Custom Query Extensions

Write your own query extensions for custom chain modules and integrate them with QueryClient

If your chain has custom modules, you can write your own query extensions that integrate seamlessly with QueryClient. This works with or without protobuf definitions.

From Protobuf Definitions

If you have generated TypeScript types from your .proto files (using ts-proto or similar), wire them up with createProtobufRpcClient:

import { createProtobufRpcClient, QueryClient } from "@cosmjs/stargate";
import { QueryClientImpl } from "./generated/mymodule/query";

export interface MyModuleExtension {
  readonly mymodule: {
    readonly myQuery: (param: string) => Promise<MyQueryResponse>;
  };
}

export function setupMyModuleExtension(base: QueryClient): MyModuleExtension {
  const rpc = createProtobufRpcClient(base);
  const queryService = new QueryClientImpl(rpc);

  return {
    mymodule: {
      myQuery: async (param: string) => {
        return queryService.MyQuery({ param });
      },
    },
  };
}

Using the Extension

Compose your custom extension alongside built-in ones:

import { QueryClient, setupBankExtension } from "@cosmjs/stargate";
import { connectComet } from "@cosmjs/tendermint-rpc";

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

const result = await queryClient.mymodule.myQuery("cosmos1senderaddress...");

Without Protobuf Definitions

You can also query any ABCI path directly using the raw query interface:

import { connectComet } from "@cosmjs/tendermint-rpc";
import { QueryClient } from "@cosmjs/stargate";

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

const response = await queryClient.queryAbci(
  "/my.custom.module.Query/MyMethod",
  encodedRequest,
);

Next Steps

Querying Overview

All built-in query extensions.

CosmWasm Queries

Smart contract queries using the wasm extension.