Add idempotency policy validation

apps/admin-api/src/app.rs

@@ -2336,6 +2336,7 @@ mod tests {
                 timeout_ms: 1_000,
                 retry_policy: None,
                 response_cache: None,
+                idempotency: None,
                 auth_profile_ref: None,
                 headers: BTreeMap::new(),
             },

apps/admin-api/src/service.rs

@@ -2860,6 +2860,7 @@ impl AdminService {
         self.validate_operation_capabilities(payload.protocol, payload.security_level)?;
         validate_protocol_target(payload.protocol, &payload.target)?;
         validate_response_cache_policy(&payload.target, &payload.execution_config)?;
+        validate_idempotency_policy(&payload.target, &payload.execution_config)?;
         payload.input_mapping.validate_paths()?;
         payload.output_mapping.validate_paths()?;
         Ok(())
@@ -2869,6 +2870,7 @@ impl AdminService {
         self.validate_operation_capabilities(operation.protocol, operation.security_level)?;
         validate_protocol_target(operation.protocol, &operation.target)?;
         validate_response_cache_policy(&operation.target, &operation.execution_config)?;
+        validate_idempotency_policy(&operation.target, &operation.execution_config)?;
         operation.input_mapping.validate_paths()?;
         operation.output_mapping.validate_paths()?;
         Ok(())
@@ -3443,6 +3445,7 @@ fn demo_rest_operation_payload() -> OperationPayload {
             timeout_ms: 10_000,
             retry_policy: None,
             response_cache: None,
+            idempotency: None,
             auth_profile_ref: None,
             headers: BTreeMap::new(),
         },
@@ -3509,6 +3512,7 @@ fn demo_archived_operation_payload() -> OperationPayload {
             timeout_ms: 6_000,
             retry_policy: None,
             response_cache: None,
+            idempotency: None,
             auth_profile_ref: None,
             headers: BTreeMap::new(),
         },
@@ -3804,6 +3808,54 @@ fn validate_response_cache_policy(
     Ok(())
 }
 
+fn validate_idempotency_policy(
+    target: &Target,
+    execution_config: &crank_core::ExecutionConfig,
+) -> Result<(), ApiError> {
+    let Some(policy) = execution_config.idempotency.as_ref() else {
+        return Ok(());
+    };
+
+    if policy.mode == crank_core::IdempotencyMode::Disabled {
+        return Ok(());
+    }
+
+    if policy.ttl_ms == 0 {
+        return Err(ApiError::validation_with_context(
+            "idempotency ttl must be greater than zero".to_owned(),
+            json!({
+                "field": "execution_config.idempotency.ttl_ms",
+            }),
+        ));
+    }
+
+    match target {
+        Target::Rest(rest_target) if rest_target.method != crank_core::HttpMethod::Get => {}
+        _ => {
+            return Err(ApiError::validation_with_context(
+                "idempotency is supported only for mutating REST operations".to_owned(),
+                json!({
+                    "field": "execution_config.idempotency",
+                }),
+            ));
+        }
+    }
+
+    if policy.mode == crank_core::IdempotencyMode::Required
+        && policy.input_field.as_deref().is_none_or(str::is_empty)
+        && policy.header_name.as_deref().is_none_or(str::is_empty)
+    {
+        return Err(ApiError::validation_with_context(
+            "required idempotency needs input_field or header_name".to_owned(),
+            json!({
+                "field": "execution_config.idempotency",
+            }),
+        ));
+    }
+
+    Ok(())
+}
+
 fn tool_quality_schema_node(schema: &Schema) -> ToolQualitySchemaNode {
     ToolQualitySchemaNode {
         kind: tool_quality_schema_kind(&schema.kind),
@@ -3858,10 +3910,14 @@ fn tool_quality_mapping_rule(rule: &MappingRule) -> ToolQualityMappingRule {
 mod tests {
     use std::collections::BTreeMap;
 
-    use crank_core::{ExecutionConfig, HttpMethod, ResponseCachePolicy, RestTarget, Target};
+    use crank_core::{
+        ExecutionConfig, HttpMethod, IdempotencyMode, IdempotencyPolicy, ResponseCachePolicy,
+        RestTarget, Target,
+    };
 
     use super::{
-        validate_profile_display_name, validate_profile_email, validate_response_cache_policy,
+        validate_idempotency_policy, validate_profile_display_name, validate_profile_email,
+        validate_response_cache_policy,
     };
 
     fn cacheable_execution_config() -> ExecutionConfig {
@@ -3869,6 +3925,23 @@ mod tests {
             timeout_ms: 1_000,
             retry_policy: None,
             response_cache: Some(ResponseCachePolicy { ttl_ms: 5_000 }),
+            idempotency: None,
+            auth_profile_ref: None,
+            headers: BTreeMap::new(),
+        }
+    }
+
+    fn idempotent_execution_config(mode: IdempotencyMode) -> ExecutionConfig {
+        ExecutionConfig {
+            timeout_ms: 1_000,
+            retry_policy: None,
+            response_cache: None,
+            idempotency: Some(IdempotencyPolicy {
+                mode,
+                ttl_ms: 5_000,
+                input_field: Some("request_id".to_owned()),
+                header_name: Some("Idempotency-Key".to_owned()),
+            }),
             auth_profile_ref: None,
             headers: BTreeMap::new(),
         }
@@ -3907,6 +3980,67 @@ mod tests {
         );
     }
 
