Feature/mcp wallet server with bnb agent

README.md

@@ -41,6 +41,7 @@ language, description, and tags to help you find what you need quickly.
 | [typescript/bnbchain-mcp](./typescript/bnbchain-mcp)   | TypeScript | AI-powered blockchain assistant using Claude | AI, BSC, MCP        |
 | [typescript/eliza-chatbot](./typescript/eliza-chatbot) | TypeScript | A chatbot example using Eliza plugin-bnb     | AI, BSC, opBNB      |
 | [typescript/ai-trading-assistant](./typescript/ai-trading-assistant) | Typescript | AI-powered trading assistant for BNB Chain ecosystem with real USDT→BNB swaps via PancakeSwap, technical analysis, and natural language interface | BNBChain, trading, analysis, PancakeSwap, AI, MCP |
+| [go/mcp-bnb-wallet-agent](./go/mcp-bnb-wallet-agent) | Go | This is an example that contains two mcp server, bnb agent and wallet, and a mcp client that has langchain from open ai | BSC, opBNB, AI, Wallet |
 More examples are coming soon—stay tuned for updates!
 
 ## How to Add a New Example

go/mcp-bnb-wallet-agent/.env.example

@@ -0,0 +1,13 @@
+# MongoDB Connection String
+# Default: mongodb://localhost:27017
+MONGO_URI=mongodb://localhost:27017
+
+# BNB Chain RPC Endpoint
+# For BSC Testnet (recommended for testing):
+BNB_RPC=https://data-seed-prebsc-1-s1.binance.org:8545
+
+# For BSC Mainnet (production):
+# BNB_RPC=https://bsc-dataseed.binance.org/
+
+# MCP Server Port (optional, defaults to 8085)
+PORT=8085

go/mcp-bnb-wallet-agent/.gitignore

@@ -0,0 +1,39 @@
+# Binaries for programs and plugins
+*.exe
+*.exe~
+*.dll
+*.so
+*.dylib
+
+# Test binary, built with `go test -c`
+*.test
+
+# Output of the go coverage tool
+*.out
+
+# Go workspace file
+go.work
+go.work.sum
+
+# Dependency directories
+vendor/
+
+# Environment files
+.env
+.env.local
+
+# IDE specific files
+.idea/
+.vscode/
+*.swp
+*.swo
+*~
+
+# OS specific files
+.DS_Store
+Thumbs.db
+
+# Build artifacts
+bin/
+dist/
+

