,
+            ..Default::default()
+        }))
+        .await
+        .map_err(|e| format!("Failed to list MCP containers: {}", e))?;
+
+    let expected = format!("/{}", container_name);
+    for c in &containers {
+        if let Some(names) = &c.names {
+            if names.iter().any(|n| n == &expected) {
+                return Ok(c.id.clone());
+            }
+        }
+    }
+
+    Ok(None)
+}
+
+/// Create a Docker container for an MCP server.
+pub async fn create_mcp_container(
+    server: &McpServer,
+    network_name: &str,
+) -> Result<String, String> {
+    let docker = get_docker()?;
+    let container_name = server.mcp_container_name();
+
+    let image = server
+        .docker_image
+        .as_ref()
+        .ok_or_else(|| format!("MCP server '{}' has no docker_image", server.name))?;
+
+    let mut env_vars: Vec<String> = Vec::new();
+    for (k, v) in &server.env {
+        env_vars.push(format!("{}={}", k, v));
+    }
+
+    // Build command + args as Cmd
+    let mut cmd: Vec<String> = Vec::new();
+    if let Some(ref command) = server.command {
+        cmd.push(command.clone());
+    }
+    cmd.extend(server.args.iter().cloned());
+
+    let mut labels = HashMap::new();
+    labels.insert("triple-c.managed".to_string(), "true".to_string());
+    labels.insert("triple-c.mcp-server".to_string(), server.id.clone());
+
+    let host_config = HostConfig {
+        network_mode: Some(network_name.to_string()),
+        ..Default::default()
+    };
+
+    let config = Config {
+        image: Some(image.clone()),
+        env: if env_vars.is_empty() { None } else { Some(env_vars) },
+        cmd: if cmd.is_empty() { None } else { Some(cmd) },
+        labels: Some(labels),
+        host_config: Some(host_config),
+        ..Default::default()
+    };
+
+    let options = CreateContainerOptions {
+        name: container_name.clone(),
+        ..Default::default()
+    };
+
+    let response = docker
+        .create_container(Some(options), config)
+        .await
+        .map_err(|e| format!("Failed to create MCP container '{}': {}", container_name, e))?;
+
+    log::info!(
+        "Created MCP container {} (image: {}) on network {}",
+        container_name,
+        image,
+        network_name
+    );
+    Ok(response.id)
+}
+
+/// Start all Docker-based MCP server containers. Finds or creates each one.
+pub async fn start_mcp_containers(
+    servers: &[McpServer],
+    network_name: &str,
+) -> Result<(), String> {
+    for server in servers {
+        if !server.is_docker() {
+            continue;
+        }
+
+        let container_id = if let Some(existing_id) = find_mcp_container(server).await? {
+            log::debug!("Found existing MCP container for '{}'", server.name);
+            existing_id
+        } else {
+            create_mcp_container(server, network_name).await?
+        };
+
+        // Start the container (ignore already-started errors)
+        if let Err(e) = start_container(&container_id).await {
+            let err_str = e.to_string();
+            if err_str.contains("already started") || err_str.contains("304") {
+                log::debug!("MCP container '{}' already running", server.name);
+            } else {
+                return Err(format!(
+                    "Failed to start MCP container '{}': {}",
+                    server.name, e
+                ));
+            }
+        }
+
+        log::info!("MCP container '{}' started", server.name);
+    }
+
+    Ok(())
+}
+
+/// Stop all Docker-based MCP server containers (best-effort).
+pub async fn stop_mcp_containers(servers: &[McpServer]) -> Result<(), String> {
+    for server in servers {
+        if !server.is_docker() {
+            continue;
+        }
+        if let Ok(Some(container_id)) = find_mcp_container(server).await {
+            if let Err(e) = stop_container(&container_id).await {
+                log::warn!("Failed to stop MCP container '{}': {}", server.name, e);
+            } else {
+                log::info!("Stopped MCP container '{}'", server.name);
+            }
+        }
+    }
+    Ok(())
+}
+
+/// Stop and remove all Docker-based MCP server containers (best-effort).
+pub async fn remove_mcp_containers(servers: &[McpServer]) -> Result<(), String> {
+    for server in servers {
+        if !server.is_docker() {
+            continue;
+        }
+        if let Ok(Some(container_id)) = find_mcp_container(server).await {
+            let _ = stop_container(&container_id).await;
+            if let Err(e) = remove_container(&container_id).await {
+                log::warn!("Failed to remove MCP container '{}': {}", server.name, e);
+            } else {
+                log::info!("Removed MCP container '{}'", server.name);
+            }
+        }
+    }
+    Ok(())
+}

