diff --git a/packages/cli/examples/delegate.ts b/packages/cli/examples/delegate.ts
index 9d6fc327..88a4a47e 100644
--- a/packages/cli/examples/delegate.ts
+++ b/packages/cli/examples/delegate.ts
@@ -1,5 +1,7 @@
-const pen = await Secp256k1Pen.fromMnemonic("enlist hip relief stomach skate base shallow young switch frequent cry park");
-const senderAddress = pen.address("cosmos");
+const wallet = await Secp256k1Wallet.fromMnemonic(
+  "enlist hip relief stomach skate base shallow young switch frequent cry park",
+);
+const [{ address: senderAddress }] = await wallet.getAccounts();
 
 const client = new CosmosClient("http://localhost:1317");
 
@@ -11,8 +13,8 @@ const msg: MsgDelegate = {
     //   curl http://localhost:1317/staking/validators | jq '.result[0].operator_address'
     validator_address: "cosmosvaloper1gjvanqxc774u6ed9thj4gpn9gj5zus5u32enqn",
     amount: coin(300000, "ustake"),
-  }
-}
+  },
+};
 const fee = {
   amount: coins(2000, "ucosm"),
   gas: "120000", // 120k
@@ -26,7 +28,7 @@ const { accountNumber, sequence } = await client.getNonce(senderAddress);
 console.log("Account/sequence:", accountNumber, sequence);
 
 const signBytes = makeSignBytes([msg], fee, chainId, memo, accountNumber, sequence);
-const signature = await pen.sign(signBytes);
+const signature = await wallet.sign(senderAddress, signBytes);
 const signedTx: StdTx = {
   msg: [msg],
   fee: fee,
diff --git a/packages/cli/examples/faucet_addresses.ts b/packages/cli/examples/faucet_addresses.ts
index a7be953b..211ff61f 100644
--- a/packages/cli/examples/faucet_addresses.ts
+++ b/packages/cli/examples/faucet_addresses.ts
@@ -1,9 +1,9 @@
-const mnemonic = "economy stock theory fatal elder harbor betray wasp final emotion task crumble siren bottom lizard educate guess current outdoor pair theory focus wife stone";
+const mnemonic =
+  "economy stock theory fatal elder harbor betray wasp final emotion task crumble siren bottom lizard educate guess current outdoor pair theory focus wife stone";
 
 for (let i of [0, 1, 2, 3, 4]) {
-  const pen = await Secp256k1Pen.fromMnemonic(mnemonic, makeCosmoshubPath(i));
-  const pubkey = toBase64(pen.pubkey);
-  const address = pubkeyToAddress(encodeSecp256k1Pubkey(pen.pubkey), "cosmos");
+  const wallet = await Secp256k1Wallet.fromMnemonic(mnemonic, makeCosmoshubPath(i), "cosmos");
+  const [{ address, pubkey }] = await wallet.getAccounts();
   console.info(`Address ${i}: ${address}`);
   console.info(`Pubkey ${i}: ${pubkey}`);
 }
diff --git a/packages/cli/examples/generate_address.ts b/packages/cli/examples/generate_address.ts
index e0ccfb0e..cbf7ae95 100644
--- a/packages/cli/examples/generate_address.ts
+++ b/packages/cli/examples/generate_address.ts
@@ -1,7 +1,6 @@
 const mnemonic = Bip39.encode(Random.getBytes(16)).toString();
-const pen = await Secp256k1Pen.fromMnemonic(mnemonic);
-const pubkey = encodeSecp256k1Pubkey(pen.pubkey);
-const address = pubkeyToAddress(pubkey, "cosmos");
+const wallet = await Secp256k1Wallet.fromMnemonic(mnemonic);
+const [{ address, pubkey }] = await wallet.getAccounts();
 
 console.info("mnemonic:", mnemonic);
 console.info("pubkey:", pubkey);
diff --git a/packages/cli/examples/helpers.ts b/packages/cli/examples/helpers.ts
index c52ddc40..3e39b1af 100644
--- a/packages/cli/examples/helpers.ts
+++ b/packages/cli/examples/helpers.ts
@@ -4,7 +4,7 @@ interface Options {
   feeToken: string;
   gasPrice: number;
   bech32prefix: string;
-};
+}
 
 const defaultOptions: Options = {
   httpUrl: "https://lcd.demo-09.cosmwasm.com",
@@ -12,7 +12,7 @@ const defaultOptions: Options = {
   feeToken: "ucosm",
   gasPrice: 0.025,
   bech32prefix: "cosmos",
-}
+};
 
 const defaultFaucetUrl = "https://faucet.demo-09.cosmwasm.com/credit";
 
@@ -22,7 +22,7 @@ const buildFeeTable = (feeToken: string, gasPrice: number): FeeTable => {
     return {
       amount: [{ amount: amount.toString(), denom: denom }],
       gas: gas.toString(),
-    }
+    };
   };
 
   return {
@@ -32,7 +32,7 @@ const buildFeeTable = (feeToken: string, gasPrice: number): FeeTable => {
     exec: stdFee(200000, feeToken, gasPrice),
     send: stdFee(80000, feeToken, gasPrice),
     changeAdmin: stdFee(80000, feeToken, gasPrice),
-  }
+  };
 };
 
 // TODO: hit faucet
@@ -43,22 +43,20 @@ const buildFeeTable = (feeToken: string, gasPrice: number): FeeTable => {
 //   }
 // }
 
-const penAddress = (pen: Secp256k1Pen, prefix: string): string => {
-  const pubkey = encodeSecp256k1Pubkey(pen.pubkey);
-  return pubkeyToAddress(pubkey, prefix);
-}
-
-const connect = async (mnemonic: string, opts: Partial<Options>): Promise<{
-  client: SigningCosmWasmClient,
-  address: string,
+const connect = async (
+  mnemonic: string,
+  opts: Partial<Options>,
+): Promise<{
+  client: SigningCosmWasmClient;
+  address: string;
 }> => {
-  const options: Options = {...defaultOptions, ...opts};
+  const options: Options = { ...defaultOptions, ...opts };
   const feeTable = buildFeeTable(options.feeToken, options.gasPrice);
-  const pen = await Secp256k1Pen.fromMnemonic(mnemonic);
-  const address = penAddress(pen, options.bech32prefix);
+  const wallet = await Secp256k1Wallet.fromMnemonic(mnemonic);
+  const [{ address }] = await wallet.getAccounts();
 
-  const client = new SigningCosmWasmClient(options.httpUrl, address, signBytes => pen.sign(signBytes), feeTable);
-  return {client, address};
+  const client = new SigningCosmWasmClient(options.httpUrl, address, wallet, feeTable);
+  return { client, address };
 };
 
 // smartQuery assumes the content is proper JSON data and parses before returning it
@@ -80,32 +78,32 @@ const loadOrCreateMnemonic = (filename: string): string => {
     fs.writeFileSync(filename, mnemonic, "utf8");
     return mnemonic;
   }
-}
+};
 
 const hitFaucet = async (faucetUrl: string, address: string, ticker: string): Promise<void> => {
   const r = await axios.post(defaultFaucetUrl, { ticker, address });
   console.log(r.status);
   console.log(r.data);
-}
+};
 
 const randomAddress = async (prefix: string): Promise<string> => {
   const mnemonic = Bip39.encode(Random.getBytes(16)).toString();
   return mnemonicToAddress(prefix, mnemonic);
-}
+};
 
 const mnemonicToAddress = async (prefix: string, mnemonic: string): Promise<string> => {
-  const pen = await Secp256k1Pen.fromMnemonic(mnemonic);
-  const pubkey = encodeSecp256k1Pubkey(pen.pubkey);
-  return pubkeyToAddress(pubkey, prefix);
-}
+  const wallet = await Secp256k1Wallet.fromMnemonic(mnemonic);
+  const [{ address }] = await wallet.getAccounts();
+  return address;
+};
 
 const downloadWasm = async (url: string): Promise<Uint8Array> => {
-  const r = await axios.get(url, { responseType: "arraybuffer"});
+  const r = await axios.get(url, { responseType: "arraybuffer" });
   if (r.status !== 200) {
     throw new Error(`Download error: ${r.status}`);
   }
   return r.data;
-}
+};
 
-const getAttibute = (logs: readonly logs.Log[], key: string): string|undefined =>
-  logs[0].events[0].attributes.find(x => x.key == key)?.value
+const getAttibute = (logs: readonly logs.Log[], key: string): string | undefined =>
+  logs[0].events[0].attributes.find((x) => x.key == key)?.value;
diff --git a/packages/cli/examples/local_faucet.ts b/packages/cli/examples/local_faucet.ts
index 687e3512..ce72447f 100644
--- a/packages/cli/examples/local_faucet.ts
+++ b/packages/cli/examples/local_faucet.ts
@@ -14,5 +14,5 @@ const faucetMnemonic =
   "economy stock theory fatal elder harbor betray wasp final emotion task crumble siren bottom lizard educate guess current outdoor pair theory focus wife stone";
 const faucetAddress = "cosmos1pkptre7fdkl6gfrzlesjjvhxhlc3r4gmmk8rs6";
 
-const pen = await Secp256k1Pen.fromMnemonic(faucetMnemonic);
+const wallet = await Secp256k1Wallet.fromMnemonic(faucetMnemonic);
 const client = new LcdClient(defaultHttpUrl);
diff --git a/packages/cli/src/cli.ts b/packages/cli/src/cli.ts
index d5ead030..41c4474a 100644
--- a/packages/cli/src/cli.ts
+++ b/packages/cli/src/cli.ts
@@ -97,10 +97,10 @@ export function main(originalArgs: readonly string[]): void {
         "MsgDelegate",
         "MsgSend",
         "LcdClient",
-        "Pen",
+        "OfflineSigner",
         "PubKey",
         "pubkeyToAddress",
-        "Secp256k1Pen",
+        "Secp256k1Wallet",
         "SigningCosmosClient",
         "StdFee",
         "StdTx",
@@ -145,11 +145,10 @@ export function main(originalArgs: readonly string[]): void {
       assert(Decimal.fromAtomics("12870000", 6).toString() === "12.87");
 
       const mnemonic = Bip39.encode(Random.getBytes(16)).toString();
-      const pen = await Secp256k1Pen.fromMnemonic(mnemonic, makeCosmoshubPath(0));
-      const pubkey = encodeSecp256k1Pubkey(pen.pubkey);
-      const address = pubkeyToAddress(pubkey, "cosmos");
+      const wallet = await Secp256k1Wallet.fromMnemonic(mnemonic, makeCosmoshubPath(0));
+      const [{ address }] = await wallet.getAccounts();
       const data = toAscii("foo bar");
-      const signature = await pen.sign(data);
+      const signature = await wallet.sign(address, data);
 
       console.info("Done testing, will exit now.");
       process.exit(0);
diff --git a/packages/cosmwasm/src/cosmwasmclient.searchtx.spec.ts b/packages/cosmwasm/src/cosmwasmclient.searchtx.spec.ts
index e114e219..19979b42 100644
--- a/packages/cosmwasm/src/cosmwasmclient.searchtx.spec.ts
+++ b/packages/cosmwasm/src/cosmwasmclient.searchtx.spec.ts
@@ -7,7 +7,7 @@ import {
   LcdClient,
   makeSignBytes,
   MsgSend,
-  Secp256k1Pen,
+  Secp256k1Wallet,
 } from "@cosmjs/sdk38";
 import { assert, sleep } from "@cosmjs/utils";
 
@@ -48,10 +48,8 @@ describe("CosmWasmClient.searchTx", () => {
 
   beforeAll(async () => {
     if (wasmdEnabled()) {
-      const pen = await Secp256k1Pen.fromMnemonic(alice.mnemonic);
-      const client = new SigningCosmWasmClient(wasmd.endpoint, alice.address0, (signBytes) =>
-        pen.sign(signBytes),
-      );
+      const wallet = await Secp256k1Wallet.fromMnemonic(alice.mnemonic);
+      const client = new SigningCosmWasmClient(wasmd.endpoint, alice.address0, wallet);
 
