diff --git a/src/app/(dashboard)/docs/ai-analysis/page.tsx b/src/app/(dashboard)/docs/ai-analysis/page.tsx
index 95c6845..b9bef47 100644
--- a/src/app/(dashboard)/docs/ai-analysis/page.tsx
+++ b/src/app/(dashboard)/docs/ai-analysis/page.tsx
@@ -1,6 +1,6 @@
 "use client";
 
-import { Bot, TrendingUp, Calendar, Zap, AlertTriangle, ShieldCheck, Scale, Info } from "lucide-react";
+import { Bot, TrendingUp, Calendar, Zap, AlertTriangle, ShieldCheck, Scale, Info, Brain } from "lucide-react";
 import { cn } from "@/lib/utils";
 
 export default function AiAnalysisDocPage() {
@@ -83,6 +83,20 @@ export default function AiAnalysisDocPage() {
                         À l'inverse, un produit à faible volume peut être un <strong>Contributeur de Marge</strong> précieux s'il possède un Prix Moyen de Vente (PMV) élevé.
                     </p>
                 </DocCard>
+
+                {/* 5. Règles IA Fournisseur */}
+                <DocCard
+                    icon={Brain}
+                    title="Règles Métier Fournisseur"
+                    description="Priorité absolue aux directives personnalisées."
+                    accent="indigo"
+                >
+                    <p className="text-[13px] leading-relaxed">
+                        Vous pouvez définir des <strong>Règles IA</strong> spécifiques pour chaque fournisseur (via le bouton avec le cerveau 🧠).
+                        Ces directives sont mémorisées d'une session à l'autre et l'IA a pour consigne stricte de les <strong>respecter en priorité absolue</strong>
+                        sur les calculs algorithmiques standards.
+                    </p>
+                </DocCard>
             </div>
 
             {/* Footer / Tip */}
diff --git a/src/app/api/ai/analyze/route.ts b/src/app/api/ai/analyze/route.ts
index c97ad9d..d2f1507 100644
--- a/src/app/api/ai/analyze/route.ts
+++ b/src/app/api/ai/analyze/route.ts
@@ -2,6 +2,9 @@ import { NextRequest, NextResponse } from "next/server";
 import { getSavedDatabaseConfig } from "@/features/settings/actions";
 import { OpenRouterClient } from "@/features/ai-copilot/data/open-router-client";
 import { ProductAnalysisInput } from "@/features/ai-copilot/models/ai-analysis.types";
+import { db } from "@/db";
+import { aiSupplierContext } from "@/db/schema";
+import { eq } from "drizzle-orm";
 
 export async function POST(req: NextRequest) {
     const config = await getSavedDatabaseConfig();
@@ -16,6 +19,21 @@ export async function POST(req: NextRequest) {
     try {
         const body: ProductAnalysisInput = await req.json();
 
+        // Inject supplier context if available
+        if (body.codeFournisseur) {
+            try {
+                const contextRecord = await db.select()
+                    .from(aiSupplierContext)
+                    .where(eq(aiSupplierContext.codeFournisseur, body.codeFournisseur))
+                    .limit(1);
+                if (contextRecord.length > 0 && contextRecord[0].context) {
+                    body.supplierContext = contextRecord[0].context;
+                }
+            } catch (err) {
+                console.error("[AI] Failed to fetch supplier context:", err);
+            }
+        }
+
         const client = new OpenRouterClient({ apiKey, model });
         const result = await client.analyzeProduct(body);
 
