BSC PancakeSwap Trading Skill

Purpose & Scope

This skill enables an AI agent to trade tokens on PancakeSwap (BSC mainnet). It covers:

• Wallet creation — Generate a BSC keypair and store it locally for transaction signing.
• Token discovery — Resolve any BEP-20 token by contract address, check pair existence and liquidity.
• Swaps — Execute token swaps through PancakeSwap V2 Router with slippage protection.
• Balance checks — Query native BNB and BEP-20 token balances.
• Top-ups — Provide the agent's BSC address so the user can fund it.

What This Skill Does NOT Do

• It does not manage ClawChain agent registration. For that, see the clawchain skill (skill.md or curl_skills.md).
• It does not provide investment advice or execute trades without user confirmation.
• It does not access any files outside of ~/.config/bsc_agent/ and optionally ~/.config/clawchain/credentials.json (read-only, for EVM key registration only).

Transparency: Files Accessed

File	Access	Purpose
~/.config/bsc_agent/wallet.json	Read/Write (created once)	Stores the agent's BSC private key and address for signing transactions
~/.config/clawchain/credentials.json	Read-only (optional)	Used only if registering BSC public key on ClawChain for EVM event tracking

Transparency: Network Calls

Endpoint	Purpose
BSC RPC (BSC_RPC_URL)	Read blockchain state (balances, pair info) and submit signed transactions
PancakeSwap Router contract	On-chain calls to discover pairs, get quotes, execute swaps

---

Configuration (BSC Mainnet)

Set these environment variables before using the skill. All have sensible defaults for BSC mainnet:

export BSC_RPC_URL="https://bsc-dataseed1.binance.org"
export BSC_CHAIN_ID=56

# PancakeSwap V2 (BSC mainnet)
export PANCAKE_ROUTER="0x10ED43C718714eb63d5aA57B78B54704E256024E"
export WBNB="0xbb4CdB9CBd36B01bD1cBaEBF2De08d9173bc095c"

Block explorer: https://bscscan.com

PancakeSwap UI: https://pancakeswap.finance/swap?chain=bsc

Optional: Switch to Testnet

For testnet (tBNB, tCHR, etc.), override the defaults:

export BSC_RPC_URL="https://data-seed-prebsc-1-s1.binance.org:8545"
export BSC_CHAIN_ID=97
export PANCAKE_ROUTER="0xD99D1c33F9fC3444f8101754aBC46c52416550D1"
export WBNB="0xae13d989dac2f0debff460ac112a837c89baa7cd"

Prerequisites

This skill requires Node.js 18+ and the ethers npm package (v6):

npm install ethers
# or: pnpm add ethers

---

1. Wallet Setup — Create Wallet and Save Keys

The agent needs a local wallet file containing a private key and public address so it can sign transactions. This file is created once during initial setup and reused for all subsequent operations.

⚠️ Security: The wallet file contains sensitive key material. See the Security Notes section for encryption and file permission best practices. Only use a dedicated, small-balance wallet — never your main funds.

Option A: Using Node.js (recommended)

Run this script to generate a new wallet and write it to a file:

node -e "
const fs = require('fs');
const path = require('path');
const { ethers } = require('ethers');
const wallet = ethers.Wallet.createRandom();
const dir = process.env.HOME + '/.config/bsc_agent';
fs.mkdirSync(dir, { recursive: true });
const file = dir + '/wallet.json';
fs.writeFileSync(file, JSON.stringify({
  privateKey: wallet.privateKey,
  address: wallet.address,
  publicKey: wallet.publicKey
}, null, 2), { mode: 0o600 });
console.log('Wallet saved to ' + file);
console.log('Address: ' + wallet.address);
"

Default file location: ~/.config/bsc_agent/wallet.json

File format (wallet.json):

{
  "privateKey": "0x...",
  "address": "0x...",
  "publicKey": "0x..."
}

• privateKey — Used to sign transactions. This file is restricted to owner-only access (chmod 600). Never log or expose this value.
• address — The agent's BSC account. The user sends BNB/tokens to this address to fund the agent.
• publicKey — Derived from private key. Used optionally for ClawChain EVM event tracking registration.

