diff --git a/frontend/src/components/script-editor/ParameterDetectorStepper.tsx b/frontend/src/components/script-editor/ParameterDetectorStepper.tsx
new file mode 100644
index 00000000..68e54cef
--- /dev/null
+++ b/frontend/src/components/script-editor/ParameterDetectorStepper.tsx
@@ -0,0 +1,245 @@
+import { useState } from 'react'
+import { ChevronRight, SkipForward, Info, Check } from 'lucide-react'
+import { cn } from '@/lib/utils'
+import { Input } from '@/components/ui/Input'
+import type { ParameterCandidate, ScriptParameter } from '@/types'
+
+const PARAM_TYPES: { value: ScriptParameter['type']; label: string }[] = [
+  { value: 'text', label: 'Text' },
+  { value: 'password', label: 'Password' },
+  { value: 'textarea', label: 'Textarea' },
+  { value: 'number', label: 'Number' },
+  { value: 'boolean', label: 'Boolean' },
+  { value: 'select', label: 'Select' },
+  { value: 'multi_text', label: 'Multi-text' },
+]
+
+interface Props {
+  candidates: ParameterCandidate[]
+  existingKeys: string[]
+  onAccept: (candidate: ParameterCandidate, overrides: {
+    key: string
+    label: string
+    type: ScriptParameter['type']
+    sensitive: boolean
+    required: boolean
+    defaultValue: string | boolean | number | null
+  }) => void
+  onSkip: (candidate: ParameterCandidate) => void
+  onFinish: (acceptedCount: number, totalCount: number) => void
+}
+
+export function ParameterDetectorStepper({
+  candidates,
+  existingKeys,
+  onAccept,
+  onSkip,
+  onFinish,
+}: Props) {
+  const [currentIndex, setCurrentIndex] = useState(0)
+  const [acceptedCount, setAcceptedCount] = useState(0)
+  const [showInferenceInfo, setShowInferenceInfo] = useState(false)
+
+  const current = candidates[currentIndex]
+  const [key, setKey] = useState(current.suggestedKey)
+  const [label, setLabel] = useState(current.suggestedLabel)
+  const [type, setType] = useState<ScriptParameter['type']>(current.suggestedType)
+  const [sensitive, setSensitive] = useState(current.sensitive)
+  const [required, setRequired] = useState(true)
+  const [defaultValue, setDefaultValue] = useState(
+    current.defaultValue !== null ? String(current.defaultValue) : ''
+  )
+
+  const isLast = currentIndex === candidates.length - 1
+
+  const resetFieldsForIndex = (index: number) => {
+    const c = candidates[index]
+    setKey(c.suggestedKey)
+    setLabel(c.suggestedLabel)
+    setType(c.suggestedType)
+    setSensitive(c.sensitive)
+    setRequired(true)
+    setDefaultValue(c.defaultValue !== null ? String(c.defaultValue) : '')
+    setShowInferenceInfo(false)
+  }
+
+  const handleAccept = () => {
+    const parsedDefault = type === 'boolean'
+      ? defaultValue === 'true'
+      : type === 'number'
+        ? (defaultValue ? Number(defaultValue) : null)
+        : (defaultValue || null)
+
+    onAccept(current, {
+      key,
+      label,
+      type,
+      sensitive,
+      required,
+      defaultValue: parsedDefault,
+    })
+
+    const newAccepted = acceptedCount + 1
+    setAcceptedCount(newAccepted)
+
+    if (isLast) {
+      onFinish(newAccepted, candidates.length)
+    } else {
+      const nextIndex = currentIndex + 1
+      setCurrentIndex(nextIndex)
+      resetFieldsForIndex(nextIndex)
+    }
+  }
+
+  const handleSkip = () => {
+    onSkip(current)
+
+    if (isLast) {
+      onFinish(acceptedCount, candidates.length)
+    } else {
+      const nextIndex = currentIndex + 1
+      setCurrentIndex(nextIndex)
+      resetFieldsForIndex(nextIndex)
+    }
+  }
+
+  return (
+    <div className="border border-primary/20 rounded-xl bg-primary/[0.03] p-4 space-y-3">
+      {/* Progress */}
+      <div className="flex items-center justify-between">
+        <p className="text-xs font-medium text-foreground">
+          Candidate {currentIndex + 1} of {candidates.length}
+        </p>
+        <div className="flex items-center gap-1">
+          {candidates.map((_, i) => (
+            <div
+              key={i}
+              className={cn(
+                'h-1.5 w-1.5 rounded-full transition-colors',
+                i < currentIndex ? 'bg-primary' :
+                i === currentIndex ? 'bg-primary animate-pulse' :
+                'bg-border'
+              )}
+            />
+          ))}
+        </div>
+      </div>
+
+      {/* Matched line */}
+      <div className="rounded-lg bg-black/20 px-3 py-2">
