feat: makeStargateClient

packages/client-utils/package.json

@@ -36,6 +36,7 @@
     "@agoric/smart-wallet": "^0.5.3",
     "@agoric/store": "^0.9.2",
     "@agoric/vats": "^0.15.1",
+    "@cosmjs/proto-signing": "^0.32.4",
     "@cosmjs/stargate": "^0.32.3",
     "@endo/common": "^1.2.7",
     "@endo/errors": "^1.2.7",

packages/client-utils/src/cosmjs.js

@@ -0,0 +1,26 @@
+import { DirectSecp256k1HdWallet } from '@cosmjs/proto-signing';
+import { SigningStargateClient } from '@cosmjs/stargate';
+
+/**
+ * @import {MinimalNetworkConfig} from './rpc.js';
+ */
+
+const bech32Prefix = 'agoric';
+
+/**
+ * @param {MinimalNetworkConfig} config
+ * @param {string} mnemonic
+ * @returns {Promise<SigningStargateClient>}
+ */
+const makeStargateClient = async (config, mnemonic) => {
+  // TODO distribute load
+  const endpoint = config.rpcAddrs.at(-1);
+  assert(endpoint, 'no endpoints');
+
+  const signer = await DirectSecp256k1HdWallet.fromMnemonic(mnemonic, {
+    prefix: bech32Prefix,
+  });
+
+  return SigningStargateClient.connectWithSigner(endpoint, signer);
+};
+harden(makeStargateClient);