Use H081 with Claude

Before you start

Do steps 1 to 3 of Getting started first: Node.js 20.11 or newer, an agent key, and a little SOL and USDG in the agent wallet. If you have not made the key yet:

npx -y @h081lll/agent init --rpc <your Solana RPC URL>

At the end, init prints a ready-made line for Claude Code with your real key path. That line is all you need for the next section.

Set up Claude Code

1. Add the H081 tools

   Copy the claude mcp add line that init printed and run it in a terminal. Or fill in your two values here: the full path to your key file and your RPC URL.

   claude mcp add --scope user h081 -e H081_SOLANA_KEYPAIR=/Users/you/.h081/agent.json -e H081_RPC_URL=<your RPC> -- npx -y @h081lll/agent mcp

   claude mcp add --scope user h081 -e H081_SOLANA_KEYPAIR=C:\Users\you\.h081\agent.json -e H081_RPC_URL=<your RPC> -- cmd /c npx -y @h081lll/agent mcp

   --scope user makes the tools work in every folder, not only the one you ran it in. On Windows, cmd /c before npx is needed; the line init prints already has it.

2. Check that it is connected

   claude mcp list

   h081: npx -y @h081lll/agent mcp - ✓ Connected

   The important part is h081 and Connected.

3. Ask a first, read-only question

   Start a new Claude Code session and ask:

   Show me the H081 protocol info and my balance.

   Claude should use h081_protocol_info and h081_bank_balance. Both only read; nothing is sent.

Set up Claude Desktop

1. Open the settings file

   In Claude Desktop, open Settings › Developer › Edit Config. This opens a file called claude_desktop_config.json.

2. Add the H081 server

   Paste this in, with your own key path and RPC URL. If the file already has an "mcpServers" section, add the "h081" part inside it.

   {
     "mcpServers": {
       "h081": {
         "command": "npx",
         "args": ["-y", "@h081lll/agent", "mcp"],
         "env": {
           "H081_SOLANA_KEYPAIR": "/Users/you/.h081/agent.json",
           "H081_RPC_URL": "https://YOUR-RPC-URL"
         }
       }
     }
   }

   {
     "mcpServers": {
       "h081": {
         "command": "cmd",
         "args": ["/c", "npx", "-y", "@h081lll/agent", "mcp"],
         "env": {
           "H081_SOLANA_KEYPAIR": "C:\\Users\\you\\.h081\\agent.json",
           "H081_RPC_URL": "https://YOUR-RPC-URL"
         }
       }
     }
   }

   On Windows the command is cmd with /c first, and every backslash in the path is doubled, because the file is JSON.

3. Restart Claude Desktop and ask

   Quit Claude Desktop completely and open it again. Then ask the same first question:

   Show me the H081 protocol info and my balance.

If it does not connect

No h081 tools in Claude Code

It was probably added without --scope user, so it only works in one folder. Remove it, then add it again with the line from step 1.

The first start times out

The first run downloads the package. Run this once in a terminal, then restart Claude: npx -y @h081lll/agent fetch-circuits.

"no file at …"

The key path is wrong. Check it, or leave H081_SOLANA_KEYPAIR out to use ~/.h081/agent.json.

"429 Too Many Requests"

The public Solana RPC is limiting you. Put your own RPC URL in H081_RPC_URL.

claude mcp remove h081

What Claude can do

Claude gets thirteen tools. You never type their names; Claude picks them from what you ask. The last column matters most: it says whether a tool can move money and whether it shows a plan first.

Plan first, with Claude

On the command line, nothing is sent without --yes. With Claude, it works a little differently, and it is worth knowing how:

• The budget tools (give, take back, pass on) and the lender's open, fund, settle and close steps have a real plan step. Claude calls them once and gets a plan back; nothing is sent. Only a second call with confirm: true sends it. Ask Claude to show you that plan before it confirms.
• Deposit, withdraw, transfer, pay, borrow, staking and the lender's claim, collect and sweep send as soon as Claude calls them. So ask Claude to tell you the plan in words (amount, fee, what arrives, who sends it) and to wait for your "yes" before it calls the tool.
• Your Claude app normally asks your permission before it runs a tool, unless you told it to always allow that tool. Do not choose "always allow" for the tools that move money.

Example prompts

Copy one, change the numbers and addresses, and paste it into Claude. Wallet addresses below are shortened (9xQe…); use the full address.

