feat: add opt-in Coder identity headers for MCP servers (#25153)

site/src/api/typesGenerated.ts

@@ -3071,6 +3071,11 @@ export interface CreateMCPServerConfigRequest {
 	readonly enabled: boolean;
 	readonly model_intent: boolean;
 	readonly allow_in_plan_mode: boolean;
+	/**
+	 * ForwardCoderHeaders, when true, forwards Coder identity
+	 * headers on every outgoing MCP request. See MCPServerConfig.
+	 */
+	readonly forward_coder_headers: boolean;
 }
 
 // From codersdk/organizations.go
@@ -4775,6 +4780,14 @@ export interface MCPServerConfig {
 	readonly enabled: boolean;
 	readonly model_intent: boolean;
 	readonly allow_in_plan_mode: boolean;
+	/**
+	 * ForwardCoderHeaders forwards the same Coder identity headers we
+	 * send to LLM providers (X-Coder-Owner-Id, X-Coder-Chat-Id, and the
+	 * optional X-Coder-Subchat-Id and X-Coder-Workspace-Id) to this
+	 * MCP server on every request. Off by default to avoid leaking
+	 * chat identity to third-party servers.
+	 */
+	readonly forward_coder_headers: boolean;
 	readonly created_at: string;
 	readonly updated_at: string;
 	/**
@@ -8230,6 +8243,11 @@ export interface UpdateMCPServerConfigRequest {
 	readonly enabled?: boolean;
 	readonly model_intent?: boolean;
 	readonly allow_in_plan_mode?: boolean;
+	/**
+	 * ForwardCoderHeaders, when set, updates whether Coder identity
+	 * headers are forwarded on every outgoing MCP request.
+	 */
+	readonly forward_coder_headers?: boolean;
 }
 
 // From codersdk/notifications.go

site/src/pages/AgentsPage/components/AgentChatInput.stories.tsx

@@ -707,6 +707,7 @@ const makeMCPServer = (
 	enabled: overrides.enabled ?? true,
 	model_intent: overrides.model_intent ?? false,
 	allow_in_plan_mode: overrides.allow_in_plan_mode ?? false,
+	forward_coder_headers: overrides.forward_coder_headers ?? false,
 	created_at: overrides.created_at ?? now,
 	updated_at: overrides.updated_at ?? now,
 	auth_connected: overrides.auth_connected ?? false,

site/src/pages/AgentsPage/components/ChatElements/tools/Tool.stories.tsx

@@ -757,6 +757,7 @@ const sampleMCPServers = [
 		enabled: true,
 		model_intent: false,
 		allow_in_plan_mode: false,
+		forward_coder_headers: false,
 		auth_connected: true,
 		created_at: "2025-01-01T00:00:00Z",
 		updated_at: "2025-01-01T00:00:00Z",

site/src/pages/AgentsPage/components/MCPServerAdminPanel.stories.tsx

@@ -34,6 +34,7 @@ const createServerConfig = (
 	enabled: overrides.enabled ?? true,
 	model_intent: overrides.model_intent ?? false,
 	allow_in_plan_mode: overrides.allow_in_plan_mode ?? false,
+	forward_coder_headers: overrides.forward_coder_headers ?? false,
 	created_at: overrides.created_at ?? now,
 	updated_at: overrides.updated_at ?? now,
 	auth_connected: overrides.auth_connected ?? false,

site/src/pages/AgentsPage/components/MCPServerAdminPanel.tsx

@@ -347,6 +347,7 @@ interface MCPServerFormValues {
 	enabled: boolean;
 	modelIntent: boolean;
 	allowInPlanMode: boolean;
+	forwardCoderHeaders: boolean;
 	toolAllowList: string;
 	toolDenyList: string;
 	customHeaders: Array<{ key: string; value: string }>;
@@ -377,6 +378,7 @@ const buildInitialValues = (
 	enabled: server?.enabled ?? true,
 	modelIntent: server?.model_intent ?? false,
 	allowInPlanMode: server?.allow_in_plan_mode ?? false,
+	forwardCoderHeaders: server?.forward_coder_headers ?? false,
 	toolAllowList: joinList(server?.tool_allow_list),
 	toolDenyList: joinList(server?.tool_deny_list),
 	customHeaders: [],
@@ -435,6 +437,7 @@ const ServerForm: FC<ServerFormProps> = ({
 				enabled: values.enabled,
 				model_intent: values.modelIntent,
 				allow_in_plan_mode: values.allowInPlanMode,
+				forward_coder_headers: values.forwardCoderHeaders,
 				...(values.authType === "oauth2" && {
 					oauth2_client_id: values.oauth2ClientID.trim(),
 					oauth2_client_secret: effectiveOAuth2Secret,
@@ -933,7 +936,8 @@ const ServerForm: FC<ServerFormProps> = ({
 											Behavior
 										</h3>
 										<p className="m-0 text-xs text-content-secondary">
-											Availability, model intent, and tool governance.
+											Availability, model intent, identity headers, and tool
+											governance.
 										</p>
 									</div>
 									{showBehavior ? (
@@ -1017,6 +1021,31 @@ const ServerForm: FC<ServerFormProps> = ({
 									/>
 								</div>
 
+								<div className="flex items-start justify-between gap-4">
+									<div className="min-w-0 space-y-1">
+										<Label
+											htmlFor={`${formId}-forward-coder-headers`}
+											className="text-sm font-medium text-content-primary"
+										>
+											Forward Coder identity headers
+										</Label>
+										<p className="m-0 text-xs text-content-secondary">
+											When enabled, every outgoing MCP request includes the
+											Coder owner, chat, subchat, and workspace IDs as
+											<code>X-Coder-*</code> headers. Off by default. Only
+											enable for first-party or trusted MCP servers.
+										</p>
+									</div>
+									<Switch
+										id={`${formId}-forward-coder-headers`}
+										checked={form.values.forwardCoderHeaders}
+										onCheckedChange={(v) => {
+											form.setFieldValue("forwardCoderHeaders", v);
+										}}
+										disabled={isDisabled}
+									/>
+								</div>
+
 								<div className="grid items-start gap-4 sm:grid-cols-2">
 									<Field
 										label="Tool Allow List"

site/src/pages/AgentsPage/components/MCPServerPicker.stories.tsx

@@ -33,6 +33,7 @@ const createServerConfig = (
 	enabled: overrides.enabled ?? true,
 	model_intent: overrides.model_intent ?? false,
 	allow_in_plan_mode: overrides.allow_in_plan_mode ?? false,
+	forward_coder_headers: overrides.forward_coder_headers ?? false,
 	created_at: overrides.created_at ?? now,
 	updated_at: overrides.updated_at ?? now,
 	auth_connected: overrides.auth_connected ?? false,