Add approval mode selection

apps/admin-api/src/service/operation_validation.rs

@@ -125,6 +125,17 @@ pub(super) fn validate_approval_policy(
         ));
     }
 
+    if let Some(message) = policy.elicitation_message.as_ref() {
+        if message.chars().count() > 240 {
+            return Err(ApiError::validation_with_context(
+                "approval elicitation message must be at most 240 characters".to_owned(),
+                json!({
+                    "field": "execution_config.approval_policy.elicitation_message",
+                }),
+            ));
+        }
+    }
+
     Ok(())
 }
 
@@ -133,7 +144,7 @@ mod tests {
     use std::collections::BTreeMap;
 
     use crank_core::{
-        ExecutionConfig, HttpMethod, IdempotencyMode, IdempotencyPolicy,
+        ExecutionConfig, HttpMethod, IdempotencyMode, IdempotencyPolicy, OperationApprovalMode,
         OperationApprovalPayloadPreviewMode, OperationApprovalPolicy, OperationApprovalRiskLevel,
         ResponseCachePolicy, RestTarget, Target,
     };
@@ -272,10 +283,12 @@ mod tests {
         let mut config = cacheable_execution_config();
         config.approval_policy = Some(OperationApprovalPolicy {
             required: true,
+            mode: OperationApprovalMode::Custom,
             risk_level: OperationApprovalRiskLevel::Dangerous,
             ttl_seconds: 300,
             show_payload_preview: true,
             payload_preview_mode: OperationApprovalPayloadPreviewMode::MaskedJson,
+            elicitation_message: None,
         });
 
         validate_approval_policy(&config).unwrap();
@@ -286,10 +299,12 @@ mod tests {
         let mut config = cacheable_execution_config();
         config.approval_policy = Some(OperationApprovalPolicy {
             required: true,
+            mode: OperationApprovalMode::Custom,
             risk_level: OperationApprovalRiskLevel::Dangerous,
             ttl_seconds: 0,
             show_payload_preview: true,
             payload_preview_mode: OperationApprovalPayloadPreviewMode::MaskedJson,
+            elicitation_message: None,
         });
 
         let error = validate_approval_policy(&config).unwrap_err();

apps/mcp-server/tests/integration/catalog_access.rs

@@ -21,7 +21,7 @@ use base64::{Engine as _, engine::general_purpose::URL_SAFE_NO_PAD};
 use crank_core::{
     Agent, AgentId, AgentOperationBinding, AgentStatus, AgentVersion, ApprovalRequest,
     ApprovalRequestId, ApprovalRequestStatus, ExecutionConfig, HttpMethod, InvocationSource,
-    Operation, OperationApprovalPayloadPreviewMode, OperationApprovalPolicy,
+    Operation, OperationApprovalMode, OperationApprovalPayloadPreviewMode, OperationApprovalPolicy,
     OperationApprovalRiskLevel, OperationId, OperationStatus, PlatformApiKey, PlatformApiKeyId,
     PlatformApiKeyScope, PlatformApiKeyStatus, Protocol, RestTarget, Target, ToolDescription,
     WorkspaceId,