Option B: Custom path

To use a different path, set the environment variable:

export BSC_WALLET_FILE="$HOME/.config/bsc_agent/wallet.json"
# Then in the script, write to process.env.BSC_WALLET_FILE

After wallet setup

1. Read address and publicKey from wallet.json.
2. Tell the user: My BSC address for top-ups is: <address>
3. The user must send native BNB (for gas) and any tokens they want the agent to swap to this address.
4. (Optional) Register your BSC public key on ClawChain for EVM event tracking — see Section 1.5.

---

1.5. Register Public Key on ClawChain (Optional)

This step is optional. It links your BSC wallet public key to your ClawChain agent account to enable tracking EVM events on Chromia. Skip this if you don't need on-chain event tracking.

Prerequisite: You must already have a registered and claimed agent on ClawChain. See the clawchain skill for registration instructions.

Prerequisites

• A registered agent account on ClawChain (Chromia)
• An authenticated session (FT4 keypair from ClawChain registration)
• Your wallet.json file with publicKey (required) and optionally address
• The ClawChain credentials file at ~/.config/clawchain/credentials.json (created by the clawchain skill)

Environment Variables for ClawChain

These are the same variables used by the clawchain skill — set them if not already configured:

export CLAWCHAIN_BRID="9D728CC635A9D33DAABAC8217AA8131997A8CBF946447ED0B98760245CE5207E"
export CLAWCHAIN_NODE="https://chromia.01node.com:7740"

Registration Steps

Option A: Using Chromia CLI

# Read wallet info
WALLET_FILE="${BSC_WALLET_FILE:-$HOME/.config/bsc_agent/wallet.json}"
PUBLIC_KEY=$(cat $WALLET_FILE | grep -o '"publicKey": "[^"]*' | cut -d'"' -f4)
ADDRESS=$(cat $WALLET_FILE | grep -o '"address": "[^"]*' | cut -d'"' -f4)

# Register public key on Chromia
chr tx register_evm_public_key \
  "pancakeswap" \
  "$PUBLIC_KEY" \
  "BSC" \
  56 \
  "$ADDRESS" \
  --ft-auth \
  --secret ~/.config/clawchain/credentials.json \
  -brid $CLAWCHAIN_BRID \
  --api-url $CLAWCHAIN_NODE \
  --await

Arguments: wallet_type public_key chain network_id address

Network IDs:

• BSC Mainnet: 56
• BSC Testnet: 97
• Ethereum Mainnet: 1
• Ethereum Goerli: 5
• Polygon Mainnet: 137

Note: If you don't have an address, use "" (empty string) for the last parameter.

Option B: Using JavaScript/TypeScript

If you're integrating this into a web application with an authenticated FT4 session:

const fs = require('fs');
const walletFile = process.env.BSC_WALLET_FILE || '~/.config/bsc_agent/wallet.json';
const walletData = JSON.parse(fs.readFileSync(walletFile, 'utf8'));

// Assuming you have a Chromia session object (from @chromia/ft4)
const result = await session.call({
  name: 'register_evm_public_key',
  args: [
    'pancakeswap',              // wallet_type
    walletData.publicKey,      // public_key (required)
    'BSC',                      // chain
    56,                         // network_id (56 for BSC mainnet, 97 for testnet)
    walletData.address || ""   // address (optional)
  ]
});

console.log('Public key registered:', result);

Query Registered Public Keys

To check which public keys are registered for your agent:

# Get all registered public keys for an agent
chr query get_evm_public_keys 'agent_name=your_agent_name' \
  -brid $CLAWCHAIN_BRID --api-url $CLAWCHAIN_NODE

# Get specific public key by wallet type
chr query get_evm_public_key_by_type \
  'agent_name=your_agent_name' \
  'wallet_type=pancakeswap' \
  -brid $CLAWCHAIN_BRID --api-url $CLAWCHAIN_NODE

Error Handling

• "Public key already registered": The public key is already registered for this agent. Query existing keys to verify.
• "Public key is required for EIF event tracking": You must provide a public key.
• "Invalid public key format": Public key must start with 0x and be at least 66 characters (0x + 64 hex chars).
• "Agent not found": Ensure your agent account exists on ClawChain.
• Authentication errors: Ensure you have a valid FT4 session authenticated with your Chromia account.

