diff --git a/src/entries/Background/rpc.ts b/src/entries/Background/rpc.ts
index fb5606a..dc20e99 100644
--- a/src/entries/Background/rpc.ts
+++ b/src/entries/Background/rpc.ts
@@ -528,6 +528,7 @@ async function runPluginProver(request: BackgroundAction, now = Date.now()) {
     websocketProxyUrl: _websocketProxyUrl,
     maxSentData: _maxSentData,
     maxRecvData: _maxRecvData,
+    metadata,
   } = request.data;
   const notaryUrl = _notaryUrl || (await getNotaryApi());
   const websocketProxyUrl = _websocketProxyUrl || (await getProxyApi());
@@ -547,6 +548,7 @@ async function runPluginProver(request: BackgroundAction, now = Date.now()) {
     maxSentData,
     secretHeaders,
     secretResps,
+    metadata,
   });
 
   await setNotaryRequestStatus(id, 'pending');
diff --git a/src/entries/SidePanel/SidePanel.tsx b/src/entries/SidePanel/SidePanel.tsx
index ecda919..280a87f 100644
--- a/src/entries/SidePanel/SidePanel.tsx
+++ b/src/entries/SidePanel/SidePanel.tsx
@@ -7,6 +7,7 @@ import {
   makePlugin,
   PluginConfig,
   StepConfig,
+  InputFieldConfig,
 } from '../../utils/misc';
 import DefaultPluginIcon from '../../assets/img/default-plugin-icon.png';
 import logo from '../../assets/img/icon-128.png';
@@ -225,13 +226,27 @@ function StepContent(
     p2p = false,
     clientId = '',
     parameterValues,
+    inputs,
   } = props;
   const [completed, setCompleted] = useState(false);
   const [pending, setPending] = useState(false);
   const [error, setError] = useState('');
   const [notarizationId, setNotarizationId] = useState('');
+  const [inputValues, setInputValues] = useState<Record<string, string>>({});
   const notaryRequest = useRequestHistory(notarizationId);
 
+  useEffect(() => {
+    if (inputs) {
+      const initialValues: Record<string, string> = {};
+      inputs.forEach((input) => {
+        if (input.defaultValue) {
+          initialValues[input.name] = input.defaultValue;
+        }
+      });
+      setInputValues(initialValues);
+    }
+  }, [inputs]);
+
   const getPlugin = useCallback(async () => {
     const hex = (await getPluginByUrl(url)) || _hex;
     const arrayBuffer = hexToArrayBuffer(hex!);
@@ -243,16 +258,31 @@ function StepContent(
     if (!plugin) return;
     if (index > 0 && !lastResponse) return;
 
+    // Validate required input fields
+    if (inputs) {
+      for (const input of inputs) {
+        if (
+          input.required &&
+          (!inputValues[input.name] || inputValues[input.name].trim() === '')
+        ) {
+          setError(`${input.label} is required`);
+          return;
+        }
+      }
+    }
+
     setPending(true);
     setError('');
 
     try {
-      const out = await plugin.call(
-        action,
-        index > 0
-          ? JSON.stringify(lastResponse)
-          : JSON.stringify(parameterValues),
-      );
+      let stepData: any;
+      if (index > 0) {
+        stepData = lastResponse;
+      } else {
+        stepData = { ...parameterValues, ...inputValues };
+      }
+
+      const out = await plugin.call(action, JSON.stringify(stepData));
       const val = JSON.parse(out!.string());
       if (val && prover) {
         setNotarizationId(val);
@@ -266,7 +296,16 @@ function StepContent(
     } finally {
       setPending(false);
     }
-  }, [action, index, lastResponse, prover, getPlugin]);
+  }, [
+    action,
+    index,
+    lastResponse,
+    prover,
+    getPlugin,
+    inputs,
+    inputValues,
+    parameterValues,
+  ]);
 
   const onClick = useCallback(() => {
     if (
@@ -311,8 +350,11 @@ function StepContent(
   }, []);
 
   useEffect(() => {
-    processStep();
-  }, [processStep]);
+    // only auto-progress if this step does need inputs
+    if (!inputs || inputs.length === 0) {
+      processStep();
+    }
+  }, [processStep, inputs]);
 
   let btnContent = null;
 