go/mcp-bnb-wallet-agent/README.md

@@ -0,0 +1,240 @@
+# BNB Chain Wallet MCP Server
+
+A Model Context Protocol (MCP) server implementation for managing BNB Chain wallets. This example demonstrates how to build an MCP server that provides wallet creation, transaction signing, and balance checking capabilities for BNB Smart Chain.
+
+## Overview
+
+This project provides:
+- **MCP Server**: Exposes wallet operations as MCP tools that can be used by AI agents
+- **MongoDB Integration**: Stores user wallets securely with their private keys
+- **BNB Chain Support**: Works with both BSC Mainnet (chain ID 56) and BSC Testnet (chain ID 97)
+- **Example Client**: Shows how to interact with the MCP server programmatically
+
+## Features
+
+### Available MCP Tools
+
+1. **create_wallet** - Generate a new Ethereum-compatible wallet for a user
+2. **read_wallet** - Retrieve a user's public wallet address
+3. **get_wallet_balance** - Check the BNB balance of a wallet
+4. **transfer_asset** - Send native BNB to another address
+5. **sign_transaction** - Sign and broadcast custom transactions
+
+## Prerequisites
+
+- Go 1.23 or higher
+- MongoDB (local or remote instance)
+- BNB Chain RPC endpoint (testnet or mainnet)
+
+## Installation
+
+1. Clone the repository:
+```bash
+git clone <repository-url>
+cd go/mcp-bnb-wallet-agent
+```
+
+2. Install dependencies:
+```bash
+go mod download
+```
+
+3. Set up environment variables:
+```bash
+# MongoDB connection string
+export MONGO_URI="mongodb://localhost:27017"
+
+# BNB Chain RPC endpoint
+export BNB_RPC="https://data-seed-prebsc-1-s1.binance.org:8545"  # Testnet
+# Or for mainnet: https://bsc-dataseed.binance.org/
+
+# Optional: Custom server port (defaults to 8085)
+export PORT="8085"
+```
+
+## Running the Project
+
+### Start the MCP Server
+
+```bash
+cd wallet-mcp
+go run main.go
+```
+
+The server will start on `http://localhost:8085/mcp`
+
+You should see output like:
+```
+Connected to MongoDB successfully
+Registered MCP tool: create_wallet
+Registered MCP tool: read_wallet
+Registered MCP tool: sign_transaction
+Registered MCP tool: transfer_asset
+Registered MCP tool: get_wallet_balance
+Starting MCP server on port 8085...
+```
+
+### Run the Example Client
+
+In a separate terminal:
+
+```bash
+go run example_client.go
+```
+
+This demonstrates how to:
+- Create a wallet for a user
+- Retrieve the wallet address
+- Check wallet balance
+- Transfer BNB to another address
+- Sign custom transactions
+
+## Usage
+
+### Creating a Wallet
+
+```go
+client := NewMCPClient("http://localhost:8085/mcp")
+
+walletAddress, err := client.CallTool("create_wallet", map[string]interface{}{
+    "user_id": "user_12345",
+})
+if err != nil {
+    log.Fatal(err)
+}
+```
+
+### Checking Balance
+
+```go
+balance, err := client.CallTool("get_wallet_balance", map[string]interface{}{
+    "user_id": "user_12345",
+})
+if err != nil {
+    log.Fatal(err)
+}
+```
+
+### Transferring BNB
+
+```go
+txHash, err := client.CallTool("transfer_asset", map[string]interface{}{
+    "user_id":    "user_12345",
+    "chain_id":   "97",  // BSC Testnet
+    "to_address": "0x5A2D55362b3ce1Bb5434c16a2aBd923c429a3446",
+    "amount":     "100000000000000",  // 0.0001 BNB in wei
+})
+if err != nil {
+    log.Fatal(err)
+}
+```
+
+## Project Structure
+
+```
+mcp-bnb-wallet-agent/
+├── wallet-mcp/
+│   ├── main.go                    # MCP server entry point
+│   ├── db/
+│   │   └── mongodb.go             # MongoDB connection utilities
+│   ├── types/
+│   │   └── types.go               # Type definitions
+│   └── functions/
+│       ├── structs.go             # Data structures
+│       ├── create.go              # Wallet creation
+│       ├── read.go                # Wallet reading
+│       ├── sign.go                # Transaction signing
+│       ├── transferAsset.go       # BNB transfers
+│       ├── walletBalance.go       # Balance checking
+│       ├── mcpToolGenerator.go    # MCP tool registration
+│       └── tests/                 # Unit tests
+├── example_client.go              # Example usage
+├── go.mod                         # Go module definition
+└── README.md                      # This file
+```
+
+## Testing
+
+Run the test suite:
+
+```bash
+cd wallet-mcp/functions
+go test ./tests/... -v
+```
+
+**Note**: Tests require:
+- MongoDB running on `localhost:27017`
+- `BNB_RPC` environment variable set
+- Sufficient testnet BNB in test wallets for transaction tests
+
+## Security Considerations
+
+⚠️ **Important**: This is an example project for educational purposes.
+
+- Private keys are stored unencrypted in MongoDB
+- In production, you should:
+  - Encrypt private keys before storage
+  - Use hardware security modules (HSM) or secure enclaves
+  - Implement proper access controls
+  - Add rate limiting
+  - Use secure key management solutions
+
+## Chain IDs
+
+- **BSC Mainnet**: 56
+- **BSC Testnet**: 97
+
+## API Reference
+
+### MCP Tools
+
+#### create_wallet
+- **Description**: Create a new BNB Chain wallet for a user
+- **Parameters**:
+  - `user_id` (string, required): Unique identifier for the user
+- **Returns**: Public wallet address
+
+#### read_wallet
+- **Description**: Retrieve a user's public wallet address
+- **Parameters**:
+  - `user_id` (string, required): Unique identifier for the user
+- **Returns**: Public wallet address
+
+#### get_wallet_balance
+- **Description**: Get the native BNB balance of a user's wallet
+- **Parameters**:
+  - `user_id` (string, required): Unique identifier for the user
+- **Returns**: Balance in wei (string)
+
+#### transfer_asset
+- **Description**: Transfer native BNB to another address
+- **Parameters**:
+  - `user_id` (string, required): Unique identifier for the user
+  - `chain_id` (string, required): Chain ID (e.g., "56" for mainnet, "97" for testnet)
+  - `to_address` (string, required): Recipient wallet address
+  - `amount` (string, required): Amount to send in wei
+- **Returns**: Transaction hash
+
+#### sign_transaction
+- **Description**: Sign and broadcast a transaction to BNB Chain
+- **Parameters**:
+  - `user_id` (string, required): Unique identifier for the user
+  - `chain_id` (string, required): Chain ID
+  - `to_address` (string, required): Destination address
+  - `data` (string, optional): Hex-encoded transaction data
+  - `value` (string, optional): Amount of BNB to send in wei
+- **Returns**: Transaction hash
+
+## Contributing
+
+Contributions are welcome! Please feel free to submit a Pull Request.
+
+## License
+
+This project is part of the BNB Chain examples repository.
+
+## Resources
+
+- [BNB Chain Documentation](https://docs.bnbchain.org/)
+- [MCP Protocol Specification](https://modelcontextprotocol.io/)
+- [Go Ethereum Documentation](https://geth.ethereum.org/docs)