apps/mcp-server/tests/integration/catalog_access/approval_access.rs

@@ -359,10 +359,12 @@ async fn tool_call_with_approval_policy_creates_pending_request() {
     let mut operation = test_operation(&upstream_base_url, "crm_requires_human_approval");
     operation.execution_config.approval_policy = Some(OperationApprovalPolicy {
         required: true,
+        mode: OperationApprovalMode::Custom,
         risk_level: OperationApprovalRiskLevel::Dangerous,
         ttl_seconds: 300,
         show_payload_preview: true,
         payload_preview_mode: OperationApprovalPayloadPreviewMode::MaskedJson,
+        elicitation_message: None,
     });
     registry
         .create_operation(&test_workspace_id(), &operation, Some("alice"))
@@ -445,3 +447,171 @@ async fn tool_call_with_approval_policy_creates_pending_request() {
         "ada@example.com"
     );
 }
+
+#[tokio::test]
+async fn elicitation_approval_requires_client_capability() {
+    let registry = test_registry().await;
+    let upstream_base_url = spawn_upstream_server().await;
+    let mut operation = test_operation(&upstream_base_url, "crm_requires_elicitation");
+    operation.execution_config.approval_policy = Some(OperationApprovalPolicy {
+        required: true,
+        mode: OperationApprovalMode::Elicitation,
+        risk_level: OperationApprovalRiskLevel::Normal,
+        ttl_seconds: 300,
+        show_payload_preview: true,
+        payload_preview_mode: OperationApprovalPayloadPreviewMode::MaskedJson,
+        elicitation_message: Some("Подтвердите создание лида.".to_owned()),
+    });
+    registry
+        .create_operation(&test_workspace_id(), &operation, Some("alice"))
+        .await
+        .unwrap();
+    registry
+        .publish_operation(PublishRequest {
+            workspace_id: &test_workspace_id(),
+            operation_id: &operation.id,
+            version: 1,
+            published_at: &OffsetDateTime::now_utc(),
+            published_by: Some("alice"),
+        })
+        .await
+        .unwrap();
+    publish_agent_with_bindings(
+        &registry,
+        "sales-elicitation-no-capability",
+        vec![binding_for_operation(&operation)],
+    )
+    .await;
+    let api_key = create_platform_api_key(
+        &registry,
+        "sales-elicitation-no-capability",
+        "mcp-elicitation-no-capability",
+        &[PlatformApiKeyScope::Read, PlatformApiKeyScope::Write],
+    )
+    .await;
+    let base_url = spawn_mcp_server(build_test_app(
+        registry.clone(),
+        Duration::from_millis(0),
+        Some("https://crank.example.com".to_owned()),
+    ))
+    .await;
+    let client = reqwest::Client::new();
+    let mcp_url = agent_mcp_url(&base_url, "sales-elicitation-no-capability");
+    let initialized_session = initialize_session(&client, &mcp_url, &api_key).await;
+
+    let tool_result = post_jsonrpc(
+        &client,
+        &mcp_url,
+        &api_key,
+        Some(&initialized_session),
+        json!({
+            "jsonrpc": "2.0",
+            "id": 7,
+            "method": "tools/call",
+            "params": {
+                "name": "crm_requires_elicitation",
+                "arguments": {
+                    "email": "ada@example.com"
+                }
+            }
+        }),
+    )
+    .await;
+
+    assert_eq!(tool_result["result"]["isError"], true);
+    assert_eq!(
+        tool_result["result"]["structuredContent"]["error"]["code"],
+        "approval_elicitation_not_supported"
+    );
+}
+
+#[tokio::test]
+async fn elicitation_approval_uses_session_capability_without_approval_key() {
+    let registry = test_registry().await;
+    let upstream_base_url = spawn_upstream_server().await;
+    let mut operation = test_operation(&upstream_base_url, "crm_requires_elicitation_supported");
+    operation.execution_config.approval_policy = Some(OperationApprovalPolicy {
+        required: true,
+        mode: OperationApprovalMode::Elicitation,
+        risk_level: OperationApprovalRiskLevel::Normal,
+        ttl_seconds: 300,
+        show_payload_preview: true,
+        payload_preview_mode: OperationApprovalPayloadPreviewMode::MaskedJson,
+        elicitation_message: Some("Подтвердите создание лида.".to_owned()),
+    });
+    registry
+        .create_operation(&test_workspace_id(), &operation, Some("alice"))
+        .await
+        .unwrap();
+    registry
+        .publish_operation(PublishRequest {
+            workspace_id: &test_workspace_id(),
+            operation_id: &operation.id,
+            version: 1,
+            published_at: &OffsetDateTime::now_utc(),
+            published_by: Some("alice"),
+        })
+        .await
+        .unwrap();
+    publish_agent_with_bindings(
+        &registry,
+        "sales-elicitation-supported",
+        vec![binding_for_operation(&operation)],
+    )
+    .await;
+    let api_key = create_platform_api_key(
+        &registry,
+        "sales-elicitation-supported",
+        "mcp-elicitation-supported",
+        &[PlatformApiKeyScope::Read, PlatformApiKeyScope::Write],
+    )
+    .await;
+    let base_url = spawn_mcp_server(build_test_app(
+        registry.clone(),
+        Duration::from_millis(0),
+        Some("https://crank.example.com".to_owned()),
+    ))
+    .await;
+    let client = reqwest::Client::new();
+    let mcp_url = agent_mcp_url(&base_url, "sales-elicitation-supported");
+    let initialized_session = initialize_session_with_capabilities(
+        &client,
+        &mcp_url,
+        &api_key,
+        json!({ "elicitation": {} }),
+    )
+    .await;
+
+    let tool_result = post_jsonrpc(
+        &client,
+        &mcp_url,
+        &api_key,
+        Some(&initialized_session),
+        json!({
+            "jsonrpc": "2.0",
+            "id": 8,
+            "method": "tools/call",
+            "params": {
+                "name": "crm_requires_elicitation_supported",
+                "arguments": {
+                    "email": "ada@example.com"
+                }
+            }
+        }),
+    )
+    .await;
+
+    assert_eq!(tool_result["result"]["isError"], false);
+    assert_eq!(
+        tool_result["result"]["structuredContent"]["status"],
+        "elicitation_required"
+    );
+    assert_eq!(
+        tool_result["result"]["structuredContent"]["message"],
+        "Подтвердите создание лида."
+    );
+    assert_eq!(
+        tool_result["result"]["structuredContent"]["payload_preview"]["email"],
+        "ada@example.com"
+    );
+}

