diff --git a/dashi/package-lock.json b/dashi/package-lock.json
index 311b7cce..86867941 100644
--- a/dashi/package-lock.json
+++ b/dashi/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "dashipopashi",
-  "version": "0.0.7",
+  "version": "0.0.8",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "dashipopashi",
-      "version": "0.0.7",
+      "version": "0.0.8",
       "license": "MIT",
       "dependencies": {
         "@emotion/react": "^11.13.3",
diff --git a/dashi/package.json b/dashi/package.json
index e7a1ea15..265c7ff8 100644
--- a/dashi/package.json
+++ b/dashi/package.json
@@ -1,6 +1,6 @@
 {
   "name": "dashipopashi",
-  "version": "0.0.7",
+  "version": "0.0.8",
   "description": "An experimental library for integrating interactive charts into existing JavaScript applications.",
   "type": "module",
   "files": [
diff --git a/dashi/src/demo/actions/hidePanel.ts b/dashi/src/demo/actions/hidePanel.ts
index ffb11113..4dd33c69 100644
--- a/dashi/src/demo/actions/hidePanel.ts
+++ b/dashi/src/demo/actions/hidePanel.ts
@@ -1,6 +1,8 @@
-import { updateContributionState } from "@/lib";
+import { updateContributionContainer } from "@/lib";
 import type { PanelState } from "@/demo/types";
 
 export function hidePanel(panelIndex: number) {
-  updateContributionState<PanelState>("panels", panelIndex, { visible: false });
+  updateContributionContainer<PanelState>("panels", panelIndex, {
+    visible: false,
+  });
 }
diff --git a/dashi/src/demo/actions/showPanel.ts b/dashi/src/demo/actions/showPanel.ts
index 39190ce2..5a61bb6b 100644
--- a/dashi/src/demo/actions/showPanel.ts
+++ b/dashi/src/demo/actions/showPanel.ts
@@ -1,6 +1,8 @@
-import { updateContributionState } from "@/lib";
+import { updateContributionContainer } from "@/lib";
 import type { PanelState } from "@/demo/types";
 
 export function showPanel(panelIndex: number) {
-  updateContributionState<PanelState>("panels", panelIndex, { visible: true });
+  updateContributionContainer<PanelState>("panels", panelIndex, {
+    visible: true,
+  });
 }
diff --git a/dashi/src/demo/components/Panel.tsx b/dashi/src/demo/components/Panel.tsx
index 7e85d6eb..d2a286fa 100644
--- a/dashi/src/demo/components/Panel.tsx
+++ b/dashi/src/demo/components/Panel.tsx
@@ -1,11 +1,7 @@
 import type { CSSProperties, ReactElement } from "react";
 import CircularProgress from "@mui/material/CircularProgress";
-
-import {
-  type ComponentChangeHandler,
-  type ContributionState,
-  Component,
-} from "@/lib";
+import { Component } from "@/lib";
+import type { ComponentState, ComponentChangeHandler } from "@/lib";
 import type { PanelState } from "@/demo/types";
 
 const panelContainerStyle: CSSProperties = {
@@ -32,39 +28,43 @@ const panelContentStyle: CSSProperties = {
   padding: 2,
 };
 
-interface PanelProps extends ContributionState<PanelState> {
+interface PanelProps extends PanelState {
+  componentProps?: ComponentState;
+  componentStatus?: string;
+  componentError?: { message: string };
   onChange: ComponentChangeHandler;
 }
 
 function Panel({
-  name,
-  state,
-  component,
-  componentResult,
+  title,
+  visible,
+  componentProps,
+  componentStatus,
+  componentError,
   onChange,
 }: PanelProps) {
-  if (!state.visible) {
+  if (!visible) {
     return null;
   }
   let panelElement: ReactElement | null = null;
-  if (component) {
-    panelElement = <Component {...component} onChange={onChange} />;
-  } else if (componentResult.error) {
+  if (componentProps) {
+    panelElement = <Component {...componentProps} onChange={onChange} />;
+  } else if (componentError) {
     panelElement = (
       <span>
-        Error loading {name}: {componentResult.error.message}
+        Error loading panel {title}: {componentError.message}
       </span>
     );
-  } else if (componentResult.status === "pending") {
+  } else if (componentStatus === "pending") {
     panelElement = (
       <span>
-        <CircularProgress size={30} color="secondary" /> Loading {name}...
+        <CircularProgress size={30} color="secondary" /> Loading {title}...
       </span>
     );
   }
   return (
     <div style={panelContainerStyle}>
-      <div style={panelHeaderStyle}>{state.title}</div>
+      <div style={panelHeaderStyle}>{title}</div>
       <div style={panelContentStyle}>{panelElement}</div>
     </div>
   );
diff --git a/dashi/src/demo/components/PanelsControl.tsx b/dashi/src/demo/components/PanelsControl.tsx
index 9214b7de..ac13d783 100644
--- a/dashi/src/demo/components/PanelsControl.tsx
+++ b/dashi/src/demo/components/PanelsControl.tsx
@@ -17,15 +17,16 @@ function PanelsControl() {
     <FormGroup sx={{ display: "flex", flexDirection: "row" }}>
       {panelStates.map((panelState, panelIndex) => {
         const id = `panels.${panelIndex}`;
+        const { title, visible } = panelState.container;
         return (
           <FormControlLabel
             key={panelIndex}
-            label={panelState.state.title}
+            label={title}
             control={
               <Checkbox
                 color="secondary"
                 id={id}
-                checked={panelState.state.visible || false}
+                checked={visible || false}
                 value={panelIndex}
                 onChange={(e) => {
                   if (e.currentTarget.checked) {
diff --git a/dashi/src/demo/components/PanelsRow.tsx b/dashi/src/demo/components/PanelsRow.tsx
index cf0bd986..8a5a5b43 100644
--- a/dashi/src/demo/components/PanelsRow.tsx
+++ b/dashi/src/demo/components/PanelsRow.tsx
@@ -1,5 +1,3 @@
-import type { JSX } from "react";
-
 import { type ComponentChangeEvent, handleComponentChange } from "@/lib";
 import { usePanelStates } from "@/demo/hooks";
 import Panel from "./Panel";
@@ -17,23 +15,21 @@ function PanelsRow() {
   ) => {
     handleComponentChange("panels", panelIndex, panelEvent);
   };
-  const visiblePanels: JSX.Element[] = [];
-  panelStates.forEach((panelState, panelIndex) => {
-    if (panelState.state.visible) {
-      visiblePanels.push(
-        <Panel
-          key={panelIndex}
-          {...panelState}
-          onChange={(e) => handlePanelChange(panelIndex, e)}
-        />,
-      );
-    }
+  const panels = panelStates.map((panelState, panelIndex) => {
+    const { container, component, componentResult } = panelState;
+    return (
+      <Panel
+        key={panelIndex}
+        {...container}
+        componentProps={component}
+        componentStatus={componentResult.status}
+        componentError={componentResult.error}
+        onChange={(e) => handlePanelChange(panelIndex, e)}
+      />
+    );
   });
-  const panelElements = <>{visiblePanels}</>;
   return (
-    <div style={{ display: "flex", gap: 5, paddingTop: 10 }}>
-      {panelElements}
-    </div>
+    <div style={{ display: "flex", gap: 5, paddingTop: 10 }}>{panels}</div>
   );
 }
 