       {
         const recipient = makeRandomAddress();
@@ -107,7 +105,7 @@ describe("CosmWasmClient.searchTx", () => {
         const { accountNumber, sequence } = await client.getNonce();
         const chainId = await client.getChainId();
         const signBytes = makeSignBytes([sendMsg], fee, chainId, memo, accountNumber, sequence);
-        const signature = await pen.sign(signBytes);
+        const signature = await wallet.sign(alice.address0, signBytes);
         const tx: CosmosSdkTx = {
           type: "cosmos-sdk/StdTx",
           value: {
diff --git a/packages/cosmwasm/src/cosmwasmclient.spec.ts b/packages/cosmwasm/src/cosmwasmclient.spec.ts
index 3928a075..555e113c 100644
--- a/packages/cosmwasm/src/cosmwasmclient.spec.ts
+++ b/packages/cosmwasm/src/cosmwasmclient.spec.ts
@@ -1,7 +1,7 @@
 /* eslint-disable @typescript-eslint/camelcase */
 import { Sha256 } from "@cosmjs/crypto";
 import { Bech32, fromHex, fromUtf8, toAscii, toBase64 } from "@cosmjs/encoding";
-import { makeSignBytes, MsgSend, Secp256k1Pen, StdFee } from "@cosmjs/sdk38";
+import { makeSignBytes, MsgSend, Secp256k1Wallet, StdFee } from "@cosmjs/sdk38";
 import { assert, sleep } from "@cosmjs/utils";
 import { ReadonlyDate } from "readonly-date";
 
@@ -204,7 +204,7 @@ describe("CosmWasmClient", () => {
   describe("postTx", () => {
     it("works", async () => {
       pendingWithoutWasmd();
-      const pen = await Secp256k1Pen.fromMnemonic(alice.mnemonic);
+      const wallet = await Secp256k1Wallet.fromMnemonic(alice.mnemonic);
       const client = new CosmWasmClient(wasmd.endpoint);
 
       const memo = "My first contract on chain";
@@ -235,7 +235,7 @@ describe("CosmWasmClient", () => {
       const chainId = await client.getChainId();
       const { accountNumber, sequence } = await client.getNonce(alice.address0);
       const signBytes = makeSignBytes([sendMsg], fee, chainId, memo, accountNumber, sequence);
-      const signature = await pen.sign(signBytes);
+      const signature = await wallet.sign(alice.address0, signBytes);
       const signedTx = {
         msg: [sendMsg],
         fee: fee,
@@ -388,10 +388,8 @@ describe("CosmWasmClient", () => {
     beforeAll(async () => {
       if (wasmdEnabled()) {
         pendingWithoutWasmd();
-        const pen = await Secp256k1Pen.fromMnemonic(alice.mnemonic);
-        const client = new SigningCosmWasmClient(wasmd.endpoint, alice.address0, (signBytes) =>
-          pen.sign(signBytes),
-        );
+        const wallet = await Secp256k1Wallet.fromMnemonic(alice.mnemonic);
+        const client = new SigningCosmWasmClient(wasmd.endpoint, alice.address0, wallet);
         const { codeId } = await client.upload(getHackatom().data);
         const initMsg = { verifier: makeRandomAddress(), beneficiary: makeRandomAddress() };
         const { contractAddress } = await client.instantiate(codeId, initMsg, "random hackatom");
@@ -441,10 +439,8 @@ describe("CosmWasmClient", () => {
     beforeAll(async () => {
       if (wasmdEnabled()) {
         pendingWithoutWasmd();
-        const pen = await Secp256k1Pen.fromMnemonic(alice.mnemonic);
-        const client = new SigningCosmWasmClient(wasmd.endpoint, alice.address0, (signBytes) =>
-          pen.sign(signBytes),
-        );
+        const wallet = await Secp256k1Wallet.fromMnemonic(alice.mnemonic);
+        const client = new SigningCosmWasmClient(wasmd.endpoint, alice.address0, wallet);
         const { codeId } = await client.upload(getHackatom().data);
         const initMsg = { verifier: makeRandomAddress(), beneficiary: makeRandomAddress() };
         const { contractAddress } = await client.instantiate(codeId, initMsg, "a different hackatom");
diff --git a/packages/cosmwasm/src/lcdapi/wasm.spec.ts b/packages/cosmwasm/src/lcdapi/wasm.spec.ts
index 08dac3cf..0d3aa836 100644
--- a/packages/cosmwasm/src/lcdapi/wasm.spec.ts
+++ b/packages/cosmwasm/src/lcdapi/wasm.spec.ts
@@ -8,9 +8,9 @@ import {
   coins,
   LcdClient,
   makeSignBytes,
-  Pen,
+  OfflineSigner,
   PostTxsResponse,
-  Secp256k1Pen,
+  Secp256k1Wallet,
   setupAuthExtension,
   StdFee,
 } from "@cosmjs/sdk38";
@@ -47,7 +47,7 @@ function makeWasmClient(apiUrl: string): WasmClient {
 
 async function uploadContract(
   client: WasmClient,
-  pen: Pen,
+  signer: OfflineSigner,
   contract: ContractUploadInstructions,
 ): Promise<PostTxsResponse> {
   const memo = "My first contract on chain";
@@ -72,14 +72,14 @@ async function uploadContract(
 
   const { account_number, sequence } = (await client.auth.account(alice.address0)).result.value;
   const signBytes = makeSignBytes([theMsg], fee, wasmd.chainId, memo, account_number, sequence);
-  const signature = await pen.sign(signBytes);
+  const signature = await signer.sign(alice.address0, signBytes);
   const signedTx = makeSignedTx(theMsg, fee, memo, signature);
   return client.postTx(signedTx);
 }
 
 async function instantiateContract(
   client: WasmClient,
-  pen: Pen,
+  signer: OfflineSigner,
   codeId: number,
   beneficiaryAddress: string,
   transferAmount?: readonly Coin[],
@@ -110,14 +110,14 @@ async function instantiateContract(
 
   const { account_number, sequence } = (await client.auth.account(alice.address0)).result.value;
   const signBytes = makeSignBytes([theMsg], fee, wasmd.chainId, memo, account_number, sequence);
-  const signature = await pen.sign(signBytes);
+  const signature = await signer.sign(alice.address0, signBytes);
   const signedTx = makeSignedTx(theMsg, fee, memo, signature);
   return client.postTx(signedTx);
 }
 
 async function executeContract(
   client: WasmClient,
-  pen: Pen,
+  signer: OfflineSigner,
   contractAddress: string,
   msg: object,
 ): Promise<PostTxsResponse> {
@@ -138,7 +138,7 @@ async function executeContract(
 
   const { account_number, sequence } = (await client.auth.account(alice.address0)).result.value;
   const signBytes = makeSignBytes([theMsg], fee, wasmd.chainId, memo, account_number, sequence);
-  const signature = await pen.sign(signBytes);
+  const signature = await signer.sign(alice.address0, signBytes);
   const signedTx = makeSignedTx(theMsg, fee, memo, signature);
   return client.postTx(signedTx);
 }
@@ -256,7 +256,7 @@ describe("wasm", () => {
   describe("postTx", () => {
     it("can upload, instantiate and execute wasm", async () => {
       pendingWithoutWasmd();
-      const pen = await Secp256k1Pen.fromMnemonic(alice.mnemonic);
+      const wallet = await Secp256k1Wallet.fromMnemonic(alice.mnemonic);
       const client = makeWasmClient(wasmd.endpoint);
 
       const transferAmount = [coin(1234, "ucosm"), coin(321, "ustake")];
@@ -267,7 +267,7 @@ describe("wasm", () => {
       // upload
       {
         // console.log("Raw log:", result.raw_log);
-        const result = await uploadContract(client, pen, getHackatom());
+        const result = await uploadContract(client, wallet, getHackatom());
         expect(result.code).toBeFalsy();
         const logs = parseLogs(result.logs);
         const codeIdAttr = findAttribute(logs, "message", "code_id");
@@ -281,7 +281,7 @@ describe("wasm", () => {
 
       // instantiate
       {
-        const result = await instantiateContract(client, pen, codeId, beneficiaryAddress, transferAmount);
+        const result = await instantiateContract(client, wallet, codeId, beneficiaryAddress, transferAmount);
         expect(result.code).toBeFalsy();
         // console.log("Raw log:", result.raw_log);
         const logs = parseLogs(result.logs);
@@ -297,7 +297,7 @@ describe("wasm", () => {
 
       // execute
       {
-        const result = await executeContract(client, pen, contractAddress, { release: {} });
+        const result = await executeContract(client, wallet, contractAddress, { release: {} });
         expect(result.data).toEqual("F00BAA");
         expect(result.code).toBeFalsy();
         // console.log("Raw log:", result.logs);
@@ -324,7 +324,7 @@ describe("wasm", () => {
   describe("query", () => {
     it("can list upload code", async () => {
       pendingWithoutWasmd();
-      const pen = await Secp256k1Pen.fromMnemonic(alice.mnemonic);
+      const wallet = await Secp256k1Wallet.fromMnemonic(alice.mnemonic);
       const client = makeWasmClient(wasmd.endpoint);
 
       // check with contracts were here first to compare
@@ -334,7 +334,7 @@ describe("wasm", () => {
 
       // upload data
       const hackatom = getHackatom();
-      const result = await uploadContract(client, pen, hackatom);
+      const result = await uploadContract(client, wallet, hackatom);
       expect(result.code).toBeFalsy();
       const logs = parseLogs(result.logs);
       const codeIdAttr = findAttribute(logs, "message", "code_id");
@@ -362,7 +362,7 @@ describe("wasm", () => {
 
     it("can list contracts and get info", async () => {
       pendingWithoutWasmd();
-      const pen = await Secp256k1Pen.fromMnemonic(alice.mnemonic);
+      const wallet = await Secp256k1Wallet.fromMnemonic(alice.mnemonic);
       const client = makeWasmClient(wasmd.endpoint);
       const beneficiaryAddress = makeRandomAddress();
       const transferAmount: readonly Coin[] = [
@@ -378,7 +378,7 @@ describe("wasm", () => {
       if (existingInfos.length > 0) {
         codeId = existingInfos[existingInfos.length - 1].id;
       } else {
-        const uploadResult = await uploadContract(client, pen, getHackatom());
+        const uploadResult = await uploadContract(client, wallet, getHackatom());
         expect(uploadResult.code).toBeFalsy();
         const uploadLogs = parseLogs(uploadResult.logs);
         const codeIdAttr = findAttribute(uploadLogs, "message", "code_id");
@@ -394,7 +394,7 @@ describe("wasm", () => {
         expect(contract.label).toMatch(/^.+$/);
       }
 