app/src-tauri/src/docker/mod.rs

@@ -2,8 +2,10 @@ pub mod client;
 pub mod container;
 pub mod image;
 pub mod exec;
+pub mod network;
 
 pub use client::*;
 pub use container::*;
 pub use image::*;
 pub use exec::*;
+pub use network::*;

app/src-tauri/src/docker/network.rs

@@ -0,0 +1,128 @@
+use bollard::network::{CreateNetworkOptions, InspectNetworkOptions};
+use std::collections::HashMap;
+
+use super::client::get_docker;
+
+/// Network name for a project's MCP containers.
+fn project_network_name(project_id: &str) -> String {
+    format!("triple-c-net-{}", project_id)
+}
+
+/// Ensure a Docker bridge network exists for the project.
+/// Returns the network name.
+pub async fn ensure_project_network(project_id: &str) -> Result<String, String> {
+    let docker = get_docker()?;
+    let network_name = project_network_name(project_id);
+
+    // Check if network already exists
+    match docker
+        .inspect_network(&network_name, None::<InspectNetworkOptions<String>>)
+        .await
+    {
+        Ok(_) => {
+            log::debug!("Network {} already exists", network_name);
+            return Ok(network_name);
+        }
+        Err(_) => {
+            // Network doesn't exist, create it
+        }
+    }
+
+    let options = CreateNetworkOptions {
+        name: network_name.clone(),
+        driver: "bridge".to_string(),
+        labels: HashMap::from([
+            ("triple-c.managed".to_string(), "true".to_string()),
+            ("triple-c.project-id".to_string(), project_id.to_string()),
+        ]),
+        ..Default::default()
+    };
+
+    docker
+        .create_network(options)
+        .await
+        .map_err(|e| format!("Failed to create network {}: {}", network_name, e))?;
+
+    log::info!("Created Docker network {}", network_name);
+    Ok(network_name)
+}
+
+/// Connect a container to the project network.
+pub async fn connect_container_to_network(
+    container_id: &str,
+    network_name: &str,
+) -> Result<(), String> {
+    let docker = get_docker()?;
+
+    let config = bollard::network::ConnectNetworkOptions {
+        container: container_id.to_string(),
+        ..Default::default()
+    };
+
+    docker
+        .connect_network(network_name, config)
+        .await
+        .map_err(|e| {
+            format!(
+                "Failed to connect container {} to network {}: {}",
+                container_id, network_name, e
+            )
+        })?;
+
+    log::debug!(
+        "Connected container {} to network {}",
+        container_id,
+        network_name
+    );
+    Ok(())
+}
+
+/// Remove the project network (best-effort). Disconnects all containers first.
+pub async fn remove_project_network(project_id: &str) -> Result<(), String> {
+    let docker = get_docker()?;
+    let network_name = project_network_name(project_id);
+
+    // Inspect to get connected containers
+    let info = match docker
+        .inspect_network(&network_name, None::<InspectNetworkOptions<String>>)
+        .await
+    {
+        Ok(info) => info,
+        Err(_) => {
+            log::debug!(
+                "Network {} not found, nothing to remove",
+                network_name
+            );
+            return Ok(());
+        }
+    };
+
+    // Disconnect all containers
+    if let Some(containers) = info.containers {
+        for (container_id, _) in containers {
+            let disconnect_opts = bollard::network::DisconnectNetworkOptions {
+                container: container_id.clone(),
+                force: true,
+            };
+            if let Err(e) = docker
+                .disconnect_network(&network_name, disconnect_opts)
+                .await
+            {
+                log::warn!(
+                    "Failed to disconnect container {} from network {}: {}",
+                    container_id,
+                    network_name,
+                    e
+                );
+            }
+        }
+    }
+
+    // Remove the network
+    match docker.remove_network(&network_name).await {
+        Ok(_) => log::info!("Removed Docker network {}", network_name),
+        Err(e) => log::warn!("Failed to remove network {}: {}", network_name, e),
+    }
+
+    Ok(())
+}

