The missing payment layer for HTTP. pay handles x402 and MPP payment challenges with user-authorized stablecoin signing.
Wrap a selected set of command line tools (curl, claude, codex, whoami, etc.) -- when a stablecoin-gated API returns 402, pay detects the payment protocol, prepares the stablecoin transaction, asks the local wallet to authorize and sign it, then retries with the payment proof.
Install · Quick Start · Docs
# Without pay — you get a 402 curl https://debugger.pay.sh/mpp/quote/AAPL # With pay -- it handles the 402 challenge and returns the response pay --sandbox curl https://debugger.pay.sh/mpp/quote/AAPL
Key Features
💵 Transparent 402 Handling
Wrap your CLI (curl, claude, codex, etc.) -- when an API returns 402, pay detects the payment protocol, prepares the stablecoin transaction, asks the local wallet to authorize and sign it, then retries with the payment proof.
Supports both live payment standards on Solana:
Stablecoins deployed to Solana are supported out of the box.
🤖 AI-Native with MCP
pay ships with a built-in MCP server, letting AI assistants request paid API calls through the same local wallet-approval flow.
# Run Claude Code or Codex with pay injected into the agent session
pay claude
pay codex🛠️ Payment debugging and simulations
pay ships with an embedded Payment Debugger — a local web UI that visualizes every 402 challenge-response cycle as a sequence diagram. See exactly which headers were sent, which protocol was used (MPP or x402), and where things went wrong.
Everything runs locally — no data leaves your machine.
# Start a gateway with the debugger on any API spec pay server start --debugger spec.yml # Or run the bundled demo (sandbox + debugger + sample endpoints) pay server demo
A public debugger is also available.
🔐 Gated Payments via Biometrics
pay lets AI agents use paid APIs without giving them your private key or an API-wide spending credential.
When a command, Claude Code, Codex, or another MCP client hits a paid endpoint, pay prepares the payment locally and asks your wallet backend to authorize the signature. On macOS, that means Touch ID via Keychain. On Windows, Windows Hello. On Linux, GNOME Keyring / polkit. If you reject the prompt, the payment is not signed and the request does not go through.
pay setup # Touch ID on macOS, Windows Hello on Windows, GNOME Keyring on Linux, or choose 1Password📚 Open Source Catalog
The paid API catalog is open source in the pay-skills repo.
Anyone can contribute a provider listing, improve endpoint metadata, or add usage guidance for agents. Catalog entries follow the pay-skills contributing guide, which defines the metadata, pricing, endpoint, and usage-note standards that keep Agent experience consistent.
pay skills search "maps"Good catalog entries make paid APIs easier for both humans and agents to discover, compare, and use safely.
Installation
Prebuilt Binaries
# macOS brew install pay # via NPM npm install -g @solana/pay
From Source
git clone https://github.com/solana-foundation/pay.git
cd pay
just install payVerify
pay --version
Quick Start
# 1. Setup your account pay setup pay whoami # 2. Make a paid gated API call to https://debugger.pay.sh sandbox endpoints pay --sandbox curl https://debugger.pay.sh/mpp/quote/AAPL # 3. Or let your AI agent handle it pay claude
Contributing
cd rust just build # release binary just test # all tests just lint # clippy (warnings = errors)
We welcome contributions — check open issues to get started.
Troubleshooting
Linux: pay topup or pay curl errors with "auth failed"
GNOME Keyring auth uses polkit, which requires a one-time setup step:
sudo cp rust/config/polkit/sh.pay.unlock-keypair.policy /usr/share/polkit-1/actions/
This grants pay the right to prompt for your password or fingerprint before accessing the keypair.
License
MIT — see LICENSE.
Subject to the foregoing, the Terms of Service available at solana.com/tos