-      const result = await instantiateContract(client, pen, codeId, beneficiaryAddress, transferAmount);
+      const result = await instantiateContract(client, wallet, codeId, beneficiaryAddress, transferAmount);
       expect(result.code).toBeFalsy();
       const logs = parseLogs(result.logs);
       const contractAddressAttr = findAttribute(logs, "message", "contract_address");
@@ -438,12 +438,12 @@ describe("wasm", () => {
 
       beforeAll(async () => {
         if (wasmdEnabled()) {
-          const pen = await Secp256k1Pen.fromMnemonic(alice.mnemonic);
-          const uploadResult = await uploadContract(client, pen, getHackatom());
+          const wallet = await Secp256k1Wallet.fromMnemonic(alice.mnemonic);
+          const uploadResult = await uploadContract(client, wallet, getHackatom());
           assert(!uploadResult.code);
           const uploadLogs = parseLogs(uploadResult.logs);
           const codeId = Number.parseInt(findAttribute(uploadLogs, "message", "code_id").value, 10);
-          const instantiateResult = await instantiateContract(client, pen, codeId, makeRandomAddress());
+          const instantiateResult = await instantiateContract(client, wallet, codeId, makeRandomAddress());
           assert(!instantiateResult.code);
           const instantiateLogs = parseLogs(instantiateResult.logs);
           const contractAddressAttr = findAttribute(instantiateLogs, "message", "contract_address");
diff --git a/packages/cosmwasm/src/signingcosmwasmclient.spec.ts b/packages/cosmwasm/src/signingcosmwasmclient.spec.ts
index b1e71f07..927458a7 100644
--- a/packages/cosmwasm/src/signingcosmwasmclient.spec.ts
+++ b/packages/cosmwasm/src/signingcosmwasmclient.spec.ts
@@ -1,6 +1,6 @@
 import { Sha256 } from "@cosmjs/crypto";
 import { toHex } from "@cosmjs/encoding";
-import { AuthExtension, coin, coins, LcdClient, Secp256k1Pen, setupAuthExtension } from "@cosmjs/sdk38";
+import { AuthExtension, coin, coins, LcdClient, Secp256k1Wallet, setupAuthExtension } from "@cosmjs/sdk38";
 import { assert } from "@cosmjs/utils";
 
 import { isPostTxFailure, PrivateCosmWasmClient } from "./cosmwasmclient";
@@ -17,8 +17,8 @@ function makeWasmClient(apiUrl: string): LcdClient & AuthExtension & WasmExtensi
 describe("SigningCosmWasmClient", () => {
   describe("makeReadOnly", () => {
     it("can be constructed", async () => {
-      const pen = await Secp256k1Pen.fromMnemonic(alice.mnemonic);
-      const client = new SigningCosmWasmClient(httpUrl, alice.address0, (signBytes) => pen.sign(signBytes));
+      const wallet = await Secp256k1Wallet.fromMnemonic(alice.mnemonic);
+      const client = new SigningCosmWasmClient(httpUrl, alice.address0, wallet);
       expect(client).toBeTruthy();
     });
   });
@@ -26,8 +26,8 @@ describe("SigningCosmWasmClient", () => {
   describe("getHeight", () => {
     it("always uses authAccount implementation", async () => {
       pendingWithoutWasmd();
-      const pen = await Secp256k1Pen.fromMnemonic(alice.mnemonic);
-      const client = new SigningCosmWasmClient(httpUrl, alice.address0, (signBytes) => pen.sign(signBytes));
+      const wallet = await Secp256k1Wallet.fromMnemonic(alice.mnemonic);
+      const client = new SigningCosmWasmClient(httpUrl, alice.address0, wallet);
 
       const openedClient = (client as unknown) as PrivateCosmWasmClient;
       const blockLatestSpy = spyOn(openedClient.lcdClient, "blocksLatest").and.callThrough();
@@ -44,8 +44,8 @@ describe("SigningCosmWasmClient", () => {
   describe("upload", () => {
     it("works", async () => {
       pendingWithoutWasmd();
-      const pen = await Secp256k1Pen.fromMnemonic(alice.mnemonic);
-      const client = new SigningCosmWasmClient(httpUrl, alice.address0, (signBytes) => pen.sign(signBytes));
+      const wallet = await Secp256k1Wallet.fromMnemonic(alice.mnemonic);
+      const client = new SigningCosmWasmClient(httpUrl, alice.address0, wallet);
       const wasm = getHackatom().data;
       const {
         codeId,
@@ -63,8 +63,8 @@ describe("SigningCosmWasmClient", () => {
 
     it("can set builder and source", async () => {
       pendingWithoutWasmd();
-      const pen = await Secp256k1Pen.fromMnemonic(alice.mnemonic);
-      const client = new SigningCosmWasmClient(httpUrl, alice.address0, (signBytes) => pen.sign(signBytes));
+      const wallet = await Secp256k1Wallet.fromMnemonic(alice.mnemonic);
+      const client = new SigningCosmWasmClient(httpUrl, alice.address0, wallet);
       const hackatom = getHackatom();
 
       const meta: UploadMeta = {
@@ -82,8 +82,8 @@ describe("SigningCosmWasmClient", () => {
   describe("instantiate", () => {
     it("works with transfer amount", async () => {
       pendingWithoutWasmd();
-      const pen = await Secp256k1Pen.fromMnemonic(alice.mnemonic);
-      const client = new SigningCosmWasmClient(httpUrl, alice.address0, (signBytes) => pen.sign(signBytes));
+      const wallet = await Secp256k1Wallet.fromMnemonic(alice.mnemonic);
+      const client = new SigningCosmWasmClient(httpUrl, alice.address0, wallet);
       const { codeId } = await client.upload(getHackatom().data);
 
       const transferAmount = [coin(1234, "ucosm"), coin(321, "ustake")];
@@ -108,8 +108,8 @@ describe("SigningCosmWasmClient", () => {
 
     it("works with admin", async () => {
       pendingWithoutWasmd();
-      const pen = await Secp256k1Pen.fromMnemonic(alice.mnemonic);
-      const client = new SigningCosmWasmClient(httpUrl, alice.address0, (signBytes) => pen.sign(signBytes));
+      const wallet = await Secp256k1Wallet.fromMnemonic(alice.mnemonic);
+      const client = new SigningCosmWasmClient(httpUrl, alice.address0, wallet);
       const { codeId } = await client.upload(getHackatom().data);
 
       const beneficiaryAddress = makeRandomAddress();
@@ -131,8 +131,8 @@ describe("SigningCosmWasmClient", () => {
 
     it("can instantiate one code multiple times", async () => {
       pendingWithoutWasmd();
-      const pen = await Secp256k1Pen.fromMnemonic(alice.mnemonic);
-      const client = new SigningCosmWasmClient(httpUrl, alice.address0, (signBytes) => pen.sign(signBytes));
+      const wallet = await Secp256k1Wallet.fromMnemonic(alice.mnemonic);
+      const client = new SigningCosmWasmClient(httpUrl, alice.address0, wallet);
       const { codeId } = await client.upload(getHackatom().data);
 
       const contractAddress1 = await client.instantiate(
@@ -158,8 +158,8 @@ describe("SigningCosmWasmClient", () => {
   describe("updateAdmin", () => {
     it("can update an admin", async () => {
       pendingWithoutWasmd();
-      const pen = await Secp256k1Pen.fromMnemonic(alice.mnemonic);
-      const client = new SigningCosmWasmClient(httpUrl, alice.address0, (signBytes) => pen.sign(signBytes));
+      const wallet = await Secp256k1Wallet.fromMnemonic(alice.mnemonic);
+      const client = new SigningCosmWasmClient(httpUrl, alice.address0, wallet);
       const { codeId } = await client.upload(getHackatom().data);
 
       const beneficiaryAddress = makeRandomAddress();
@@ -191,8 +191,8 @@ describe("SigningCosmWasmClient", () => {
   describe("clearAdmin", () => {
     it("can clear an admin", async () => {
       pendingWithoutWasmd();
-      const pen = await Secp256k1Pen.fromMnemonic(alice.mnemonic);
-      const client = new SigningCosmWasmClient(httpUrl, alice.address0, (signBytes) => pen.sign(signBytes));
+      const wallet = await Secp256k1Wallet.fromMnemonic(alice.mnemonic);
+      const client = new SigningCosmWasmClient(httpUrl, alice.address0, wallet);
       const { codeId } = await client.upload(getHackatom().data);
 
       const beneficiaryAddress = makeRandomAddress();
@@ -224,8 +224,8 @@ describe("SigningCosmWasmClient", () => {
   describe("migrate", () => {
     it("can can migrate from one code ID to another", async () => {
       pendingWithoutWasmd();
-      const pen = await Secp256k1Pen.fromMnemonic(alice.mnemonic);
-      const client = new SigningCosmWasmClient(httpUrl, alice.address0, (signBytes) => pen.sign(signBytes));
+      const wallet = await Secp256k1Wallet.fromMnemonic(alice.mnemonic);
+      const client = new SigningCosmWasmClient(httpUrl, alice.address0, wallet);
       const { codeId: codeId1 } = await client.upload(getHackatom().data);
       const { codeId: codeId2 } = await client.upload(getHackatom().data);
 
@@ -263,8 +263,8 @@ describe("SigningCosmWasmClient", () => {
   describe("execute", () => {
     it("works", async () => {
       pendingWithoutWasmd();
-      const pen = await Secp256k1Pen.fromMnemonic(alice.mnemonic);
-      const client = new SigningCosmWasmClient(httpUrl, alice.address0, (signBytes) => pen.sign(signBytes));
+      const wallet = await Secp256k1Wallet.fromMnemonic(alice.mnemonic);
+      const client = new SigningCosmWasmClient(httpUrl, alice.address0, wallet);
       const { codeId } = await client.upload(getHackatom().data);
 
       // instantiate
@@ -304,8 +304,8 @@ describe("SigningCosmWasmClient", () => {
   describe("sendTokens", () => {
     it("works", async () => {
       pendingWithoutWasmd();
-      const pen = await Secp256k1Pen.fromMnemonic(alice.mnemonic);
-      const client = new SigningCosmWasmClient(httpUrl, alice.address0, (signBytes) => pen.sign(signBytes));
+      const wallet = await Secp256k1Wallet.fromMnemonic(alice.mnemonic);
+      const client = new SigningCosmWasmClient(httpUrl, alice.address0, wallet);
 
       // instantiate
       const transferAmount = coins(7890, "ucosm");
diff --git a/packages/cosmwasm/src/signingcosmwasmclient.ts b/packages/cosmwasm/src/signingcosmwasmclient.ts
index e713e82f..4a4b1df9 100644
--- a/packages/cosmwasm/src/signingcosmwasmclient.ts
+++ b/packages/cosmwasm/src/signingcosmwasmclient.ts
@@ -7,6 +7,7 @@ import {
   coins,
   makeSignBytes,
   MsgSend,
+  OfflineSigner,
   StdFee,
   StdSignature,
   StdTx,
@@ -164,7 +165,7 @@ function createPostTxErrorMessage(result: PostTxFailure): string {
 export class SigningCosmWasmClient extends CosmWasmClient {
   public readonly senderAddress: string;
 
-  private readonly signCallback: SigningCallback;
+  private readonly signer: OfflineSigner;
   private readonly fees: FeeTable;
 
   /**
@@ -175,14 +176,14 @@ export class SigningCosmWasmClient extends CosmWasmClient {
    *
    * @param apiUrl The URL of a Cosmos SDK light client daemon API (sometimes called REST server or REST API)
    * @param senderAddress The address that will sign and send transactions using this instance
-   * @param signCallback An asynchonous callback to create a signature for a given transaction. This can be implemented using secure key stores that require user interaction.
+   * @param signer An implementation of OfflineSigner which can provide signatures for transactions, potentially requiring user input.
    * @param customFees The fees that are paid for transactions
    * @param broadcastMode Defines at which point of the transaction processing the postTx method (i.e. transaction broadcasting) returns
    */
   public constructor(
     apiUrl: string,
     senderAddress: string,
-    signCallback: SigningCallback,
+    signer: OfflineSigner,
     customFees?: Partial<FeeTable>,
     broadcastMode = BroadcastMode.Block,
   ) {
@@ -190,7 +191,7 @@ export class SigningCosmWasmClient extends CosmWasmClient {
     this.anyValidAddress = senderAddress;
 
     this.senderAddress = senderAddress;
-    this.signCallback = signCallback;
+    this.signer = signer;
     this.fees = { ...defaultFees, ...(customFees || {}) };
   }
 
@@ -222,7 +223,7 @@ export class SigningCosmWasmClient extends CosmWasmClient {
     const { accountNumber, sequence } = await this.getNonce();
     const chainId = await this.getChainId();
     const signBytes = makeSignBytes([storeCodeMsg], fee, chainId, memo, accountNumber, sequence);
-    const signature = await this.signCallback(signBytes);
+    const signature = await this.signer.sign(this.senderAddress, signBytes);
     const signedTx: StdTx = {
       msg: [storeCodeMsg],
       fee: fee,
@@ -272,7 +273,7 @@ export class SigningCosmWasmClient extends CosmWasmClient {
     const chainId = await this.getChainId();
     const signBytes = makeSignBytes([instantiateMsg], fee, chainId, memo, accountNumber, sequence);
 