app/src-tauri/src/models/mcp_server.rs

@@ -5,8 +5,8 @@ use std::collections::HashMap;
 #[serde(rename_all = "snake_case")]
 pub enum McpTransportType {
     Stdio,
+    #[serde(alias = "sse")]
     Http,
-    Sse,
 }
 
 impl Default for McpTransportType {
@@ -29,6 +29,10 @@ pub struct McpServer {
     pub url: Option<String>,
     #[serde(default)]
     pub headers: HashMap<String, String>,
+    #[serde(default)]
+    pub docker_image: Option<String>,
+    #[serde(default)]
+    pub container_port: Option<u16>,
     pub created_at: String,
     pub updated_at: String,
 }
@@ -45,8 +49,22 @@ impl McpServer {
             env: HashMap::new(),
             url: None,
             headers: HashMap::new(),
+            docker_image: None,
+            container_port: None,
             created_at: now.clone(),
             updated_at: now,
         }
     }
+
+    pub fn is_docker(&self) -> bool {
+        self.docker_image.is_some()
+    }
+
+    pub fn mcp_container_name(&self) -> String {
+        format!("triple-c-mcp-{}", self.id)
+    }
+
+    pub fn effective_container_port(&self) -> u16 {
+        self.container_port.unwrap_or(3000)
+    }
 }

app/src/components/layout/Sidebar.tsx

@@ -24,7 +24,7 @@ export default function Sidebar() {
           Projects
         </button>
         <button onClick={() => setSidebarView("mcp")} className={tabCls("mcp")}>
-          MCP
+          MCP <span className="text-[0.6rem] px-1 py-0.5 rounded bg-yellow-500/20 text-yellow-400 ml-0.5">Beta</span>
         </button>
         <button onClick={() => setSidebarView("settings")} className={tabCls("settings")}>
           Settings

app/src/components/mcp/McpPanel.tsx

@@ -26,7 +26,10 @@ export default function McpPanel() {
   return (
     <div className="space-y-3 p-2">
       <div>
-        <h2 className="text-sm font-semibold text-[var(--text-primary)]">MCP Servers</h2>
+        <h2 className="text-sm font-semibold text-[var(--text-primary)]">
+          MCP Servers{" "}
+          <span className="text-xs px-1.5 py-0.5 rounded bg-yellow-500/20 text-yellow-400">Beta</span>
+        </h2>
         <p className="text-xs text-[var(--text-secondary)] mt-0.5">
           Define MCP servers globally, then enable them per-project.
         </p>

app/src/components/mcp/McpServerCard.tsx

@@ -16,6 +16,8 @@ export default function McpServerCard({ server, onUpdate, onRemove }: Props) {
   const [envPairs, setEnvPairs] = useState<[string, string][]>(Object.entries(server.env));
   const [url, setUrl] = useState(server.url ?? "");
   const [headerPairs, setHeaderPairs] = useState<[string, string][]>(Object.entries(server.headers));
+  const [dockerImage, setDockerImage] = useState(server.docker_image ?? "");
+  const [containerPort, setContainerPort] = useState(server.container_port?.toString() ?? "3000");
 
   useEffect(() => {
     setName(server.name);
@@ -25,6 +27,8 @@ export default function McpServerCard({ server, onUpdate, onRemove }: Props) {
     setEnvPairs(Object.entries(server.env));
     setUrl(server.url ?? "");
     setHeaderPairs(Object.entries(server.headers));
+    setDockerImage(server.docker_image ?? "");
+    setContainerPort(server.container_port?.toString() ?? "3000");
   }, [server]);
 
   const saveServer = async (patch: Partial<McpServer>) => {
@@ -57,6 +61,15 @@ export default function McpServerCard({ server, onUpdate, onRemove }: Props) {
     saveServer({ url: url || null });
   };
 
