fix: format erc20 balance

typescript/agentkit/CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## Unreleased
 
+### Fixed
+
+- Fixed erc20 `get_balance` action to format erc20 balance with correct number of decimals.
+
 ## [0.2.2] - 2025-02-19
 
 ### Added

typescript/agentkit/src/action-providers/erc20/README.md

@@ -1 +1,39 @@
-# ERC20 Action Provider
+# ERC20 Action Provider
+
+This directory contains the **ERC20ActionProvider** implementation, which provides actions to interact with **ERC20 tokens** on EVM-compatible networks.
+
+## Directory Structure
+
+```
+erc20/
+├── erc20ActionProvider.ts         # Main provider with ERC20 token functionality
+├── erc20ActionProvider.test.ts    # Test file for ERC20 provider
+├── constants.ts                   # Constants for ERC20 provider
+├── schemas.ts                     # Token action schemas
+├── index.ts                       # Main exports
+└── README.md                      # This file
+```
+
+## Actions
+
+### ERC20 Token Actions
+
+- `get_balance`: Get the balance of an ERC20 token
+  - Returns the **balance** of the token in the wallet
+  - Formats the balance with the correct number of decimals
+
+- `transfer`: Transfer ERC20 tokens to another address
+  - Constructs and sends the transfer transaction
+  - Returns the **transaction hash** upon success
+
+## Adding New Actions
+
+To add new ERC20 actions:
+
+1. Define your action schema in `schemas.ts`. See [Defining the input schema](https://github.com/coinbase/agentkit/blob/main/CONTRIBUTING-TYPESCRIPT.md#defining-the-input-schema) for more information.
+2. Implement the action in `erc20ActionProvider.ts`
+3. Implement tests in `erc20ActionProvider.test.ts`
+
+## Notes
+
+For more information on the **ERC20 token standard**, visit [ERC20 Token Standard](https://ethereum.org/en/developers/docs/standards/tokens/erc-20/).

typescript/agentkit/src/action-providers/erc20/erc20ActionProvider.test.ts

@@ -5,6 +5,7 @@ import { encodeFunctionData, Hex } from "viem";
 import { abi } from "./constants";
 
 const MOCK_AMOUNT = 15;
+const MOCK_DECIMALS = 6;
 const MOCK_CONTRACT_ADDRESS = "0x1234567890123456789012345678901234567890";
 const MOCK_DESTINATION = "0x9876543210987654321098765432109876543210";
 const MOCK_ADDRESS = "0x1234567890123456789012345678901234567890";
@@ -40,11 +41,12 @@ describe("Get Balance Action", () => {
       getAddress: jest.fn().mockReturnValue(MOCK_ADDRESS),
       readContract: jest.fn(),
     } as unknown as jest.Mocked<EvmWalletProvider>;
-
-    mockWallet.readContract.mockResolvedValue(MOCK_AMOUNT);
   });
 
   it("should successfully respond", async () => {
+    mockWallet.readContract.mockResolvedValueOnce(MOCK_AMOUNT);
+    mockWallet.readContract.mockResolvedValueOnce(MOCK_DECIMALS);
+
     const args = {
       contractAddress: MOCK_CONTRACT_ADDRESS,
     };
@@ -57,7 +59,9 @@ describe("Get Balance Action", () => {
       functionName: "balanceOf",
       args: [mockWallet.getAddress()],
     });
-    expect(response).toContain(`Balance of ${MOCK_CONTRACT_ADDRESS} is ${MOCK_AMOUNT}`);
+    expect(response).toContain(
+      `Balance of ${MOCK_CONTRACT_ADDRESS} is ${MOCK_AMOUNT / 10 ** MOCK_DECIMALS}`,
+    );
   });
 
   it("should fail with an error", async () => {

typescript/agentkit/src/action-providers/erc20/erc20ActionProvider.ts

@@ -4,7 +4,7 @@ import { Network } from "../../network";
 import { CreateAction } from "../actionDecorator";
 import { GetBalanceSchema, TransferSchema } from "./schemas";
 import { abi } from "./constants";
-import { encodeFunctionData, Hex } from "viem";
+import { encodeFunctionData, formatUnits, Hex } from "viem";
 import { EvmWalletProvider } from "../../wallet-providers";
 
 /**
@@ -41,10 +41,17 @@ export class ERC20ActionProvider extends ActionProvider<EvmWalletProvider> {
         address: args.contractAddress as Hex,
         abi,
         functionName: "balanceOf",
-        args: [walletProvider.getAddress()],
+        args: [walletProvider.getAddress() as Hex],
       });
 
