From 0e17e8f713c678c9d417eec313271e3017ae6a68 Mon Sep 17 00:00:00 2001
From: phroi <90913182+phroi@users.noreply.github.com>
Date: Sat, 28 Feb 2026 11:26:22 +0000
Subject: [PATCH] feat(core): add isDaoOutputLimitExceeded for NervosDAO
 64-output guard

---
 .changeset/fluffy-readers-warn.md    |  5 ++++
 packages/core/src/ckb/transaction.ts | 36 ++++++++++++++++++++++++++++
 2 files changed, 41 insertions(+)
 create mode 100644 .changeset/fluffy-readers-warn.md

diff --git a/.changeset/fluffy-readers-warn.md b/.changeset/fluffy-readers-warn.md
new file mode 100644
index 00000000..f15370ac
--- /dev/null
+++ b/.changeset/fluffy-readers-warn.md
@@ -0,0 +1,5 @@
+---
+"@ckb-ccc/core": minor
+---
+
+feat(core): add isDaoOutputLimitExceeded utility for NervosDAO 64-output guard
diff --git a/packages/core/src/ckb/transaction.ts b/packages/core/src/ckb/transaction.ts
index 2cb60e90..3d3bc325 100644
--- a/packages/core/src/ckb/transaction.ts
+++ b/packages/core/src/ckb/transaction.ts
@@ -2426,6 +2426,42 @@ export class Transaction extends Entity.Base<TransactionLike, Transaction>() {
   }
 }
 
+/**
+ * Checks whether a NervosDAO transaction exceeds the 64-output limit.
+ * Returns true if the transaction is DAO-related and has more than 64 outputs.
+ * Short-circuits to false when outputs <= 64.
+ *
+ * @param tx - The transaction to check
+ * @param client - CKB client for resolving the NervosDAO script and input cell info
+ * @returns true if the DAO output limit is exceeded
+ */
+export async function isDaoOutputLimitExceeded(
+  tx: Transaction,
+  client: Client,
+): Promise<boolean> {
+  if (tx.outputs.length <= 64) {
+    return false;
+  }
+
+  const { codeHash, hashType } = await client.getKnownScript(
+    KnownScript.NervosDao,
+  );
+  const dao = Script.from({ codeHash, hashType, args: "0x" });
+
+  if (tx.outputs.some((o) => o.type?.eq(dao))) {
+    return true;
+  }
+
+  for (const input of tx.inputs) {
+    await input.completeExtraInfos(client);
+    if (input.cellOutput?.type?.eq(dao)) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
 /**
  * Calculate Nervos DAO profit between two blocks.
  * This function computes the profit earned from a Nervos DAO deposit