JustLend Skills¶

GitHub: https://github.com/justlend/justlend-skills

JustLend Skills (@justlend/justlend-skills) is an AI Agent skills package for the JustLend DAO protocol on TRON. It provides structured skill instructions and a lightweight MCP server (15 tools) that enables AI agents (Claude Code, Claude Desktop, Cursor, Codex, etc.) to query market data, manage lending positions, and execute DeFi operations.

It also works as a standalone CLI tool for quick market checks and lending operations directly from the terminal.

Note

For advanced features (sTRX staking, energy rental, governance voting, 54 tools, 24+ markets), use the full MCP server: @justlend/mcp-server-justlend.

Overview¶

JustLend DAO is the largest lending protocol on TRON, based on the Compound V2 architecture. JustLend Skills wraps the core lending functionality into MCP tools and structured skill instructions that AI agents can use.

Key Capabilities¶

Market Data: Real-time APYs (including mining rewards), TVL, utilization rates for all markets
Protocol Dashboard: Total supply, borrow volume, TVL, and user count across the protocol
Account Analysis: Health factor monitoring, liquidation risk assessment, balance queries
Lending Operations: Supply assets, borrow against collateral, repay loans, withdraw positions
Token Approvals: Check and manage TRC20 approvals for JustLend contracts

Skill Modules¶

The project includes 4 structured skill modules in the /skills directory that provide AI agents with domain-specific instructions and workflows:

Skill	Description	MCP Server Required
justlend-lending-v1	Supply, borrow, repay, withdraw workflows with health factor monitoring	JustLend Skills (built-in)
justlend-trx-staking	Stake TRX for sTRX liquid staking tokens	Full MCP Server
justlend-energy-rental	Rent TRON Energy at discounted rates (50-80% cheaper)	Full MCP Server
justlend-governance-v1	View proposals, deposit JST for voting power, cast votes	Full MCP Server

Supported Markets¶

jToken	Underlying	Description
jTRX	TRX	Native TRON token
jUSDT	USDT	Tether USD
jUSDD	USDD	Decentralized USD
jUSDC	USDC	USD Coin
jBTC	BTC	Bitcoin (TRC20)
jETH	ETH	Ethereum (TRC20)
jSUN	SUN	SUN Token
jWIN	WIN	WINkLink

Tip

The full MCP server supports 24+ markets including jsTRX, jwstUSDT, jWBTC, and more.

Prerequisites¶

Node.js 20.0.0 or higher
TronGrid API key (required)
A burner wallet private key for write operations — never use your main wallet

Installation¶

git clone https://github.com/justlend/justlend-skills.git
cd justlend-skills
bash install.sh

Or manually:

npm install
cp .env.example .env   # Then edit .env with your keys

Configuration¶

Edit .env:

# Required — get from https://www.trongrid.io/
TRONGRID_API_KEY=your_trongrid_api_key

# Required for write operations (supply, borrow, repay, etc.)
# SECURITY: Use a BURNER WALLET — never your main wallet!
TRON_PRIVATE_KEY=your_burner_wallet_private_key

# Network: mainnet (default) or nile (testnet)
NETWORK=mainnet

Warning

Always use a dedicated burner wallet with minimal funds. Never configure your main wallet's private key. Omit TRON_PRIVATE_KEY entirely for read-only mode.

Client Configuration¶

Claude Desktop¶

Edit ~/Library/Application Support/Claude/claude_desktop_config.json:

{
  "mcpServers": {
    "justlend": {
      "command": "node",
      "args": ["/ABSOLUTE_PATH_TO/justlend-skills/scripts/mcp_server.mjs"],
      "env": {
        "TRONGRID_API_KEY": "your_key",
        "TRON_PRIVATE_KEY": "your_burner_key"
      }
    }
  }
}

Cursor¶

Add to .cursor/mcp.json:

{
  "mcpServers": {
    "justlend": {
      "command": "node",
      "args": ["/ABSOLUTE_PATH_TO/justlend-skills/scripts/mcp_server.mjs"],
      "env": {
        "TRONGRID_API_KEY": "your_key",
        "TRON_PRIVATE_KEY": "your_burner_key"
      }
    }
  }
}

Claude Code¶

Add to .claude/settings.local.json:

