HPP x402 MCP Bridge

io.github.hpp-ioPublished by GitHub account hpp-iov0.1.24Updated Nov 3, 2026

MCP bridge for autonomous x402 payments in HPP USDC.e — discover and pay for services per call.

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Overview

HPP x402 MCP Bridge's local MCP server; no sign-in required; STDIO.

No AI overview yet: these facts come from the registry entry and the server itself.

Installation

In SourceWeft

  1. Open HPP x402 MCP Bridge in the dashboard and add it to a workspace.
  2. Enable the server for the chats that should use its tools.

Desktop only via STDIO. STDIO servers start a local process, so they need the SourceWeft desktop host.

Other MCP clients

Follow the launch instructions in the repository.

README

@hpp-io/x402-mcp-bridge

[npm] [MCP Registry] [License] [Node]

The agent payment rail for HPP. A stdio MCP bridge + the hpp-x402 CLI that let Claude Desktop / Claude Code / Cursor / Windsurf / OpenClaw make autonomous HPP USDC.e payments over x402 — discover paid services, pay per call, within a spend cap. No API keys, no manual signing.

📖 Full documentation

hpp-io/x402-tools — the complete manual: how it works, every command, buyer and seller flows, payment schemes (exact / upto), wallet modes, and troubleshooting. This README is a quick reference.

Install

bash
# macOS / Linuxcurl -fsSL https://raw.githubusercontent.com/hpp-io/x402-tools/main/install/install.sh | bash# Windows (PowerShell)irm https://raw.githubusercontent.com/hpp-io/x402-tools/main/install/install.ps1 | iex# …or npmnpm install -g @hpp-io/x402-mcp-bridge

Needs Node 20+. On a headless box (no OS keychain) use setup --print-key — see the manual.

Quick start

bash
hpp-x402 setup --install claude-code   # create a wallet + register into your hosthpp-x402 fund                          # where to send USDC.e (gasless, no native gas)hpp-x402 status                        # confirm it's wired

Restart your host and your agent can discover and pay for services. Browse and pay from the terminal too:

bash
hpp-x402 discover "price prediction"               # semantic search; your network onlyhpp-x402 describe <id>                             # input args (schema + example) — no paymenthpp-x402 call <url-or-id> --body '{"hi":"there"}'  # pay + call — a URL, or an id from discover

Pay from your HPP Smart Wallet instead

Rather than funding the agent's key, let it pay from your HPP Smart Wallet under a spending limit you set. In the wallet, open Agents → New, paste the agent's address (hpp-x402 wallet address), issue the delegation, then run the command the wallet shows — it is this, with the value filled in:

bash
hpp-x402 install claude-code -n eip155:190415 --delegation 0x…

Run it on the machine where the agent's key lives. The value is checked against that key and the network before it is written, and again each time the bridge starts. The value can only be used by that key, within the limit, until it expires — but it does end up in your shell history, so treat it like a card with a cap. To stop the agent, revoke the delegation in the wallet.

Full command reference, selling (serve), schemes, and Safe mode → the manual.

Use it from an MCP host

The host spawns the bridge over stdio. A bare entry boots zero-config on HPP Sepolia with an auto-created keychain wallet:

jsonc
{ "mcpServers": { "hpp-x402": {  "command": "npx", "args": ["-y", "@hpp-io/x402-mcp-bridge"]} } }

hpp-x402 install <host> writes this for you. Note: a bare npx @hpp-io/x402-mcp-bridge runs the MCP server (what the host wants) — for the CLI use npx -y -p @hpp-io/x402-mcp-bridge hpp-x402 <command>.

Host-facing tools

ToolWhat it does
wallet_addressreport your wallet address (to fund it)
hpp_discoverlist/search the curated HPP directory (read-only)
hpp_describeone service's input args — schema + example (read-only)
hpp_callcall a discovered service (HTTP/MCP/A2A); pays via your wallet
x402_http_callpay + call any x402 HTTP endpoint
pay_a2a_agentpay + message another A2A agent

Every paid call stays within your spend cap (per-call cap defaults to 1 USDC.e; raise it with wallet_set_limit) and is paid only in allowlisted tokens; discovery never holds funds or sees your keys.

Key env (all optional)

VarNotes
DELEGATE_PRIVATE_KEYauto-created in the OS keychain if unset
HPP_NETWORKeip155:181228 Sepolia (default) / eip155:190415 Mainnet
HPP_X402_ALLOWED_ASSETSextra tokens the bridge may pay in (comma-separated addresses). By default only USDC.e (both networks) and HAC (Sepolia test token); a 402 priced in any other token is refused before signing
RESOURCE_SERVER_URLproxy one upstream MCP server (omit = local tools only)
SAFE_ADDRESS + ALLOWANCE_MODULE_ADDRESSset both = Safe (governance) mode
HPP_PAYMENT_DELEGATIONERC-7710 payment delegation a wallet granted to this key: pays erc7710 accepts from the user's smart account under on-chain caps — this key needs no USDC.e. hpp-x402 install <host> --delegation <value> writes it. Checked against the key and the network at install and at boot (a value issued on the other network, revoked, or expired stops the bridge with the reason); without it such accepts are skipped

Full environment reference + Safe/governance setup are in the manual.

Related

Building an agent / SDK integration (LangChain, OpenAI function-calling, AgentKit, A2A)? See the runnable gallery → hpp-io/hpp-x402-agent-sample

License

Apache-2.0

Source: README.md at commit d26997e

Tools

0
SourceWeft has not started this package in its sandbox yet, so its tools are not known.

Version history

5
  1. v0.1.24LatestNov 3, 2026
  2. v0.1.23Oct 22, 2026
  3. v0.1.22Oct 15, 2026
  4. v0.1.21Oct 2, 2026
  5. v0.1.18Sep 16, 2026

Score

40% of the applicable checks met

How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.

  • Reached in the last 30 days25 pts

    Keep the endpoint answering the MCP handshake; SourceWeft probes it every 30 days.

  • Auth declared10 pts

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  • Tools listed15 pts

    Answer tools/list without a credential, or ship a package that starts in a sandbox without one.

  • DescriptionRequired15 pts
  • Logo10 pts
  • Documentation15 pts
  • License10 pts

    Declare a license in the repository or the registry entry.