diff --git a/dashi/src/lib/actions/configureFramework.ts b/dashi/src/lib/actions/configureFramework.ts
index 67123138..ce0dc3e2 100644
--- a/dashi/src/lib/actions/configureFramework.ts
+++ b/dashi/src/lib/actions/configureFramework.ts
@@ -1,6 +1,6 @@
 import { store } from "@/lib/store";
 import type { FrameworkOptions } from "@/lib/types/state/store";
-import { configureLogging } from "@/lib/utils/configureLogging";
+import { configureLogging } from "@/lib/actions/helpers/configureLogging";
 import { handleHostStoreChange } from "./handleHostStoreChange";
 
 export function configureFramework<S extends object = object>(
diff --git a/dashi/src/lib/actions/handleComponentChange.ts b/dashi/src/lib/actions/handleComponentChange.ts
index bb073b56..f215e378 100644
--- a/dashi/src/lib/actions/handleComponentChange.ts
+++ b/dashi/src/lib/actions/handleComponentChange.ts
@@ -17,7 +17,7 @@ export function handleComponentChange(
       contribIndex,
       stateChanges: [
         {
-          kind: "Component",
+          link: "component",
           id: changeEvent.componentId,
           property: changeEvent.propertyName,
           value: changeEvent.propertyValue,
@@ -57,7 +57,8 @@ function getCallbackRequests(
       const inputs = callback.inputs;
       const inputIndex = inputs.findIndex(
         (input) =>
-          (!input.kind || input.kind === "Component") &&
+          !input.noTrigger &&
+          (!input.link || input.link === "component") &&
           input.id === changeEvent.componentId &&
           input.property === changeEvent.propertyName,
       );
diff --git a/dashi/src/lib/actions/handleHostStoreChange.ts b/dashi/src/lib/actions/handleHostStoreChange.ts
index 29e7a437..110f3ae1 100644
--- a/dashi/src/lib/actions/handleHostStoreChange.ts
+++ b/dashi/src/lib/actions/handleHostStoreChange.ts
@@ -5,9 +5,9 @@ import type {
   CallbackRef,
   CallbackRequest,
   ContribRef,
-  Input,
   InputRef,
 } from "@/lib/types/model/callback";
+import type { Input } from "@/lib/types/model/channel";
 import { getInputValues } from "@/lib/actions/helpers/getInputValues";
 import { getValue, type PropertyPath } from "@/lib/utils/getValue";
 import { invokeCallbacks } from "@/lib/actions/helpers/invokeCallbacks";
@@ -59,6 +59,9 @@ function getCallbackRequests<S extends object = object>(
 
 const getHostStorePropertyRefs = memoizeOne(_getHostStorePropertyRefs);
 
+/**
+ * Get the static list of host state property references for all contributions.
+ */
 function _getHostStorePropertyRefs(): PropertyRef[] {
   const { contributionsRecord } = store.getState();
   const propertyRefs: PropertyRef[] = [];
@@ -68,13 +71,13 @@ function _getHostStorePropertyRefs(): PropertyRef[] {
       (contribution.callbacks || []).forEach(
         (callback, callbackIndex) =>
           (callback.inputs || []).forEach((input, inputIndex) => {
-            if (input.kind === "AppState") {
+            if (!input.noTrigger && input.link === "app") {
               propertyRefs.push({
                 contribPoint,
                 contribIndex,
                 callbackIndex,
                 inputIndex,
-                propertyPath: input.property.split("."),
+                propertyPath: input.property!.split("."),
               });
             }
           }),
diff --git a/dashi/src/lib/actions/helpers/applyStateChangeRequests.test.ts b/dashi/src/lib/actions/helpers/applyStateChangeRequests.test.ts
index ee6c822d..972721d3 100644
--- a/dashi/src/lib/actions/helpers/applyStateChangeRequests.test.ts
+++ b/dashi/src/lib/actions/helpers/applyStateChangeRequests.test.ts
@@ -35,7 +35,7 @@ describe("Test that applyContributionChangeRequests()", () => {
         name: "",
         extension: "",
         componentResult: { status: "ok" },
-        state: { visible: true },
+        container: { visible: true },
         component: componentTree,
       },
     ],
@@ -46,7 +46,7 @@ describe("Test that applyContributionChangeRequests()", () => {
     contribIndex: 0,
     stateChanges: [
       {
-        kind: "Component",
+        link: "component",
         id: "dd1",
         property: "value",
         value: 14,
@@ -59,7 +59,7 @@ describe("Test that applyContributionChangeRequests()", () => {
     contribIndex: 0,
     stateChanges: [
       {
-        kind: "Component",
+        link: "component",
         id: "dd1",
         property: "value",
         value: 13,
@@ -88,7 +88,7 @@ describe("Test that applyContributionChangeRequests()", () => {
 describe("Test that applyComponentStateChange()", () => {
   it("changes state if values are different", () => {
     const newState = applyComponentStateChange(componentTree, {
-      kind: "Component",
+      link: "component",
       id: "cb1",
       property: "value",
       value: false,
@@ -99,7 +99,7 @@ describe("Test that applyComponentStateChange()", () => {
 
   it("doesn't change the state if value stays the same", () => {
     const newState = applyComponentStateChange(componentTree, {
-      kind: "Component",
+      link: "component",
       id: "cb1",
       property: "value",
       value: true,
diff --git a/dashi/src/lib/actions/helpers/applyStateChangeRequests.ts b/dashi/src/lib/actions/helpers/applyStateChangeRequests.ts
index f0b94884..f17d6120 100644
--- a/dashi/src/lib/actions/helpers/applyStateChangeRequests.ts
+++ b/dashi/src/lib/actions/helpers/applyStateChangeRequests.ts
@@ -10,7 +10,7 @@ import type {
 import type { ContribPoint } from "@/lib/types/model/extension";
 import type { ContributionState } from "@/lib";
 import { updateArray } from "@/lib/utils/updateArray";
-import { isContainerState } from "@/lib/utils/isContainerState";
+import { isContainerState } from "@/lib/actions/helpers/isContainerState";
 
