From c00da0cd8716c9018b5fdc32cbe983454eaa5c72 Mon Sep 17 00:00:00 2001
From: catloversg <152669316+catloversg@users.noreply.github.com>
Date: Tue, 17 Mar 2026 02:46:06 +0700
Subject: [PATCH] BUGFIX: hacknetNodeCost formula API throws when using
 documented optional parameter (#2577)

---
 ...tburner.hacknetnodesformulas.hacknetnodecost.md |  4 ++--
 src/NetscriptFunctions/Formulas.ts                 | 14 ++++++++------
 src/ScriptEditor/NetscriptDefinitions.d.ts         |  2 +-
 3 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/markdown/bitburner.hacknetnodesformulas.hacknetnodecost.md b/markdown/bitburner.hacknetnodesformulas.hacknetnodecost.md
index 60d88ad22..a10f07343 100644
--- a/markdown/bitburner.hacknetnodesformulas.hacknetnodecost.md
+++ b/markdown/bitburner.hacknetnodesformulas.hacknetnodecost.md
@@ -9,7 +9,7 @@ Calculate the cost of a hacknet node.
 **Signature:**
 
 ```typescript
-hacknetNodeCost(n: number, mult: number): number;
+hacknetNodeCost(n: number, mult?: number): number;
 ```
 
 ## Parameters
@@ -58,7 +58,7 @@ number
 
 </td><td>
 
-player cost reduction (defaults to 1)
+_(Optional)_ player cost reduction (defaults to 1)
 
 
 </td></tr>
diff --git a/src/NetscriptFunctions/Formulas.ts b/src/NetscriptFunctions/Formulas.ts
index 1d90ca544..0a10a14b1 100644
--- a/src/NetscriptFunctions/Formulas.ts
+++ b/src/NetscriptFunctions/Formulas.ts
@@ -274,12 +274,14 @@ export function NetscriptFormulas(): InternalAPI<IFormulas> {
           checkFormulasAccess(ctx);
           return calculateCoreUpgradeCost(startingCore, extraCores, costMult);
         },
-      hacknetNodeCost: (ctx) => (_n, _mult) => {
-        const n = helpers.number(ctx, "n", _n);
-        const mult = helpers.number(ctx, "mult", _mult);
-        checkFormulasAccess(ctx);
-        return calculateNodeCost(n, mult);
-      },
+      hacknetNodeCost:
+        (ctx) =>
+        (_n, _mult = 1) => {
+          const n = helpers.number(ctx, "n", _n);
+          const mult = helpers.number(ctx, "mult", _mult);
+          checkFormulasAccess(ctx);
+          return calculateNodeCost(n, mult);
+        },
       constants: (ctx) => () => {
         checkFormulasAccess(ctx);
         return Object.assign({}, HacknetNodeConstants);
diff --git a/src/ScriptEditor/NetscriptDefinitions.d.ts b/src/ScriptEditor/NetscriptDefinitions.d.ts
index 202463df7..b0b3fce80 100644
--- a/src/ScriptEditor/NetscriptDefinitions.d.ts
+++ b/src/ScriptEditor/NetscriptDefinitions.d.ts
@@ -6328,7 +6328,7 @@ interface HacknetNodesFormulas {
    * @param mult - player cost reduction (defaults to 1)
    * @returns The calculated cost.
    */
-  hacknetNodeCost(n: number, mult: number): number;
+  hacknetNodeCost(n: number, mult?: number): number;
   /**
    * All constants used by the game.
    * @returns An object with all hacknet node constants used by the game.