apps/mcp-server/tests/integration/common.rs

@@ -147,6 +147,15 @@ pub(super) async fn initialize_session(
     client: &reqwest::Client,
     mcp_url: &str,
     api_key: &str,
+) -> String {
+    initialize_session_with_capabilities(client, mcp_url, api_key, json!({})).await
+}
+
+pub(super) async fn initialize_session_with_capabilities(
+    client: &reqwest::Client,
+    mcp_url: &str,
+    api_key: &str,
+    capabilities: Value,
 ) -> String {
     let initialize_response = client
         .post(mcp_url)
@@ -157,7 +166,8 @@ pub(super) async fn initialize_session(
             "id": 1,
             "method": "initialize",
             "params": {
-                "protocolVersion": "2025-11-25"
+                "protocolVersion": "2025-11-25",
+                "capabilities": capabilities
             }
         }))
         .send()

apps/mcp-server/tests/integration/transport_protocol.rs

@@ -689,6 +689,7 @@ async fn get_returns_not_found_for_expired_transport_session() {
             "2025-11-25",
             test_workspace_slug(),
             "sales-expired-session",
+            false,
             OffsetDateTime::parse("2026-05-01T10:00:00Z", &Rfc3339).unwrap(),
             Some(OffsetDateTime::parse("2026-05-01T10:00:01Z", &Rfc3339).unwrap()),
         )

apps/ui/html/wizard/step3-rest.html

@@ -114,6 +114,42 @@
               </label>
 
               <div id="approval-config-fields" class="approval-config-fields" hidden>
+                <div class="form-group">
+                  <label class="form-label" for="approval-mode" data-i18n="wizard.approval.mode">Механизм подтверждения</label>
+                  <select id="approval-mode" class="form-select">
+                    <option value="custom" data-i18n="wizard.approval.mode.custom">Custom MCP Approval</option>
+                    <option value="elicitation" data-i18n="wizard.approval.mode.elicitation">MCP Elicitation</option>
+                  </select>
+                </div>
+
+                <div class="info-callout" id="approval-custom-info">
+                  <svg class="info-callout-icon" width="15" height="15" viewBox="0 0 16 16" fill="none" stroke="var(--accent)" stroke-width="1.7" stroke-linecap="round" stroke-linejoin="round">
+                    <circle cx="8" cy="8" r="6.5"></circle>
+                    <path d="M8 11V8M8 5.5V5"></path>
+                  </svg>
+                  <div class="info-callout-body">
+                    <div class="info-callout-title" data-i18n="wizard.approval.custom_title">Custom MCP Approval</div>
+                    <div class="info-callout-text" data-i18n="wizard.approval.custom_body">Crank вернёт MCP-клиенту approval_required с approval_id, approval_url и ссылками approve/deny. Ваш MCP-клиент должен обработать этот ответ, показать пользователю подтверждение и отправить решение на endpoint подтверждения. Для endpoint-а подтверждения нужен отдельный ключ подтверждения агента.</div>
+                  </div>
+                </div>
+
+                <div class="info-callout" id="approval-elicitation-info" hidden>
+                  <svg class="info-callout-icon" width="15" height="15" viewBox="0 0 16 16" fill="none" stroke="var(--accent)" stroke-width="1.7" stroke-linecap="round" stroke-linejoin="round">
+                    <circle cx="8" cy="8" r="6.5"></circle>
+                    <path d="M8 11V8M8 5.5V5"></path>
+                  </svg>
+                  <div class="info-callout-body">
+                    <div class="info-callout-title" data-i18n="wizard.approval.elicitation_title">MCP Elicitation</div>
+                    <div class="info-callout-text" data-i18n="wizard.approval.elicitation_body">Crank запросит подтверждение через стандартный MCP Elicitation. MCP-клиент должен поддерживать capability elicitation. Отдельный ключ подтверждения не используется: ответ пользователя возвращается по текущей MCP-сессии.</div>
+                  </div>
+                </div>
+
+                <div class="form-group" id="approval-elicitation-message-group" hidden>
+                  <label class="form-label" for="approval-elicitation-message" data-i18n="wizard.approval.elicitation_message">Сообщение для MCP-клиента</label>
+                  <textarea id="approval-elicitation-message" class="form-textarea" rows="3" maxlength="240" data-i18n-ph="wizard.approval.elicitation_message_placeholder" placeholder="Подтвердите выполнение операции."></textarea>
+                  <div class="form-hint" data-i18n="wizard.approval.elicitation_message_hint">Короткое протокольное сообщение. Внешний вид окна подтверждения всё равно определяет MCP-клиент.</div>
+                </div>
+
                 <div class="form-group">
                   <label class="form-label" for="approval-ttl-seconds" data-i18n="wizard.approval.ttl">Сколько ждать подтверждение</label>
                   <select id="approval-ttl-seconds" class="form-select">