+    #[test]
+    fn accepts_idempotency_for_mutating_rest_operation() {
+        let target = Target::Rest(RestTarget {
+            base_url: "http://example.invalid".to_owned(),
+            method: HttpMethod::Post,
+            path_template: "/orders".to_owned(),
+            static_headers: BTreeMap::new(),
+        });
+
+        let result = validate_idempotency_policy(
+            &target,
+            &idempotent_execution_config(IdempotencyMode::Required),
+        );
+
+        assert!(result.is_ok());
+    }
+
+    #[test]
+    fn rejects_idempotency_for_rest_get() {
+        let target = Target::Rest(RestTarget {
+            base_url: "http://example.invalid".to_owned(),
+            method: HttpMethod::Get,
+            path_template: "/orders".to_owned(),
+            static_headers: BTreeMap::new(),
+        });
+
+        let error = validate_idempotency_policy(
+            &target,
+            &idempotent_execution_config(IdempotencyMode::Optional),
+        )
+        .unwrap_err();
+
+        assert!(matches!(error, crate::error::ApiError::Validation { .. }));
+        assert_eq!(
+            error.to_string(),
+            "idempotency is supported only for mutating REST operations"
+        );
+    }
+
+    #[test]
+    fn rejects_required_idempotency_without_key_source() {
+        let target = Target::Rest(RestTarget {
+            base_url: "http://example.invalid".to_owned(),
+            method: HttpMethod::Post,
+            path_template: "/orders".to_owned(),
+            static_headers: BTreeMap::new(),
+        });
+        let mut config = idempotent_execution_config(IdempotencyMode::Required);
+        let policy = config.idempotency.as_mut().unwrap();
+        policy.input_field = None;
+        policy.header_name = None;
+
+        let error = validate_idempotency_policy(&target, &config).unwrap_err();
+
+        assert!(matches!(error, crate::error::ApiError::Validation { .. }));
+        assert_eq!(
+            error.to_string(),
+            "required idempotency needs input_field or header_name"
+        );
+    }
+
     #[test]
     fn validates_profile_identity_fields() {
         assert_eq!(

apps/mcp-server/src/main.rs

@@ -1852,6 +1852,7 @@ mod tests {
                 timeout_ms: 1_000,
                 retry_policy: None,
                 response_cache: None,
+                idempotency: None,
                 auth_profile_ref: None,
                 headers: BTreeMap::new(),
             },

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

@@ -82,6 +82,7 @@ fn operation() -> RegistryOperation {
             timeout_ms: 10_000,
             retry_policy: None,
             response_cache: None,
+            idempotency: None,
             auth_profile_ref: None,
             headers: BTreeMap::new(),
         },

crates/crank-core/src/lib.rs

@@ -56,9 +56,9 @@ pub use observability::{
     InvocationLevel, InvocationLog, InvocationSource, InvocationStatus, UsagePeriod, UsageRollup,
 };
 pub use operation::{
-    ConfigExport, ExecutionConfig, GeneratedDraft, GeneratedDraftStatus, Operation,
-    OperationStatus, ResponseCachePolicy, RestTarget, RetryPolicy, Samples, Target,
-    ToolDescription, ToolExample, WizardState,
+    ConfigExport, ExecutionConfig, GeneratedDraft, GeneratedDraftStatus, IdempotencyMode,
+    IdempotencyPolicy, Operation, 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

@@ -52,7 +52,25 @@ pub struct ResponseCachePolicy {
     pub ttl_ms: u64,
 }
 
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(rename_all = "snake_case")]
+pub enum IdempotencyMode {
+    Disabled,
+    Optional,
+    Required,
+}
+
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
+pub struct IdempotencyPolicy {
+    pub mode: IdempotencyMode,
+    pub ttl_ms: u64,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub input_field: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub header_name: Option<String>,
+}
+
+#[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize)]
 pub struct ExecutionConfig {
     pub timeout_ms: u64,
     #[serde(skip_serializing_if = "Option::is_none")]
@@ -60,6 +78,8 @@ pub struct ExecutionConfig {
     #[serde(skip_serializing_if = "Option::is_none")]
     pub response_cache: Option<ResponseCachePolicy>,
     #[serde(skip_serializing_if = "Option::is_none")]
+    pub idempotency: Option<IdempotencyPolicy>,
+    #[serde(skip_serializing_if = "Option::is_none")]
     pub auth_profile_ref: Option<AuthProfileId>,
     #[serde(default, skip_serializing_if = "BTreeMap::is_empty")]
     pub headers: BTreeMap<String, String>,
@@ -352,6 +372,7 @@ updated_at: 2026-03-25T08:10:00Z
                 timeout_ms: 10_000,
                 retry_policy: None,
                 response_cache: None,
+                idempotency: None,
                 auth_profile_ref: Some(AuthProfileId::new("auth_01")),
                 headers: BTreeMap::new(),
             },

crates/crank-registry/src/postgres/mod.rs

@@ -2053,7 +2053,7 @@ mod tests {
                 retry_policy: Some(RetryPolicy { max_attempts: 3 }),
                 auth_profile_ref: Some("auth_crank".into()),
                 headers: BTreeMap::from([("X-Request-Id".to_owned(), "static".to_owned())]),
-                response_cache: None,
+                ..ExecutionConfig::default()
             },
             tool_description: ToolDescription {
                 title: "Create lead".to_owned(),

crates/crank-runtime/tests/integration/no_input_get.rs

@@ -69,6 +69,7 @@ fn no_input_get_operation() -> Operation<Schema, MappingSet> {
             timeout_ms: 1_000,
             retry_policy: None,
             response_cache: None,
+            idempotency: None,
             auth_profile_ref: None,
             headers: BTreeMap::new(),
         },