-    const signature = await this.signCallback(signBytes);
+    const signature = await this.signer.sign(this.senderAddress, signBytes);
     const signedTx: StdTx = {
       msg: [instantiateMsg],
       fee: fee,
@@ -306,7 +307,7 @@ export class SigningCosmWasmClient extends CosmWasmClient {
     const { accountNumber, sequence } = await this.getNonce();
     const chainId = await this.getChainId();
     const signBytes = makeSignBytes([updateAdminMsg], fee, chainId, memo, accountNumber, sequence);
-    const signature = await this.signCallback(signBytes);
+    const signature = await this.signer.sign(this.senderAddress, signBytes);
     const signedTx: StdTx = {
       msg: [updateAdminMsg],
       fee: fee,
@@ -336,7 +337,7 @@ export class SigningCosmWasmClient extends CosmWasmClient {
     const { accountNumber, sequence } = await this.getNonce();
     const chainId = await this.getChainId();
     const signBytes = makeSignBytes([clearAdminMsg], fee, chainId, memo, accountNumber, sequence);
-    const signature = await this.signCallback(signBytes);
+    const signature = await this.signer.sign(this.senderAddress, signBytes);
     const signedTx: StdTx = {
       msg: [clearAdminMsg],
       fee: fee,
@@ -374,7 +375,7 @@ export class SigningCosmWasmClient extends CosmWasmClient {
     const { accountNumber, sequence } = await this.getNonce();
     const chainId = await this.getChainId();
     const signBytes = makeSignBytes([msg], fee, chainId, memo, accountNumber, sequence);
-    const signature = await this.signCallback(signBytes);
+    const signature = await this.signer.sign(this.senderAddress, signBytes);
     const signedTx: StdTx = {
       msg: [msg],
       fee: fee,
@@ -412,7 +413,7 @@ export class SigningCosmWasmClient extends CosmWasmClient {
     const { accountNumber, sequence } = await this.getNonce();
     const chainId = await this.getChainId();
     const signBytes = makeSignBytes([executeMsg], fee, chainId, memo, accountNumber, sequence);
-    const signature = await this.signCallback(signBytes);
+    const signature = await this.signer.sign(this.senderAddress, signBytes);
     const signedTx: StdTx = {
       msg: [executeMsg],
       fee: fee,
@@ -449,7 +450,7 @@ export class SigningCosmWasmClient extends CosmWasmClient {
     const { accountNumber, sequence } = await this.getNonce();
     const chainId = await this.getChainId();
     const signBytes = makeSignBytes([sendMsg], fee, chainId, memo, accountNumber, sequence);
-    const signature = await this.signCallback(signBytes);
+    const signature = await this.signer.sign(this.senderAddress, signBytes);
     const signedTx: StdTx = {
       msg: [sendMsg],
       fee: fee,
diff --git a/packages/cosmwasm/types/signingcosmwasmclient.d.ts b/packages/cosmwasm/types/signingcosmwasmclient.d.ts
index 2a3e17ea..18949878 100644
--- a/packages/cosmwasm/types/signingcosmwasmclient.d.ts
+++ b/packages/cosmwasm/types/signingcosmwasmclient.d.ts
@@ -1,4 +1,4 @@
-import { BroadcastMode, Coin, StdFee, StdSignature } from "@cosmjs/sdk38";
+import { BroadcastMode, Coin, OfflineSigner, StdFee, StdSignature } from "@cosmjs/sdk38";
 import { Account, CosmWasmClient, GetNonceResult, PostTxResult } from "./cosmwasmclient";
 import { Log } from "./logs";
 export interface SigningCallback {
@@ -83,7 +83,7 @@ export interface ExecuteResult {
 }
 export declare class SigningCosmWasmClient extends CosmWasmClient {
   readonly senderAddress: string;
-  private readonly signCallback;
+  private readonly signer;
   private readonly fees;
   /**
    * Creates a new client with signing capability to interact with a CosmWasm blockchain. This is the bigger brother of CosmWasmClient.
@@ -93,14 +93,14 @@ export declare class SigningCosmWasmClient extends CosmWasmClient {
    *
    * @param apiUrl The URL of a Cosmos SDK light client daemon API (sometimes called REST server or REST API)
    * @param senderAddress The address that will sign and send transactions using this instance
-   * @param signCallback An asynchonous callback to create a signature for a given transaction. This can be implemented using secure key stores that require user interaction.
+   * @param signer An implementation of OfflineSigner which can provide signatures for transactions, potentially requiring user input.
    * @param customFees The fees that are paid for transactions
    * @param broadcastMode Defines at which point of the transaction processing the postTx method (i.e. transaction broadcasting) returns
    */
   constructor(
     apiUrl: string,
     senderAddress: string,
-    signCallback: SigningCallback,
+    signer: OfflineSigner,
     customFees?: Partial<FeeTable>,
     broadcastMode?: BroadcastMode,
   );
diff --git a/packages/demo-staking/src/index.spec.ts b/packages/demo-staking/src/index.spec.ts
index 49bd7877..6c6fa869 100644
--- a/packages/demo-staking/src/index.spec.ts
+++ b/packages/demo-staking/src/index.spec.ts
@@ -1,6 +1,6 @@
 /* eslint-disable @typescript-eslint/camelcase */
 import { SigningCosmWasmClient } from "@cosmjs/cosmwasm";
-import { Coin, coins, makeCosmoshubPath, Secp256k1Pen } from "@cosmjs/sdk38";
+import { Coin, coins, makeCosmoshubPath, Secp256k1Wallet } from "@cosmjs/sdk38";
 
 import {
   BalanceResponse,
@@ -40,26 +40,19 @@ describe("Staking demo", () => {
   it("works", async () => {
     pendingWithoutWasmd();
     // The owner of the contract that will collect the tax
-    const ownerPen = await Secp256k1Pen.fromMnemonic(alice.mnemonic);
-    const ownerAddress = ownerPen.address("cosmos");
-    const ownerClient = new SigningCosmWasmClient(httpUrl, ownerAddress, (signBytes) =>
-      ownerPen.sign(signBytes),
-    );
+    const ownerWallet = await Secp256k1Wallet.fromMnemonic(alice.mnemonic);
+    const [{ address: ownerAddress }] = await ownerWallet.getAccounts();
+    const ownerClient = new SigningCosmWasmClient(httpUrl, ownerAddress, ownerWallet);
 
     // a user of the contract
-    const userPen = await Secp256k1Pen.fromMnemonic(alice.mnemonic, makeCosmoshubPath(1));
-    const userAddress = userPen.address("cosmos");
-    const userClient = new SigningCosmWasmClient(
-      httpUrl,
-      userAddress,
-      (signBytes) => userPen.sign(signBytes),
-      {
-        exec: {
-          amount: coins(5000, "ucosm"),
-          gas: "300000", // 300k, needed for unbonding
-        },
+    const userWallet = await Secp256k1Wallet.fromMnemonic(alice.mnemonic, makeCosmoshubPath(1));
+    const [{ address: userAddress }] = await userWallet.getAccounts();
+    const userClient = new SigningCosmWasmClient(httpUrl, userAddress, userWallet, {
+      exec: {
+        amount: coins(5000, "ucosm"),
+        gas: "300000", // 300k, needed for unbonding
       },
-    );
+    });
 
     const initMsg: InitMsg = {
       name: params.name,
diff --git a/packages/faucet/src/actions/generate.ts b/packages/faucet/src/actions/generate.ts
index 73ed15c1..ad876dae 100644
--- a/packages/faucet/src/actions/generate.ts
+++ b/packages/faucet/src/actions/generate.ts
@@ -1,7 +1,7 @@
 import { Bip39, Random } from "@cosmjs/crypto";
 
 import * as constants from "../constants";
-import { createPens } from "../profile";
+import { createWallets } from "../profile";
 
 export async function generate(args: readonly string[]): Promise<void> {
   if (args.length < 1) {
@@ -16,5 +16,5 @@ export async function generate(args: readonly string[]): Promise<void> {
   console.info(`FAUCET_MNEMONIC="${mnemonic}"`);
 
   // Log the addresses
-  await createPens(mnemonic, chainId, constants.concurrency, true);
+  await createWallets(mnemonic, chainId, constants.concurrency, true);
 }
diff --git a/packages/faucet/src/faucet.ts b/packages/faucet/src/faucet.ts
index b6450956..d1b0ee6f 100644
--- a/packages/faucet/src/faucet.ts
+++ b/packages/faucet/src/faucet.ts
@@ -1,8 +1,8 @@
-import { CosmosClient, Pen, SigningCosmosClient } from "@cosmjs/sdk38";
+import { CosmosClient, OfflineSigner, SigningCosmosClient } from "@cosmjs/sdk38";
 import { sleep } from "@cosmjs/utils";
 
 import { debugAccount, logAccountsState, logSendJob } from "./debugging";
-import { createPens } from "./profile";
+import { createWallets } from "./profile";
 import { TokenManager } from "./tokenmanager";
 import { MinimalAccount, SendJob, TokenConfiguration } from "./types";
 
@@ -19,8 +19,8 @@ export class Faucet {
     numberOfDistributors: number,
     logging = false,
   ): Promise<Faucet> {
-    const pens = await createPens(mnemonic, addressPrefix, numberOfDistributors, logging);
-    return new Faucet(apiUrl, addressPrefix, config, pens, logging);
+    const wallets = await createWallets(mnemonic, addressPrefix, numberOfDistributors, logging);
+    return new Faucet(apiUrl, addressPrefix, config, wallets, logging);
   }
 
   public readonly addressPrefix: string;
@@ -38,7 +38,7 @@ export class Faucet {
     apiUrl: string,
     addressPrefix: string,
     config: TokenConfiguration,
-    pens: ReadonlyArray<readonly [string, Pen]>,
+    wallets: ReadonlyArray<readonly [string, OfflineSigner]>,
     logging = false,
   ) {
     this.addressPrefix = addressPrefix;
@@ -47,15 +47,13 @@ export class Faucet {
 
     this.readOnlyClient = new CosmosClient(apiUrl);
 
-    this.holderAddress = pens[0][0];
-    this.distributorAddresses = pens.slice(1).map((pair) => pair[0]);
+    this.holderAddress = wallets[0][0];
+    this.distributorAddresses = wallets.slice(1).map((pair) => pair[0]);
 
     // we need one client per sender
     const clients: { [senderAddress: string]: SigningCosmosClient } = {};
-    for (const [senderAddress, pen] of pens) {
-      clients[senderAddress] = new SigningCosmosClient(apiUrl, senderAddress, (signBytes) =>
-        pen.sign(signBytes),
-      );
+    for (const [senderAddress, wallet] of wallets) {
+      clients[senderAddress] = new SigningCosmosClient(apiUrl, senderAddress, wallet);
     }
     this.clients = clients;
     this.logging = logging;
diff --git a/packages/faucet/src/profile.ts b/packages/faucet/src/profile.ts
index 0abc05a9..1ef5cce2 100644
--- a/packages/faucet/src/profile.ts
+++ b/packages/faucet/src/profile.ts
@@ -1,26 +1,26 @@
 import { pathToString } from "@cosmjs/crypto";
-import { makeCosmoshubPath, Pen, Secp256k1Pen } from "@cosmjs/sdk38";
+import { makeCosmoshubPath, OfflineSigner, Secp256k1Wallet } from "@cosmjs/sdk38";
 
-export async function createPens(
+export async function createWallets(
   mnemonic: string,
   addressPrefix: string,
   numberOfDistributors: number,
   logging = false,
-): Promise<ReadonlyArray<readonly [string, Pen]>> {
-  const pens = new Array<readonly [string, Pen]>();
+): Promise<ReadonlyArray<readonly [string, OfflineSigner]>> {
+  const wallets = new Array<readonly [string, OfflineSigner]>();
 
   // first account is the token holder
   const numberOfIdentities = 1 + numberOfDistributors;
   for (let i = 0; i < numberOfIdentities; i++) {
     const path = makeCosmoshubPath(i);
-    const pen = await Secp256k1Pen.fromMnemonic(mnemonic, path);
-    const address = pen.address(addressPrefix);
+    const wallet = await Secp256k1Wallet.fromMnemonic(mnemonic, path, addressPrefix);
+    const [{ address }] = await wallet.getAccounts();
     if (logging) {
       const role = i === 0 ? "token holder " : `distributor ${i}`;
       console.info(`Created ${role} (${pathToString(path)}): ${address}`);
     }
-    pens.push([address, pen]);
+    wallets.push([address, wallet]);
   }
 