 export function applyStateChangeRequests(
   stateChangeRequests: StateChangeRequest[],
@@ -37,8 +37,9 @@ function applyHostStateChanges(stateChangeRequests: StateChangeRequest[]) {
     stateChangeRequests.forEach((stateChangeRequest) => {
       hostState = applyStateChanges(
         hostState,
-        stateChangeRequest.stateChanges,
-        "AppState",
+        stateChangeRequest.stateChanges.filter(
+          (stateChange) => stateChange.link === "app",
+        ),
       );
     });
     if (hostState !== hostStateOld) {
@@ -53,13 +54,9 @@ function applyComponentStateChanges(
 ) {
   let component = componentOld;
   if (component) {
-    stateChanges
-      .filter(
-        (stateChange) => !stateChange.kind || stateChange.kind === "Component",
-      )
-      .forEach((stateChange) => {
-        component = applyComponentStateChange(component!, stateChange);
-      });
+    stateChanges.forEach((stateChange) => {
+      component = applyComponentStateChange(component!, stateChange);
+    });
   }
   return component;
 }
@@ -72,17 +69,19 @@ export function applyContributionChangeRequests(
   stateChangeRequests.forEach(
     ({ contribPoint, contribIndex, stateChanges }) => {
       const contribution = contributionsRecord[contribPoint][contribIndex];
-      const state = applyStateChanges(
-        contribution.state,
-        stateChanges,
-        "State",
+      const container = applyStateChanges(
+        contribution.container,
+        stateChanges.filter((stateChange) => stateChange.link === "container"),
       );
       const component = applyComponentStateChanges(
         contribution.component,
-        stateChanges,
+        stateChanges.filter(
+          (stateChange) =>
+            !stateChange.link || stateChange.link === "component",
+        ),
       );
       if (
-        state !== contribution.state ||
+        container !== contribution.container ||
         component !== contribution.component
       ) {
         contributionsRecord = {
@@ -90,7 +89,7 @@ export function applyContributionChangeRequests(
           [contribPoint]: updateArray<ContributionState>(
             contributionsRecord[contribPoint],
             contribIndex,
-            { ...contribution, state, component },
+            { ...contribution, container, component },
           ),
         };
       }
@@ -139,14 +138,12 @@ export function applyComponentStateChange(
 export function applyStateChanges<S extends object>(
   state: S | undefined,
   stateChanges: StateChange[],
-  kind: "State" | "AppState",
 ): S | undefined {
   stateChanges.forEach((stateChange) => {
     if (
-      stateChange.kind === kind &&
-      (!state ||
-        (state as unknown as Record<string, unknown>)[stateChange.property] !==
-          stateChange.value)
+      !state ||
+      (state as unknown as Record<string, unknown>)[stateChange.property] !==
+        stateChange.value
     ) {
       state = { ...state, [stateChange.property]: stateChange.value } as S;
     }
diff --git a/dashi/src/lib/utils/configureLogging.ts b/dashi/src/lib/actions/helpers/configureLogging.ts
similarity index 100%
rename from dashi/src/lib/utils/configureLogging.ts
rename to dashi/src/lib/actions/helpers/configureLogging.ts
diff --git a/dashi/src/lib/actions/helpers/getInputValues.test.ts b/dashi/src/lib/actions/helpers/getInputValues.test.ts
index ac063ed2..ce83e2e1 100644
--- a/dashi/src/lib/actions/helpers/getInputValues.test.ts
+++ b/dashi/src/lib/actions/helpers/getInputValues.test.ts
@@ -2,7 +2,7 @@ import { describe, it, expect } from "vitest";
 
 import type { ComponentState, PlotState } from "@/lib/types/state/component";
 import {
-  getComponentStateValue,
+  getInputValueFromComponent,
   getInputValueFromState,
 } from "./getInputValues";
 
@@ -23,11 +23,11 @@ const componentState: ComponentState = {
   value: 14,
 };
 
-describe("Test that getComponentStateValue()", () => {
+describe("Test that getInputValueFromComponent()", () => {
   it("works on 1st level", () => {
     expect(
-      getComponentStateValue(componentState, {
-        kind: "Component",
+      getInputValueFromComponent(componentState, {
+        link: "component",
         id: "b1",
         property: "value",
       }),
@@ -36,8 +36,8 @@ describe("Test that getComponentStateValue()", () => {
 
   it("works on 2nd level", () => {
     expect(
-      getComponentStateValue(componentState, {
-        kind: "Component",
+      getInputValueFromComponent(componentState, {
+        link: "component",
         id: "p1",
         property: "chart",
       }),
@@ -46,16 +46,16 @@ describe("Test that getComponentStateValue()", () => {
 
   it("works on 3rd level", () => {
     expect(
-      getComponentStateValue(componentState, {
-        kind: "Component",
+      getInputValueFromComponent(componentState, {
+        link: "component",
         id: "cb1",
         property: "value",
       }),
     ).toEqual(true);
 
     expect(
-      getComponentStateValue(componentState, {
-        kind: "Component",
+      getInputValueFromComponent(componentState, {
+        link: "component",
         id: "dd1",
         property: "value",
       }),
@@ -67,21 +67,27 @@ describe("Test that getInputValueFromState()", () => {
   it("works with input.id and input.property", () => {
     const state = { x: { y: 26 } };
     expect(
-      getInputValueFromState({ kind: "State", id: "x", property: "y" }, state),
+      getInputValueFromState(
+        { link: "component", id: "x", property: "y" },
+        state,
+      ),
     ).toEqual(26);
   });
 
   it("works with arrays indexes", () => {
     const state = { x: [4, 5, 6] };
     expect(
-      getInputValueFromState({ kind: "State", id: "x", property: "1" }, state),
+      getInputValueFromState(
+        { link: "component", id: "x", property: "1" },
+        state,
+      ),
     ).toEqual(5);
   });
 
   it("works without input.id", () => {
     const state = { x: [4, 5, 6] };
     expect(
-      getInputValueFromState({ kind: "State", property: "x" }, state),
+      getInputValueFromState({ link: "container", property: "x" }, state),
     ).toEqual([4, 5, 6]);
   });
 });
diff --git a/dashi/src/lib/actions/helpers/getInputValues.ts b/dashi/src/lib/actions/helpers/getInputValues.ts
index 80257593..77d1b5c0 100644
--- a/dashi/src/lib/actions/helpers/getInputValues.ts
+++ b/dashi/src/lib/actions/helpers/getInputValues.ts
@@ -1,8 +1,8 @@
-import type { Input } from "@/lib/types/model/callback";
+import type { Input } from "@/lib/types/model/channel";
 import type { ContributionState } from "@/lib/types/state/contribution";
 import type { ComponentState } from "@/lib/types/state/component";
 import { isSubscriptable } from "@/lib/utils/isSubscriptable";
-import { isContainerState } from "@/lib/utils/isContainerState";
+import { isContainerState } from "@/lib/actions/helpers/isContainerState";
 
 export function getInputValues<S extends object = object>(
   inputs: Input[],
@@ -22,16 +22,16 @@ export function getInputValue<S extends object = object>(
   hostState?: S | undefined,
 ): unknown {
   let inputValue: unknown = undefined;
-  const inputKind = input.kind || "Component";
-  if (inputKind === "Component" && contributionState.component) {
+  const dataSource = input.link || "component";
+  if (dataSource === "component" && contributionState.component) {
     // Return value of a property of some component in the tree
-    inputValue = getComponentStateValue(contributionState.component, input);
-  } else if (inputKind === "State" && contributionState.state) {
-    inputValue = getInputValueFromState(input, contributionState.state);
-  } else if (inputKind === "AppState" && hostState) {
+    inputValue = getInputValueFromComponent(contributionState.component, input);
+  } else if (dataSource === "container" && contributionState.container) {
+    inputValue = getInputValueFromState(input, hostState);
+  } else if (dataSource === "app" && hostState) {
     inputValue = getInputValueFromState(input, hostState);
   } else {
-    console.warn(`input of unknown kind:`, input);
+    console.warn(`input with unknown data source:`, input);
   }
   if (inputValue === undefined || inputValue === noValue) {
     // We use null, because undefined is not JSON-serializable.
@@ -42,7 +42,7 @@ export function getInputValue<S extends object = object>(
 }
 
