@agenticpay/eliza-plugin

Pay-per-call x402 USDC micropayments for Eliza agents on Solana.

Wrap any paywalled HTTP endpoint (your own MCP server, third-party paid API) as a native Eliza Action. The agent decides when to call it; the plugin signs and settles the USDC payment on Solana; the result lands back in the conversation. Sub-cent fees, sub-second finality.

Install

pnpm add @agenticpay/eliza-plugin
# peer dep — should already be in your Eliza project
pnpm add @elizaos/core

Usage

import { createAgenticpayPlugin } from "@agenticpay/eliza-plugin";

export const agentpay = createAgenticpayPlugin({
  network: "solana:EtWTRABZaYq6iMfeYKouRu166VU2xqa1", // devnet
  rpcUrl: "https://api.devnet.solana.com",
  // 64-byte JSON array (format `solana-keygen new` writes), exposed via
  // runtime setting or process.env.
  keypairBytesEnvVar: "AGENT_SOLANA_KEYPAIR_BYTES",
  paidActions: [
    {
      name: "REVERSE_STRING",
      description: "Reverse a string. Costs 0.001 USDC.",
      similes: ["reverse this", "flip the text"],
      url: "http://localhost:4021/tools/reverse",
      extractInput: (msg) => ({ text: msg.content.text ?? "" }),
      formatOutput: (body) =>
        `Reversed: ${(body as { result: string }).result}`,
    },
    {
      name: "WORD_COUNT",
      description: "Count words in a string. Costs 0.0005 USDC.",
      url: "http://localhost:4021/tools/word-count",
      extractInput: (msg) => ({ text: msg.content.text ?? "" }),
      formatOutput: (body) =>
        `Words: ${(body as { count: number }).count}`,
    },
  ],
});

// Register in your character / runtime config.

How it works

1. At plugin init time we hydrate an x402Client from the agent's Solana keypair (loaded from keypairBytesEnvVar or keypairBytes).
2. Every paidAction becomes a native Eliza Action. When the model calls it, the plugin's wrapped fetch:
   • issues the request,
   • on HTTP 402 reads the payment requirements,
   • signs a USDC payload using the agent's keypair,
   • retries with the X-PAYMENT header,
   • returns the response after the facilitator settles on-chain (~1.5–2 s on devnet).
3. The agent's reply is built by your formatOutput(jsonBody) callback, so the model never sees the payment plumbing.

Pointing at the hosted facilitator

The endpoints you wrap are typically backed by @agenticpay/mcp-server or any other x402-compatible server. Either self-host a facilitator with @agenticpay/facilitator, or point at the public devnet one:

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

Funding the agent

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

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

Check balance with @agenticpay/cli:

npx -p @agenticpay/cli agentpay balance --wallet ./agent-wallet.json --cluster devnet

Status

Pre-alpha. Devnet validated end-to-end via the agenticpay monorepo. Mainnet support requires a mainnet-capable facilitator (Coinbase CDP or self-hosted with mainnet RPC + funded fee_payer).

MIT licensed.