-  return pens;
+  return wallets;
 }
diff --git a/packages/sdk38/src/cosmosclient.searchtx.spec.ts b/packages/sdk38/src/cosmosclient.searchtx.spec.ts
index cb6ca4de..3f244466 100644
--- a/packages/sdk38/src/cosmosclient.searchtx.spec.ts
+++ b/packages/sdk38/src/cosmosclient.searchtx.spec.ts
@@ -6,7 +6,6 @@ import { CosmosClient, isPostTxFailure } from "./cosmosclient";
 import { makeSignBytes } from "./encoding";
 import { LcdClient } from "./lcdapi";
 import { isMsgSend, MsgSend } from "./msgs";
-import { Secp256k1Pen } from "./pen";
 import { SigningCosmosClient } from "./signingcosmosclient";
 import {
   faucet,
@@ -17,6 +16,7 @@ import {
   wasmdEnabled,
 } from "./testutils.spec";
 import { CosmosSdkTx } from "./types";
+import { Secp256k1Wallet } from "./wallet";
 
 interface TestTxSend {
   readonly sender: string;
@@ -32,10 +32,10 @@ describe("CosmosClient.searchTx", () => {
 
   beforeAll(async () => {
     if (wasmdEnabled()) {
-      const pen = await Secp256k1Pen.fromMnemonic(faucet.mnemonic);
-      const client = new SigningCosmosClient(wasmd.endpoint, faucet.address, (signBytes) =>
-        pen.sign(signBytes),
-      );
+      const wallet = await Secp256k1Wallet.fromMnemonic(faucet.mnemonic);
+      const accounts = await wallet.getAccounts();
+      const [{ address: walletAddress }] = accounts;
+      const client = new SigningCosmosClient(wasmd.endpoint, faucet.address, wallet);
 
       {
         const memo = "Sending more than I can afford";
@@ -58,7 +58,7 @@ describe("CosmosClient.searchTx", () => {
         const { accountNumber, sequence } = await client.getNonce();
         const chainId = await client.getChainId();
         const signBytes = makeSignBytes([sendMsg], fee, chainId, memo, accountNumber, sequence);
-        const signature = await pen.sign(signBytes);
+        const signature = await wallet.sign(walletAddress, signBytes);
         const tx: CosmosSdkTx = {
           type: "cosmos-sdk/StdTx",
           value: {
diff --git a/packages/sdk38/src/cosmosclient.spec.ts b/packages/sdk38/src/cosmosclient.spec.ts
index 64d9806d..29e2d991 100644
--- a/packages/sdk38/src/cosmosclient.spec.ts
+++ b/packages/sdk38/src/cosmosclient.spec.ts
@@ -6,7 +6,6 @@ import { CosmosClient, isPostTxFailure, PrivateCosmWasmClient } from "./cosmoscl
 import { makeSignBytes } from "./encoding";
 import { findAttribute } from "./logs";
 import { MsgSend } from "./msgs";
-import { Secp256k1Pen } from "./pen";
 import cosmoshub from "./testdata/cosmoshub.json";
 import {
   faucet,
@@ -17,6 +16,7 @@ import {
   wasmd,
 } from "./testutils.spec";
 import { StdFee } from "./types";
+import { Secp256k1Wallet } from "./wallet";
 
 const blockTime = 1_000; // ms
 
@@ -193,7 +193,9 @@ describe("CosmosClient", () => {
   describe("postTx", () => {
     it("works", async () => {
       pendingWithoutWasmd();
-      const pen = await Secp256k1Pen.fromMnemonic(faucet.mnemonic);
+      const wallet = await Secp256k1Wallet.fromMnemonic(faucet.mnemonic);
+      const accounts = await wallet.getAccounts();
+      const [{ address: walletAddress }] = accounts;
       const client = new CosmosClient(wasmd.endpoint);
 
       const memo = "My first contract on chain";
@@ -224,7 +226,7 @@ describe("CosmosClient", () => {
       const chainId = await client.getChainId();
       const { accountNumber, sequence } = await client.getNonce(faucet.address);
       const signBytes = makeSignBytes([sendMsg], fee, chainId, memo, accountNumber, sequence);
-      const signature = await pen.sign(signBytes);
+      const signature = await wallet.sign(walletAddress, signBytes);
       const signedTx = {
         msg: [sendMsg],
         fee: fee,
diff --git a/packages/sdk38/src/index.ts b/packages/sdk38/src/index.ts
index f7d21dc6..4233a729 100644
--- a/packages/sdk38/src/index.ts
+++ b/packages/sdk38/src/index.ts
@@ -50,9 +50,9 @@ export {
   TxsResponse,
 } from "./lcdapi";
 export { isMsgDelegate, isMsgSend, Msg, MsgDelegate, MsgSend } from "./msgs";
-export { Pen, Secp256k1Pen, makeCosmoshubPath } from "./pen";
 export { decodeBech32Pubkey, encodeBech32Pubkey, encodeSecp256k1Pubkey } from "./pubkey";
 export { findSequenceForSignedTx } from "./sequence";
 export { encodeSecp256k1Signature, decodeSignature } from "./signature";
-export { FeeTable, SigningCallback, SigningCosmosClient } from "./signingcosmosclient";
+export { FeeTable, SigningCosmosClient } from "./signingcosmosclient";
 export { isStdTx, pubkeyType, CosmosSdkTx, PubKey, StdFee, StdSignature, StdTx } from "./types";
+export { OfflineSigner, Secp256k1Wallet, makeCosmoshubPath } from "./wallet";
diff --git a/packages/sdk38/src/lcdapi/lcdclient.spec.ts b/packages/sdk38/src/lcdapi/lcdclient.spec.ts
index 627075e1..b928af0c 100644
--- a/packages/sdk38/src/lcdapi/lcdclient.spec.ts
+++ b/packages/sdk38/src/lcdapi/lcdclient.spec.ts
@@ -1,13 +1,11 @@
 /* eslint-disable @typescript-eslint/camelcase */
 import { assert, sleep } from "@cosmjs/utils";
 
-import { rawSecp256k1PubkeyToAddress } from "../address";
 import { Coin } from "../coins";
 import { isPostTxFailure } from "../cosmosclient";
 import { makeSignBytes } from "../encoding";
 import { parseLogs } from "../logs";
 import { MsgSend } from "../msgs";
-import { makeCosmoshubPath, Secp256k1Pen } from "../pen";
 import { SigningCosmosClient } from "../signingcosmosclient";
 import cosmoshub from "../testdata/cosmoshub.json";
 import {
@@ -21,6 +19,7 @@ import {
   wasmdEnabled,
 } from "../testutils.spec";
 import { StdFee } from "../types";
+import { makeCosmoshubPath, Secp256k1Wallet } from "../wallet";
 import { setupAuthExtension } from "./auth";
 import { TxsResponse } from "./base";
 import { LcdApiArray, LcdClient, normalizeLcdApiArray } from "./lcdclient";
@@ -217,10 +216,10 @@ describe("LcdClient", () => {
 
     beforeAll(async () => {
       if (wasmdEnabled()) {
-        const pen = await Secp256k1Pen.fromMnemonic(faucet.mnemonic);
-        const client = new SigningCosmosClient(wasmd.endpoint, faucet.address, (signBytes) =>
-          pen.sign(signBytes),
-        );
+        const wallet = await Secp256k1Wallet.fromMnemonic(faucet.mnemonic);
+        const accounts = await wallet.getAccounts();
+        const [{ address: walletAddress }] = accounts;
+        const client = new SigningCosmosClient(wasmd.endpoint, faucet.address, wallet);
 
         {
           const recipient = makeRandomAddress();
@@ -267,7 +266,7 @@ describe("LcdClient", () => {
           const { accountNumber, sequence } = await client.getNonce();
           const chainId = await client.getChainId();
           const signBytes = makeSignBytes([sendMsg], fee, chainId, memo, accountNumber, sequence);
-          const signature = await pen.sign(signBytes);
+          const signature = await wallet.sign(walletAddress, signBytes);
           const signedTx = {
             msg: [sendMsg],
             fee: fee,
@@ -351,10 +350,8 @@ describe("LcdClient", () => {
 
     beforeAll(async () => {
       if (wasmdEnabled()) {
-        const pen = await Secp256k1Pen.fromMnemonic(faucet.mnemonic);
-        const client = new SigningCosmosClient(wasmd.endpoint, faucet.address, (signBytes) =>
-          pen.sign(signBytes),
-        );
+        const wallet = await Secp256k1Wallet.fromMnemonic(faucet.mnemonic);
+        const client = new SigningCosmosClient(wasmd.endpoint, faucet.address, wallet);
 
         const recipient = makeRandomAddress();
         const transferAmount = [
@@ -534,7 +531,9 @@ describe("LcdClient", () => {
   describe("postTx", () => {
     it("can send tokens", async () => {
       pendingWithoutWasmd();
-      const pen = await Secp256k1Pen.fromMnemonic(faucet.mnemonic);
+      const wallet = await Secp256k1Wallet.fromMnemonic(faucet.mnemonic);
+      const accounts = await wallet.getAccounts();
+      const [{ address: walletAddress }] = accounts;
 
       const memo = "My first contract on chain";
       const theMsg: MsgSend = {
@@ -565,7 +564,7 @@ describe("LcdClient", () => {
       const { account_number, sequence } = (await client.auth.account(faucet.address)).result.value;
 
       const signBytes = makeSignBytes([theMsg], fee, wasmd.chainId, memo, account_number, sequence);
-      const signature = await pen.sign(signBytes);
+      const signature = await wallet.sign(walletAddress, signBytes);
       const signedTx = makeSignedTx(theMsg, fee, memo, signature);
       const result = await client.postTx(signedTx);
       expect(result.code).toBeUndefined();
@@ -582,12 +581,14 @@ describe("LcdClient", () => {
 
     it("can't send transaction with additional signatures", async () => {
       pendingWithoutWasmd();
-      const account1 = await Secp256k1Pen.fromMnemonic(faucet.mnemonic, makeCosmoshubPath(0));
-      const account2 = await Secp256k1Pen.fromMnemonic(faucet.mnemonic, makeCosmoshubPath(1));
-      const account3 = await Secp256k1Pen.fromMnemonic(faucet.mnemonic, makeCosmoshubPath(2));
-      const address1 = rawSecp256k1PubkeyToAddress(account1.pubkey, "cosmos");
-      const address2 = rawSecp256k1PubkeyToAddress(account2.pubkey, "cosmos");
-      const address3 = rawSecp256k1PubkeyToAddress(account3.pubkey, "cosmos");
+      const account1 = await Secp256k1Wallet.fromMnemonic(faucet.mnemonic, makeCosmoshubPath(0));
+      const account2 = await Secp256k1Wallet.fromMnemonic(faucet.mnemonic, makeCosmoshubPath(1));
+      const account3 = await Secp256k1Wallet.fromMnemonic(faucet.mnemonic, makeCosmoshubPath(2));
+      const [address1, address2, address3] = await Promise.all(
+        [account1, account2, account3].map(async (wallet) => {
+          return (await wallet.getAccounts())[0].address;
+        }),
+      );
 
       const memo = "My first contract on chain";
       const theMsg: MsgSend = {
@@ -622,9 +623,9 @@ describe("LcdClient", () => {
       const signBytes1 = makeSignBytes([theMsg], fee, wasmd.chainId, memo, an1, sequence1);
       const signBytes2 = makeSignBytes([theMsg], fee, wasmd.chainId, memo, an2, sequence2);
       const signBytes3 = makeSignBytes([theMsg], fee, wasmd.chainId, memo, an3, sequence3);
-      const signature1 = await account1.sign(signBytes1);
-      const signature2 = await account2.sign(signBytes2);
-      const signature3 = await account3.sign(signBytes3);
+      const signature1 = await account1.sign(address1, signBytes1);
+      const signature2 = await account2.sign(address2, signBytes2);
+      const signature3 = await account3.sign(address3, signBytes3);
       const signedTx = {
         msg: [theMsg],
         fee: fee,
@@ -638,14 +639,15 @@ describe("LcdClient", () => {
 
     it("can send multiple messages with one signature", async () => {
       pendingWithoutWasmd();
-      const account1 = await Secp256k1Pen.fromMnemonic(faucet.mnemonic, makeCosmoshubPath(0));
-      const address1 = rawSecp256k1PubkeyToAddress(account1.pubkey, "cosmos");
+      const wallet = await Secp256k1Wallet.fromMnemonic(faucet.mnemonic, makeCosmoshubPath(0));
+      const accounts = await wallet.getAccounts();
+      const [{ address: walletAddress }] = accounts;
 
