From 61d8b53d6726d5ef36d4c619d4eac45806100a28 Mon Sep 17 00:00:00 2001
From: aelmanaa <aelmanaa@users.noreply.github.com>
Date: Wed, 30 Sep 2026 02:07:50 +0200
Subject: [PATCH] feat(sdk): add rpc.multisigChangeThreshold

`multisigChangeThreshold` was exposed in `instructions` and
`transactions` (#99) but not in `rpc`, unlike the other controlled
multisig config instructions such as `multisigSetTimeLock`.

Also make the unused `spendingLimit` parameter of
`transactions.multisigChangeThreshold` optional, so callers no longer
need to pass a placeholder key.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
---
 sdk/multisig/src/rpc/index.ts                 |  1 +
 .../src/rpc/multisigChangeThreshold.ts        | 53 +++++++++++++++++
 .../transactions/multisigChangeThreshold.ts   |  3 +-
 tests/suites/multisig-sdk.ts                  | 59 +++++++++++++++++++
 4 files changed, 115 insertions(+), 1 deletion(-)
 create mode 100644 sdk/multisig/src/rpc/multisigChangeThreshold.ts

diff --git a/sdk/multisig/src/rpc/index.ts b/sdk/multisig/src/rpc/index.ts
index 2eed0925..b4b11032 100644
--- a/sdk/multisig/src/rpc/index.ts
+++ b/sdk/multisig/src/rpc/index.ts
@@ -6,6 +6,7 @@ export * from "./configTransactionAccountsClose.js";
 export * from "./configTransactionCreate.js";
 export * from "./configTransactionExecute.js";
 export * from "./multisigAddMember.js";
+export * from "./multisigChangeThreshold.js";
 export * from "./multisigRemoveMember.js";
 export * from "./multisigAddSpendingLimit.js";
 export * from "./multisigRemoveSpendingLimit.js";
diff --git a/sdk/multisig/src/rpc/multisigChangeThreshold.ts b/sdk/multisig/src/rpc/multisigChangeThreshold.ts
new file mode 100644
index 00000000..0bc15d24
--- /dev/null
+++ b/sdk/multisig/src/rpc/multisigChangeThreshold.ts
@@ -0,0 +1,53 @@
+import {
+  Connection,
+  PublicKey,
+  SendOptions,
+  Signer,
+  TransactionSignature,
+} from "@solana/web3.js";
+import * as transactions from "../transactions";
+import { translateAndThrowAnchorError } from "../errors";
+
+/** Change the `threshold` of a controlled multisig. */
+export async function multisigChangeThreshold({
+  connection,
+  multisigPda,
+  configAuthority,
+  rentPayer,
+  newThreshold,
+  memo,
+  signers,
+  sendOptions,
+  programId,
+}: {
+  connection: Connection;
+  multisigPda: PublicKey;
+  configAuthority: PublicKey;
+  /** Pays the transaction fee. */
+  rentPayer: Signer;
+  newThreshold: number;
+  memo?: string;
+  signers?: Signer[];
+  sendOptions?: SendOptions;
+  programId?: PublicKey;
+}): Promise<TransactionSignature> {
+  const blockhash = (await connection.getLatestBlockhash()).blockhash;
+
+  const tx = transactions.multisigChangeThreshold({
+    blockhash,
+    multisigPda,
+    configAuthority,
+    rentPayer: rentPayer.publicKey,
+    newThreshold,
+    memo,
+    programId,
+  });
+
+  tx.sign([rentPayer, ...(signers ?? [])]);
+
+  try {
+    return await connection.sendTransaction(tx, sendOptions);
+  } catch (err) {
+    translateAndThrowAnchorError(err);
+  }
+}
diff --git a/sdk/multisig/src/transactions/multisigChangeThreshold.ts b/sdk/multisig/src/transactions/multisigChangeThreshold.ts
index 05660558..9d20afa8 100644
--- a/sdk/multisig/src/transactions/multisigChangeThreshold.ts
+++ b/sdk/multisig/src/transactions/multisigChangeThreshold.ts
@@ -23,7 +23,8 @@ export function multisigChangeThreshold({
 }: {
   blockhash: string;
   multisigPda: PublicKey;
-  spendingLimit: PublicKey;
+  /** Unused. */
+  spendingLimit?: PublicKey;
   configAuthority: PublicKey;
   rentPayer: PublicKey;
   newThreshold: number;
diff --git a/tests/suites/multisig-sdk.ts b/tests/suites/multisig-sdk.ts
index db2da09c..5660b2ae 100644
--- a/tests/suites/multisig-sdk.ts
+++ b/tests/suites/multisig-sdk.ts
@@ -373,6 +373,65 @@ describe("Multisig SDK", () => {
     });
   });
 
+  describe("multisig_change_threshold for a controlled multisig", () => {
+    let multisigPda: PublicKey;
+    let configAuthority: Keypair;
+    let wrongConfigAuthority: Keypair;
+    before(async () => {
+      configAuthority = await generateFundedKeypair(connection);
+      wrongConfigAuthority = await generateFundedKeypair(connection);
+
+      // Create new controlled multisig.
+      multisigPda = (
+        await createControlledMultisig({
+          connection,
+          createKey: Keypair.generate(),
+          members,
+          threshold: 1,
+          configAuthority: configAuthority.publicKey,
+          timeLock: 0,
+          programId,
+        })
+      )[0];
+    });
+
+    it("error: invalid authority", async () => {
+      const rentPayer = await generateFundedKeypair(connection);
+      await assert.rejects(
+        multisig.rpc.multisigChangeThreshold({
+          connection,
+          multisigPda,
+          configAuthority: wrongConfigAuthority.publicKey,
+          rentPayer,
+          newThreshold: 2,
+          signers: [wrongConfigAuthority],
+          programId,
+        }),
+        /Attempted to perform an unauthorized action/
+      );
+    });
+
+    it("change `threshold` for the controlled multisig", async () => {
+      const rentPayer = await generateFundedKeypair(connection);
+      const signature = await multisig.rpc.multisigChangeThreshold({
+        connection,
+        multisigPda,
+        configAuthority: configAuthority.publicKey,
+        rentPayer,
+        newThreshold: 2,
+        signers: [configAuthority],
+        programId,
+      });
+      await connection.confirmTransaction(signature);
+
+      const multisigAccount = await Multisig.fromAccountAddress(
+        connection,
+        multisigPda
+      );
+      assert.strictEqual(multisigAccount.threshold, 2);
+    });
+  });
+
   describe("multisig_set_config_authority", () => {
     let multisigPda: PublicKey;
     let configAuthority: Keypair;