---

2. How the User Can Top Up the Agent Account

The agent does not have an "account" on a server — it has a BSC address (from wallet.json). Fund the agent by sending BNB and tokens to that address:

Get BNB for gas and swaps

1. Buy BNB on an exchange or bridge from another chain.
2. Send BNB to the agent address: <address> from wallet.json.
3. Add BSC Mainnet in MetaMask (Chain ID 56, RPC above), then transfer BNB to the agent.

Get tokens

• Send any BEP-20 token to <address>. The agent can swap via PancakeSwap if a pair exists (e.g. USDT/BNB, BUSD/BNB).

Check balance

• Native (BNB): provider.getBalance(address)
• Any BEP-20 token: call balanceOf(address) on the token contract.

---

3. Discovering Available Tokens and Swaps

The agent can work with any BEP-20 token and determine which swaps are possible. No fixed token list is required.

Which tokens are available

• By contract address: Any BEP-20 token is identified by its contract address. Accept token addresses from the user or from token lists.
• Resolve symbol and decimals: Call the token contract (ERC-20/BEP-20):
  • symbol() → e.g. "USDT", "WBNB"
  • decimals() → use for amount math and display (e.g. 18 or 6)
  • name() → full name (optional)
• Token lists (optional): PancakeSwap and BSC publish token lists; the agent can also accept any user-provided contract address.
• Native gas token: BNB is the chain native token; the wrapped version is WBNB (address in config). Use WBNB in router paths.

Which swaps are available

• Get the Factory: Call the router's factory() (read-only) to get the PancakeSwap V2 Factory address.
• Check if a pair exists: Call factory.getPair(tokenA, tokenB). If the result is the zero address (0x000...), no pair exists. Otherwise it is the pair contract address.
• Check liquidity: On the pair contract, call getReserves(). If both reserves are > 0, the pair has liquidity and that swap is available.
• Quote before swapping: Use the router's getAmountsOut(amountIn, path) (read-only). If the call reverts or returns zero for the output amount, the swap is not feasible (no liquidity or invalid path).
• Multi-hop paths: If there is no direct A–B pair, try a path via WBNB: [tokenA, WBNB, tokenB]. Call getAmountsOut(amountIn, path); if it succeeds and returns a positive amount, the swap is available.
• Optional: PancakeSwap API or subgraph can list pairs for a token; the agent may use these to discover pairs in addition to on-chain checks.

---

4. Making a Trade (Swap on PancakeSwap)

The agent uses the private key from wallet.json to sign a swap transaction and sends it to BSC.

PancakeSwap V2 router (BSC mainnet)

Contract	Address
Router	0x10ED43C718714eb63d5aA57B78B54704E256024E
WBNB	0xbb4CdB9CBd36B01bD1cBaEBF2De08d9173bc095c

Common swap methods

Method	Use case
swapExactETHForTokens	Swap exact BNB for tokens (min amount out)
swapExactTokensForETH	Swap exact tokens for BNB
swapExactTokensForTokens	Swap exact token A for token B
swapTokensForExactTokens	Swap tokens for exact amount of token B

Swap flow (any token pair with liquidity)

1. Load wallet from wallet.json (privateKey + address).
2. Connect to BSC: new ethers.JsonRpcProvider(BSC_RPC_URL) (mainnet: chain id 56).
3. Resolve tokens: Use token contract addresses (from user or discovery). For native BNB use WBNB in the path.
4. Check swap availability: Call router getAmountsOut(amountIn, path). If it reverts or returns zero, try a multi-hop path (e.g. [tokenA, WBNB, tokenB]) or inform the user the pair has no liquidity.
5. Build path: e.g. BNB → token: [WBNB, tokenAddress]; token → BNB: [tokenAddress, WBNB]; token → token: [tokenA, WBNB, tokenB] (or direct if pair exists).
6. Get router contract (address above), ABI for swapExactETHForTokens, swapExactTokensForETH, or swapExactTokensForTokens.
7. Deadline: Math.floor(Date.now() / 1000) + 300 (e.g. 5 minutes).
8. amountOutMin: from getAmountsOut(amountIn, path) then apply slippage (e.g. 1% = amountOut * 0.99).
9. Sign and send: For BNB → token use { value: amountInWei }; for token → BNB or token → token, approve router for the token first, then call the swap.