       const memo = "My first contract on chain";
       const msg1: MsgSend = {
         type: "cosmos-sdk/MsgSend",
         value: {
-          from_address: address1,
+          from_address: walletAddress,
           to_address: defaultRecipientAddress,
           amount: [
             {
@@ -658,7 +660,7 @@ describe("LcdClient", () => {
       const msg2: MsgSend = {
         type: "cosmos-sdk/MsgSend",
         value: {
-          from_address: address1,
+          from_address: walletAddress,
           to_address: defaultRecipientAddress,
           amount: [
             {
@@ -680,10 +682,10 @@ describe("LcdClient", () => {
       };
 
       const client = LcdClient.withExtensions({ apiUrl: wasmd.endpoint }, setupAuthExtension);
-      const { account_number, sequence } = (await client.auth.account(address1)).result.value;
+      const { account_number, sequence } = (await client.auth.account(walletAddress)).result.value;
 
       const signBytes = makeSignBytes([msg1, msg2], fee, wasmd.chainId, memo, account_number, sequence);
-      const signature1 = await account1.sign(signBytes);
+      const signature1 = await wallet.sign(walletAddress, signBytes);
       const signedTx = {
         msg: [msg1, msg2],
         fee: fee,
@@ -696,10 +698,13 @@ describe("LcdClient", () => {
 
     it("can send multiple messages with multiple signatures", async () => {
       pendingWithoutWasmd();
-      const account1 = await Secp256k1Pen.fromMnemonic(faucet.mnemonic, makeCosmoshubPath(0));
-      const account2 = await Secp256k1Pen.fromMnemonic(faucet.mnemonic, makeCosmoshubPath(1));
-      const address1 = rawSecp256k1PubkeyToAddress(account1.pubkey, "cosmos");
-      const address2 = rawSecp256k1PubkeyToAddress(account2.pubkey, "cosmos");
+      const account1 = await Secp256k1Wallet.fromMnemonic(faucet.mnemonic, makeCosmoshubPath(0));
+      const account2 = await Secp256k1Wallet.fromMnemonic(faucet.mnemonic, makeCosmoshubPath(1));
+      const [address1, address2] = await Promise.all(
+        [account1, account2].map(async (wallet) => {
+          return (await wallet.getAccounts())[0].address;
+        }),
+      );
 
       const memo = "My first contract on chain";
       const msg1: MsgSend = {
@@ -745,8 +750,8 @@ describe("LcdClient", () => {
 
       const signBytes1 = makeSignBytes([msg2, msg1], fee, wasmd.chainId, memo, an1, sequence1);
       const signBytes2 = makeSignBytes([msg2, msg1], fee, wasmd.chainId, memo, an2, sequence2);
-      const signature1 = await account1.sign(signBytes1);
-      const signature2 = await account2.sign(signBytes2);
+      const signature1 = await account1.sign(address1, signBytes1);
+      const signature2 = await account2.sign(address2, signBytes2);
       const signedTx = {
         msg: [msg2, msg1],
         fee: fee,
@@ -764,10 +769,13 @@ describe("LcdClient", () => {
 
     it("can't send transaction with wrong signature order (1)", async () => {
       pendingWithoutWasmd();
-      const account1 = await Secp256k1Pen.fromMnemonic(faucet.mnemonic, makeCosmoshubPath(0));
-      const account2 = await Secp256k1Pen.fromMnemonic(faucet.mnemonic, makeCosmoshubPath(1));
-      const address1 = rawSecp256k1PubkeyToAddress(account1.pubkey, "cosmos");
-      const address2 = rawSecp256k1PubkeyToAddress(account2.pubkey, "cosmos");
+      const account1 = await Secp256k1Wallet.fromMnemonic(faucet.mnemonic, makeCosmoshubPath(0));
+      const account2 = await Secp256k1Wallet.fromMnemonic(faucet.mnemonic, makeCosmoshubPath(1));
+      const [address1, address2] = await Promise.all(
+        [account1, account2].map(async (wallet) => {
+          return (await wallet.getAccounts())[0].address;
+        }),
+      );
 
       const memo = "My first contract on chain";
       const msg1: MsgSend = {
@@ -813,8 +821,8 @@ describe("LcdClient", () => {
 
       const signBytes1 = makeSignBytes([msg1, msg2], fee, wasmd.chainId, memo, an1, sequence1);
       const signBytes2 = makeSignBytes([msg1, msg2], fee, wasmd.chainId, memo, an2, sequence2);
-      const signature1 = await account1.sign(signBytes1);
-      const signature2 = await account2.sign(signBytes2);
+      const signature1 = await account1.sign(address1, signBytes1);
+      const signature2 = await account2.sign(address2, signBytes2);
       const signedTx = {
         msg: [msg1, msg2],
         fee: fee,
@@ -827,10 +835,13 @@ describe("LcdClient", () => {
 
     it("can't send transaction with wrong signature order (2)", async () => {
       pendingWithoutWasmd();
-      const account1 = await Secp256k1Pen.fromMnemonic(faucet.mnemonic, makeCosmoshubPath(0));
-      const account2 = await Secp256k1Pen.fromMnemonic(faucet.mnemonic, makeCosmoshubPath(1));
-      const address1 = rawSecp256k1PubkeyToAddress(account1.pubkey, "cosmos");
-      const address2 = rawSecp256k1PubkeyToAddress(account2.pubkey, "cosmos");
+      const account1 = await Secp256k1Wallet.fromMnemonic(faucet.mnemonic, makeCosmoshubPath(0));
+      const account2 = await Secp256k1Wallet.fromMnemonic(faucet.mnemonic, makeCosmoshubPath(1));
+      const [address1, address2] = await Promise.all(
+        [account1, account2].map(async (wallet) => {
+          return (await wallet.getAccounts())[0].address;
+        }),
+      );
 
       const memo = "My first contract on chain";
       const msg1: MsgSend = {
@@ -876,8 +887,8 @@ describe("LcdClient", () => {
 
       const signBytes1 = makeSignBytes([msg2, msg1], fee, wasmd.chainId, memo, an1, sequence1);
       const signBytes2 = makeSignBytes([msg2, msg1], fee, wasmd.chainId, memo, an2, sequence2);
-      const signature1 = await account1.sign(signBytes1);
-      const signature2 = await account2.sign(signBytes2);
+      const signature1 = await account1.sign(address1, signBytes1);
+      const signature2 = await account2.sign(address2, signBytes2);
       const signedTx = {
         msg: [msg2, msg1],
         fee: fee,
diff --git a/packages/sdk38/src/pen.spec.ts b/packages/sdk38/src/pen.spec.ts
deleted file mode 100644
index 89b37d1b..00000000
--- a/packages/sdk38/src/pen.spec.ts
+++ /dev/null
@@ -1,54 +0,0 @@
-import { Secp256k1, Secp256k1Signature, Sha256 } from "@cosmjs/crypto";
-import { fromHex, toAscii } from "@cosmjs/encoding";
-
-import { Secp256k1Pen } from "./pen";
-import { decodeSignature } from "./signature";
-
-describe("Sec256k1Pen", () => {
-  it("can be constructed", async () => {
-    const pen = await Secp256k1Pen.fromMnemonic(
-      "zebra slush diet army arrest purpose hawk source west glimpse custom record",
-    );
-    expect(pen).toBeTruthy();
-  });
-
-  describe("pubkey", () => {
-    it("returns compressed pubkey", async () => {
-      // special sign fit simple patrol salute grocery chicken wheat radar tonight ceiling
-      // m/44'/118'/0'/0/0
-      // pubkey: 02baa4ef93f2ce84592a49b1d729c074eab640112522a7a89f7d03ebab21ded7b6
-      const pen = await Secp256k1Pen.fromMnemonic(
-        "special sign fit simple patrol salute grocery chicken wheat radar tonight ceiling",
-      );
-      expect(pen.pubkey).toEqual(
-        fromHex("02baa4ef93f2ce84592a49b1d729c074eab640112522a7a89f7d03ebab21ded7b6"),
-      );
-    });
-  });
-
-  describe("sign", () => {
-    it("creates correct signatures", async () => {
-      const pen = await Secp256k1Pen.fromMnemonic(
-        "special sign fit simple patrol salute grocery chicken wheat radar tonight ceiling",
-      );
-      const data = toAscii("foo bar");
-      const { pubkey, signature } = decodeSignature(await pen.sign(data));
-
-      const valid = await Secp256k1.verifySignature(
-        Secp256k1Signature.fromFixedLength(signature),
-        new Sha256(data).digest(),
-        pubkey,
-      );
-      expect(valid).toEqual(true);
-    });
-  });
-
-  describe("address", () => {
-    it("creates same address as Go imlementation", async () => {
-      const pen = await Secp256k1Pen.fromMnemonic(
-        "oyster design unusual machine spread century engine gravity focus cave carry slot",
-      );
-      expect(pen.address("cosmos")).toEqual("cosmos1cjsxept9rkggzxztslae9ndgpdyt2408lk850u");
-    });
-  });
-});
diff --git a/packages/sdk38/src/pen.ts b/packages/sdk38/src/pen.ts
deleted file mode 100644
index 1c65a0da..00000000
--- a/packages/sdk38/src/pen.ts
+++ /dev/null
@@ -1,92 +0,0 @@
-import {
-  Bip39,
-  EnglishMnemonic,
-  Secp256k1,
-  Sha256,
-  Sha512,
-  Slip10,
-  Slip10Curve,
-  Slip10RawIndex,
-} from "@cosmjs/crypto";
-
-import { rawSecp256k1PubkeyToAddress } from "./address";
-import { encodeSecp256k1Signature } from "./signature";
-import { StdSignature } from "./types";
-
-export type PrehashType = "sha256" | "sha512" | null;
-
-/**
- * A pen is the most basic tool you can think of for signing. It works
- * everywhere and can be used intuitively by everyone. However, it does not
- * come with a great amount of features. End of semi suitable metaphor.
- *
- * This wraps a single keypair and allows for signing.
- *
- * Non-goals of this types are: multi account support, persistency, data migrations,
- * obfuscation of sensitive data.
- */
-export interface Pen {
-  readonly pubkey: Uint8Array;
-  readonly sign: (signBytes: Uint8Array, prehashType?: PrehashType) => Promise<StdSignature>;
-}
-
-function prehash(bytes: Uint8Array, type: PrehashType): Uint8Array {
-  switch (type) {
-    case null:
-      return new Uint8Array([...bytes]);
-    case "sha256":
-      return new Sha256(bytes).digest();
-    case "sha512":
-      return new Sha512(bytes).digest();
-    default:
-      throw new Error("Unknown prehash type");
-  }
-}
-
-/**
- * The Cosmoshub derivation path in the form `m/44'/118'/0'/0/a`
- * with 0-based account index `a`.
- */
-export function makeCosmoshubPath(a: number): readonly Slip10RawIndex[] {
-  return [
-    Slip10RawIndex.hardened(44),
-    Slip10RawIndex.hardened(118),
-    Slip10RawIndex.hardened(0),
-    Slip10RawIndex.normal(0),
-    Slip10RawIndex.normal(a),
-  ];
-}
-
-export class Secp256k1Pen implements Pen {
-  public static async fromMnemonic(
-    mnemonic: string,
-    hdPath: readonly Slip10RawIndex[] = makeCosmoshubPath(0),
-  ): Promise<Secp256k1Pen> {
-    const seed = await Bip39.mnemonicToSeed(new EnglishMnemonic(mnemonic));
-    const { privkey } = Slip10.derivePath(Slip10Curve.Secp256k1, seed, hdPath);
-    const uncompressed = (await Secp256k1.makeKeypair(privkey)).pubkey;
-    return new Secp256k1Pen(privkey, Secp256k1.compressPubkey(uncompressed));
-  }
-
-  public readonly pubkey: Uint8Array;
-  private readonly privkey: Uint8Array;
-
-  private constructor(privkey: Uint8Array, pubkey: Uint8Array) {
-    this.privkey = privkey;
-    this.pubkey = pubkey;
-  }
-
-  /**
-   * Creates and returns a signature
-   */
-  public async sign(signBytes: Uint8Array, prehashType: PrehashType = "sha256"): Promise<StdSignature> {
-    const message = prehash(signBytes, prehashType);
-    const signature = await Secp256k1.createSignature(message, this.privkey);
-    const fixedLengthSignature = new Uint8Array([...signature.r(32), ...signature.s(32)]);
-    return encodeSecp256k1Signature(this.pubkey, fixedLengthSignature);
-  }
-
-  public address(prefix: string): string {
-    return rawSecp256k1PubkeyToAddress(this.pubkey, prefix);
-  }
-}
diff --git a/packages/sdk38/src/signingcosmosclient.spec.ts b/packages/sdk38/src/signingcosmosclient.spec.ts
index ece3473c..ac5c6e5f 100644
--- a/packages/sdk38/src/signingcosmosclient.spec.ts
+++ b/packages/sdk38/src/signingcosmosclient.spec.ts
@@ -2,9 +2,9 @@ import { assert } from "@cosmjs/utils";
 
 import { Coin } from "./coins";
 import { isPostTxFailure, PrivateCosmWasmClient } from "./cosmosclient";
-import { Secp256k1Pen } from "./pen";
 import { SigningCosmosClient } from "./signingcosmosclient";
 import { makeRandomAddress, pendingWithoutWasmd } from "./testutils.spec";
+import { Secp256k1Wallet } from "./wallet";
 
 const httpUrl = "http://localhost:1317";
 