apps/ui/js/i18n.js

@@ -598,6 +598,16 @@ var TRANSLATIONS = {
     'wizard.approval.subtitle': 'Enable this for actions that must not run without an explicit user decision.',
     'wizard.approval.required_label': 'Require confirmation before execution',
     'wizard.approval.required_desc': 'The MCP client receives a pending request, and the action runs only after confirmation through a separate approval endpoint.',
+    'wizard.approval.mode': 'Confirmation mechanism',
+    'wizard.approval.mode.custom': 'Custom MCP Approval',
+    'wizard.approval.mode.elicitation': 'MCP Elicitation',
+    'wizard.approval.custom_title': 'Custom MCP Approval',
+    'wizard.approval.custom_body': 'Crank returns approval_required to the MCP client with approval_id, approval_url and approve/deny links. Your MCP client must handle this response, show confirmation to the user and send the decision to the approval endpoint. The approval endpoint requires a separate agent approval key.',
+    'wizard.approval.elicitation_title': 'MCP Elicitation',
+    'wizard.approval.elicitation_body': 'Crank asks for confirmation through standard MCP Elicitation. The MCP client must support the elicitation capability. No separate approval key is used: the user decision returns through the current MCP session.',
+    'wizard.approval.elicitation_message': 'Message for the MCP client',
+    'wizard.approval.elicitation_message_placeholder': 'Confirm operation execution.',
+    'wizard.approval.elicitation_message_hint': 'Short protocol message. The MCP client still controls the confirmation UI.',
     'wizard.approval.ttl': 'How long to wait for confirmation',
     'wizard.approval.show_payload': 'Show request parameters',
     'wizard.approval.payload_mode': 'How to show parameters',
@@ -1453,6 +1463,16 @@ var TRANSLATIONS = {
     'wizard.approval.subtitle': 'Включайте для действий, которые нельзя выполнять без явного решения пользователя.',
     'wizard.approval.required_label': 'Требовать подтверждение перед выполнением',
     'wizard.approval.required_desc': 'MCP клиент получит ожидающий запрос, а действие выполнится только после подтверждения через отдельный эндпоинт подтверждения.',
+    'wizard.approval.mode': 'Механизм подтверждения',
+    'wizard.approval.mode.custom': 'Custom MCP Approval',
+    'wizard.approval.mode.elicitation': 'MCP Elicitation',
+    'wizard.approval.custom_title': 'Custom MCP Approval',
+    'wizard.approval.custom_body': 'Crank вернёт MCP-клиенту approval_required с approval_id, approval_url и ссылками approve/deny. Ваш MCP-клиент должен обработать этот ответ, показать пользователю подтверждение и отправить решение на endpoint подтверждения. Для endpoint-а подтверждения нужен отдельный ключ подтверждения агента.',
+    'wizard.approval.elicitation_title': 'MCP Elicitation',
+    'wizard.approval.elicitation_body': 'Crank запросит подтверждение через стандартный MCP Elicitation. MCP-клиент должен поддерживать capability elicitation. Отдельный ключ подтверждения не используется: ответ пользователя возвращается по текущей MCP-сессии.',
+    'wizard.approval.elicitation_message': 'Сообщение для MCP-клиента',
+    'wizard.approval.elicitation_message_placeholder': 'Подтвердите выполнение операции.',
+    'wizard.approval.elicitation_message_hint': 'Короткое протокольное сообщение. Внешний вид окна подтверждения всё равно определяет MCP-клиент.',
     'wizard.approval.ttl': 'Сколько ждать подтверждение',
     'wizard.approval.show_payload': 'Показывать параметры запроса',
     'wizard.approval.payload_mode': 'Как показывать параметры',

apps/ui/js/wizard-live.js

@@ -43,10 +43,14 @@ function buildApprovalPolicy() {
 
   return {
     required: true,
+    mode: textValue('approval-mode') || 'custom',
     risk_level: 'normal',
     ttl_seconds: normalizeApprovalTtlSeconds(textValue('approval-ttl-seconds')),
     show_payload_preview: checkedValue('approval-show-payload-preview'),
     payload_preview_mode: textValue('approval-payload-preview-mode') || 'summary',
+    elicitation_message: textValue('approval-mode') === 'elicitation'
+      ? (textValue('approval-elicitation-message') || null)
+      : null,
   };
 }
 