+  const handleDockerImageBlur = () => {
+    saveServer({ docker_image: dockerImage || null });
+  };
+
+  const handleContainerPortBlur = () => {
+    const port = parseInt(containerPort, 10);
+    saveServer({ container_port: isNaN(port) ? null : port });
+  };
+
   const saveEnv = (pairs: [string, string][]) => {
     const env: Record<string, string> = {};
     for (const [k, v] of pairs) {
@@ -75,12 +88,15 @@ export default function McpServerCard({ server, onUpdate, onRemove }: Props) {
 
   const inputCls = "w-full px-2 py-1 bg-[var(--bg-primary)] border border-[var(--border-color)] rounded text-xs text-[var(--text-primary)] focus:outline-none focus:border-[var(--accent)]";
 
+  const isDocker = !!dockerImage;
+
   const transportBadge = {
     stdio: "Stdio",
     http: "HTTP",
-    sse: "SSE",
   }[transportType];
 
+  const modeBadge = isDocker ? "Docker" : "Manual";
+
   return (
     <div className="border border-[var(--border-color)] rounded bg-[var(--bg-primary)]">
       {/* Header */}
@@ -94,6 +110,9 @@ export default function McpServerCard({ server, onUpdate, onRemove }: Props) {
           <span className="text-xs px-1.5 py-0.5 rounded bg-[var(--bg-secondary)] text-[var(--text-secondary)]">
             {transportBadge}
           </span>
+          <span className={`text-xs px-1.5 py-0.5 rounded ${isDocker ? "bg-blue-500/20 text-blue-400" : "bg-[var(--bg-secondary)] text-[var(--text-secondary)]"}`}>
+            {modeBadge}
+          </span>
         </button>
         <button
           onClick={() => { if (confirm(`Remove MCP server "${server.name}"?`)) onRemove(server.id); }}
@@ -117,11 +136,26 @@ export default function McpServerCard({ server, onUpdate, onRemove }: Props) {
             />
           </div>
 
+          {/* Docker Image (primary field — determines Docker vs Manual mode) */}
+          <div>
+            <label className="block text-xs text-[var(--text-secondary)] mb-0.5">Docker Image</label>
+            <input
+              value={dockerImage}
+              onChange={(e) => setDockerImage(e.target.value)}
+              onBlur={handleDockerImageBlur}
+              placeholder="e.g. mcp/filesystem:latest (leave empty for manual mode)"
+              className={inputCls}
+            />
+            <p className="text-xs text-[var(--text-secondary)] mt-0.5 opacity-60">
+              Set a Docker image to run this MCP server as a container. Leave empty for manual mode.
+            </p>
+          </div>
+
           {/* Transport type */}
           <div>
             <label className="block text-xs text-[var(--text-secondary)] mb-0.5">Transport</label>
             <div className="flex items-center gap-1">
-              {(["stdio", "http", "sse"] as McpTransportType[]).map((t) => (
+              {(["stdio", "http"] as McpTransportType[]).map((t) => (
                 <button
                   key={t}
                   onClick={() => handleTransportChange(t)}
@@ -131,12 +165,29 @@ export default function McpServerCard({ server, onUpdate, onRemove }: Props) {
                       : "text-[var(--text-secondary)] hover:text-[var(--text-primary)] hover:bg-[var(--bg-secondary)]"
                   }`}
                 >
-                  {t === "stdio" ? "Stdio" : t === "http" ? "HTTP" : "SSE"}
+                  {t === "stdio" ? "Stdio" : "HTTP"}
                 </button>
               ))}
             </div>
           </div>
 