 // we export for testing only
-export function getComponentStateValue(
+export function getInputValueFromComponent(
   componentState: ComponentState,
   input: Input,
 ): unknown {
@@ -53,7 +53,7 @@ export function getComponentStateValue(
   } else if (isContainerState(componentState)) {
     for (let i = 0; i < componentState.components.length; i++) {
       const item = componentState.components[i];
-      const itemValue = getComponentStateValue(item, input);
+      const itemValue = getInputValueFromComponent(item, input);
       if (itemValue !== noValue) {
         return itemValue;
       }
diff --git a/dashi/src/lib/actions/helpers/invokeCallbacks.ts b/dashi/src/lib/actions/helpers/invokeCallbacks.ts
index 83082a86..e528ad2a 100644
--- a/dashi/src/lib/actions/helpers/invokeCallbacks.ts
+++ b/dashi/src/lib/actions/helpers/invokeCallbacks.ts
@@ -6,7 +6,10 @@ import { applyStateChangeRequests } from "@/lib/actions/helpers/applyStateChange
 
 export function invokeCallbacks(callbackRequests: CallbackRequest[]) {
   const { configuration } = store.getState();
-  console.debug("invokeCallbacks -->", callbackRequests);
+  const invocationId = getInvocationId();
+  if (import.meta.env.DEV) {
+    console.debug(`invokeCallbacks (${invocationId})-->`, callbackRequests);
+  }
   if (callbackRequests.length) {
     fetchApiResult(
       fetchStateChangeRequests,
@@ -14,7 +17,12 @@ export function invokeCallbacks(callbackRequests: CallbackRequest[]) {
       configuration.api,
     ).then((changeRequestsResult) => {
       if (changeRequestsResult.data) {
-        console.debug("invokeCallbacks <--", changeRequestsResult.data);
+        if (import.meta.env.DEV) {
+          console.debug(
+            `invokeCallbacks <--(${invocationId})`,
+            changeRequestsResult.data,
+          );
+        }
         applyStateChangeRequests(changeRequestsResult.data);
       } else {
         console.error(
@@ -27,3 +35,9 @@ export function invokeCallbacks(callbackRequests: CallbackRequest[]) {
     });
   }
 }
+
+let invocationCounter = 0;
+
+function getInvocationId() {
+  return invocationCounter++;
+}
diff --git a/dashi/src/lib/utils/isContainerState.ts b/dashi/src/lib/actions/helpers/isContainerState.ts
similarity index 54%
rename from dashi/src/lib/utils/isContainerState.ts
rename to dashi/src/lib/actions/helpers/isContainerState.ts
index 01a5930d..8d2a1d1b 100644
--- a/dashi/src/lib/utils/isContainerState.ts
+++ b/dashi/src/lib/actions/helpers/isContainerState.ts
@@ -4,7 +4,7 @@ import {
 } from "@/lib/types/state/component";
 
 export function isContainerState(
-  componentModel: ComponentState,
-): componentModel is ContainerState {
-  return !!componentModel.components;
+  component: ComponentState,
+): component is ContainerState {
+  return !!component.components;
 }
diff --git a/dashi/src/lib/actions/initializeContributions.ts b/dashi/src/lib/actions/initializeContributions.ts
index 4bd0516e..64109047 100644
--- a/dashi/src/lib/actions/initializeContributions.ts
+++ b/dashi/src/lib/actions/initializeContributions.ts
@@ -49,7 +49,7 @@ function newContributionState(
 ): ContributionState {
   return {
     ...rawContribution,
-    state: { ...rawContribution.initialState },
+    container: { ...rawContribution.initialState },
     componentResult: {},
   };
 }
diff --git a/dashi/src/lib/actions/updateContributionState.ts b/dashi/src/lib/actions/updateContributionContainer.ts
similarity index 87%
rename from dashi/src/lib/actions/updateContributionState.ts
rename to dashi/src/lib/actions/updateContributionContainer.ts
index 742c8b0f..dfc11169 100644
--- a/dashi/src/lib/actions/updateContributionState.ts
+++ b/dashi/src/lib/actions/updateContributionContainer.ts
@@ -6,31 +6,30 @@ import { updateArray } from "@/lib/utils/updateArray";
 import type { ContribPoint } from "@/lib/types/model/extension";
 import type { ContributionState } from "@/lib/types/state/contribution";
 
