x402-only model
The CLI is x402-only. It does not send an x-api-key header, and it ignores BRICKKEN_API_KEY / BKN_API_KEY if they are set. Instead, every request is paid through x402:
- The CLI calls a Brickken endpoint (e.g.
/prepare-transactions).
- If payment is required, the API responds
402 Payment Required with a PAYMENT-REQUIRED header.
- The CLI signs the x402 payment locally and retries with an
X-Payment header.
The same private key is used both to sign blockchain transactions and to sign x402 payments.
Your private key never leaves your machine. Both transaction signing and x402 payment signing happen locally. Treat the key as a secret: prefer an .env file or environment variable over passing --private-key inline.
Provide a private key
export BRICKKEN_PRIVATE_KEY=0x...
BKN_PRIVATE_KEY is accepted as an alias.
Environments and base URLs
Select the environment with --env or BRICKKEN_ENV (default: sandbox):
| Environment | Base URL |
|---|
sandbox (default) | https://api.sandbox.brickken.com |
production | https://api.brickken.com |
--base-url or BRICKKEN_BASE_URL when needed.
The CLI’s default sandbox base URL is https://api.sandbox.brickken.com. Some older API Reference pages show https://api-sandbox.brickken.com — use the value above for the CLI.
Networks and chain IDs
Pass the target chain with --chain. Both decimal and hex forms are accepted, and common decimal IDs are normalized automatically — for example Sepolia can be passed as 11155111 or aa36a7.
| Network | Decimal | Hex |
|---|
| Ethereum mainnet | 1 | 0x1 |
| Base mainnet | 8453 | 0x2105 |
| BNB Smart Chain | 56 | 0x38 |
| Polygon mainnet | 137 | 0x89 |
| Sepolia testnet | 11155111 | 0xaa36a7 |
| Polygon Amoy testnet | 80002 | 0x13882 |
RPC URL
Some commands (notably create-token) wait for the deployment receipt to read back the deployed tokenAddress. Sepolia has a built-in public RPC fallback; for other chains set an RPC:
export BRICKKEN_RPC_URL="https://ethereum-sepolia-rpc.publicnode.com"
BKN_RPC_URL is accepted as an alias, or use --rpc-url.
Configuration precedence
Configuration is resolved in this order (highest priority first):
- Command-line flags —
--env, --base-url, --private-key, --rpc-url, --env-file, --json
- Environment variables —
BRICKKEN_* or BKN_*
.env file in the current working directory (or the path given by --env-file)- Defaults —
sandbox environment, public Sepolia RPC fallback
Global flags
| Flag | Description |
|---|
--env <sandbox|production> | Target Brickken environment |
--base-url <url> | Override the Brickken API base URL |
--private-key <key> | Private key for local signing and x402 payments |
--rpc-url <url> | RPC URL used to wait for token deployment receipts |
--env-file <path> | Env file to load before resolving config |
--json | Print machine-readable JSON output |
Environment variables
| Variable | Alias | Purpose |
|---|
BRICKKEN_PRIVATE_KEY | BKN_PRIVATE_KEY | Signing and x402 payment key |
BRICKKEN_BASE_URL | BKN_BASE_URL | API base URL |
BRICKKEN_RPC_URL | BKN_RPC_URL | RPC for receipt polling |
BRICKKEN_ENV | BKN_ENV | sandbox or production |
Budget note
Both prepare and send are x402-priced. Budget testnet USDC accordingly — a full run with retries can consume roughly 0.02 USDC per executed command. Fund the wallet behind BRICKKEN_PRIVATE_KEY with enough USDC on the chain you target.