+          {/* Container Port (HTTP+Docker only) */}
+          {transportType === "http" && isDocker && (
+            <div>
+              <label className="block text-xs text-[var(--text-secondary)] mb-0.5">Container Port</label>
+              <input
+                value={containerPort}
+                onChange={(e) => setContainerPort(e.target.value)}
+                onBlur={handleContainerPortBlur}
+                placeholder="3000"
+                className={inputCls}
+              />
+              <p className="text-xs text-[var(--text-secondary)] mt-0.5 opacity-60">
+                Port inside the MCP container (default: 3000)
+              </p>
+            </div>
+          )}
+
           {/* Stdio fields */}
           {transportType === "stdio" && (
             <>
@@ -146,7 +197,7 @@ export default function McpServerCard({ server, onUpdate, onRemove }: Props) {
                   value={command}
                   onChange={(e) => setCommand(e.target.value)}
                   onBlur={handleCommandBlur}
-                  placeholder="npx"
+                  placeholder={isDocker ? "Command inside container" : "npx"}
                   className={inputCls}
                 />
               </div>
@@ -169,8 +220,8 @@ export default function McpServerCard({ server, onUpdate, onRemove }: Props) {
             </>
           )}
 
-          {/* HTTP/SSE fields */}
+          {/* HTTP fields (only for manual mode — Docker mode auto-generates URL) */}
-          {(transportType === "http" || transportType === "sse") && (
+          {transportType === "http" && !isDocker && (
             <>
               <div>
                 <label className="block text-xs text-[var(--text-secondary)] mb-0.5">URL</label>
@@ -190,6 +241,16 @@ export default function McpServerCard({ server, onUpdate, onRemove }: Props) {
               />
             </>
           )}
+
+          {/* Environment variables for HTTP+Docker */}
+          {transportType === "http" && isDocker && (
+            <KeyValueEditor
+              label="Environment Variables"
+              pairs={envPairs}
+              onChange={(pairs) => { setEnvPairs(pairs); }}
+              onSave={saveEnv}
+            />
+          )}
         </div>
       )}
     </div>

app/src/components/projects/ProjectCard.tsx

@@ -622,6 +622,7 @@ export default function ProjectCard({ project }: Props) {
                   <div className="space-y-1">
                     {mcpServers.map((server) => {
                       const enabled = project.enabled_mcp_servers.includes(server.id);
+                      const isDocker = !!server.docker_image;
                       return (
                         <label key={server.id} className="flex items-center gap-2 cursor-pointer">
                           <input
@@ -642,10 +643,18 @@ export default function ProjectCard({ project }: Props) {
                           />
                           <span className="text-xs text-[var(--text-primary)]">{server.name}</span>
                           <span className="text-xs text-[var(--text-secondary)]">({server.transport_type})</span>
+                          <span className={`text-xs px-1 py-0.5 rounded ${isDocker ? "bg-blue-500/20 text-blue-400" : "bg-[var(--bg-secondary)] text-[var(--text-secondary)]"}`}>
+                            {isDocker ? "Docker" : "Manual"}
+                          </span>
                         </label>
                       );
                     })}
                   </div>
+                  {mcpServers.some((s) => s.docker_image && s.transport_type === "stdio" && project.enabled_mcp_servers.includes(s.id)) && (
+                    <p className="text-xs text-[var(--text-secondary)] mt-1 opacity-70">
+                      Docker access will be auto-enabled for stdio+Docker MCP servers.
+                    </p>
+                  )}
                 </div>
               )}
 

app/src/lib/types.ts

@@ -117,7 +117,7 @@ export interface ReleaseAsset {
   size: number;
 }
 
-export type McpTransportType = "stdio" | "http" | "sse";
+export type McpTransportType = "stdio" | "http";
 
 export interface McpServer {
   id: string;
@@ -128,6 +128,8 @@ export interface McpServer {
   env: Record<string, string>;
   url: string | null;
   headers: Record<string, string>;
+  docker_image: string | null;
+  container_port: number | null;
   created_at: string;
   updated_at: string;
 }