L402 Setup

Install and configure the Axo pay-per-call stack with Axo Pay, Axo Fetch, and Axo CLI.

Use this page to stand up the full pay-per-call flow quickly.

1) Install Packages

npm install @axobot/pay

npm install @axobot/fetch

npm install -g @axobot/cli

2) Configure Environment

Variable	Required	Default	Used By
`ZBD_API_KEY`	Yes	none	`Axo Pay`, `Axo Fetch` example, `axo`
`ZBD_API_BASE_URL`	No	`https://api.zbdpay.com`	`Axo Pay`, `Axo CLI`
`ZBD_WALLET_TOKEN_CACHE`	No	`~/.zbd-wallet/token-cache.json`	`axo fetch`

Info

Axo Pay can also take apiKey directly in PaymentConfig. If omitted, it falls back to ZBD_API_KEY.

3) Initialize Wallet Identity (Optional but Recommended)

axo init --key <your_api_key>
axo info
axo balance

4) Run the End-to-End Local Demo

From the agents workspace:

npm --prefix axobot-pay run build
ZBD_API_KEY=<your_api_key> npm --prefix axobot-pay run example:http-server

In a second terminal:

npm --prefix axobot-fetch run build
PROTECTED_URL="http://localhost:8787/protected" ZBD_API_KEY=<your_api_key> npm --prefix axobot-fetch run example:zbd

Or use wallet CLI directly:

axo fetch "http://localhost:8787/protected" --max-sats 100

5) Understand Package Roles

@axobot/pay: generates invoice challenge + verifies payment proof on incoming requests.
@axobot/fetch: handles 402 parsing, invoice payment hook, retry with proof, and token caching.
@axobot/cli: CLI workflows (axo) including axo fetch powered by Axo Fetch.

Protect Routes

Add L402 middleware in Express, Hono, and Next.js.

Client Calls

Implement automatic challenge payment and retry.