@agenticpay/ai-sdk

Vercel AI SDK helpers for x402 paid tool calls. Wraps paywalled HTTP endpoints into a tools object you can drop straight into generateText, streamText, or streamUI. The model decides when to invoke; this package signs the USDC payment, settles on Solana, returns the result.

Install

npm install @agenticpay/ai-sdk
# peer deps you probably already have:
npm install ai zod

Usage

import { generateText } from "ai";
import { anthropic } from "@ai-sdk/anthropic";
import { createAgenticpayTools } from "@agenticpay/ai-sdk";
import { z } from "zod";

const senderKeypairBytes: number[] = JSON.parse(
  process.env.AGENT_SOLANA_KEYPAIR_BYTES!
);

const tools = await createAgenticpayTools({
  network: "solana:EtWTRABZaYq6iMfeYKouRu166VU2xqa1", // devnet
  rpcUrl: "https://api.devnet.solana.com",
  keypairBytes: senderKeypairBytes,
  paidTools: {
    reverseString: {
      description: "Reverse a string. Costs 0.001 USDC via x402 on Solana.",
      parameters: z.object({ text: z.string() }),
      url: "http://localhost:4021/tools/reverse",
    },
    wordCount: {
      description: "Count words in a string. Costs 0.0005 USDC.",
      parameters: z.object({ text: z.string() }),
      url: "http://localhost:4021/tools/word-count",
    },
  },
});

const { text } = await generateText({
  model: anthropic("claude-opus-4-7"),
  tools,
  prompt: "Reverse 'agenticpay rocks' and count words in 'open source wins'",
});

How it works

createAgenticpayTools() builds an x402Client once per call (cached), hydrates it with the agent's Solana keypair, and wraps fetch with @x402/fetch. Each paid tool becomes a normal Vercel AI SDK tool — the AI SDK layer never sees the payment plumbing.

When the model invokes the tool:

1. We POST to url with the model's parameters.
2. Server returns HTTP 402 with payment requirements.
3. The wrapper signs a USDC payload using the agent's keypair.
4. Retries with X-PAYMENT header.
5. Facilitator settles on-chain (~1.5–2 s on devnet).
6. Server returns the result; we hand it back to the model.

Pointing at a facilitator

Your paywalled endpoints (url above) are typically backed by @agenticpay/mcp-server or any other x402-compatible server. Either self-host with @agenticpay/facilitator or point the resource server at the public devnet facilitator:

FACILITATOR_URL=https://agentpay-facilitator-e9b20a5fee6a.herokuapp.com

Funding the agent

The agent only needs USDC — the facilitator's fee_payer covers the SOL gas. For devnet:

• SOL: https://faucet.solana.com
• USDC: https://faucet.circle.com (Solana Devnet)

Status

Pre-alpha. Devnet validated end-to-end via the agenticpay monorepo.

MIT licensed.