{
  "mcpServers": {
    "justlend": {
      "command": "node",
      "args": ["/ABSOLUTE_PATH_TO/justlend-skills/scripts/mcp_server.mjs"],
      "env": {
        "TRONGRID_API_KEY": "your_key",
        "TRON_PRIVATE_KEY": "your_burner_key"
      }
    }
  }
}

Codex CLI¶

git clone https://github.com/justlend/justlend-skills ~/.codex/justlend-skills
cd ~/.codex/justlend-skills && bash install.sh
mkdir -p ~/.agents/skills
ln -s ~/.codex/justlend-skills/skills ~/.agents/skills/justlend-skills

Usage¶

MCP Server Mode¶

For AI agent integrations (Claude Desktop, Cursor, Claude Code, etc.):

npm start

The server communicates over stdio and exposes 15 MCP tools.

CLI Tool Mode¶

For quick checks and operations directly from the terminal:

# Market data
node scripts/justlend_api.mjs markets              # List all markets with APY
node scripts/justlend_api.mjs dashboard            # Protocol dashboard (TVL, users)
node scripts/justlend_api.mjs supported-markets    # List supported markets & addresses

# Account queries
node scripts/justlend_api.mjs address              # Show wallet address
node scripts/justlend_api.mjs balance <addr>       # Check TRX balance
node scripts/justlend_api.mjs balance <addr> USDT  # Check token balance
node scripts/justlend_api.mjs account <addr>       # Account health status
node scripts/justlend_api.mjs account-api <addr>   # Full account data from API
node scripts/justlend_api.mjs jtoken-details <jtoken>  # Detailed jToken info
node scripts/justlend_api.mjs allowance <addr> USDT    # Check TRC20 approval

# Write operations
node scripts/justlend_api.mjs supply TRX 10        # Supply 10 TRX
node scripts/justlend_api.mjs approve USDT 1000    # Approve 1000 USDT

Skills Reference¶

JustLend Lending (justlend-lending-v1)¶

Core lending skill providing supply, borrow, repay, and withdraw workflows with built-in health factor monitoring and TRC20 approval handling.

Workflow Rules:

Always check before acting — use get_all_markets for APYs, get_account_summary for health factor, and get_trx_balance / get_token_balance to verify funds
TRC20 approval required — before supply or repay for TRC20 tokens, call check_allowance then approve_underlying if needed. Native TRX needs no approval.
Post-operation verification — call get_account_summary after any write operation to confirm success

Typical Workflow — Supply TRC20 (e.g., USDT):

get_token_balance — verify sufficient funds
check_allowance — check if already approved
approve_underlying — approve if needed
supply — deposit USDT
get_account_summary — confirm position updated

sTRX Staking (justlend-trx-staking)¶

Liquid staking skill for TRX. Stake TRX to receive sTRX tokens that earn staking rewards automatically while remaining usable in DeFi.

Note

This skill requires the full MCP server for tool execution.

How it works: Deposit TRX → receive sTRX → rewards accrue via exchange rate appreciation → unstake with ~14 day unbonding period.

Energy Rental (justlend-energy-rental)¶

Rent TRON Energy from the JustLend marketplace at 50-80% lower cost than burning TRX for transaction fees.

Note

This skill requires the full MCP server for tool execution.

DAO Governance (justlend-governance-v1)¶

Participate in JustLend DAO governance proposals. Deposit JST for voting power (1 JST = 1 Vote), cast votes, and reclaim votes after proposals end.

Note

This skill requires the full MCP server for tool execution.

Voting Workflow:

get_proposal_list — find active proposals
get_vote_info — check available voting power
If no votes: approve_jst_for_voting → deposit_jst_for_votes
cast_vote — vote FOR or AGAINST
After proposal ends: withdraw_votes_from_proposal → withdraw_votes_to_jst

MCP Tools Reference¶

Read-Only Tools¶

Tool	Inputs	Description
`get_all_markets`	—	All markets with supply/borrow APY, mining rewards, and TVL
`get_dashboard`	—	Protocol overview: total supply, borrow, TVL, user count
`get_supported_markets`	—	List all supported markets with jToken/underlying addresses
`get_jtoken_details`	`jtokenAddr`	Detailed jToken info: interest rate model, reserves, mining rewards
`get_wallet_address`	—	Currently configured wallet address
`get_account_summary`	`address`	Health factor, liquidity, liquidation risk
`get_account_data_from_api`	`address`	Comprehensive account data from API (positions, rewards)
`get_trx_balance`	`address`	Native TRX balance
`get_token_balance`	`address`, `token`	TRC20 token balance (USDT, USDD, etc.)
`check_allowance`	`address`, `asset`	Check TRC20 approval status for JustLend contracts