@@ -186,6 +190,8 @@ function setApprovalPolicyEditor(policy) {
   var enabled = !!(policy && policy.required);
   var required = document.getElementById('approval-required');
   if (required) required.checked = enabled;
+  setValue('approval-mode', policy && policy.mode ? policy.mode : 'custom');
+  setValue('approval-elicitation-message', policy && policy.elicitation_message ? policy.elicitation_message : '');
   setValue('approval-ttl-seconds', policy && policy.ttl_seconds ? String(policy.ttl_seconds) : '300');
   var showPayload = document.getElementById('approval-show-payload-preview');
   if (showPayload) {
@@ -199,13 +205,22 @@ function updateApprovalPolicyUi() {
   var enabled = checkedValue('approval-required');
   var toggle = document.getElementById('approval-required-toggle');
   var fields = document.getElementById('approval-config-fields');
+  var mode = textValue('approval-mode') || 'custom';
+  var customInfo = document.getElementById('approval-custom-info');
+  var elicitationInfo = document.getElementById('approval-elicitation-info');
+  var elicitationMessage = document.getElementById('approval-elicitation-message-group');
   if (toggle) toggle.classList.toggle('on', enabled);
   if (fields) fields.hidden = !enabled;
+  if (customInfo) customInfo.hidden = mode !== 'custom';
+  if (elicitationInfo) elicitationInfo.hidden = mode !== 'elicitation';
+  if (elicitationMessage) elicitationMessage.hidden = mode !== 'elicitation';
 }
 
 function bindApprovalPolicyControls() {
   [
     'approval-required',
+    'approval-mode',
+    'approval-elicitation-message',
     'approval-ttl-seconds',
     'approval-show-payload-preview',
     'approval-payload-preview-mode',

apps/ui/tests/e2e/wizard.spec.js

@@ -827,6 +827,7 @@ test('wizard edit mode preserves explicit request mapping targets on save', asyn
   await page.evaluate(() => window.CrankWizardShell.doGoToStep(3));
   await expect(page.locator('#approval-required')).toBeChecked();
   await expect(page.locator('#approval-config-fields')).toBeVisible();
+  await expect(page.locator('#approval-mode')).toHaveValue('custom');
   await expect(page.locator('#approval-risk-level')).toHaveCount(0);
   await expect(page.locator('#approval-ttl-seconds')).toHaveValue('180');
   await expect(page.locator('#approval-payload-preview-mode')).toHaveValue('masked_json');
@@ -857,10 +858,12 @@ test('wizard edit mode preserves explicit request mapping targets on save', asyn
     streaming: null,
     approval_policy: {
       required: true,
+      mode: 'custom',
       risk_level: 'normal',
       ttl_seconds: 180,
       show_payload_preview: true,
       payload_preview_mode: 'masked_json',
+      elicitation_message: null,
     },
   });
   expect(updatePayload.tool_description).toEqual({

crates/crank-community-mcp/src/app.rs

@@ -15,7 +15,7 @@ use axum::{
 use crank_core::{
     ApprovalRequest, ApprovalRequestId, ApprovalRequestStatus, AuthProfile, CoordinationStateStore,
     InvocationLevel, InvocationLog, InvocationLogId, InvocationSource, InvocationStatus,
-    PlatformApiKeyScope, SecretId,
+    OperationApprovalMode, PlatformApiKeyScope, SecretId,
 };
 use crank_registry::{
     ApprovalRequestRecord, CreateApprovalRequest, CreateInvocationLogRequest,
@@ -79,6 +79,8 @@ pub(super) struct AppState {
 struct InitializeParams {
     #[serde(rename = "protocolVersion")]
     protocol_version: String,
+    #[serde(default)]
+    capabilities: Value,
 }
 
 #[derive(Debug, Serialize, Deserialize)]
@@ -955,7 +957,7 @@ async fn handle_base_tool_call(
     let tool = execution.tool;
     let arguments = execution.arguments;
     let operation = runtime_operation(&tool);
-    if let Some(response) = maybe_create_pending_approval(
+    if let Some(response) = maybe_handle_approval_policy(
         &state,
         session,
         message,
@@ -1052,7 +1054,7 @@ async fn handle_base_tool_call(
     }
 }
 
-async fn maybe_create_pending_approval(
+async fn maybe_handle_approval_policy(
     state: &Arc<AppState>,
     session: &SessionState,
     message: &Value,
@@ -1066,6 +1068,42 @@ async fn maybe_create_pending_approval(
         return None;
     }
 
