# Global flags > Flags that select network, account, automation, protocol, and debugger behavior — plus the environment variables that override defaults. Global flags come before the subcommand. Precedence: explicit flags override environment variables, which override `pay.toml`, which overrides built-in defaults. ```sh pay --sandbox curl pay --mainnet --account work curl pay --no-dna --sandbox curl pay --debugger claude ``` ## Network `--sandbox`, `--local`, and `--mainnet` are mutually exclusive. With no network flag, `pay` reads the network from the 402 challenge advertisement. | Flag | Short | What it does | | ----------- | ----- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `--sandbox` | `-s` | Route to the hosted Surfpool localnet (`https://402.surfnet.dev:8899`) and auto-fund an ephemeral wallet on first use. Use this for everything except real spend. | | `--local` | — | Route to a local Surfpool at `http://localhost:8899`. Useful when developing the validator side. | | `--mainnet` | — | Force mainnet. Signs with the wallet bound to `mainnet` in `accounts.yml`. | ### Default endpoints | Network | RPC URL | Override | | -------------------- | ------------------------------------- | ------------------------------------------ | | mainnet | `https://api.mainnet-beta.solana.com` | `PAY_MAINNET_RPC_URL`, `pay.toml: rpc_url` | | sandbox | `https://402.surfnet.dev:8899` | `PAY_RPC_URL`, or pass `--local` | | localnet (`--local`) | `http://localhost:8899` | `PAY_RPC_URL` | The sandbox host is a hosted [Surfpool](https://surfpool.run) cluster that auto-funds ephemeral wallets on first use — no setup required for tests and examples. ## Account | Flag | Type | Description | | ------------------ | ------ | ------------------------------------------------------------------------------------------------------------------------------------------------ | | `--account ` | string | Use a named account from `accounts.yml`. In sandbox/local modes this selects a wallet within `localnet`; on mainnet it overrides `active: true`. | ## Automation and logging | Flag | Short | Description | | ----------- | ----- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `--no-dna` | — | Mark the caller as automation. Forces JSON output and non-interactive defaults. Also set by the `NO_DNA` environment variable, and implicit when stdout is not a TTY. | | `--verbose` | `-v` | Show verbose tracing. Equivalent to `RUST_LOG=pay=info,warn`. | When `--no-dna` is active, 402 challenges and payment events are emitted as structured JSON on stderr; the response body still lands on stdout, so pipelines work unchanged. ## Protocol | Flag | Description | | -------- | ------------------------------------------------------------------------------- | | `--x402` | Force the x402 payment protocol. Refuses MPP fallback. Conflicts with `--mpp`. | | `--mpp` | Force the MPP payment protocol. Refuses x402 fallback. Conflicts with `--x402`. | Without either flag, `pay` negotiates from the 402 challenge advertisement. ## Debugger ```sh pay --debugger claude pay --debugger curl ``` `--debugger` launches the Payment Debugger proxy on `0.0.0.0:1402`. The PDB UI is served at `http://127.0.0.1:1402/`; MCP `curl` requests are routed through it (via `PAY_DEBUGGER_PROXY`) so every payment exchange is captured and replayable. ## Environment variables | Variable | Purpose | Default | | ----------------------- | ------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------- | | `PAY_API_URL` | pay-api host (stablecoin balances, onramp). | `https://api.gateway-402.com` | | `PAY_ONRAMP_HOST` | Browser onramp host. Hits `/onramp`, which redirects to MoonPay with the server-side API key. | `https://api.gateway-402.com` | | `PAY_RPC_URL` | Solana RPC URL used by the payment client. Set by `--sandbox`/`--local`; otherwise read from the challenge or `pay.toml`. | _challenge-driven_ | | `PAY_MAINNET_RPC_URL` | Mainnet RPC override for balance queries. | `https://api.mainnet-beta.solana.com` | | `PAY_NETWORK_ENFORCED` | Set internally by `--sandbox`/`--mainnet`/`--local` so the MCP `curl` tool inherits the override. | _unset_ | | `PAY_PROTOCOL_ENFORCED` | Set internally by `--x402`/`--mpp`. | _unset_ | | `PAY_ACTIVE_ACCOUNT` | Force a specific account name (overrides `active: true` in `accounts.yml`). | _resolved from `accounts.yml`_ | | `PAY_CONFIG` | Path to a `pay.toml` config file. | `./pay.toml`, then `~/.config/pay/pay.toml` | | `PAY_DEBUGGER_PROXY` | Proxy URL injected into the MCP `curl` tool. Set by `--debugger`. | _unset_ | | `PAY_API_FEE_PAYER` | Fee-payer override for gateway-routed subscription cancellations. | _unset_ | | `PAY_ENV` | Deployment environment label for telemetry. | _unset_ | | `NO_DNA` | When set, marks the caller as an AI agent: enables auto-pay and JSON output. | _unset_ | | `RUST_LOG` | Tracing filter. `--verbose` sets `pay=info,warn`; otherwise `warn`. | `warn` | ## Hidden flags Two flags exist but are hidden from `--help` because they're experimental safety gates. Use only when you understand the trade-off. | Flag | What it does | | -------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `--yolo-upto ` | Automatically satisfy 402 challenges up to this stablecoin micro-units cap, without prompting. Subscription currencies that aren't priced against stablecoins still prompt. | | `--dev` | Alias for `--sandbox`. Retained for compatibility. | The flags will likely change shape; don't put them in CI scripts.