diff --git a/crates/owlry-core/src/ipc.rs b/crates/owlry-core/src/ipc.rs
new file mode 100644
index 0000000..0090ade
--- /dev/null
+++ b/crates/owlry-core/src/ipc.rs
@@ -0,0 +1,66 @@
+use serde::{Deserialize, Serialize};
+
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+#[serde(tag = "type", rename_all = "snake_case")]
+pub enum Request {
+    Query {
+        text: String,
+        #[serde(skip_serializing_if = "Option::is_none")]
+        modes: Option<Vec<String>>,
+    },
+    Launch {
+        item_id: String,
+        provider: String,
+    },
+    Providers,
+    Refresh {
+        provider: String,
+    },
+    Toggle,
+    Submenu {
+        plugin_id: String,
+        data: String,
+    },
+}
+
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+#[serde(tag = "type", rename_all = "snake_case")]
+pub enum Response {
+    Results {
+        items: Vec<ResultItem>,
+    },
+    Providers {
+        list: Vec<ProviderDesc>,
+    },
+    SubmenuItems {
+        items: Vec<ResultItem>,
+    },
+    Ack,
+    Error {
+        message: String,
+    },
+}
+
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub struct ResultItem {
+    pub id: String,
+    pub title: String,
+    pub description: String,
+    pub icon: String,
+    pub provider: String,
+    pub score: i64,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub command: Option<String>,
+    #[serde(default, skip_serializing_if = "Vec::is_empty")]
+    pub tags: Vec<String>,
+}
+
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub struct ProviderDesc {
+    pub id: String,
+    pub name: String,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub prefix: Option<String>,
+    pub icon: String,
+    pub position: String,
+}
diff --git a/crates/owlry-core/src/lib.rs b/crates/owlry-core/src/lib.rs
index 7396113..dfedc76 100644
--- a/crates/owlry-core/src/lib.rs
+++ b/crates/owlry-core/src/lib.rs
@@ -1,6 +1,7 @@
 pub mod config;
 pub mod data;
 pub mod filter;
+pub mod ipc;
 pub mod notify;
 pub mod paths;
 pub mod plugins;
diff --git a/crates/owlry-core/tests/ipc_test.rs b/crates/owlry-core/tests/ipc_test.rs
new file mode 100644
index 0000000..79928bb
--- /dev/null
+++ b/crates/owlry-core/tests/ipc_test.rs
@@ -0,0 +1,109 @@
+use owlry_core::ipc::{ProviderDesc, Request, Response, ResultItem};
+
+#[test]
+fn test_query_request_roundtrip() {
+    let req = Request::Query {
+        text: "fire".into(),
+        modes: Some(vec!["app".into(), "cmd".into()]),
+    };
+    let json = serde_json::to_string(&req).unwrap();
+    let parsed: Request = serde_json::from_str(&json).unwrap();
+    assert_eq!(req, parsed);
+}
+
+#[test]
+fn test_query_request_without_modes() {
+    let req = Request::Query {
+        text: "fire".into(),
+        modes: None,
+    };
+    let json = serde_json::to_string(&req).unwrap();
+    assert!(!json.contains("modes"));
+    let parsed: Request = serde_json::from_str(&json).unwrap();
+    assert_eq!(req, parsed);
+}
+
+#[test]
+fn test_launch_request_roundtrip() {
+    let req = Request::Launch {
+        item_id: "firefox.desktop".into(),
+        provider: "app".into(),
+    };
+    let json = serde_json::to_string(&req).unwrap();
+    let parsed: Request = serde_json::from_str(&json).unwrap();
+    assert_eq!(req, parsed);
+}
+
+#[test]
+fn test_results_response_roundtrip() {
+    let resp = Response::Results {
+        items: vec![ResultItem {
+            id: "firefox.desktop".into(),
+            title: "Firefox".into(),
+            description: "Web Browser".into(),
+            icon: "firefox".into(),
+            provider: "app".into(),
+            score: 95,
+            command: Some("firefox".into()),
+            tags: vec![],
+        }],
+    };
+    let json = serde_json::to_string(&resp).unwrap();
+    let parsed: Response = serde_json::from_str(&json).unwrap();
+    assert_eq!(resp, parsed);
+}
+
+#[test]
+fn test_providers_response() {
+    let resp = Response::Providers {
+        list: vec![ProviderDesc {
+            id: "app".into(),
+            name: "Applications".into(),
+            prefix: Some(":app".into()),
+            icon: "application-x-executable".into(),
+            position: "normal".into(),
+        }],
+    };
+    let json = serde_json::to_string(&resp).unwrap();
+    let parsed: Response = serde_json::from_str(&json).unwrap();
+    assert_eq!(resp, parsed);
+}
+
+#[test]
+fn test_error_response() {
+    let resp = Response::Error {
+        message: "plugin not found".into(),
+    };
+    let json = serde_json::to_string(&resp).unwrap();
+    let parsed: Response = serde_json::from_str(&json).unwrap();
+    assert_eq!(resp, parsed);
+}
+
+#[test]
+fn test_toggle_request() {
+    let req = Request::Toggle;
+    let json = serde_json::to_string(&req).unwrap();
+    let parsed: Request = serde_json::from_str(&json).unwrap();
+    assert_eq!(req, parsed);
+}
+
+#[test]
+fn test_submenu_request() {
+    let req = Request::Submenu {
+        plugin_id: "systemd".into(),
+        data: "docker.service".into(),
+    };
+    let json = serde_json::to_string(&req).unwrap();
+    let parsed: Request = serde_json::from_str(&json).unwrap();
+    assert_eq!(req, parsed);
+}
+
+#[test]
+fn test_refresh_request() {
+    let req = Request::Refresh {
+        provider: "clipboard".into(),
+    };
+    let json = serde_json::to_string(&req).unwrap();
+    let parsed: Request = serde_json::from_str(&json).unwrap();
+    assert_eq!(req, parsed);
+}