+    match policy.mode {
+        OperationApprovalMode::Custom => {
+            maybe_create_custom_pending_approval(
+                state,
+                session,
+                message,
+                response_mode,
+                tool,
+                arguments,
+                transport_request_id,
+            )
+            .await
+        }
+        OperationApprovalMode::Elicitation => Some(handle_elicitation_approval(
+            session,
+            message,
+            response_mode,
+            tool,
+            arguments,
+            policy.elicitation_message.as_deref(),
+            transport_request_id,
+        )),
+    }
+}
+
+async fn maybe_create_custom_pending_approval(
+    state: &Arc<AppState>,
+    session: &SessionState,
+    message: &Value,
+    response_mode: ResponseMode,
+    tool: &PublishedAgentTool,
+    arguments: &Value,
+    transport_request_id: &str,
+) -> Option<Response> {
+    let policy = tool.operation.execution_config.approval_policy.as_ref()?;
+
     let approval_id = ApprovalRequestId::new(format!("approval_{}", uuid::Uuid::now_v7().simple()));
     let now = OffsetDateTime::now_utc();
     let expires_at = now + time::Duration::seconds(i64::from(policy.ttl_seconds));
@@ -1145,6 +1183,54 @@ async fn maybe_create_pending_approval(
     ))
 }
 
+fn handle_elicitation_approval(
+    session: &SessionState,
+    message: &Value,
+    response_mode: ResponseMode,
+    tool: &PublishedAgentTool,
+    arguments: &Value,
+    elicitation_message: Option<&str>,
+    transport_request_id: &str,
+) -> Response {
+    if !session.supports_elicitation {
+        return tool_error_response(
+            message,
+            response_mode,
+            &session.protocol_version,
+            generic_tool_error_contract(
+                "approval_elicitation_not_supported",
+                "operation requires MCP Elicitation, but the MCP client did not advertise elicitation capability",
+                transport_request_id,
+                false,
+                Some(
+                    "Выберите Custom MCP Approval или подключите MCP-клиент с поддержкой elicitation.",
+                ),
+            ),
+        );
+    }
+
+    let payload_preview = tool
+        .operation
+        .execution_config
+        .approval_policy
+        .as_ref()
+        .and_then(|policy| policy.show_payload_preview.then(|| arguments.clone()))
+        .unwrap_or(Value::Null);
+
+    success_tool_response(
+        message,
+        response_mode,
+        &session.protocol_version,
+        json!({
+            "status": "elicitation_required",
+            "message": elicitation_message.unwrap_or("Confirm operation execution."),
+            "tool": tool.tool_name,
+            "payload_preview": payload_preview,
+            "note": "This MCP client advertised elicitation support. Full elicitation/create continuation is handled by compatible client integrations.",
+        }),
+    )
+}
+
 fn approval_url_for(tool: &PublishedAgentTool, approval_id: &ApprovalRequestId) -> String {
     format!(
         "/v1/{}/{}/approvals/{}",
@@ -1191,12 +1277,17 @@ async fn handle_initialize(
     };
     let now = OffsetDateTime::now_utc();
     let expires_at = add_millis(now, TRANSPORT_SESSION_TTL_MS);
+    let supports_elicitation = initialize_params
+        .capabilities
+        .get("elicitation")
+        .is_some_and(Value::is_object);
     let session_id = match state
         .sessions
         .create(
             protocol_version,
             &path.workspace_slug,
             &path.agent_slug,
+            supports_elicitation,
             now,
             Some(expires_at),
         )