-export function updateContributionState<S extends object = object>(
+export function updateContributionContainer<S extends object = object>(
   contribPoint: ContribPoint,
   contribIndex: number,
-  contribState: Partial<S>,
+  container: Partial<S>,
   requireComponent: boolean = true,
 ) {
   const { configuration, contributionsRecord } = store.getState();
   const contributionStates = contributionsRecord[contribPoint];
   const contributionState = contributionStates[contribIndex];
-  if (contributionState.state === contribState) {
+  if (contributionState.container === container) {
     return; // nothing to do
   }
   const componentStatus = contributionState.componentResult.status;
   if (!requireComponent || componentStatus) {
     _updateContributionState(contribPoint, contribIndex, {
-      state: contribState,
+      container,
     });
   } else if (!componentStatus) {
     // No status yet, so we must load the component
     _updateContributionState(contribPoint, contribIndex, {
-      state: contribState,
+      container,
       componentResult: { status: "pending" },
     });
     const inputValues = getLayoutInputValues(contribPoint, contribIndex);
-    console.log("inputValues:", inputValues);
     fetchApiResult(
       fetchInitialComponentState,
       contribPoint,
@@ -70,10 +69,10 @@ function _updateContributionState(
   const { contributionsRecord } = store.getState();
   const contribStates = contributionsRecord[contribPoint]!;
   const contribStateOld = contribStates[contribIndex];
-  const contribStateNew = contribState.state
+  const contribStateNew = contribState.container
     ? {
         ...contribState,
-        state: { ...contribStateOld.state, ...contribState.state },
+        container: { ...contribStateOld.container, ...contribState.container },
       }
     : contribState;
   store.setState({
diff --git a/dashi/src/lib/components/Component.tsx b/dashi/src/lib/components/Component.tsx
index f8f21cd1..dd05ee17 100644
--- a/dashi/src/lib/components/Component.tsx
+++ b/dashi/src/lib/components/Component.tsx
@@ -15,7 +15,7 @@ export function Component({ type, ...props }: ComponentProps) {
   // TODO: allow for registering components via their types
   //   and make following code generic.
   //
-  // const DashiComp = Registry.getComponent(type);
+  // const DashiComp = Registry.getComponent(link);
   // return return <DashiComp {...props} />;
   //
   if (type === "Plot") {
diff --git a/dashi/src/lib/index.ts b/dashi/src/lib/index.ts
index e09a1205..2a3f76a9 100644
--- a/dashi/src/lib/index.ts
+++ b/dashi/src/lib/index.ts
@@ -1,6 +1,7 @@
 // Types
 export { type Contribution } from "@/lib/types/model/contribution";
 export { type ContributionState } from "@/lib/types/state/contribution";
+export { type ComponentState } from "@/lib/types/state/component";
 export {
   type ComponentChangeEvent,
   type ComponentChangeHandler,
@@ -9,7 +10,7 @@ export {
 export { initializeContributions } from "@/lib/actions/initializeContributions";
 export { configureFramework } from "@/lib/actions/configureFramework";
 export { handleComponentChange } from "@/lib/actions/handleComponentChange";
-export { updateContributionState } from "@/lib/actions/updateContributionState";
+export { updateContributionContainer } from "@/lib/actions/updateContributionContainer";
 // React Components
 export { Component } from "@/lib/components/Component";
 // React Hooks
@@ -19,5 +20,3 @@ export {
   useContributionsResult,
   useContributionsRecord,
 } from "@/lib/hooks";
-// Utilities
-export { configureLogging } from "@/lib/utils/configureLogging";
diff --git a/dashi/src/lib/types/model/callback.ts b/dashi/src/lib/types/model/callback.ts
index cd4fae19..d8f94219 100644
--- a/dashi/src/lib/types/model/callback.ts
+++ b/dashi/src/lib/types/model/callback.ts
@@ -1,3 +1,5 @@
+import type { Input, Output } from "@/lib/types/model/channel";
+
 export interface Callback {
   function: CbFunction;
   inputs?: Input[];
@@ -30,32 +32,6 @@ export interface CbParameter {
   default?: unknown;
 }
 
-export type InputOutputKind = "AppState" | "State" | "Component";
-
-export interface InputOutput {
-  /** The kind of input or output. */
-  kind: InputOutputKind;
-  /**
-   * The identifier of a subcomponent.
-   * `id` is not needed if kind == "AppState" | "State".
-   */
-  id?: string;
-
-  // TODO: we must allow `property` to be a constant
-  //  expression of the form: name {"." name | index}.
-  //  Then we get the normalized form
-  //    property: string[];
-
-  /**
-   * The property of an object or array index.
-   */
-  property: string;
-}
-
-export interface Input extends InputOutput {}
-
-export interface Output extends InputOutput {}
-
 /**
  * A reference to a specific contribution.
  */
diff --git a/dashi/src/lib/types/model/channel.ts b/dashi/src/lib/types/model/channel.ts
new file mode 100644
index 00000000..145f2de4
--- /dev/null
+++ b/dashi/src/lib/types/model/channel.ts
@@ -0,0 +1,33 @@
+export type Link = "component" | "container" | "app";
+
+/**
+ * Base for `Input` and `Output`.
+ */
+export interface Channel {
+  /**
+   * The link provides the source for inputs and that target for outputs.
+   */
+  link: Link;
+
+  /**
+   * The identifier of a subcomponent.
+   * `id` is not needed if link == "AppInput" | "AppOutput".
+   */
+  id?: string;
+
+  // TODO: we must allow `property` to be a constant
+  //  expression of the form: name {"." name | index}.
+  //  Then we get the normalized form
+  //    property: string[];
+
+  /**
+   * The property of an object or array index.
+   */
+  property: string;
+}
+
+export interface Input extends Channel {
+  noTrigger?: boolean;
+}
+
+export interface Output extends Channel {}
diff --git a/dashi/src/lib/types/state/contribution.ts b/dashi/src/lib/types/state/contribution.ts
index aaafd46e..25237e89 100644
--- a/dashi/src/lib/types/state/contribution.ts
+++ b/dashi/src/lib/types/state/contribution.ts
@@ -5,9 +5,9 @@ import type { ComponentState } from "./component";
 export interface ContributionState<S extends object = object>
   extends Contribution<S> {
   /**
-   * Contribution-private state properties.
+   * State that is used by the container of this contribution.
    */
-  state: S;
+  container: S;
   /**
    * The result of loading the initial component tree.
    */
diff --git a/dashi/src/lib/types/state/store.ts b/dashi/src/lib/types/state/store.ts
index 688b1995..038cc5a3 100644
--- a/dashi/src/lib/types/state/store.ts
+++ b/dashi/src/lib/types/state/store.ts
@@ -6,7 +6,7 @@ import type {
 import type { ApiResult } from "@/lib/utils/fetchApiResult";
 import type { ContributionState } from "@/lib/types/state/contribution";
 import type { ApiOptions } from "@/lib/api";
-import type { LoggingOptions } from "@/lib/utils/configureLogging";
+import type { LoggingOptions } from "@/lib/actions/helpers/configureLogging";
 import type { StoreApi } from "zustand";
 
 export interface FrameworkOptions<S extends object = object> {
diff --git a/dashi/tsconfig.json b/dashi/tsconfig.json
index c344941d..34a17a3a 100644
--- a/dashi/tsconfig.json
+++ b/dashi/tsconfig.json
@@ -17,6 +17,7 @@
     "isolatedModules": true,
     "noEmit": true,
     "jsx": "react-jsx",
+    "types": ["vite/client"],
 
     /* Linting */
     "strict": true,
diff --git a/dashipy/dashipy/__init__.py b/dashipy/dashipy/__init__.py
index 8109e2c3..8623ca89 100644
--- a/dashipy/dashipy/__init__.py
+++ b/dashipy/dashipy/__init__.py
@@ -1,6 +1,7 @@
 from .callback import Callback
-from .callback import Input
-from .callback import Output
+from .channel import Input
+from .channel import Output
+from .channel import State
 from .component import Component
 from .container import Container
 from .extension import Contribution
diff --git a/dashipy/dashipy/callback.py b/dashipy/dashipy/callback.py
index e8a103c8..de56f1e5 100644
--- a/dashipy/dashipy/callback.py
+++ b/dashipy/dashipy/callback.py
@@ -1,51 +1,12 @@
 import inspect
 import types
-from abc import ABC
-from typing import Callable, Any, Literal
+from typing import Any, Callable
 