diff --git a/src/app/api/ai/context/route.ts b/src/app/api/ai/context/route.ts
new file mode 100644
index 0000000..f637122
--- /dev/null
+++ b/src/app/api/ai/context/route.ts
@@ -0,0 +1,56 @@
+import { NextResponse } from "next/server";
+import { db } from "@/db";
+import { aiSupplierContext } from "@/db/schema";
+import { eq } from "drizzle-orm";
+
+export async function GET(request: Request) {
+    const { searchParams } = new URL(request.url);
+    const codeFournisseur = searchParams.get("fournisseur");
+
+    if (!codeFournisseur) {
+        return NextResponse.json({ error: "Fournisseur manquant" }, { status: 400 });
+    }
+
+    try {
+        const result = await db.select()
+            .from(aiSupplierContext)
+            .where(eq(aiSupplierContext.codeFournisseur, codeFournisseur))
+            .limit(1);
+
+        return NextResponse.json({ context: result[0]?.context || "" });
+    } catch (error) {
+        console.error("Error fetching AI context:", error);
+        // Fallback en cas d'erreur de BDD ou si la table n'est pas encore créée
+        return NextResponse.json({ context: "" });
+    }
+}
+
+export async function POST(request: Request) {
+    try {
+        const body = await request.json();
+        const { codeFournisseur, context } = body;
+
+        if (!codeFournisseur) {
+            return NextResponse.json({ error: "Fournisseur manquant" }, { status: 400 });
+        }
+
+        await db.insert(aiSupplierContext)
+            .values({
+                codeFournisseur,
+                context: context || "",
+                updatedAt: new Date()
+            })
+            .onConflictDoUpdate({
+                target: aiSupplierContext.codeFournisseur,
+                set: {
+                    context: context || "",
+                    updatedAt: new Date()
+                }
+            });
+
+        return NextResponse.json({ success: true });
+    } catch (error) {
+        console.error("Error saving AI context:", error);
+        return NextResponse.json({ error: "Erreur lors de la sauvegarde" }, { status: 500 });
+    }
+}
diff --git a/src/db/schema.ts b/src/db/schema.ts
index 35ccf2e..3a98813 100644
--- a/src/db/schema.ts
+++ b/src/db/schema.ts
@@ -76,3 +76,13 @@ export const sessionSnapshots = pgTable("session_snapshots", {
   type: varchar("type", { length: 20 }).default("snapshot"),
   createdAt: timestamp("created_at").defaultNow(),
 });
+
+/** AI Context rules per supplier (Epic: AI Context) */
+export const aiSupplierContext = pgTable("ai_supplier_context", {
+  /** Supplier code serving as the primary key */
+  codeFournisseur: varchar("code_fournisseur", { length: 20 }).primaryKey(),
+  /** The business rules text provided by the user */
+  context: text("context").notNull(),
+  /** When it was last updated */
+  updatedAt: timestamp("updated_at").defaultNow(),
+});
diff --git a/src/features/ai-copilot/business/analysis-engine.ts b/src/features/ai-copilot/business/analysis-engine.ts
index 7544992..154edc3 100644
--- a/src/features/ai-copilot/business/analysis-engine.ts
+++ b/src/features/ai-copilot/business/analysis-engine.ts
@@ -38,9 +38,15 @@ CONTRIBUTION(%) :
     GARDES-FOUS : ${p.scoring.isTop30Supplier ? "Oui (Top 30% Fournisseur)" : "Non"} | Récent : ${p.scoring.isRecent ? "Oui" : "Non"} | Dernier Prod: ${p.scoring.isLastProduct ? "Oui" : "Non"}
 ` : "";
 
+        const contextRules = p.supplierContext ? `
+--- RÈGLES MÉTIER SPÉCIFIQUES ---
+Le manager a défini ces règles absolues pour ce fournisseur (TU DOIS LES RESPECTER EN PRIORITÉ) :
+"${p.supplierContext}"
+` : "";
+
         return `PRODUIT: ${p.libelle1} (${p.codein})
 PERFORMANCE: Score Global ${p.score.toFixed(1)}/100 | Marge ${p.tauxMarge.toFixed(1)}% | PMV ${pmv.toFixed(2)}€
-${weights}${scoringInfo}
+${weights}${scoringInfo}${contextRules}
 Verdict algorithmique: ${p.scoring?.decision || "Non calculé"}
 Justifie ce verdict auprès de l'utilisateur.`;
     }
diff --git a/src/features/ai-copilot/models/ai-analysis.types.ts b/src/features/ai-copilot/models/ai-analysis.types.ts
index 9e87ee3..12e1e21 100644
--- a/src/features/ai-copilot/models/ai-analysis.types.ts
+++ b/src/features/ai-copilot/models/ai-analysis.types.ts
@@ -31,16 +31,18 @@ export interface ProductAnalysisInput {
     codeFournisseur?: string;
     totalMagasins?: number;
     isLastProductOfSupplier?: boolean;
-    /** Résultats du ScoringEngine (optionnel pour l'IA) */
+    /** Scoring metadata */
     scoring?: {
         compositeScore: number;
-        decision: string;
+        decision: "A" | "Z";
         labelProfil: string;
         isTop30Supplier: boolean;
         isRecent: boolean;
         isLastProduct: boolean;
         threshold: number;
     };
+    /** Optional context rules for the supplier */
+    supplierContext?: string;
 }
 
 export interface AnalysisResult {
diff --git a/src/features/grid/components/bulk-ai-analyzer.tsx b/src/features/grid/components/bulk-ai-analyzer.tsx
index 6a28ec2..1cbea61 100644
--- a/src/features/grid/components/bulk-ai-analyzer.tsx
+++ b/src/features/grid/components/bulk-ai-analyzer.tsx
@@ -7,8 +7,13 @@ import { ScoringEngine } from "@/features/ai-copilot/business/scoring-engine";
 import { Sparkles, Loader2, CheckCircle2, XCircle } from "lucide-react";
 import { ProductRow, GammeCode } from "@/types/grid";
 import { ProductAnalysisInput } from "@/features/ai-copilot/models/ai-analysis.types";
+import { SupplierAiContextModal } from "./supplier-ai-context-modal";
 
 export function BulkAiAnalyzer() {
+    const rows = useGridStore((s) => s.rows);
+    const supplierCode = rows.length > 0 ? rows[0].codeFournisseur : null;
+    const supplierName = rows.length > 0 ? rows[0].nomFournisseur : null;
+
     const [isAnalyzing, setIsAnalyzing] = useState(false);
     const [progress, setProgress] = useState({ current: 0, total: 0, message: "", errors: 0 });
     const isCancelledRef = useRef(false);
@@ -243,12 +248,15 @@ export function BulkAiAnalyzer() {
     }
 