@@ -21,8 +21,8 @@ const faucet = {
 describe("SigningCosmosClient", () => {
   describe("makeReadOnly", () => {
     it("can be constructed", async () => {
-      const pen = await Secp256k1Pen.fromMnemonic(faucet.mnemonic);
-      const client = new SigningCosmosClient(httpUrl, faucet.address, (signBytes) => pen.sign(signBytes));
+      const wallet = await Secp256k1Wallet.fromMnemonic(faucet.mnemonic);
+      const client = new SigningCosmosClient(httpUrl, faucet.address, wallet);
       expect(client).toBeTruthy();
     });
   });
@@ -30,8 +30,8 @@ describe("SigningCosmosClient", () => {
   describe("getHeight", () => {
     it("always uses authAccount implementation", async () => {
       pendingWithoutWasmd();
-      const pen = await Secp256k1Pen.fromMnemonic(faucet.mnemonic);
-      const client = new SigningCosmosClient(httpUrl, faucet.address, (signBytes) => pen.sign(signBytes));
+      const wallet = await Secp256k1Wallet.fromMnemonic(faucet.mnemonic);
+      const client = new SigningCosmosClient(httpUrl, faucet.address, wallet);
 
       const openedClient = (client as unknown) as PrivateCosmWasmClient;
       const blockLatestSpy = spyOn(openedClient.lcdClient, "blocksLatest").and.callThrough();
@@ -48,8 +48,8 @@ describe("SigningCosmosClient", () => {
   describe("sendTokens", () => {
     it("works", async () => {
       pendingWithoutWasmd();
-      const pen = await Secp256k1Pen.fromMnemonic(faucet.mnemonic);
-      const client = new SigningCosmosClient(httpUrl, faucet.address, (signBytes) => pen.sign(signBytes));
+      const wallet = await Secp256k1Wallet.fromMnemonic(faucet.mnemonic);
+      const client = new SigningCosmosClient(httpUrl, faucet.address, wallet);
 
       // instantiate
       const transferAmount: readonly Coin[] = [
diff --git a/packages/sdk38/src/signingcosmosclient.ts b/packages/sdk38/src/signingcosmosclient.ts
index 74f23fef..63d7f89a 100644
--- a/packages/sdk38/src/signingcosmosclient.ts
+++ b/packages/sdk38/src/signingcosmosclient.ts
@@ -3,11 +3,8 @@ import { Account, CosmosClient, GetNonceResult, PostTxResult } from "./cosmoscli
 import { makeSignBytes } from "./encoding";
 import { BroadcastMode } from "./lcdapi";
 import { MsgSend } from "./msgs";
-import { StdFee, StdSignature, StdTx } from "./types";
-
-export interface SigningCallback {
-  (signBytes: Uint8Array): Promise<StdSignature>;
-}
+import { StdFee, StdTx } from "./types";
+import { OfflineSigner } from "./wallet";
 
 export interface FeeTable {
   readonly upload: StdFee;
@@ -38,7 +35,7 @@ const defaultFees: FeeTable = {
 export class SigningCosmosClient extends CosmosClient {
   public readonly senderAddress: string;
 
-  private readonly signCallback: SigningCallback;
+  private readonly signer: OfflineSigner;
   private readonly fees: FeeTable;
 
   /**
@@ -49,14 +46,14 @@ export class SigningCosmosClient extends CosmosClient {
    *
    * @param apiUrl The URL of a Cosmos SDK light client daemon API (sometimes called REST server or REST API)
    * @param senderAddress The address that will sign and send transactions using this instance
-   * @param signCallback An asynchonous callback to create a signature for a given transaction. This can be implemented using secure key stores that require user interaction.
+   * @param signer An implementation of OfflineSigner which can provide signatures for transactions, potentially requiring user input.
    * @param customFees The fees that are paid for transactions
    * @param broadcastMode Defines at which point of the transaction processing the postTx method (i.e. transaction broadcasting) returns
    */
   public constructor(
     apiUrl: string,
     senderAddress: string,
-    signCallback: SigningCallback,
+    signer: OfflineSigner,
     customFees?: Partial<FeeTable>,
     broadcastMode = BroadcastMode.Block,
   ) {
@@ -64,7 +61,7 @@ export class SigningCosmosClient extends CosmosClient {
     this.anyValidAddress = senderAddress;
 
     this.senderAddress = senderAddress;
-    this.signCallback = signCallback;
+    this.signer = signer;
     this.fees = { ...defaultFees, ...(customFees || {}) };
   }
 