-      return `Balance of ${args.contractAddress} is ${balance}`;
+      const decimals = await walletProvider.readContract({
+        address: args.contractAddress as Hex,
+        abi,
+        functionName: "decimals",
+        args: [],
+      });
+
+      return `Balance of ${args.contractAddress} is ${formatUnits(balance, decimals)}`;
     } catch (error) {
       return `Error getting balance: ${error}`;
     }

typescript/agentkit/src/action-providers/erc721/erc721ActionProvider.ts

@@ -132,7 +132,7 @@ It takes the following inputs:
         address: args.contractAddress as Hex,
         abi: ERC721_ABI,
         functionName: "balanceOf",
-        args: [address],
+        args: [address as Hex],
       });
 
       return `Balance of NFTs for contract ${args.contractAddress} at address ${address} is ${balance}`;

typescript/agentkit/src/wallet-providers/cdpWalletProvider.ts

@@ -11,6 +11,9 @@ import {
   keccak256,
   Signature,
   PublicClient,
+  Abi,
+  ContractFunctionName,
+  ContractFunctionArgs,
 } from "viem";
 import { EvmWalletProvider } from "./evmWalletProvider";
 import { Network } from "../network";
@@ -425,8 +428,14 @@ export class CdpWalletProvider extends EvmWalletProvider {
    * @param params - The parameters to read the contract.
    * @returns The response from the contract.
    */
-  async readContract(params: ReadContractParameters): Promise<ReadContractReturnType> {
-    return this.#publicClient!.readContract(params);
+  async readContract<
+    const abi extends Abi | readonly unknown[],
+    functionName extends ContractFunctionName<abi, "pure" | "view">,
+    const args extends ContractFunctionArgs<abi, "pure" | "view", functionName>,
+  >(
+    params: ReadContractParameters<abi, functionName, args>,
+  ): Promise<ReadContractReturnType<abi, functionName, args>> {
+    return this.#publicClient!.readContract<abi, functionName, args>(params);
   }
 
   /**

typescript/agentkit/src/wallet-providers/evmWalletProvider.ts

@@ -2,7 +2,14 @@
 /* eslint-disable @typescript-eslint/no-explicit-any */
 
 import { WalletProvider } from "./walletProvider";
-import { TransactionRequest, ReadContractParameters, ReadContractReturnType } from "viem";
+import {
+  TransactionRequest,
+  ReadContractParameters,
+  ReadContractReturnType,
+  ContractFunctionName,
+  Abi,
+  ContractFunctionArgs,
+} from "viem";
 
 /**
  * EvmWalletProvider is the abstract base class for all EVM wallet providers.
@@ -56,5 +63,11 @@ export abstract class EvmWalletProvider extends WalletProvider {
    * @param params - The parameters to read the contract.
    * @returns The response from the contract.
    */
-  abstract readContract(params: ReadContractParameters): Promise<ReadContractReturnType>;
+  abstract readContract<
+    const abi extends Abi | readonly unknown[],
+    functionName extends ContractFunctionName<abi, "pure" | "view">,
+    const args extends ContractFunctionArgs<abi, "pure" | "view", functionName>,
+  >(
+    params: ReadContractParameters<abi, functionName, args>,
+  ): Promise<ReadContractReturnType<abi, functionName, args>>;
 }

typescript/agentkit/src/wallet-providers/viemWalletProvider.ts

@@ -10,6 +10,9 @@ import {
   ReadContractParameters,
   ReadContractReturnType,
   parseEther,
+  Abi,
+  ContractFunctionName,
+  ContractFunctionArgs,
 } from "viem";
 import { EvmWalletProvider } from "./evmWalletProvider";
 import { Network } from "../network";
@@ -214,8 +217,14 @@ export class ViemWalletProvider extends EvmWalletProvider {
    * @param params - The parameters to read the contract.
    * @returns The response from the contract.
    */
-  async readContract(params: ReadContractParameters): Promise<ReadContractReturnType> {
-    return this.#publicClient.readContract(params);
+  async readContract<
+    const abi extends Abi | readonly unknown[],
+    functionName extends ContractFunctionName<abi, "pure" | "view">,
+    const args extends ContractFunctionArgs<abi, "pure" | "view", functionName>,
+  >(
+    params: ReadContractParameters<abi, functionName, args>,
+  ): Promise<ReadContractReturnType<abi, functionName, args>> {
+    return this.#publicClient.readContract<abi, functionName, args>(params);
   }
 
   /**