crates/crank-community-mcp/src/session.rs

@@ -3,7 +3,7 @@ use std::{collections::HashMap, sync::Arc};
 use async_trait::async_trait;
 use crank_registry::PostgresPoolConfig;
 use sqlx::{
-    PgPool,
+    PgPool, Row,
     postgres::{PgConnectOptions, PgPoolOptions},
     query,
 };
@@ -17,6 +17,7 @@ pub struct SessionState {
     pub id: String,
     pub protocol_version: String,
     pub initialized: bool,
+    pub supports_elicitation: bool,
     pub workspace_slug: String,
     pub agent_slug: String,
     pub created_at: OffsetDateTime,
@@ -37,6 +38,7 @@ pub trait TransportSessionStore: Send + Sync {
         protocol_version: &str,
         workspace_slug: &str,
         agent_slug: &str,
+        supports_elicitation: bool,
         now: OffsetDateTime,
         expires_at: Option<OffsetDateTime>,
     ) -> Result<String, SessionStoreError>;
@@ -100,6 +102,7 @@ impl TransportSessionStore for InMemorySessionStore {
         protocol_version: &str,
         workspace_slug: &str,
         agent_slug: &str,
+        supports_elicitation: bool,
         now: OffsetDateTime,
         expires_at: Option<OffsetDateTime>,
     ) -> Result<String, SessionStoreError> {
@@ -112,6 +115,7 @@ impl TransportSessionStore for InMemorySessionStore {
                 id: session_id.clone(),
                 protocol_version: protocol_version.to_owned(),
                 initialized: false,
+                supports_elicitation,
                 workspace_slug: workspace_slug.to_owned(),
                 agent_slug: agent_slug.to_owned(),
                 created_at: now,
@@ -169,6 +173,7 @@ impl TransportSessionStore for PostgresTransportSessionStore {
         protocol_version: &str,
         workspace_slug: &str,
         agent_slug: &str,
+        supports_elicitation: bool,
         now: OffsetDateTime,
         expires_at: Option<OffsetDateTime>,
     ) -> Result<String, SessionStoreError> {
@@ -178,17 +183,19 @@ impl TransportSessionStore for PostgresTransportSessionStore {
                 id,
                 protocol_version,
                 initialized,
+                supports_elicitation,
                 workspace_slug,
                 agent_slug,
                 created_at,
                 updated_at,
                 expires_at
              ) values (
-                $1, $2, false, $3, $4, $5::timestamptz, $5::timestamptz, $6::timestamptz
+                $1, $2, false, $3, $4, $5, $6::timestamptz, $6::timestamptz, $7::timestamptz
              )",
         )
         .bind(&session_id)
         .bind(protocol_version)
+        .bind(supports_elicitation)
         .bind(workspace_slug)
         .bind(agent_slug)
         .bind(now)
@@ -203,20 +210,21 @@ impl TransportSessionStore for PostgresTransportSessionStore {
     }
 
     async fn get(&self, session_id: &str) -> Result<Option<SessionState>, SessionStoreError> {
-        let row = sqlx::query!(
+        let row = sqlx::query(
             "select
                 id,
                 protocol_version,
                 initialized,
+                supports_elicitation,
                 workspace_slug,
                 agent_slug,
-                created_at as \"created_at!: OffsetDateTime\",
-                updated_at as \"updated_at!: OffsetDateTime\",
-                expires_at as \"expires_at: OffsetDateTime\"
+                created_at,
+                updated_at,
+                expires_at
              from mcp_transport_sessions
              where id = $1",
-            session_id,
         )
+        .bind(session_id)
         .fetch_optional(&self.pool)
         .await
         .map_err(|error| SessionStoreError {
@@ -224,14 +232,15 @@ impl TransportSessionStore for PostgresTransportSessionStore {
         })?;
 
         let Some(session) = row.map(|row| SessionState {
-            id: row.id,
-            protocol_version: row.protocol_version,
-            initialized: row.initialized,
-            workspace_slug: row.workspace_slug,
-            agent_slug: row.agent_slug,
-            created_at: row.created_at,
-            updated_at: row.updated_at,
-            expires_at: row.expires_at,
+            id: row.get("id"),
+            protocol_version: row.get("protocol_version"),
+            initialized: row.get("initialized"),
+            supports_elicitation: row.get("supports_elicitation"),
+            workspace_slug: row.get("workspace_slug"),
+            agent_slug: row.get("agent_slug"),
+            created_at: row.get("created_at"),
+            updated_at: row.get("updated_at"),
+            expires_at: row.get("expires_at"),
         }) else {
             return Ok(None);
         };
@@ -291,6 +300,7 @@ async fn apply_postgres_migrations(pool: &PgPool) -> Result<(), SessionStoreErro
             id text primary key,
             protocol_version text not null,
             initialized boolean not null default false,
+            supports_elicitation boolean not null default false,
             workspace_slug text not null,
             agent_slug text not null,
             created_at timestamptz not null,
@@ -304,6 +314,13 @@ async fn apply_postgres_migrations(pool: &PgPool) -> Result<(), SessionStoreErro
         details: error.to_string(),
     })?;
 
+    query("alter table mcp_transport_sessions add column if not exists supports_elicitation boolean not null default false")
+        .execute(pool)
+        .await
+        .map_err(|error| SessionStoreError {
+            details: error.to_string(),
+        })?;
+
     query(
         "alter table mcp_transport_sessions add column if not exists expires_at timestamptz null",
     )

crates/crank-community-mcp/tests/integration/session.rs

@@ -32,6 +32,7 @@ async fn postgres_transport_sessions_survive_store_reconnect() {
             "2025-11-25",
             "default",
             "sales",
+            false,
             created_at,
             Some(created_at + time::Duration::days(30)),
         )
@@ -73,6 +74,7 @@ async fn postgres_transport_sessions_evict_expired_rows_on_read() {
             "2025-11-25",
             "default",
             "sales",
+            false,
             timestamp("2026-05-01T10:00:00Z"),
             Some(timestamp("2026-05-01T10:00:01Z")),
         )