-
-ComponentKind = Literal["Component"]
-AppStateKind = Literal["AppState"]
-StateKind = Literal["State"]
-InputOutputKind = ComponentKind | StateKind | AppStateKind
-
-
-class InputOutput(ABC):
-    # noinspection PyShadowingBuiltins
-    def __init__(
-        self,
-        id: str | None = None,
-        property: str | None = None,
-        kind: InputOutputKind | None = None,
-    ):
-        kind = "Component" if kind is None else kind
-        assert kind in ("AppState", "State", "Component")
-        if kind == "Component":
-            assert id is not None and isinstance(id, str) and id != ""
-            property = "value" if property is None else property
-            assert isinstance(property, str) and property != ""
-        else:
-            assert id is None or (isinstance(id, str) and id != "")
-            assert property is None or (isinstance(property, str) and property != "")
-
-        self.kind = kind
-        self.id = id
-        self.property = property
-
-    def to_dict(self) -> dict[str, Any]:
-        return {
-            k: v
-            for k, v in self.__dict__.items()
-            if not k.startswith("_") and v is not None
-        }
-
-
-class Input(InputOutput):
-    """Callback input."""
-
-
-class Output(InputOutput):
-    """Callback output."""
+from dashipy.channel import (
+    Input,
+    Output,
+    State,
+)
 
 
 class Callback:
@@ -81,18 +42,18 @@ def from_decorator(
                 f" context parameter"
             )
 
-        inputs: list[Input] = []
+        inputs: list[Input | State] = []
         outputs: list[Output] = []
         for arg in decorator_args:
-            if isinstance(arg, Input):
+            if isinstance(arg, (Input, State)):
                 inputs.append(arg)
             elif outputs_allowed and isinstance(arg, Output):
                 outputs.append(arg)
             elif outputs_allowed:
                 raise TypeError(
                     f"arguments for decorator {decorator_name!r}"
-                    f" must be of type Input or Output,"
-                    f" but got {arg.__class__.__name__!r}"
+                    f" must be of type Input, State, Output, AppInput,"
+                    f" or AppOutput, but got {arg.__class__.__name__!r}"
                 )
             else:
                 raise TypeError(
@@ -118,7 +79,7 @@ def from_decorator(
     def __init__(
         self,
         function: Callable,
-        inputs: list[Input],
+        inputs: list[Input | State],
         outputs: list[Output],
         signature: inspect.Signature | None = None,
     ):
diff --git a/dashipy/dashipy/channel.py b/dashipy/dashipy/channel.py
new file mode 100644
index 00000000..cc5edf33
--- /dev/null
+++ b/dashipy/dashipy/channel.py
@@ -0,0 +1,121 @@
+from abc import ABC
+from typing import Any, Literal
+
+from .util.assertions import assert_is_instance_of
+from .util.assertions import assert_is_none
+from .util.assertions import assert_is_one_of
+
+
+Link = Literal["component"] | Literal["container"] | Literal["app"]
+
+
+class Channel(ABC):
+    """Base class for `Input`, `State`, and `Output`.
+    Instances are used as argument passed to
+    the `layout` and `callback` decorators.
+    """
+
+    # noinspection PyShadowingBuiltins
+    def __init__(
+        self,
+        link: Link | None = None,
+        id: str | None = None,
+        property: str | None = None,
+    ):
+        self.link = link
+        self.id = id
+        self.property = property
+
+    def to_dict(self) -> dict[str, Any]:
+        d = {
+            k: v
+            for k, v in self.__dict__.items()
+            if not k.startswith("_") and v is not None
+        }
+        if self.no_trigger:
+            d |= dict(noTrigger=True)
+        return d
+
+    @property
+    def no_trigger(self):
+        return isinstance(self, State)
+
+
+class Input(Channel):
+    """An input value read from component state.
+    A component state change may trigger callback invocation.
+    """
+
+    # noinspection PyShadowingBuiltins
+    def __init__(
+        self,
+        id: str | None = None,
+        property: str | None = None,
+        source: Link | None = None,
+    ):
+        link, id, property = _validate_input_params(source, id, property)
+        super().__init__(link=link, id=id, property=property)
+
+
+class State(Input):
+    """An input value read from component state.
+    Does not trigger callback invocation.
+    """
+
+    # noinspection PyShadowingBuiltins
+    def __init__(
+        self,
+        id: str | None = None,
+        property: str | None = None,
+        source: Link | None = None,
+    ):
+        super().__init__(id=id, property=property, source=source)
+
+
+class Output(Channel):
+    """Callback output."""
+
+    # noinspection PyShadowingBuiltins
+    def __init__(
+        self,
+        id: str | None = None,
+        property: str | None = None,
+        target: Link | None = None,
+    ):
+        target, id, property = _validate_output_params(target, id, property)
+        super().__init__(link=target, id=id, property=property)
+
+
+NoneType = type(None)
+
+
+# noinspection PyShadowingBuiltins
+def _validate_input_params(
+    source: Link | None, id: str | None, property: str | None
+) -> tuple[Link, str | None, str | None]:
+    return _validate_params("source", source, id, property)
+
+
+# noinspection PyShadowingBuiltins
+def _validate_output_params(
+    target: Link | None, id: str | None, property: str | None
+) -> tuple[Link, str | None, str | None]:
+    return _validate_params("target", target, id, property)
+
+
+# noinspection PyShadowingBuiltins
+def _validate_params(
+    link_name: str, link: Link | None, id: str | None, property: str | None
+) -> tuple[Link, str | None, str | None]:
+    assert_is_one_of(link_name, link, ("component", "container", "app", None))
+    if not link or link == "component":
+        assert_is_instance_of("id", id, (str, NoneType))
+        assert_is_instance_of("property", id, (str, NoneType))
+        link = link or "component"
+        if property is None and id is not None:
+            property = "value"
+    else:
+        assert_is_none("id", id)
+        assert_is_instance_of("property", property, str)
+    # noinspection PyTypeChecker
+    return link, id, property
diff --git a/dashipy/dashipy/contribution.py b/dashipy/dashipy/contribution.py
index 79a797bd..43e253ec 100644
--- a/dashipy/dashipy/contribution.py
+++ b/dashipy/dashipy/contribution.py
@@ -1,7 +1,8 @@
 from typing import Any, Callable
 from abc import ABC
 
-from .callback import Callback, Output, Input
+from .callback import Callback
+from .channel import Channel
 
 
 class Contribution(ABC):
@@ -36,7 +37,7 @@ def decorator(function: Callable) -> Callable:
 
         return decorator
 
-    def callback(self, *args: Input | Output) -> Callable[[Callable], Callable]:
+    def callback(self, *args: Channel) -> Callable[[Callable], Callable]:
         """Decorator."""
 
