> ## Documentation Index
> Fetch the complete documentation index at: https://cosmos-docs-cosmjs-docs.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Gas and Advanced Usage

> Gas estimation, custom messages, binary helpers, and the wasm query extension

This page covers gas configuration for CosmWasm transactions, building custom encode objects, working with the CosmWasm `Binary` type, and using the low-level wasm query extension for fine-grained pagination.

## Gas Estimation

### Auto Gas

When you pass `"auto"` as the fee, the client simulates the transaction and applies a gas multiplier:

| Operation  | Default Multiplier | Reason                                  |
| ---------- | ------------------ | --------------------------------------- |
| `upload`   | 1.1x               | Upload simulation is very accurate      |
| All others | 1.4x               | General safety margin for state changes |

You can pass a numeric multiplier instead of `"auto"` for finer control:

```typescript theme={"system"}
const result = await client.execute(
  address,
  contractAddress,
  { complex_operation: {} },
  1.6,
);
```

### Static Fees

For full control, provide an explicit fee object:

```typescript theme={"system"}
import { coins } from "@cosmjs/stargate";

const fee = {
  amount: coins(5000, "uosmo"),
  gas: "300000",
};

const result = await client.execute(address, contractAddress, { increment: {} }, fee);
```

### Gas Simulation

Simulate a transaction to estimate gas without broadcasting:

```typescript theme={"system"}
import { toUtf8 } from "@cosmjs/encoding";
import { MsgExecuteContract } from "cosmjs-types/cosmwasm/wasm/v1/tx";

const msg = {
  typeUrl: "/cosmwasm.wasm.v1.MsgExecuteContract",
  value: MsgExecuteContract.fromPartial({
    sender: address,
    contract: contractAddress,
    msg: toUtf8(JSON.stringify({ increment: {} })),
    funds: [],
  }),
};

const gasEstimate = await client.simulate(address, [msg], "estimating gas");
```

## Working with Binary Data

The `toBinary` and `fromBinary` helpers convert JavaScript objects to and from the base64-encoded JSON format used by CosmWasm `Binary` fields:

```typescript theme={"system"}
import { toBinary, fromBinary } from "@cosmjs/cosmwasm";

const encoded = toBinary({ some: "data" });
// "eyJzb21lIjoiZGF0YSJ9"

const decoded = fromBinary(encoded);
// { some: "data" }
```

This is useful when composing nested messages, such as sending a sub-message through a contract:

```typescript theme={"system"}
await client.execute(
  address,
  multisigAddress,
  {
    propose: {
      msg: toBinary({ transfer: { recipient: "osmo1...", amount: "1000000" } }),
    },
  },
  "auto",
);
```

## Building Custom Messages

For advanced use cases, construct CosmWasm encode objects directly and broadcast them via `signAndBroadcast`:

```typescript theme={"system"}
import { toUtf8 } from "@cosmjs/encoding";
import { MsgExecuteContract } from "cosmjs-types/cosmwasm/wasm/v1/tx";

const msg = {
  typeUrl: "/cosmwasm.wasm.v1.MsgExecuteContract",
  value: MsgExecuteContract.fromPartial({
    sender: address,
    contract: contractAddress,
    msg: toUtf8(JSON.stringify({ increment: {} })),
    funds: [{ denom: "uosmo", amount: "1000" }],
  }),
};

const result = await client.signAndBroadcast(address, [msg], "auto");
```

### Mixing CosmWasm and Cosmos SDK Messages

This approach lets you combine contract calls with standard Cosmos SDK messages in a single atomic transaction:

```typescript theme={"system"}
import { toUtf8 } from "@cosmjs/encoding";
import { MsgExecuteContract } from "cosmjs-types/cosmwasm/wasm/v1/tx";

const executeMsg = {
  typeUrl: "/cosmwasm.wasm.v1.MsgExecuteContract",
  value: MsgExecuteContract.fromPartial({
    sender: address,
    contract: contractAddress,
    msg: toUtf8(JSON.stringify({ claim_rewards: {} })),
    funds: [],
  }),
};

const sendMsg = {
  typeUrl: "/cosmos.bank.v1beta1.MsgSend",
  value: {
    fromAddress: address,
    toAddress: "osmo1recipient...",
    amount: [{ denom: "uosmo", amount: "500000" }],
  },
};

const result = await client.signAndBroadcast(address, [executeMsg, sendMsg], "auto");
```

## Wasm Query Extension

For fine-grained control over pagination or when building a custom query client, use the wasm extension directly instead of the high-level `CosmWasmClient` methods:

```typescript theme={"system"}
import { QueryClient } from "@cosmjs/stargate";
import { setupWasmExtension } from "@cosmjs/cosmwasm";
import { connectComet } from "@cosmjs/tendermint-rpc";

const cometClient = await connectComet("https://rpc.my-chain.network");
const queryClient = QueryClient.withExtensions(cometClient, setupWasmExtension);

const { codeInfos, pagination } = await queryClient.wasm.listCodeInfo();
const allState = await queryClient.wasm.getAllContractState("osmo1contractaddr...");
```

### Available Extension Methods

| Method                                            | Description                           |
| ------------------------------------------------- | ------------------------------------- |
| `listCodeInfo(paginationKey?)`                    | List all uploaded codes               |
| `getCode(id)`                                     | Download original Wasm by code ID     |
| `listContractsByCodeId(id, paginationKey?)`       | List contract addresses for a code ID |
| `listContractsByCreator(creator, paginationKey?)` | List contracts created by an address  |
| `getContractInfo(address)`                        | Get contract metadata                 |
| `getContractCodeHistory(address, paginationKey?)` | Get migration history                 |
| `getAllContractState(address, paginationKey?)`    | Dump all contract storage             |
| `queryContractRaw(address, key)`                  | Read a single storage key             |
| `queryContractSmart(address, query)`              | Execute a smart query                 |

## Next Steps

<CardGroup cols={2}>
  <Card title="CosmWasm Overview" icon="book" href="/cosmjs/v0.38.x/guides/cosmwasm/cosmwasm">
    Back to the CosmWasm guide overview.
  </Card>

  <Card title="Stargate vs CosmWasm" icon="code-compare" href="/cosmjs/v0.38.x/concepts/clients/stargate-vs-cosmwasm">
    Comparing the two client families and when to use each.
  </Card>
</CardGroup>