Signing & Broadcasting

A Cosmos transaction goes through several steps before it reaches the chain:

Build messages — describe what the transaction should do
Determine fees — calculate how much gas to pay
Sign — produce a cryptographic signature over the transaction bytes
Broadcast — send the signed transaction to a node
Confirm — wait for the transaction to be included in a block

CosmJS handles all of this through SigningStargateClient. You provide the messages and fee; the client handles serialization, signing, and broadcasting.

import { SigningStargateClient, GasPrice } from "@cosmjs/stargate";
import { DirectSecp256k1HdWallet } from "@cosmjs/proto-signing";

const wallet = await DirectSecp256k1HdWallet.fromMnemonic("your mnemonic ...", {
  prefix: "cosmos",
});
const [{ address }] = await wallet.getAccounts();

const client = await SigningStargateClient.connectWithSigner(
  "https://rpc.my-chain.network",
  wallet,
  { gasPrice: GasPrice.fromString("0.025uatom") },
);

signAndBroadcast

The most common method. Signs the transaction, broadcasts it, and waits for inclusion in a block:

const result = await client.signAndBroadcast(
  signerAddress,
  messages,
  fee,
  "optional memo",
);

// result.transactionHash — the tx hash
// result.code — 0 means success, non-zero means failure
// result.gasUsed — actual gas consumed
// result.gasWanted — gas limit from the fee
// result.events — transaction events

signAndBroadcastSync

Signs and broadcasts but returns immediately with just the transaction hash, without waiting for block inclusion. Useful when you don’t need to wait:

const txHash = await client.signAndBroadcastSync(
  signerAddress,
  messages,
  fee,
  "optional memo",
);

sign

Signs without broadcasting. Returns a TxRaw protobuf object — call TxRaw.encode(txRaw).finish() to serialize it into bytes that you can broadcast later or inspect:

import { TxRaw } from "cosmjs-types/cosmos/tx/v1beta1/tx";

const txRaw = await client.sign(
  signerAddress,
  messages,
  fee,
  "optional memo",
);

const txBytes = TxRaw.encode(txRaw).finish();
const result = await client.broadcastTx(txBytes);

Convenience Methods

SigningStargateClient provides high-level methods for the most common transactions. These construct the message internally and call signAndBroadcast:

Method	Description
`sendTokens(sender, recipient, amount, fee, memo?)`	Transfer tokens
`delegateTokens(delegator, validator, amount, fee, memo?)`	Delegate to a validator
`undelegateTokens(delegator, validator, amount, fee, memo?)`	Undelegate from a validator
`withdrawRewards(delegator, validator, fee, memo?)`	Withdraw staking rewards

const result = await client.sendTokens(
  senderAddress,
  recipientAddress,
  [{ denom: "uatom", amount: "1000000" }],
  "auto",
  "optional memo",
);

CosmJS

Concepts

Guides

API Reference

Signing & Broadcasting

signAndBroadcast

signAndBroadcastSync

sign

Convenience Methods

Next Steps

Building Messages

Error Handling

​signAndBroadcast

​signAndBroadcastSync

​sign

​Convenience Methods

​Next Steps

Building Messages

Error Handling

signAndBroadcast

signAndBroadcastSync

sign

Convenience Methods

Next Steps