llm

LLM example — Claude-driven buyer and seller

Both sides are driven by an LLM (Anthropic Claude) using the SDK's tool integration. Instead of hand-coded case "budget.set": branches, every incoming entry is fed to Claude, which picks a tool to call. The SDK then executes the chosen tool against the session.

What it shows

• session.availableTools() — role- and status-gated tool definitions ready to feed into a tool-using LLM.
• session.toMessages() — the conversation history flattened into a { role, content }[] shape suitable for chat-completion APIs.
• session.executeTool(name, args) — runs the tool the LLM picked, dispatching to the appropriate setBudget / fund / submit / complete / reject / sendMessage / wait method (wait is a no-op fallback so tool_choice: "any" always has a valid option).

How the loop works

agent.on("entry", async (session, entry) => {
  const tools = session.availableTools();      // gated by role + status
  const messages = await session.toMessages(); // history → chat format

  const response = await anthropic.messages.create({
    model: "claude-sonnet-4-…",
    system: "You are a … agent",
    messages: formatMessages(messages),
    tools: formatTools(tools),
    tool_choice: { type: "any" },
  });

  const toolUse = response.content.find((b) => b.type === "tool_use");
  if (toolUse) {
    await session.executeTool(toolUse.name, toolUse.input as Record<string, unknown>);
  }
});

Both buyer.ts and seller.ts are minor variations of this loop with different system prompts — the seller is told it sells memes for 0.01–0.1 USDC, the buyer is told it wants to buy a funny cat meme.

Files

File	Role
buyer.ts	Buyer agent driven by Claude
seller.ts	Seller agent driven by Claude

Setup

1. Install the Anthropic SDK — it's not a dependency of this package.

   npm install @anthropic-ai/sdk

2. Set the API key + wallet env vars — these examples share .env with the basic/ examples. Add to your .env (see examples README — shared setup):

   BUYER_WALLET_ADDRESS=0x…
   BUYER_WALLET_ID=…
   BUYER_SIGNER_PRIVATE_KEY=MIGH…
   SELLER_WALLET_ADDRESS=0x…
   SELLER_WALLET_ID=…
   SELLER_SIGNER_PRIVATE_KEY=MIGH…
   ANTHROPIC_API_KEY=sk-ant-…
   

   The buyer also reads SELLER_WALLET_ADDRESS to know which provider to target with createJob.

Run

# Terminal 1
npx tsx src/examples/llm/seller.ts

# Terminal 2
npx tsx src/examples/llm/buyer.ts

Available tools by role + status

Reference for the system prompt — these are the tools the LLM has access to at each step. The SDK gates the list automatically; you don't need to filter.

Role	Status	Tools
Provider	open	setBudget, sendMessage, wait
Provider	budget_set	setBudget
Provider	funded	submit
Client	open	sendMessage, wait
Client	budget_set	sendMessage, fund, wait
Evaluator	submitted	complete, reject

Notes

• The LLM may pick wait when it's not its turn to act — that's a no-op tool that exists specifically so tool_choice: "any" always has a valid option.
• formatTools / formatMessages are inline helpers in each file that translate between the SDK's AcpTool shape and Anthropic's tool definition schema. Swap these out (and the model client) to use a different LLM.
• For a deeper writeup, see the main README — LLM Integration section.