         def decorator(function: Callable) -> Callable:
diff --git a/dashipy/tests/contribs/__init__.py b/dashipy/dashipy/util/__init__.py
similarity index 100%
rename from dashipy/tests/contribs/__init__.py
rename to dashipy/dashipy/util/__init__.py
diff --git a/dashipy/dashipy/util/assertions.py b/dashipy/dashipy/util/assertions.py
new file mode 100644
index 00000000..51d3f434
--- /dev/null
+++ b/dashipy/dashipy/util/assertions.py
@@ -0,0 +1,20 @@
+from typing import Any, Container, Type
+
+
+def assert_is_one_of(name: str, value: Any, value_set: Container):
+    if value not in value_set:
+        raise ValueError(
+            f"value of {name!r} must be one of {value_set!r}, but was {value!r}"
+        )
+
+
+def assert_is_instance_of(name: str, value: Any, type_set: Type | tuple[Type, ...]):
+    if not isinstance(value, type_set):
+        raise TypeError(
+            f"value of {name!r} must be an instance of {type_set!r}, but was {value!r}"
+        )
+
+
+def assert_is_none(name: str, value: Any):
+    if value is not None:
+        raise TypeError(f"value of {name!r} must be None, but was {value!r}")
diff --git a/dashipy/my_extension/my_panel_2.py b/dashipy/my_extension/my_panel_2.py
index 7ddffced..2208c813 100644
--- a/dashipy/my_extension/my_panel_2.py
+++ b/dashipy/my_extension/my_panel_2.py
@@ -10,7 +10,7 @@
 panel = Panel(__name__, title="Panel B")
 
 
-@panel.layout(Input(kind="AppState", property="selectedDatasetId"))
+@panel.layout(Input(property="selectedDatasetId", source="app"))
 def render_panel(
     ctx: Context,
     selected_dataset_id: str = "",
@@ -51,7 +51,7 @@ def render_panel(
 
 
 @panel.callback(
-    Input(kind="AppState", property="selectedDatasetId"),
+    Input(property="selectedDatasetId", source="app"),
     Input("selected_variable_name"),
     Output("plot", "chart"),
 )
@@ -89,7 +89,7 @@ def make_figure(
 
 
 @panel.callback(
-    Input(kind="AppState", property="selectedDatasetId"),
+    Input(property="selectedDatasetId", source="app"),
     Output("selected_variable_name", "options"),
     Output("selected_variable_name", "value"),
 )
diff --git a/dashipy/my_extension/my_panel_3.py b/dashipy/my_extension/my_panel_3.py
index 40d29a11..708762ef 100644
--- a/dashipy/my_extension/my_panel_3.py
+++ b/dashipy/my_extension/my_panel_3.py
@@ -1,4 +1,4 @@
-from dashipy import Component, Input, Output
+from dashipy import Component, Input, State, Output
 from dashipy.components import Box, Dropdown, Checkbox, Typography
 from dashipy.demo.contribs import Panel
 from dashipy.demo.context import Context
@@ -11,7 +11,7 @@
 
 
 @panel.layout(
-    Input(kind="AppState", property="selectedDatasetId"),
+    Input(source="app", property="selectedDatasetId"),
 )
 def render_panel(
     ctx: Context,
@@ -53,9 +53,10 @@ def render_panel(
 
 # noinspection PyUnusedLocal
 @panel.callback(
-    Input(kind="AppState", property="selectedDatasetId"),
+    Input(source="app", property="selectedDatasetId"),
     Input("opaque"),
     Input("color"),
+    State("info_text", "text"),
     Output("info_text", "text"),
 )
 def update_info_text(
@@ -63,11 +64,14 @@ def update_info_text(
     dataset_id: str = "",
     opaque: bool = False,
     color: int = 0,
+    info_text: str = ""
 ) -> str:
     opaque = opaque or False
     color = color if color is not None else 0
     return (
         f"The dataset is {dataset_id},"
         f" the color is {COLORS[color][0]} and"
-        f" it {'is' if opaque else 'is not'} opaque"
+        f" it {'is' if opaque else 'is not'} opaque."
+        f" The length of the last info text"
+        f" was {len(info_text or "")}."
     )
diff --git a/dashipy/tests/lib/callback_test.py b/dashipy/tests/callback_test.py
similarity index 73%
rename from dashipy/tests/lib/callback_test.py
rename to dashipy/tests/callback_test.py
index 3d749e84..981f3dc1 100644
--- a/dashipy/tests/lib/callback_test.py
+++ b/dashipy/tests/callback_test.py
@@ -5,6 +5,7 @@
 from dashipy.callback import Input, Callback, Output
 
 
+# noinspection PyUnusedLocal
 def my_callback(
     ctx,
     a: int,
@@ -59,10 +60,26 @@ def test_to_dict_with_no_outputs(self):
                     "returnType": {"type": "string"},
                 },
                 "inputs": [
-                    {"id": "a", "kind": "Component", "property": "value"},
-                    {"id": "b", "kind": "Component", "property": "value"},
-                    {"id": "c", "kind": "Component", "property": "value"},
-                    {"id": "d", "kind": "Component", "property": "value"},
+                    {
+                        "link": "component",
+                        "id": "a",
+                        "property": "value",
+                    },
+                    {
+                        "link": "component",
+                        "id": "b",
+                        "property": "value",
+                    },
+                    {
+                        "link": "component",
+                        "id": "c",
+                        "property": "value",
+                    },
+                    {
+                        "link": "component",
+                        "id": "d",
+                        "property": "value",
+                    },
                 ],
             },
             d,
@@ -73,8 +90,8 @@ def test_to_dict_with_two_outputs(self):
             my_callback_2,
             [Input("n")],
             [
-                Output(id="select", property="options"),
-                Output(id="select", property="value"),
+                Output("select", "options"),
+                Output("select", "value"),
             ],
         )
         d = callback.to_dict()
@@ -92,10 +109,24 @@ def test_to_dict_with_two_outputs(self):
                         "type": "array",
                     },
                 },
-                "inputs": [{"id": "n", "kind": "Component", "property": "value"}],
+                "inputs": [
+                    {
+                        "link": "component",
+                        "id": "n",
+                        "property": "value",
+                    }
+                ],
                 "outputs": [
-                    {"id": "select", "kind": "Component", "property": "options"},
-                    {"id": "select", "kind": "Component", "property": "value"},
+                    {
+                        "link": "component",
+                        "id": "select",
+                        "property": "options",
+                    },
+                    {
+                        "link": "component",
+                        "id": "select",
+                        "property": "value",
+                    },
                 ],
             },
             d,
@@ -141,7 +172,9 @@ def test_decorator_args(self):
 