     return (
-        <button
-            onClick={handleAnalyze}
-            className="group flex items-center justify-center gap-2 h-10 px-6 rounded-xl text-sm font-black transition-all shadow-md bg-[var(--accent)] text-white hover:brightness-110 active:scale-95 border border-white/10"
-        >
-            <Sparkles className="w-4 h-4" />
-            Analyse IA
-        </button>
+        <div className="flex items-center gap-3">
+            <SupplierAiContextModal codeFournisseur={supplierCode} nomFournisseur={supplierName} />
+            <button
+                onClick={handleAnalyze}
+                className="group flex items-center justify-center gap-2 h-10 px-6 rounded-xl text-sm font-black transition-all shadow-md bg-[var(--accent)] text-white hover:brightness-110 active:scale-95 border border-white/10"
+            >
+                <Sparkles className="w-4 h-4" />
+                Analyse IA
+            </button>
+        </div>
     );
 }
diff --git a/src/features/grid/components/supplier-ai-context-modal.tsx b/src/features/grid/components/supplier-ai-context-modal.tsx
new file mode 100644
index 0000000..4f1ab10
--- /dev/null
+++ b/src/features/grid/components/supplier-ai-context-modal.tsx
@@ -0,0 +1,104 @@
+"use client";
+
+import { useState, useEffect } from "react";
+import { Button } from "@/components/ui/button";
+import { Dialog, DialogContent, DialogHeader, DialogTitle, DialogDescription, DialogFooter, DialogTrigger } from "@/components/ui/dialog";
+import { Textarea } from "@/components/ui/textarea";
+import { Brain } from "lucide-react";
+
+interface SupplierAiContextModalProps {
+    codeFournisseur: string | null;
+    nomFournisseur: string | null;
+}
+
+export function SupplierAiContextModal({ codeFournisseur, nomFournisseur }: SupplierAiContextModalProps) {
+    const [open, setOpen] = useState(false);
+    const [context, setContext] = useState("");
+    const [isLoading, setIsLoading] = useState(false);
+    const [isSaving, setIsSaving] = useState(false);
+
+    useEffect(() => {
+        if (open && codeFournisseur) {
+            fetchContext();
+        }
+    }, [open, codeFournisseur]);
+
+    const fetchContext = async () => {
+        setIsLoading(true);
+        try {
+            const res = await fetch(`/api/ai/context?fournisseur=${codeFournisseur}`);
+            if (res.ok) {
+                const data = await res.json();
+                setContext(data.context || "");
+            }
+        } catch (error) {
+            console.error("Failed to load AI context", error);
+        } finally {
+            setIsLoading(false);
+        }
+    };
+
+    const handleSave = async () => {
+        if (!codeFournisseur) return;
+
+        setIsSaving(true);
+        try {
+            const res = await fetch("/api/ai/context", {
+                method: "POST",
+                headers: { "Content-Type": "application/json" },
+                body: JSON.stringify({ codeFournisseur, context }),
+            });
+
+            if (res.ok) {
+                setOpen(false);
+            } else {
+                console.error("Failed to save AI context");
+            }
+        } catch (error) {
+            console.error("Failed to save AI context", error);
+        } finally {
+            setIsSaving(false);
+        }
+    };
+
+    if (!codeFournisseur) return null;
+
+    return (
+        <Dialog open={open} onOpenChange={setOpen}>
+            <DialogTrigger asChild>
+                <Button variant="outline" size="sm" className="gap-2">
+                    <Brain className="w-4 h-4" />
+                    Règles IA
+                </Button>
+            </DialogTrigger>
+            <DialogContent className="sm:max-w-[500px]">
+                <DialogHeader>
+                    <DialogTitle>Contexte IA - {nomFournisseur || codeFournisseur}</DialogTitle>
+                    <DialogDescription>
+                        Définissez ici les règles métier absolues pour ce fournisseur.
+                        Mary (l'IA) respectera ces consignes en priorité lors de ses recommandations (ex: "Les calendriers vont en gamme C").
+                    </DialogDescription>
+                </DialogHeader>
+
+                <div className="py-4">
+                    <Textarea
+                        placeholder="Ex: Les produits dont le nom contient 'Agenda' doivent toujours être classés en [A]..."
+                        value={context}
+                        onChange={(e) => setContext(e.target.value)}
+                        disabled={isLoading}
+                        className="min-h-[150px]"
+                    />
+                </div>
+
+                <DialogFooter>
+                    <Button variant="outline" onClick={() => setOpen(false)} disabled={isSaving}>
+                        Annuler
+                    </Button>
+                    <Button onClick={handleSave} disabled={isSaving || isLoading} className="gap-2 bg-gradient-to-r from-violet-600 to-indigo-600 text-white hover:from-violet-700 hover:to-indigo-700">
+                        {isSaving ? "Enregistrement..." : "Enregistrer les règles"}
+                    </Button>
+                </DialogFooter>
+            </DialogContent>
+        </Dialog>
+    );
+}