diff --git a/package.json b/package.json
index 022b613..a15f007 100644
--- a/package.json
+++ b/package.json
@@ -13,6 +13,8 @@
     "@flowindex/evm-wallet": "^0.1.0",
     "@flowindex/flow-passkey": "latest",
     "@flowindex/flow-signer": "latest",
+    "@noble/curves": "^2.0.1",
+    "@noble/hashes": "^2.0.1",
     "@onflow/fcl": "^1.21.9",
     "@onflow/rlp": "^1.2.4",
     "@radix-ui/react-avatar": "^1.1.11",
diff --git a/pages/_app.tsx b/pages/_app.tsx
index f90babd..8e40b12 100644
--- a/pages/_app.tsx
+++ b/pages/_app.tsx
@@ -41,8 +41,10 @@ async function applyUrlParams(store: Record<string, any>, setStore: (s: Record<s
   const seed = params.get('seed');
   const network = params.get('network');
   const autoSign = params.get('autoSign');
+  const address = params.get('address');
+  const rpc = params.get('rpc');
 
-  if (!seed && !network && autoSign == null) return false;
+  if (!seed && !network && autoSign == null && !rpc) return false;
 
   let updated = { ...store };
 
@@ -52,6 +54,14 @@ async function applyUrlParams(store: Record<string, any>, setStore: (s: Record<s
     updated.rpcUrl = getDefaultRpc(network);
   }
 
+  // Apply custom RPC (overrides network default)
+  if (rpc) {
+    updated.rpcUrl = rpc;
+  }
+
+  // Reconfigure FCL now so address lookups and key derivation use the right network/RPC
+  fclConfig(updated.network, updated.rpcUrl);
+
   // Apply autoSign — mark session so popups know it was activated via URL
   if (autoSign === 'true') {
     updated.autoSign = true;
@@ -76,7 +86,7 @@ async function applyUrlParams(store: Record<string, any>, setStore: (s: Record<s
       // Try to find associated on-chain address
       try {
         const { findAddressWithPK } = await import("../utils/findAddressWithPK");
-        const accounts = await findAddressWithPK(seed);
+        const accounts = await findAddressWithPK(seed, address || undefined);
         if (accounts && accounts.length > 0) {
           const acct = accounts[0];
           updated.address = acct.address;
diff --git a/tsconfig.json b/tsconfig.json
index 6b44d53..810c8c5 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -12,7 +12,7 @@
     "incremental": true,
     "esModuleInterop": true,
     "module": "esnext",
-    "moduleResolution": "node",
+    "moduleResolution": "bundler",
     "resolveJsonModule": true,
     "isolatedModules": true,
     "jsx": "react-jsx",
diff --git a/utils/sign.ts b/utils/sign.ts
index df82d19..259b4fe 100644
--- a/utils/sign.ts
+++ b/utils/sign.ts
@@ -1,6 +1,5 @@
 import { signFlowTransaction } from "@flowindex/flow-passkey";
-import { LocalSigner } from "@flowindex/flow-signer";
-import { HASH_ALGO, KEY_TYPE, SIGN_ALGO } from "./constants";
+import { KEY_TYPE } from "./constants";
 
 interface SignStore {
     id?: string;
@@ -36,6 +35,37 @@ const domainTag = (tag: string): string => {
     ).toString("hex")
 }
 
+/**
+ * Sign a hex message with a raw private key using ECDSA.
+ * Uses @noble/hashes for hashing and @noble/curves for signing —
+ * both are pure JS with no Web Crypto or network dependency.
+ * Supports ECDSA_P256 and ECDSA_secp256k1 with SHA2_256 or SHA3_256.
+ */
+async function signEcdsa(pk: string, message: string, sigAlgo: string, hashAlgo: string): Promise<string> {
+    const msgBytes = Buffer.from(message, "hex");
+
+    let hashBytes: Uint8Array;
+    if (hashAlgo === "SHA3_256") {
+        const { sha3_256 } = await import("@noble/hashes/sha3.js");
+        hashBytes = sha3_256(msgBytes);
+    } else {
+        const { sha256 } = await import("@noble/hashes/sha2.js");
+        hashBytes = sha256(msgBytes);
+    }
+
+    const pkBytes = Uint8Array.from(Buffer.from(pk, "hex"));
+    let sigBytes: Uint8Array;
+    if (sigAlgo === "ECDSA_secp256k1") {
+        const { secp256k1 } = await import("@noble/curves/secp256k1.js");
+        sigBytes = secp256k1.sign(hashBytes, pkBytes);
+    } else {
+        const { p256 } = await import("@noble/curves/nist.js");
+        sigBytes = p256.sign(hashBytes, pkBytes);
+    }
+    // sign() returns compact r||s (64 bytes) — convert directly to hex
+    return Buffer.from(sigBytes).toString("hex");
+}
+
 /**
  * Sign a hex-encoded message. Returns { signature, extensionData? }.
  * - Passkey: returns extensionData for FLIP-264
@@ -47,20 +77,10 @@ const signWithKey = async (store: SignStore, message: string): Promise<SignResul
         return await signWithPassKey(store, message);
     }
 
-    // Local key signing via flow-signer LocalSigner
+    // Local key signing — pure ECDSA, no network calls.
     const { signAlgo, hashAlgo, pk } = store.keyInfo;
-    const signerConfig = {
-        flowindexUrl: process.env.flowindexUrl || "https://flowindex.io",
-        network: (process.env.network || "mainnet") as "mainnet" | "testnet",
-    };
-    const signer = new LocalSigner(signerConfig, {
-        privateKey: pk,
-        sigAlgo: (signAlgo || "ECDSA_P256") as any,
-        hashAlgo: (hashAlgo || "SHA2_256") as any,
-    });
-    await signer.init();
-    const result = await signer.signFlowTransaction(message);
-    return { signature: result.signature };
+    const signature = await signEcdsa(pk, message, signAlgo || "ECDSA_P256", hashAlgo || "SHA2_256");
+    return { signature };
 }
 
 /**