HPP x402 MCP Bridge
MCP bridge for autonomous x402 payments in HPP USDC.e — discover and pay for services per call.
Installation
Ajoutez ceci à la configuration MCP de votre client (Claude Desktop : claude_desktop_config.json ; Cursor : .cursor/mcp.json ; VS Code et les autres utilisent la même forme « mcpServers »).
@hpp-io/x402-mcp-bridgeclaude mcp add hpp-x402-mcp-bridge -e 'DELEGATE_PRIVATE_KEY=<your delegate_private_key>' -e 'HPP_NETWORK=<HPP_NETWORK>' -e 'RESOURCE_SERVER_URL=<RESOURCE_SERVER_URL>' -e 'SAFE_ADDRESS=<SAFE_ADDRESS>' -e 'ALLOWANCE_MODULE_ADDRESS=<ALLOWANCE_MODULE_ADDRESS>' -- npx -y @hpp-io/x402-mcp-bridge@0.1.23
{
"mcpServers": {
"hpp-x402-mcp-bridge": {
"command": "npx",
"args": [
"-y",
"@hpp-io/x402-mcp-bridge@0.1.23"
],
"env": {
"DELEGATE_PRIVATE_KEY": "<your delegate_private_key>",
"HPP_NETWORK": "<HPP_NETWORK>",
"RESOURCE_SERVER_URL": "<RESOURCE_SERVER_URL>",
"SAFE_ADDRESS": "<SAFE_ADDRESS>",
"ALLOWANCE_MODULE_ADDRESS": "<ALLOWANCE_MODULE_ADDRESS>"
}
}
}
}
Variables d'environnement
DELEGATE_PRIVATE_KEYsecret Delegate EOA private key used to sign payments. Auto-created in the OS keychain if unset.HPP_NETWORKTarget network: eip155:181228 (HPP Sepolia, default) or eip155:190415 (HPP Mainnet).RESOURCE_SERVER_URLOptional upstream MCP server to proxy. Omit to expose only the local tools.SAFE_ADDRESSSafe address for governance (Safe) mode. Set together with ALLOWANCE_MODULE_ADDRESS.ALLOWANCE_MODULE_ADDRESSSafe AllowanceModule address for governance (Safe) mode. Set together with SAFE_ADDRESS.
Documentation
Tirée du README du projet sur GitHub, actualisée chaque semaine. Les liens ouvrent GitHub.
Sommaire
@hpp-io/x402-mcp-bridge
The agent payment rail for HPP. A stdio MCP bridge + the
hpp-x402CLI 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
# macOS / Linux
curl -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 npm
npm 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
hpp-x402 setup --install claude-code # create a wallet + register into your host
hpp-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:
hpp-x402 discover "price prediction" # semantic search; your network only
hpp-x402 describe <id> # input args (schema + example) — no payment
hpp-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:
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:
{ "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
| Tool | What it does |
|---|---|
wallet_address | report your wallet address (to fund it) |
hpp_discover | list/search the curated HPP directory (read-only) |
hpp_describe | one service's input args — schema + example (read-only) |
hpp_call | call a discovered service (HTTP/MCP/A2A); pays via your wallet |
x402_http_call | pay + call any x402 HTTP endpoint |
pay_a2a_agent | pay + message another A2A agent |
Every paid call stays within your spend cap; discovery never holds funds or sees your keys.
Key env (all optional)
| Var | Notes |
|---|---|
DELEGATE_PRIVATE_KEY | auto-created in the OS keychain if unset |
HPP_NETWORK | eip155:181228 Sepolia (default) / eip155:190415 Mainnet |
RESOURCE_SERVER_URL | proxy one upstream MCP server (omit = local tools only) |
SAFE_ADDRESS + ALLOWANCE_MODULE_ADDRESS | set both = Safe (governance) mode |
HPP_PAYMENT_DELEGATION | ERC-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
Questions fréquentes
Qu'est-ce que HPP x402 MCP Bridge ?
MCP bridge for autonomous x402 payments in HPP USDC.e — discover and pay for services per call.
Comment installer HPP x402 MCP Bridge ?
Il s'exécute sur votre machine. Dans Claude Code : claude mcp add hpp-x402-mcp-bridge -e 'DELEGATE_PRIVATE_KEY=<your delegate_private_key>' -e 'HPP_NETWORK=<HPP_NETWORK>' -e 'RESOURCE_SERVER_URL=<RESOURCE_SERVER_URL>' -e 'SAFE_ADDRESS=<SAFE_ADDRESS>' -e 'ALLOWANCE_MODULE_ADDRESS=<ALLOWANCE_MODULE_ADDRESS>' -- npx -y @hpp-io/x402-mcp-bridge@0.1.23. Pour les autres clients, collez la configuration JSON de cette page dans leurs réglages MCP.
Faut-il une clé API pour HPP x402 MCP Bridge ?
Oui. Il attend DELEGATE_PRIVATE_KEY, à renseigner dans sa configuration.
HPP x402 MCP Bridge est-il open source ?
Son code est public sur GitHub, mais le dépôt ne déclare pas de licence standard.
Qui maintient HPP x402 MCP Bridge ?
Il est publié par hpp-io. AI.tn le référence sans le maintenir ni le recommander.
Issu du registre MCP officiel. Être listé n'est pas une recommandation : vérifiez le code et les permissions d'un serveur avant de lui donner accès à vos données.