Check

What is my H081 balance? Include the wallet's SOL and USDG.

• "Show me the H081 protocol info: deposit limits, the relayer fee, and whether deposits are paused."
• "What is my h081-address: code? I want someone to pay me privately."
• "List my budgets: how much is left in each, and which ones I can take back."

Deposit

Deposit 5 USDG into my H081 account. Show me the plan first and wait for my yes.

• "How much USDG is in the agent wallet? Deposit all but 1 USDG, after showing me the plan."
• "Is there room in the bank for a 50 USDG deposit right now?"

Withdraw

Withdraw 2 USDG from my H081 account to 9xQe… (a fresh wallet that never touched the agent). Tell me the fee and what arrives first, and wait for my yes.

• "What would it cost to withdraw 10 USDG through the relayer? Do not send anything."
• "Does a wallet that has never held USDG cost extra to withdraw to?"

Give a budget

Give sub-account 1 a budget of 20 USDG: at most 5 USDG a day, at most 2 USDG per payment, for 30 days. Show me the plan first.

• "Give the agent with this code a 10 USDG budget for 7 days: h081-address:…. Show me the plan first."
• "Take back what is left of budget 12345. Show me how much comes back first."

More about budgets: Allowances.

Pay and transfer

Pay 2 USDG from my budget to h081-address:… privately. Tell me which budget you will use and wait for my yes.

• "Send 3 USDG from my main balance to h081-address:… privately. Wait for my yes."
• "Pay 1 USDG from my budget to the wallet 9xQe…. Tell me the fee first."

Loans

A lender gave me this terms code: h081-loan-terms:… What could I borrow against a 100 USDG budget? Just the quote, do not borrow yet.

• "Open a loan slot as a lender with a 40% share. Show me the plan; do not open it yet."
• "Here is the borrower's code: h081-loan-proof:…. Show me what funding it would cost me, and wait for my yes."
• "Show the status of my loans: what is repaid, what is still owed, what I can collect."

More about loans: Loans.

Example conversations

These show the shape of a good session: Claude explains the plan and waits for your "yes". Claude's exact wording, and the numbers on your account, will differ.

Tips

Keep a small balance

Treat the agent like a wallet in your pocket, not a savings account. Keep only what Claude should be able to spend. You can also set hard limits that the tools enforce before anything is proven. They are in base units, where 1 USDG = 1000000:

claude mcp add --scope user h081 -e H081_SOLANA_KEYPAIR=/Users/you/.h081/agent.json -e H081_RPC_URL=<your RPC> -e H081_MAX_DEPOSIT=10000000 -e H081_MAX_PAY=2000000 -e H081_MAX_GRANT=10000000 -e H081_MAX_LEND=10000000 -- npx -y @h081lll/agent mcp

In Claude Desktop, add the same names and values to the "env" section. To change them in Claude Code, remove the server and add it again.

Ask for the plan, every time

Say "show me the plan first" in every request that moves money, or paste the habit prompt at the start. Read the fee, what arrives, and who the chain will see. Then say "yes".

What Claude cannot do

• See or copy your key. The tools use ~/.h081/agent.json on your computer; no tool returns it. Backup and restore exist only on the command line.
• Go past the bank's limits. At most 1,000 USDG per deposit and 10,000 USDG in the whole bank for now. Relayed withdrawals above 100 USDG need H081 staked.
• Quietly send it another way. If the relayer is down, a withdrawal is not sent and Claude gets an error. The agent key sends it itself only if you ask for a direct withdrawal, which shows your agent wallet as the sender.
• Borrow on its own. A loan needs a real lender who funds it. Until then, nothing is borrowed.
• Pass on part of a budget yet. The proving files for that step are not published yet, so sending it is refused before anything is signed.
• Undo a payment. Once sent, a transaction is final. That is why the plan comes first.

Next steps

• BudgetsAllowancesGive another agent a budget with limits, and take back what is left.→
• AdvancedLoansBorrow against a budget, or lend. A lender never gets more than they lent.→
• Read thisPrivacy and safetyWhat the chain can see, and how to stay safe.→
• HelpErrors and fixesWhat each error means and what to do.→

New here? The 5-minute quickstart does a first private payment end to end. The package is @h081lll/agent on npm. Questions: @H081CAP on X.