voidpay Tool

voidpay is an x402 payment rail for AI agents — let your LlamaIndex agent autonomously pay for HTTP 402 endpoints, no API keys, no Stripe customer object. Identity is an Ed25519 keypair on disk.

Settlement happens off-chain in voidpay credits (Stage 1) or on-chain USDC on Base mainnet (Stage 2). The vault is Sourcify-verified at 0xd25d...4DF5 with the vault record at voidly.ai/pay/proof. Credits are not backed and not redeemable; Stage 2 is being retired.

Installation

pip install llama-index-tools-voidly-pay

Provision a wallet (10 free credits, no install)

Visit voidly.ai/pay/claim — generates an Ed25519 keypair in your browser and grants 10 credits via the public faucet. Save the keypair to ~/.voidly-pay-keypair.json and you're ready to call paid endpoints.

Usage

from llama_index.tools.voidly_pay import VoidlyPayToolSpec
from llama_index.core.agent.workflow import FunctionAgent
from llama_index.llms.openai import OpenAI

voidly_tool = VoidlyPayToolSpec()  # uses ~/.voidly-pay-keypair.json by default

agent = FunctionAgent(
    tools=voidly_tool.to_tool_list(),
    llm=OpenAI(model="gpt-4o"),
)

await agent.run(
    "Browse the voidpay marketplace, find a Wikipedia summary endpoint, "
    "and pay 1¢ to fetch the summary for 'Alan Turing'."
)

Available Functions

• pay_for_url(url, method, params, body) — call any URL; auto-pays a 402 Payment Required response by signing a transfer envelope, retries with X-Payment, and returns the body plus the signed receipt.
• discover_paid_endpoints() — list all paid endpoints currently advertised on the facilitator.
• marketplace_browse(category) — browse the open voidpay marketplace (api.voidly.ai/v1/pay/marketplace).
• health_check() — run the 6-check trust report (facilitator reachability, vault verification, wallet balance, keypair validity, settlement health). Useful before a long-running paid task.
• list_listing(name, endpoint_url, price_usdc, description, category) — list your own paid endpoint on the marketplace.

How x402 works

1. Agent calls a tool that hits a 402 Payment Required endpoint
2. Endpoint returns a signed quote (price, recipient, expiry)
3. SDK signs a transfer envelope with the agent's Ed25519 keypair
4. Endpoint verifies and returns the actual response

One round-trip after the first 402. Sub-200ms typical settlement on the live facilitator.

List your own paid endpoint

Visit voidly.ai/pay/list-your-service — browser-only Ed25519 keypair, no install. Once listed, every Voidly-aware agent (LlamaIndex, LangChain, Vercel AI, MCP) can find and call your URL. Voidly takes zero platform cut on Stage 1.

Resources

• voidpay docs
• Live marketplace JSON
• Sourcify-verified vault
• Public vault record — not a reserve; Stage 2 is being retired
• voidly-pay PyPI SDK (this tool wraps it)

This loader is designed to be used as a way to load voidpay primitives as Tools in an Agent.