fix(metamask): connect the granted subset on partial multichain session grants

.changeset/metamask-partial-grant.md

@@ -0,0 +1,5 @@
+---
+"@swapkit/wallets": patch
+---
+
+MetaMask multichain connect now connects the granted subset of requested chains instead of failing the whole connect when the wallet approves only some scopes; it throws only when nothing was granted.

packages/wallets/src/metamask/index.ts

@@ -168,13 +168,25 @@ export const metamaskWallet = createWallet({
         throw new SwapKitError("core_wallet_connection_not_found", { wallet: WalletOption.METAMASK });
       }
 
-      const chainWallets = await Promise.all(
-        chainScopes.map(async ({ chain, scope }) => {
-          const address = findAddressForScope(session, scope);
-          if (!address) {
-            throw new SwapKitError("wallet_chain_not_supported", { chain, scope, wallet: WalletOption.METAMASK });
-          }
+      // MetaMask may grant fewer scopes than requested (no Solana account, an EVM
+      // network not added/approved). Connect the granted subset and skip the rest —
+      // consumers see exactly the chains that arrived via addChain. Only a fully
+      // empty grant is an error.
+      const granted = chainScopes.flatMap(({ chain, scope }) => {
+        const address = findAddressForScope(session, scope);
+        return address ? [{ address, chain, scope }] : [];
+      });
 
+      if (granted.length === 0) {
+        throw new SwapKitError("wallet_chain_not_supported", {
+          chains: filteredChains,
+          scopes,
+          wallet: WalletOption.METAMASK,
+        });
+      }
+
+      const chainWallets = await Promise.all(
+        granted.map(async ({ address, chain, scope }) => {
           const disconnect = () => client.disconnect([scope]);
 
           if (isEVMChain(chain)) {

packages/wallets/test/metamask.test.ts

@@ -139,11 +139,29 @@ describe("metamask multichain wallet", () => {
     expect(connectionError).toHaveProperty("errorKey", "core_wallet_connection_not_found");
   });
 
-  test("does not add partially granted chains", async () => {
+  test("connects the granted subset when the wallet approves only some scopes", async () => {
     const { metamaskWallet } = await import("../src/metamask");
     const addChainCalls: Record<string, unknown>[] = [];
     sessionData = { sessionScopes: { eip155: { accounts: [`eip155:1:${ETHEREUM_ADDRESS}`] } } };
 
+    await metamaskWallet.connectMetamask.connectWallet({
+      addChain: (chainWallet) => addChainCalls.push(chainWallet as Record<string, unknown>),
+    })([Chain.Ethereum, Chain.Solana], {
+      dapp: { name: "SwapKit Test" },
+      supportedNetworks: {
+        "eip155:1": "https://ethereum.example/rpc",
+        [SOLANA_MAINNET_CAIP2]: "https://solana.example/rpc",
+      },
+    });
+
+    expect(addChainCalls.map(({ chain }) => chain)).toEqual([Chain.Ethereum]);
+  });
+
+  test("throws only when the wallet grants none of the requested scopes", async () => {
+    const { metamaskWallet } = await import("../src/metamask");
+    const addChainCalls: Record<string, unknown>[] = [];
+    sessionData = { sessionScopes: {} };
+
     await expect(
       metamaskWallet.connectMetamask.connectWallet({
         addChain: (chainWallet) => addChainCalls.push(chainWallet as Record<string, unknown>),