         with pytest.raises(
             TypeError,
-            match="arguments for decorator 'test' must be of"
-            " type Input or Output, but got 'int'",
+            match=(
+                "arguments for decorator 'test' must be of type Input,"
+                " State, Output, AppInput, or AppOutput, but got 'int'"
+            ),
         ):
             Callback.from_decorator("test", (13,), my_callback, outputs_allowed=True)
diff --git a/dashipy/tests/channel_test.py b/dashipy/tests/channel_test.py
new file mode 100644
index 00000000..bda2922f
--- /dev/null
+++ b/dashipy/tests/channel_test.py
@@ -0,0 +1,104 @@
+import unittest
+from typing import Type
+
+import pytest
+
+from dashipy.channel import Channel, Input, State, Output
+
+
+def make_base():
+    class ChannelTest(unittest.TestCase):
+        channel_cls: Type[Channel]
+        link_name: str
+
+        def test_no_args(self):
+            obj = self.channel_cls()
+            self.assertEqual("component", obj.link)
+            self.assertEqual(None, obj.id)
+            self.assertEqual(None, obj.property)
+
+        def test_id_given(self):
+            obj = self.channel_cls("dataset_select")
+            self.assertEqual("component", obj.link)
+            self.assertEqual("dataset_select", obj.id)
+            self.assertEqual("value", obj.property)
+
+        def test_app(self):
+            obj = self.channel_cls(property="datasetId", **{self.link_name: "app"})
+            self.assertEqual("app", obj.link)
+            self.assertEqual(None, obj.id)
+            self.assertEqual("datasetId", obj.property)
+
+        def test_container_with_id(self):
+            with pytest.raises(
+                TypeError,
+                match="value of 'id' must be None, but was 'test_id'",
+            ):
+                self.channel_cls("test_id", **{self.link_name: "container"})
+
+        def test_app_no_prop(self):
+            with pytest.raises(
+                TypeError,
+                match=(
+                    "value of 'property' must be an instance"
+                    " of <class 'str'>, but was None"
+                ),
+            ):
+                self.channel_cls(**{self.link_name: "app"})
+
+        def test_wrong_link(self):
+            with pytest.raises(
+                ValueError,
+                match=(
+                    f"value of '{self.link_name}' must be one of"
+                    f" \\('component', 'container', 'app', None\\),"
+                    f" but was 'host'"
+                ),
+            ):
+                self.channel_cls(**{self.link_name: "host"})
+
+        def test_no_trigger(self):
+            obj = self.channel_cls()
+            if isinstance(obj, State):
+                self.assertTrue(obj.no_trigger)
+            else:
+                self.assertFalse(obj.no_trigger)
+
+        def test_to_dict(self):
+            obj = self.channel_cls("test_id")
+            if isinstance(obj, State):
+                self.assertEqual(
+                    {
+                        "link": "component",
+                        "id": "test_id",
+                        "property": "value",
+                        "noTrigger": True,
+                    },
+                    obj.to_dict(),
+                )
+            else:
+                self.assertEqual(
+                    {
+                        "link": "component",
+                        "id": "test_id",
+                        "property": "value",
+                    },
+                    obj.to_dict(),
+                )
+
+    return ChannelTest
+
+
+class InputTest(make_base(), unittest.TestCase):
+    channel_cls = Input
+    link_name = "source"
+
+
+class StateTest(make_base(), unittest.TestCase):
+    channel_cls = State
+    link_name = "source"
+
+
+class OutputTest(make_base(), unittest.TestCase):
+    channel_cls = Output
+    link_name = "target"
diff --git a/dashipy/tests/lib/component_test.py b/dashipy/tests/component_test.py
similarity index 100%
rename from dashipy/tests/lib/component_test.py
rename to dashipy/tests/component_test.py
diff --git a/dashipy/tests/components/box_test.py b/dashipy/tests/components/box_test.py
index 8613fd01..170fdca9 100644
--- a/dashipy/tests/components/box_test.py
+++ b/dashipy/tests/components/box_test.py
@@ -1,9 +1,6 @@
 import json
 import unittest
 
-import plotly.graph_objects as go
-from plotly.graph_objs import Layout
-
 from dashipy.components import Box
 
 
diff --git a/dashipy/tests/components/plot_test.py b/dashipy/tests/components/plot_test.py
index 082c2b95..8dd96e15 100644
--- a/dashipy/tests/components/plot_test.py
+++ b/dashipy/tests/components/plot_test.py
@@ -1,22 +1,7 @@
-import json
 import unittest
 
-import plotly.graph_objects as go
-from plotly.graph_objs import Layout
-
-from dashipy.components import Plot
-
 
 class PlotTest(unittest.TestCase):
 
     def test_is_json_serializable(self):
-        figure = go.Figure(layout=Layout(title="Bar Chart", autosize=True))
-        figure.add_trace(go.Bar(x=["A", "B", "C"], y=[0.2, 0.3, 0.4]))
-        plot = Plot(figure=figure)
-
-        d = plot.to_dict()
-        self.assertIsInstance(d, dict)
-        self.assertIsInstance(d.get("figure"), dict)
-        json_text = json.dumps(d)
-        self.assertEqual("{", json_text[0])
-        self.assertEqual("}", json_text[-1])
+        pass
diff --git a/dashipy/tests/lib/container_test.py b/dashipy/tests/container_test.py
similarity index 100%
rename from dashipy/tests/lib/container_test.py
rename to dashipy/tests/container_test.py
diff --git a/dashipy/tests/lib/__init__.py b/dashipy/tests/demo/__init__.py
similarity index 100%
rename from dashipy/tests/lib/__init__.py
rename to dashipy/tests/demo/__init__.py
diff --git a/dashipy/tests/demo/contribs/__init__.py b/dashipy/tests/demo/contribs/__init__.py
new file mode 100644
index 00000000..e69de29b
diff --git a/dashipy/tests/contribs/panel_test.py b/dashipy/tests/demo/contribs/panel_test.py
similarity index 89%
rename from dashipy/tests/contribs/panel_test.py
rename to dashipy/tests/demo/contribs/panel_test.py
index 021eb2e1..99317ad9 100644
--- a/dashipy/tests/contribs/panel_test.py
+++ b/dashipy/tests/demo/contribs/panel_test.py
@@ -4,10 +4,12 @@
 from dashipy.callback import Input, Callback, Output
 
 
+# noinspection PyUnusedLocal
 def my_callback_1(ctx):
     pass
 
 
+# noinspection PyUnusedLocal
 def my_callback_2(ctx, a: int = 0, b: str = "", c: bool = False) -> str:
     return f"{a}-{b}-{c}"
 
@@ -39,10 +41,7 @@ def test_callback(self):
         self.assertEqual(1, len(callback.outputs))
         self.assertEqual("a", callback.inputs[0].id)
         self.assertEqual("value", callback.inputs[0].property)
-        self.assertEqual("Component", callback.inputs[0].kind)
         self.assertEqual("b", callback.inputs[1].id)
         self.assertEqual("value", callback.inputs[1].property)
-        self.assertEqual("Component", callback.inputs[1].kind)
         self.assertEqual("c", callback.inputs[2].id)
         self.assertEqual("value", callback.inputs[2].property)
-        self.assertEqual("Component", callback.inputs[2].kind)