go/mcp-bnb-wallet-agent/go.mod

@@ -0,0 +1,56 @@
+module mcp-bnb-wallet-agent
+
+go 1.23.0
+
+toolchain go1.24.4
+
+require (
+	github.com/ethereum/go-ethereum v1.16.2
+	github.com/mark3labs/mcp-go v0.37.0
+	github.com/stretchr/testify v1.10.0
+	go.mongodb.org/mongo-driver/v2 v2.3.0
+)
+
+require (
+	github.com/Microsoft/go-winio v0.6.2 // indirect
+	github.com/StackExchange/wmi v1.2.1 // indirect
+	github.com/bahlo/generic-list-go v0.2.0 // indirect
+	github.com/bits-and-blooms/bitset v1.20.0 // indirect
+	github.com/buger/jsonparser v1.1.1 // indirect
+	github.com/consensys/gnark-crypto v0.18.0 // indirect
+	github.com/crate-crypto/go-eth-kzg v1.3.0 // indirect
+	github.com/crate-crypto/go-ipa v0.0.0-20240724233137-53bbb0ceb27a // indirect
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/deckarep/golang-set/v2 v2.6.0 // indirect
+	github.com/decred/dcrd/dcrec/secp256k1/v4 v4.0.1 // indirect
+	github.com/ethereum/c-kzg-4844/v2 v2.1.0 // indirect
+	github.com/ethereum/go-verkle v0.2.2 // indirect
+	github.com/go-ole/go-ole v1.3.0 // indirect
+	github.com/golang/snappy v1.0.0 // indirect
+	github.com/google/uuid v1.6.0 // indirect
+	github.com/gorilla/websocket v1.4.2 // indirect
+	github.com/holiman/uint256 v1.3.2 // indirect
+	github.com/invopop/jsonschema v0.13.0 // indirect
+	github.com/klauspost/compress v1.17.6 // indirect
+	github.com/klauspost/cpuid/v2 v2.2.7 // indirect
+	github.com/mailru/easyjson v0.7.7 // indirect
+	github.com/mitchellh/mapstructure v1.5.0 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/shirou/gopsutil v3.21.4-0.20210419000835-c7a38de76ee5+incompatible // indirect
+	github.com/spf13/cast v1.7.1 // indirect
+	github.com/supranational/blst v0.3.14 // indirect
+	github.com/tklauser/go-sysconf v0.3.12 // indirect
+	github.com/tklauser/numcpus v0.6.1 // indirect
+	github.com/wk8/go-ordered-map/v2 v2.1.8 // indirect
+	github.com/xdg-go/pbkdf2 v1.0.0 // indirect
+	github.com/xdg-go/scram v1.1.2 // indirect
+	github.com/xdg-go/stringprep v1.0.4 // indirect
+	github.com/yosida95/uritemplate/v3 v3.0.2 // indirect
+	github.com/youmark/pkcs8 v0.0.0-20240726163527-a2c0da244d78 // indirect
+	golang.org/x/crypto v0.36.0 // indirect
+	golang.org/x/exp v0.0.0-20230713183714-613f0c0eb8a1 // indirect
+	golang.org/x/sync v0.12.0 // indirect
+	golang.org/x/sys v0.31.0 // indirect
+	golang.org/x/text v0.23.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)