Slippage

• amountOutMin = expected output × (1 - slippage). E.g. 1% slippage → multiply by 0.99.
• For volatile pairs use 2–5%.

Token decimals

• BNB has 18 decimals. 1 BNB = 1e18 wei.
• Many BEP-20 tokens use 18 decimals; USDT/USDC often use 6. Check the token contract or docs.

---

5. Command / Script Patterns for the Agent

Read wallet (do not expose private key in logs)

• Read ~/.config/bsc_agent/wallet.json (or BSC_WALLET_FILE).
• Use address when telling the user where to top up.
• Use privateKey only inside the signing process (ethers Wallet). Never log or print the private key.

Execute swap (high level)

1. Load wallet.json.
2. Create ethers.Wallet(privateKey, provider).
3. Build router call (e.g. swapExactETHForTokens) with path, deadline, amountOutMin.
4. Send transaction: tx = await router.swapExactETHForTokens(...); await tx.wait().
5. Return tx hash to user: https://bscscan.com/tx/<hash>.

Get quote before swapping

• Call router getAmountsOut(amountIn, path) (read-only) to get expected amountOut, then compute amountOutMin with slippage.

---

6. Example Token Addresses (BSC Mainnet)

Symbol	Address	Notes
WBNB	0xbb4CdB9CBd36B01bD1cBaEBF2De08d9173bc095c	Native wrapped; use in paths
USDT	0x55d398326f99059fF775485246999027B3197955	Stablecoin
BUSD	0xe9e7CEA3DedcA5984780Bafc599bD69ADd087D56	Stablecoin

Do not limit to these. The agent should accept any BEP-20 address and discover availability via getPair / getReserves and getAmountsOut (see §3). If a pair has no liquidity, add liquidity via the PancakeSwap UI or use another token pair.

---

7. Security Notes

File Permissions

• wallet.json must be restricted to owner-only access. The wallet creation script sets mode: 0o600 automatically. Verify with:

  chmod 600 ~/.config/bsc_agent/wallet.json
  ls -la ~/.config/bsc_agent/wallet.json
  # Should show: -rw-------
  

Dedicated Wallet

• Use this wallet only for the agent and only with amounts you accept to lose if the machine or file is compromised.
• Do not reuse a wallet that holds large funds elsewhere. Create a fresh, dedicated wallet.
• For testnet usage, no real funds are at risk.

Key Handling Best Practices

• Never log the private key to console, files, or monitoring systems.
• Never transmit the private key over the network. All signing happens locally.
• The agent reads the private key only to construct an ethers.Wallet instance for signing. It is never sent to any remote endpoint.
• Consider using encrypted keystores (ethers.js Wallet.encrypt()) for production use. The agent would prompt for a password to decrypt at startup.

Optional: Encrypted Keystore

For enhanced security, use ethers.js encrypted wallet format instead of plaintext:

// Create encrypted wallet (during setup)
const encrypted = await wallet.encrypt("your-password");
fs.writeFileSync(file, encrypted, { mode: 0o600 });

// Load encrypted wallet (during operations)
const wallet = await ethers.Wallet.fromEncryptedJson(
  fs.readFileSync(file, 'utf8'),
  "your-password"
);

---

8. Errors

Error	Meaning / action
insufficient funds	Not enough BNB for gas or not enough token/BNB for the swap. User should top up.
execution reverted: PancakeRouter: INSUFFICIENT_OUTPUT_AMOUNT	Slippage too low; increase or retry.
execution reverted: PancakeRouter: EXPIRED	Deadline passed; rebuild tx with new deadline.
nonce too low	Reuse of nonce; wait and retry or refresh nonce from chain.

---

9. Links

• PancakeSwap (BSC mainnet): https://pancakeswap.finance/swap?chain=bsc
• PancakeSwap V2 docs: https://docs.pancakeswap.finance/developers/smart-contracts/pancakeswap-exchange/v2-contracts
• BSC explorer: https://bscscan.com