@@ -420,8 +462,105 @@ function StepContent(
             </div>
           </div>
         )}
+        {inputs && inputs.length > 0 && !completed && (
+          <div className="flex flex-col gap-3 mt-3">
+            {inputs.map((input) => (
+              <InputField
+                key={input.name}
+                config={input}
+                value={inputValues[input.name] || ''}
+                onChange={(value) =>
+                  setInputValues((prev) => ({ ...prev, [input.name]: value }))
+                }
+              />
+            ))}
+          </div>
+        )}
         {btnContent}
       </div>
     </div>
   );
 }
+
+interface InputFieldProps {
+  config: InputFieldConfig;
+  value: string;
+  onChange: (value: string) => void;
+  disabled?: boolean;
+}
+
+function InputField({
+  config,
+  value,
+  onChange,
+  disabled = false,
+}: InputFieldProps): ReactElement {
+  const { name, label, type, placeholder, required, options } = config;
+
+  const baseClasses =
+    'w-full px-3 py-2 border border-gray-300 rounded-md focus:outline-none focus:ring-2 focus:ring-blue-500 focus:border-transparent';
+
+  const renderInput = () => {
+    switch (type) {
+      case 'textarea':
+        return (
+          <textarea
+            id={name}
+            name={name}
+            value={value}
+            onChange={(e) => onChange(e.target.value)}
+            placeholder={placeholder}
+            required={required}
+            disabled={disabled}
+            className={classNames(baseClasses, 'resize-y min-h-[80px]')}
+            rows={3}
+          />
+        );
+
+      case 'select':
+        return (
+          <select
+            id={name}
+            name={name}
+            value={value}
+            onChange={(e) => onChange(e.target.value)}
+            required={required}
+            disabled={disabled}
+            className={baseClasses}
+          >
+            <option value="">{placeholder || 'Select an option'}</option>
+            {options?.map((option) => (
+              <option key={option.value} value={option.value}>
+                {option.label}
+              </option>
+            ))}
+          </select>
+        );
+
+      default:
+        return (
+          <input
+            type={type}
+            id={name}
+            name={name}
+            value={value}
+            onChange={(e) => onChange(e.target.value)}
+            placeholder={placeholder}
+            required={required}
+            disabled={disabled}
+            className={baseClasses}
+          />
+        );
+    }
+  };
+
+  return (
+    <div className="flex flex-col gap-1">
+      <label htmlFor={name} className="text-sm font-medium text-gray-700">
+        {label}
+        {required && <span className="text-red-500 ml-1">*</span>}
+      </label>
+      {renderInput()}
+    </div>
+  );
+}
diff --git a/src/pages/ProofViewer/index.tsx b/src/pages/ProofViewer/index.tsx
index 156d8c7..fe91d8d 100644
--- a/src/pages/ProofViewer/index.tsx
+++ b/src/pages/ProofViewer/index.tsx
@@ -151,6 +151,15 @@ export default function ProofViewer(props?: {
               label="Notary Key"
               value={props?.notaryKey || request?.verification?.notaryKey}
             />
+
+            {request?.metadata &&
+              Object.entries(request.metadata).map(([key, value]) => (
+                <MetadataRow
+                  key={`req-${key}`}
+                  label={`Custom: ${key}`}
+                  value={String(value)}
+                />
+              ))}
           </div>
         )}
       </div>
diff --git a/src/utils/misc.ts b/src/utils/misc.ts
index 7522ce4..bf53cd4 100644
--- a/src/utils/misc.ts
+++ b/src/utils/misc.ts
@@ -188,11 +188,13 @@ export const makePlugin = async (
   } = {
     redirect: function (context: CallContext, off: bigint) {
       const r = context.read(off);
+      if (!r) throw new Error('Failed to read context');
       const url = r.text();
       browser.tabs.update(tab.id, { url });
     },
     notarize: function (context: CallContext, off: bigint) {
       const r = context.read(off);
+      if (!r) throw new Error('Failed to read context');
       const params = JSON.parse(r.text());
       const now = Date.now();
       const id = charwise.encode(now).toString('hex');
@@ -338,7 +340,10 @@ export const makePlugin = async (
 
   const pluginConfig: ExtismPluginOptions = {
     useWasi: true,
-    config: injectedConfig,
+    config: {
+      ...injectedConfig,
+      tabId: tab.id?.toString() || '',
+    },
     // allowedHosts: approvedRequests.map((r) => urlify(r.url)?.origin),
     functions: {
       'extism:host/user': funcs,
@@ -349,12 +354,23 @@ export const makePlugin = async (
   return plugin;
 };
 
+export type InputFieldConfig = {
+  name: string; // Unique identifier for the input field
+  label: string; // Display label for the input
+  type: 'text' | 'password' | 'email' | 'number' | 'textarea' | 'select'; // Input field type
+  placeholder?: string; // Optional placeholder text
+  required?: boolean; // Whether the field is required
+  defaultValue?: string; // Default value for the field
+  options?: { value: string; label: string }[]; // Options for select type
+};
+
 export type StepConfig = {
   title: string; // Text for the step's title
   description?: string; // Text for the step's description (optional)
   cta: string; // Text for the step's call-to-action button
   action: string; // The function name that this step will execute
   prover?: boolean; // Boolean indicating if this step outputs a notarization (optional)
+  inputs?: InputFieldConfig[]; // Input fields for user data collection (optional)
 };
 
 export type PluginConfig = {
@@ -382,6 +398,7 @@ export const getPluginConfig = async (
 ): Promise<PluginConfig> => {
   const plugin = data instanceof ArrayBuffer ? await makePlugin(data) : data;
   const out = await plugin.call('config');
+  if (!out) throw new Error('Plugin config call returned null');
   const config: PluginConfig = JSON.parse(out.string());
 
   assert(typeof config.title === 'string' && config.title.length);
@@ -439,6 +456,23 @@ export const getPluginConfig = async (
       assert(typeof step.cta === 'string' && step.cta.length);
       assert(typeof step.action === 'string' && step.action.length);
       assert(!step.prover || typeof step.prover === 'boolean');
+
+      if (step.inputs) {
+        for (const input of step.inputs) {
+          assert(typeof input.name === 'string' && input.name.length);
+          assert(typeof input.label === 'string' && input.label.length);
+          assert(!input.placeholder || typeof input.placeholder === 'string');
+          assert(!input.required || typeof input.required === 'boolean');
+          assert(!input.defaultValue || typeof input.defaultValue === 'string');
+          if (input.type === 'select') {
+            assert(Array.isArray(input.options) && input.options.length > 0);
+            for (const option of input.options!) {
+              assert(typeof option.value === 'string');
+              assert(typeof option.label === 'string');
+            }
+          }
+        }
+      }
     }
   }