Write Operations¶

Tool	Inputs	Description
`approve_underlying`	`asset`, `amount?`	Approve TRC20 for JustLend (required before supply/repay for TRC20 tokens)
`supply`	`asset`, `amount`	Deposit assets (TRX or TRC20) to earn interest
`withdraw`	`asset`, `amount`	Redeem supplied assets
`borrow`	`asset`, `amount`	Borrow against collateral
`repay`	`asset`, `amount`	Repay outstanding loans

Security Considerations¶

Burner Wallet Only: Always use a dedicated wallet with minimal funds for AI interactions. Never use your main wallet.
Read-Only Mode: Omit TRON_PRIVATE_KEY from .env to restrict the agent to read-only operations.
Private Keys: Stored only in .env (gitignored), never exposed via MCP tools or AI conversation logs.
Test First: Use Nile testnet (NETWORK=nile) before mainnet operations.
Health Factor: Always check account health before borrowing. If shortfallUSD > 0, the position is at liquidation risk.
Gas: Keep at least 50-100 TRX in the wallet for transaction fees (Energy and Bandwidth).

Example Conversations¶

"What are the best supply rates on JustLend?" → AI calls get_all_markets, sorts by totalSupplyAPY (includes mining rewards), presents ranking

"Show me the JustLend protocol stats" → AI calls get_dashboard, displays total TVL, supply/borrow volume, user count

"Check if my position is safe" → AI calls get_account_data_from_api for full position details, analyzes health factor

"Supply 1000 USDT to JustLend" → AI checks balance → check_allowance → if needed approve_underlying → supply → confirms

"Repay 100 TRX borrow" → AI calls repay directly (TRX needs no approval)

"What markets have mining rewards?" → AI calls get_all_markets, filters by miningAPY > 0, presents markets with active rewards

"Show me detailed info for the jUSDT market" → AI calls get_jtoken_details with jUSDT address, displays interest rate model, reserves, and mining rewards

Troubleshooting¶

`OUT_OF_ENERGY` or `BANDWIDTH_ERROR`¶

The wallet needs TRX to pay for transaction fees. Ensure at least 50-100 TRX is available in the wallet.

`REVERT` on Supply/Repay¶

TRC20 tokens (USDT, USDD) require approval before the JustLend contract can move them. Call approve_underlying first. Native TRX does not need approval.

`exit_market` Failure¶

Cannot disable collateral if it would push health factor below 1.0. Repay debt or add more collateral first.

Private Key Not Configured¶

Write operations require TRON_PRIVATE_KEY in .env. Run bash install.sh to set up the environment, or manually edit .env.

TronGrid API Errors¶

Verify your TRONGRID_API_KEY is valid and not rate-limited. Get a key from trongrid.io.

JustLend Skills¶

Overview¶

Key Capabilities¶

Skill Modules¶

Supported Markets¶

Prerequisites¶

Installation¶

Configuration¶

Client Configuration¶

Claude Desktop¶

Cursor¶

Claude Code¶

Codex CLI¶

Usage¶

MCP Server Mode¶

CLI Tool Mode¶

Skills Reference¶

JustLend Lending (justlend-lending-v1)¶

sTRX Staking (justlend-trx-staking)¶

Energy Rental (justlend-energy-rental)¶

DAO Governance (justlend-governance-v1)¶

MCP Tools Reference¶

Read-Only Tools¶

Write Operations¶

Security Considerations¶

Example Conversations¶

Troubleshooting¶

OUT_OF_ENERGY or BANDWIDTH_ERROR¶

REVERT on Supply/Repay¶

exit_market Failure¶

Private Key Not Configured¶

TronGrid API Errors¶

`OUT_OF_ENERGY` or `BANDWIDTH_ERROR`¶

`REVERT` on Supply/Repay¶

`exit_market` Failure¶