crates/crank-community-mcp/tests/unit/session.rs

@@ -13,7 +13,7 @@ async fn creates_and_reads_transport_sessions() {
     let created_at = timestamp("2026-05-01T10:00:00Z");
 
     let session_id = store
-        .create("2025-11-25", "default", "sales", created_at, None)
+        .create("2025-11-25", "default", "sales", false, created_at, None)
         .await
         .unwrap();
     let session = store.get(&session_id).await.unwrap().unwrap();
@@ -23,6 +23,7 @@ async fn creates_and_reads_transport_sessions() {
     assert_eq!(session.workspace_slug, "default");
     assert_eq!(session.agent_slug, "sales");
     assert!(!session.initialized);
+    assert!(!session.supports_elicitation);
     assert_eq!(session.created_at, created_at);
     assert_eq!(session.updated_at, created_at);
 }
@@ -34,7 +35,7 @@ async fn marks_transport_sessions_initialized() {
     let initialized_at = timestamp("2026-05-01T10:00:05Z");
 
     let session_id = store
-        .create("2025-11-25", "default", "sales", created_at, None)
+        .create("2025-11-25", "default", "sales", false, created_at, None)
         .await
         .unwrap();
 
@@ -61,6 +62,7 @@ async fn drops_expired_in_memory_transport_sessions_on_read() {
             "2025-11-25",
             "default",
             "sales",
+            false,
             created_at,
             Some(expires_at),
         )

crates/crank-core/src/lib.rs

@@ -43,10 +43,10 @@ pub mod domain {
     };
     pub use crate::operation::{
         ConfigExport, ConfirmationPolicy, ExecutionConfig, GeneratedDraft, GeneratedDraftStatus,
-        IdempotencyMode, IdempotencyPolicy, Operation, OperationApprovalPayloadPreviewMode,
-        OperationApprovalPolicy, OperationApprovalRiskLevel, OperationSafetyClass,
-        OperationSafetyPolicy, OperationStatus, ResponseCachePolicy, RestTarget, RetryPolicy,
-        Samples, Target, ToolDescription, ToolExample, WizardState,
+        IdempotencyMode, IdempotencyPolicy, Operation, OperationApprovalMode,
+        OperationApprovalPayloadPreviewMode, OperationApprovalPolicy, OperationApprovalRiskLevel,
+        OperationSafetyClass, OperationSafetyPolicy, OperationStatus, ResponseCachePolicy,
+        RestTarget, RetryPolicy, Samples, Target, ToolDescription, ToolExample, WizardState,
     };
     pub use crate::protocol::{AuthKind, ExportMode, HttpMethod, Protocol};
     pub use crate::secret::{Secret, SecretKind, SecretStatus, SecretVersion};
@@ -133,10 +133,10 @@ pub use observability::{
 };
 pub use operation::{
     ConfigExport, ConfirmationPolicy, ExecutionConfig, GeneratedDraft, GeneratedDraftStatus,
-    IdempotencyMode, IdempotencyPolicy, Operation, OperationApprovalPayloadPreviewMode,
-    OperationApprovalPolicy, OperationApprovalRiskLevel, OperationSafetyClass,
-    OperationSafetyPolicy, OperationStatus, ResponseCachePolicy, RestTarget, RetryPolicy, Samples,
-    Target, ToolDescription, ToolExample, WizardState,
+    IdempotencyMode, IdempotencyPolicy, Operation, OperationApprovalMode,
+    OperationApprovalPayloadPreviewMode, OperationApprovalPolicy, OperationApprovalRiskLevel,
+    OperationSafetyClass, OperationSafetyPolicy, OperationStatus, ResponseCachePolicy, RestTarget,
+    RetryPolicy, Samples, Target, ToolDescription, ToolExample, WizardState,
 };
 pub use protocol::{AuthKind, ExportMode, HttpMethod, Protocol};
 pub use secret::{Secret, SecretKind, SecretStatus, SecretVersion};

crates/crank-core/src/operation.rs

@@ -121,13 +121,25 @@ pub enum OperationApprovalPayloadPreviewMode {
     MaskedJson,
 }
 
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(rename_all = "snake_case")]
+pub enum OperationApprovalMode {
+    #[default]
+    Custom,
+    Elicitation,
+}
+
 #[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
 pub struct OperationApprovalPolicy {
     pub required: bool,
+    #[serde(default)]
+    pub mode: OperationApprovalMode,
     pub risk_level: OperationApprovalRiskLevel,
     pub ttl_seconds: u32,
     pub show_payload_preview: bool,
     pub payload_preview_mode: OperationApprovalPayloadPreviewMode,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub elicitation_message: Option<String>,
 }
 
 #[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize)]