pay

The missing HTTP 402 client.

Wrap curl or wget — when an API returns 402, pay detects the payment protocol, signs a transaction, and retries. The response lands on stdout as if nothing happened.

Install · Quick Start · Docs

# Without pay — you get a 402
curl https://payment-debugger.vercel.app/mpp/quote/AAPL

# With pay — it handles the 402 and you get the response
pay --sandbox curl https://payment-debugger.vercel.app/mpp/quote/AAPL

Wrap curl or wget — when an API returns 402, pay detects the payment protocol, signs the transaction, and retries. You get the response body. That's it.

Supports both live payment standards on Solana:

• MPP — Machine Payments Protocol
• x402 — x402 Payment Protocol

Stablecoins deployed to Solana are supported out of the box.

Your keys never touch disk in plaintext. pay stores keypairs in:

• macOS Keychain with Touch ID biometric protection
• GNOME Keyring with password/fingerprint prompt on every use (Linux)
• 1Password vault integration (cross-platform)
• File-based fallback for CI and scripting

pay setup    # Touch ID on macOS, GNOME Keyring on Linux, or choose 1Password

Linux note: 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. Without it, pay topup and pay curl will error.

Set a spending cap and expiration before making requests. The interactive TUI lets you control exactly how much you're willing to spend per session — no surprise charges.

pay ships with a built-in MCP server, giving AI assistants the ability to make paid API calls on your behalf.

# Run Claude Code or Codex with pay injected automatically
pay --sandbox claude
pay --sandbox codex

Get started instantly with an ephemeral keypair auto-funded via Surfpool. No setup, no mainnet tokens needed.

# Uses public sandbox (402.surfnet.dev)
pay --sandbox curl https://payment-debugger.vercel.app/mpp/quote/AAPL

# Or use a local Surfpool instance (localhost:8899)
pay --local curl http://localhost:3402/mpp/quote/AAPL

git clone https://github.com/solana-foundation/pay.git
cd pay/rust
cargo install --path crates/cli

Linux only — install the polkit action to enable keypair auth:

sudo cp rust/config/polkit/sh.pay.unlock-keypair.policy /usr/share/polkit-1/actions/

pay --version

# 1. Generate a keypair (Touch ID protected on macOS)
pay setup

# 2. Make a paid API call (--sandbox uses an ephemeral funded keypair)
pay --sandbox curl https://payment-debugger.vercel.app/mpp/quote/AAPL

# 3. Or let your AI agent handle it
pay --sandbox claude

cd rust
just build   # release binary
just test    # all tests
just lint    # clippy (warnings = errors)

We welcome contributions — check open issues to get started.

Apache-2.0 — see LICENSE.