@@ -95,7 +92,7 @@ export class SigningCosmosClient extends CosmosClient {
     const { accountNumber, sequence } = await this.getNonce();
     const chainId = await this.getChainId();
     const signBytes = makeSignBytes([sendMsg], fee, chainId, memo, accountNumber, sequence);
-    const signature = await this.signCallback(signBytes);
+    const signature = await this.signer.sign(this.senderAddress, signBytes);
     const signedTx: StdTx = {
       msg: [sendMsg],
       fee: fee,
diff --git a/packages/sdk38/src/wallet.spec.ts b/packages/sdk38/src/wallet.spec.ts
new file mode 100644
index 00000000..c016b1a8
--- /dev/null
+++ b/packages/sdk38/src/wallet.spec.ts
@@ -0,0 +1,52 @@
+import { Secp256k1, Secp256k1Signature, Sha256 } from "@cosmjs/crypto";
+import { fromBase64, fromHex, toAscii } from "@cosmjs/encoding";
+
+import { Secp256k1Wallet } from "./wallet";
+
+describe("Secp256k1Wallet", () => {
+  // m/44'/118'/0'/0/0
+  // pubkey: 02baa4ef93f2ce84592a49b1d729c074eab640112522a7a89f7d03ebab21ded7b6
+  const defaultMnemonic = "special sign fit simple patrol salute grocery chicken wheat radar tonight ceiling";
+  const defaultPubkey = fromHex("02baa4ef93f2ce84592a49b1d729c074eab640112522a7a89f7d03ebab21ded7b6");
+  const defaultAddress = "cosmos1jhg0e7s6gn44tfc5k37kr04sznyhedtc9rzys5";
+
+  it("can be constructed", async () => {
+    const wallet = await Secp256k1Wallet.fromMnemonic(defaultMnemonic);
+    expect(wallet).toBeTruthy();
+  });
+
+  describe("getAccounts", () => {
+    it("resolves to a list of accounts if enabled", async () => {
+      const wallet = await Secp256k1Wallet.fromMnemonic(defaultMnemonic);
+      const accounts = await wallet.getAccounts();
+      expect(accounts.length).toEqual(1);
+      expect(accounts[0]).toEqual({
+        address: defaultAddress,
+        algo: "secp256k1",
+        pubkey: defaultPubkey,
+      });
+    });
+
+    it("creates the same address as Go implementation", async () => {
+      const wallet = await Secp256k1Wallet.fromMnemonic(
+        "oyster design unusual machine spread century engine gravity focus cave carry slot",
+      );
+      const [{ address }] = await wallet.getAccounts();
+      expect(address).toEqual("cosmos1cjsxept9rkggzxztslae9ndgpdyt2408lk850u");
+    });
+  });
+
+  describe("sign", () => {
+    it("resolves to valid signature if enabled", async () => {
+      const wallet = await Secp256k1Wallet.fromMnemonic(defaultMnemonic);
+      const message = toAscii("foo bar");
+      const signature = await wallet.sign(defaultAddress, message);
+      const valid = await Secp256k1.verifySignature(
+        Secp256k1Signature.fromFixedLength(fromBase64(signature.signature)),
+        new Sha256(message).digest(),
+        defaultPubkey,
+      );
+      expect(valid).toEqual(true);
+    });
+  });
+});
diff --git a/packages/sdk38/src/wallet.ts b/packages/sdk38/src/wallet.ts
new file mode 100644
index 00000000..c252d9a7
--- /dev/null
+++ b/packages/sdk38/src/wallet.ts
@@ -0,0 +1,116 @@
+import {
+  Bip39,
+  EnglishMnemonic,
+  Secp256k1,
+  Sha256,
+  Sha512,
+  Slip10,
+  Slip10Curve,
+  Slip10RawIndex,
+} from "@cosmjs/crypto";
+
+import { rawSecp256k1PubkeyToAddress } from "./address";
+import { encodeSecp256k1Signature } from "./signature";
+import { StdSignature } from "./types";
+
+export type PrehashType = "sha256" | "sha512" | null;
+
+export type Algo = "secp256k1" | "ed25519" | "sr25519";
+
+export interface AccountData {
+  // bech32-encoded
+  readonly address: string;
+  readonly algo: Algo;
+  readonly pubkey: Uint8Array;
+}
+
+export interface OfflineSigner {
+  /**
+   * Get AccountData array from wallet. Rejects if not enabled.
+   */
+  readonly getAccounts: () => Promise<readonly AccountData[]>;
+
+  /**
+   * Request signature from whichever key corresponds to provided bech32-encoded address. Rejects if not enabled.
+   */
+  readonly sign: (address: string, message: Uint8Array, prehashType?: PrehashType) => Promise<StdSignature>;
+}
+
+function prehash(bytes: Uint8Array, type: PrehashType): Uint8Array {
+  switch (type) {
+    case null:
+      return new Uint8Array([...bytes]);
+    case "sha256":
+      return new Sha256(bytes).digest();
+    case "sha512":
+      return new Sha512(bytes).digest();
+    default:
+      throw new Error("Unknown prehash type");
+  }
+}
+
+/**
+ * The Cosmoshub derivation path in the form `m/44'/118'/0'/0/a`
+ * with 0-based account index `a`.
+ */
+export function makeCosmoshubPath(a: number): readonly Slip10RawIndex[] {
+  return [
+    Slip10RawIndex.hardened(44),
+    Slip10RawIndex.hardened(118),
+    Slip10RawIndex.hardened(0),
+    Slip10RawIndex.normal(0),
+    Slip10RawIndex.normal(a),
+  ];
+}
+
+export class Secp256k1Wallet implements OfflineSigner {
+  public static async fromMnemonic(
+    mnemonic: string,
+    hdPath: readonly Slip10RawIndex[] = makeCosmoshubPath(0),
+    prefix = "cosmos",
+  ): Promise<Secp256k1Wallet> {
+    const seed = await Bip39.mnemonicToSeed(new EnglishMnemonic(mnemonic));
+    const { privkey } = Slip10.derivePath(Slip10Curve.Secp256k1, seed, hdPath);
+    const uncompressed = (await Secp256k1.makeKeypair(privkey)).pubkey;
+    return new Secp256k1Wallet(privkey, Secp256k1.compressPubkey(uncompressed), prefix);
+  }
+
+  private readonly pubkey: Uint8Array;
+  private readonly privkey: Uint8Array;
+  private readonly prefix: string;
+  private readonly algo: Algo = "secp256k1";
+
+  private constructor(privkey: Uint8Array, pubkey: Uint8Array, prefix: string) {
+    this.privkey = privkey;
+    this.pubkey = pubkey;
+    this.prefix = prefix;
+  }
+
+  private get address(): string {
+    return rawSecp256k1PubkeyToAddress(this.pubkey, this.prefix);
+  }
+
+  public async getAccounts(): Promise<readonly AccountData[]> {
+    return [
+      {
+        address: this.address,
+        algo: this.algo,
+        pubkey: this.pubkey,
+      },
+    ];
+  }
+
+  public async sign(
+    address: string,
+    message: Uint8Array,
+    prehashType: PrehashType = "sha256",
+  ): Promise<StdSignature> {
+    if (address !== this.address) {
+      throw new Error(`Address ${address} not found in wallet`);
+    }
+    const hashedMessage = prehash(message, prehashType);
+    const signature = await Secp256k1.createSignature(hashedMessage, this.privkey);
+    const signatureBytes = new Uint8Array([...signature.r(32), ...signature.s(32)]);
+    return encodeSecp256k1Signature(this.pubkey, signatureBytes);
+  }
+}
diff --git a/packages/sdk38/types/index.d.ts b/packages/sdk38/types/index.d.ts
index fe529970..4fd2a02e 100644
--- a/packages/sdk38/types/index.d.ts
+++ b/packages/sdk38/types/index.d.ts
@@ -48,9 +48,9 @@ export {
   TxsResponse,
 } from "./lcdapi";
 export { isMsgDelegate, isMsgSend, Msg, MsgDelegate, MsgSend } from "./msgs";
-export { Pen, Secp256k1Pen, makeCosmoshubPath } from "./pen";
 export { decodeBech32Pubkey, encodeBech32Pubkey, encodeSecp256k1Pubkey } from "./pubkey";
 export { findSequenceForSignedTx } from "./sequence";
 export { encodeSecp256k1Signature, decodeSignature } from "./signature";
-export { FeeTable, SigningCallback, SigningCosmosClient } from "./signingcosmosclient";
+export { FeeTable, SigningCosmosClient } from "./signingcosmosclient";
 export { isStdTx, pubkeyType, CosmosSdkTx, PubKey, StdFee, StdSignature, StdTx } from "./types";
+export { OfflineSigner, Secp256k1Wallet, makeCosmoshubPath } from "./wallet";
diff --git a/packages/sdk38/types/pen.d.ts b/packages/sdk38/types/pen.d.ts
deleted file mode 100644
index 39e899f4..00000000
--- a/packages/sdk38/types/pen.d.ts
+++ /dev/null
@@ -1,33 +0,0 @@
-import { Slip10RawIndex } from "@cosmjs/crypto";
-import { StdSignature } from "./types";
-export declare type PrehashType = "sha256" | "sha512" | null;
-/**
- * A pen is the most basic tool you can think of for signing. It works
- * everywhere and can be used intuitively by everyone. However, it does not
- * come with a great amount of features. End of semi suitable metaphor.
- *
- * This wraps a single keypair and allows for signing.
- *
- * Non-goals of this types are: multi account support, persistency, data migrations,
- * obfuscation of sensitive data.
- */
-export interface Pen {
-  readonly pubkey: Uint8Array;
-  readonly sign: (signBytes: Uint8Array, prehashType?: PrehashType) => Promise<StdSignature>;
-}
-/**
- * The Cosmoshub derivation path in the form `m/44'/118'/0'/0/a`
- * with 0-based account index `a`.
- */
-export declare function makeCosmoshubPath(a: number): readonly Slip10RawIndex[];
-export declare class Secp256k1Pen implements Pen {
-  static fromMnemonic(mnemonic: string, hdPath?: readonly Slip10RawIndex[]): Promise<Secp256k1Pen>;
-  readonly pubkey: Uint8Array;
-  private readonly privkey;
-  private constructor();
-  /**
-   * Creates and returns a signature
-   */
-  sign(signBytes: Uint8Array, prehashType?: PrehashType): Promise<StdSignature>;
-  address(prefix: string): string;
-}
diff --git a/packages/sdk38/types/signingcosmosclient.d.ts b/packages/sdk38/types/signingcosmosclient.d.ts
index a733b8f6..616b3e25 100644
--- a/packages/sdk38/types/signingcosmosclient.d.ts
+++ b/packages/sdk38/types/signingcosmosclient.d.ts
@@ -1,10 +1,8 @@
 import { Coin } from "./coins";
 import { Account, CosmosClient, GetNonceResult, PostTxResult } from "./cosmosclient";
 import { BroadcastMode } from "./lcdapi";
-import { StdFee, StdSignature } from "./types";
-export interface SigningCallback {
-  (signBytes: Uint8Array): Promise<StdSignature>;
-}
+import { StdFee } from "./types";
+import { OfflineSigner } from "./wallet";
 export interface FeeTable {
   readonly upload: StdFee;
   readonly init: StdFee;
@@ -13,7 +11,7 @@ export interface FeeTable {
 }
 export declare class SigningCosmosClient extends CosmosClient {
   readonly senderAddress: string;
-  private readonly signCallback;
+  private readonly signer;
   private readonly fees;
   /**
    * Creates a new client with signing capability to interact with a CosmWasm blockchain. This is the bigger brother of CosmWasmClient.
@@ -23,14 +21,14 @@ export declare class SigningCosmosClient extends CosmosClient {
    *
    * @param apiUrl The URL of a Cosmos SDK light client daemon API (sometimes called REST server or REST API)
    * @param senderAddress The address that will sign and send transactions using this instance
-   * @param signCallback An asynchonous callback to create a signature for a given transaction. This can be implemented using secure key stores that require user interaction.
+   * @param signer An implementation of OfflineSigner which can provide signatures for transactions, potentially requiring user input.
    * @param customFees The fees that are paid for transactions
    * @param broadcastMode Defines at which point of the transaction processing the postTx method (i.e. transaction broadcasting) returns
    */
   constructor(
     apiUrl: string,
     senderAddress: string,
-    signCallback: SigningCallback,
+    signer: OfflineSigner,
     customFees?: Partial<FeeTable>,
     broadcastMode?: BroadcastMode,
   );
diff --git a/packages/sdk38/types/wallet.d.ts b/packages/sdk38/types/wallet.d.ts
new file mode 100644
index 00000000..463ce554
--- /dev/null
+++ b/packages/sdk38/types/wallet.d.ts
@@ -0,0 +1,39 @@
+import { Slip10RawIndex } from "@cosmjs/crypto";
+import { StdSignature } from "./types";
+export declare type PrehashType = "sha256" | "sha512" | null;
+export declare type Algo = "secp256k1" | "ed25519" | "sr25519";
+export interface AccountData {
+  readonly address: string;
+  readonly algo: Algo;
+  readonly pubkey: Uint8Array;
+}
+export interface OfflineSigner {
+  /**
+   * Get AccountData array from wallet. Rejects if not enabled.
+   */
+  readonly getAccounts: () => Promise<readonly AccountData[]>;
+  /**
+   * Request signature from whichever key corresponds to provided bech32-encoded address. Rejects if not enabled.
+   */
+  readonly sign: (address: string, message: Uint8Array, prehashType?: PrehashType) => Promise<StdSignature>;
+}
+/**
+ * The Cosmoshub derivation path in the form `m/44'/118'/0'/0/a`
+ * with 0-based account index `a`.
+ */
+export declare function makeCosmoshubPath(a: number): readonly Slip10RawIndex[];
+export declare class Secp256k1Wallet implements OfflineSigner {
+  static fromMnemonic(
+    mnemonic: string,
+    hdPath?: readonly Slip10RawIndex[],
+    prefix?: string,
+  ): Promise<Secp256k1Wallet>;
+  private readonly pubkey;
+  private readonly privkey;
+  private readonly prefix;
+  private readonly algo;
+  private constructor();
+  private get address();
+  getAccounts(): Promise<readonly AccountData[]>;
+  sign(address: string, message: Uint8Array, prehashType?: PrehashType): Promise<StdSignature>;
+}
diff --git a/scripts/wasmd/deploy_erc20.js b/scripts/wasmd/deploy_erc20.js
index 140b5b06..6ce0f5c9 100755
--- a/scripts/wasmd/deploy_erc20.js
+++ b/scripts/wasmd/deploy_erc20.js
@@ -2,7 +2,7 @@
 
 /* eslint-disable @typescript-eslint/camelcase */
 const { SigningCosmWasmClient } = require("@cosmjs/cosmwasm");
-const { Secp256k1Pen } = require("@cosmjs/sdk38");
+const { Secp256k1Wallet } = require("@cosmjs/sdk38");
 const fs = require("fs");
 
 const httpUrl = "http://localhost:1317";
@@ -134,8 +134,8 @@ const initDataJade = {
 };
 
 async function main() {
-  const pen = await Secp256k1Pen.fromMnemonic(alice.mnemonic);
-  const client = new SigningCosmWasmClient(httpUrl, alice.address0, (signBytes) => pen.sign(signBytes));
+  const wallet = await Secp256k1Wallet.fromMnemonic(alice.mnemonic);
+  const client = new SigningCosmWasmClient(httpUrl, alice.address0, wallet);
 
   const wasm = fs.readFileSync(__dirname + "/contracts/cw-erc20.wasm");
   const uploadReceipt = await client.upload(wasm, codeMeta, "Upload ERC20 contract");
diff --git a/scripts/wasmd/deploy_nameservice.js b/scripts/wasmd/deploy_nameservice.js
index 3f7ad0d1..1a20340e 100755
--- a/scripts/wasmd/deploy_nameservice.js
+++ b/scripts/wasmd/deploy_nameservice.js
@@ -2,7 +2,7 @@
 
 /* eslint-disable @typescript-eslint/camelcase */
 const { SigningCosmWasmClient } = require("@cosmjs/cosmwasm");
-const { Secp256k1Pen } = require("@cosmjs/sdk38");
+const { Secp256k1Wallet } = require("@cosmjs/sdk38");
 const fs = require("fs");
 
 const httpUrl = "http://localhost:1317";
@@ -36,8 +36,8 @@ const luxury = {
 };
 
 async function main() {
-  const pen = await Secp256k1Pen.fromMnemonic(alice.mnemonic);
-  const client = new SigningCosmWasmClient(httpUrl, alice.address0, (signBytes) => pen.sign(signBytes));
+  const wallet = await Secp256k1Wallet.fromMnemonic(alice.mnemonic);
+  const client = new SigningCosmWasmClient(httpUrl, alice.address0, wallet);
 
   const wasm = fs.readFileSync(__dirname + "/contracts/cw-nameservice.wasm");
   const uploadReceipt = await client.upload(wasm, codeMeta, "Upload Name Service code");
diff --git a/scripts/wasmd/deploy_staking.js b/scripts/wasmd/deploy_staking.js
index 43ae93e5..ce9b32bb 100755
--- a/scripts/wasmd/deploy_staking.js
+++ b/scripts/wasmd/deploy_staking.js
@@ -2,7 +2,7 @@
 
 /* eslint-disable @typescript-eslint/camelcase */
 const { SigningCosmWasmClient } = require("@cosmjs/cosmwasm");
-const { coins, Secp256k1Pen } = require("@cosmjs/sdk38");
+const { coins, Secp256k1Wallet } = require("@cosmjs/sdk38");
 const fs = require("fs");
 
 const httpUrl = "http://localhost:1317";
@@ -38,8 +38,8 @@ const fees = {
 };
 
 async function main() {
-  const pen = await Secp256k1Pen.fromMnemonic(alice.mnemonic);
-  const client = new SigningCosmWasmClient(httpUrl, alice.address0, (signBytes) => pen.sign(signBytes), fees);
+  const wallet = await Secp256k1Wallet.fromMnemonic(alice.mnemonic);
+  const client = new SigningCosmWasmClient(httpUrl, alice.address0, wallet, fees);
 
   const wasm = fs.readFileSync(__dirname + "/contracts/staking.wasm");
   const uploadReceipt = await client.upload(wasm, codeMeta, "Upload Staking code");