diff --git a/src/entities/chain/model.ts b/src/entities/chain/model.ts
index a6c6e1e..43cea6f 100644
--- a/src/entities/chain/model.ts
+++ b/src/entities/chain/model.ts
@@ -12,6 +12,7 @@ interface ChainState {
   updateChain: (chain: Chain) => void;
   deleteChain: (id: string) => void;
   addCommentAction: (chainId: string, action: Action) => void;
+  updateAction: (chainId: string, actionIndex: number, action: Action) => void;
 }
 
 export const useChainState = create<ChainState>((set, get) => ({
@@ -88,4 +89,22 @@ export const useChainState = create<ChainState>((set, get) => ({
       chains[chainIndex].actions = actions;
       return state;
     }),
+
+  updateAction: (chainId, actionIndex, action) =>
+    set((state) => {
+      const chains = state.chains;
+      if (!chains) return state;
+
+      const chain = state.getChain(chainId);
+
+      if (
+        !chain ||
+        typeof chain.actions === "undefined" ||
+        !chain.actions[actionIndex]
+      )
+        return state;
+
+      chain.actions[actionIndex] = action;
+      return state;
+    }),
 }));