+        <p className="font-label text-xs text-amber-400 break-all">
+          {current.matchedLine}
+        </p>
+        <p className="font-label text-[0.5rem] text-muted-foreground mt-1">
+          Line {current.lineNumber} · {current.source === 'param_block' ? 'param() block' : 'variable assignment'}
+        </p>
+      </div>
+
+      {/* Editable fields */}
+      <div className="grid grid-cols-2 gap-3">
+        <div>
+          <label className="text-xs text-muted-foreground mb-1 block">Key</label>
+          <Input
+            value={key}
+            onChange={e => setKey(e.target.value.replace(/[^a-zA-Z0-9_]/g, ''))}
+            placeholder="param_key"
+          />
+          {existingKeys.includes(key) && (
+            <p className="text-[0.625rem] text-amber-400 mt-0.5">Key already exists — consider a different name</p>
+          )}
+        </div>
+        <div>
+          <label className="text-xs text-muted-foreground mb-1 block">Label</label>
+          <Input
+            value={label}
+            onChange={e => setLabel(e.target.value)}
+            placeholder="Display Label"
+          />
+        </div>
+      </div>
+
+      <div className="grid grid-cols-2 gap-3">
+        <div>
+          <label className="text-xs text-muted-foreground mb-1 flex items-center gap-1.5">
+            Type
+            <button
+              type="button"
+              onClick={() => setShowInferenceInfo(!showInferenceInfo)}
+              className="text-muted-foreground hover:text-primary transition-colors"
+              title={current.inferenceReason}
+            >
+              <Info size={11} />
+            </button>
+          </label>
+          <select
+            value={type}
+            onChange={e => setType(e.target.value as ScriptParameter['type'])}
+            className="w-full rounded-[10px] border border-border bg-card text-foreground px-3 py-2 text-sm focus:outline-none focus:border-[rgba(6,182,212,0.3)]"
+          >
+            {PARAM_TYPES.map(t => (
+              <option key={t.value} value={t.value}>{t.label}</option>
+            ))}
+          </select>
+          {showInferenceInfo && (
+            <p className="text-[0.625rem] text-primary/80 mt-1 italic">
+              {current.inferenceReason}
+            </p>
+          )}
+        </div>
+        <div>
+          <label className="text-xs text-muted-foreground mb-1 block">Default value</label>
+          <Input
+            value={defaultValue}
+            onChange={e => setDefaultValue(e.target.value)}
+            placeholder="Original value preserved"
+          />
+        </div>
+      </div>
+
+      <div className="flex items-center gap-4">
+        <label className="flex items-center gap-2 text-sm text-foreground">
+          <input
+            type="checkbox"
+            checked={required}
+            onChange={e => setRequired(e.target.checked)}
+            className="rounded border-border"
+          />
+          Required
+        </label>
+        <label className="flex items-center gap-2 text-sm text-foreground">
+          <input
+            type="checkbox"
+            checked={sensitive}
+            onChange={e => setSensitive(e.target.checked)}
+            className="rounded border-border"
+          />
+          Sensitive
+        </label>
+      </div>
+
+      {/* Actions */}
+      <div className="flex items-center justify-end gap-2 pt-1 border-t border-border">
+        <button
+          type="button"
+          onClick={handleSkip}
+          className="flex items-center gap-1.5 text-sm text-muted-foreground hover:text-foreground transition-colors px-3 py-1.5"
+        >
+          <SkipForward size={13} />
+          {isLast ? 'Skip & Finish' : 'Skip'}
+        </button>
+        <button
+          type="button"
+          onClick={handleAccept}
+          disabled={!key.trim() || !label.trim()}
+          className="flex items-center gap-1.5 bg-gradient-brand text-[#101114] font-semibold text-sm px-4 py-1.5 rounded-[10px] hover:opacity-90 active:scale-[0.97] transition-all shadow-lg shadow-primary/20 disabled:opacity-50 disabled:cursor-not-allowed"
+        >
+          {isLast ? (
+            <><Check size={13} /> Accept &amp; Finish</>
+          ) : (
+            <><ChevronRight size={13} /> Accept &amp; Next</>
+          )}
+        </button>
+      </div>
+    </div>
+  )
+}