x402 Payment Protocol

Use the npx awal@2.10.0 x402 commands to discover, inspect, and call paid API endpoints using the X402 payment protocol. Payments are made in USDC on Base.

Workflow

The typical x402 workflow is:

• Find a service - Search the bazaar or get details for a known endpoint

• Check requirements - Inspect price, method, and input schema

• Make the request - Call the endpoint with automatic USDC payment

Commands

Search the Bazaar

Find paid services by keyword using CDP's vector search:

npx awal@2.10.0 x402 bazaar search <query> [-k <n>] [--network <network>] [--scheme <scheme>] [--max-price <price>] [--json]

Option

Description

-k, --top <n>

Number of results, 1–20 (default: 20)

--network <name>

Filter by chain (base, base-sepolia, polygon, solana, solana-devnet)

--scheme <scheme>

Filter by payment scheme: exact or upto

--max-price <price>

Maximum price in USD (e.g. 0.01)

--asset <address>

Filter by payment asset address

--pay-to <address>

Filter by recipient wallet address

--extensions <type>

Filter by extension type (e.g. outputSchema, bazaar)

--json

Output as JSON

List Bazaar Resources

Browse all available resources:

npx awal@2.10.0 x402 bazaar list [--network <network>] [--full] [--refresh] [--json]

Option

Description

--network <name>

Filter by chain (base, base-sepolia, polygon, solana, solana-devnet)

--full

Show complete details including schemas

--refresh

Re-fetch resource index from CDP API

--json

Output as JSON

Discover Payment Requirements

Inspect an endpoint's x402 payment requirements without paying:

npx awal@2.10.0 x402 details <url> [--json]

Auto-detects the correct HTTP method (GET, POST, PUT, DELETE, PATCH) by trying each until it gets a 402 response, then displays price, accepted payment schemes, network, and input/output schemas.

Make a Paid Request

Call an x402 endpoint with automatic USDC payment:

npx awal@2.10.0 x402 pay <url> [-X <method>] [-d <json>] [-q <params>] [-h <json>] [--max-amount <n>] [--json]

Option

Description

-X, --method <method>

HTTP method (default: GET)

-d, --data <json>

Request body as JSON string

-q, --query <params>

Query parameters as JSON string

-h, --headers <json>

Custom HTTP headers as JSON string

--max-amount <amount>

Max payment in USDC atomic units (1000000 = $1.00)

--correlation-id <id>

Group related operations

--json

Output as JSON

Examples

# Search for weather-related paid APIs

npx awal@2.10.0 x402 bazaar search "weather"

# Search with more results

npx awal@2.10.0 x402 bazaar search "sentiment analysis" -k 10

# Check what an endpoint costs

npx awal@2.10.0 x402 details https://example.com/api/weather

# Make a GET request (auto-pays)

npx awal@2.10.0 x402 pay https://example.com/api/weather

# Make a POST request with body

npx awal@2.10.0 x402 pay https://example.com/api/sentiment -X POST -d '{"text": "I love this product"}'

# Limit max payment to $0.10

npx awal@2.10.0 x402 pay https://example.com/api/data --max-amount 100000

# Browse all bazaar resources with full details

npx awal@2.10.0 x402 bazaar list --full

USDC Amounts

X402 uses USDC atomic units (6 decimals):

Atomic Units

USD

1000000

$1.00

100000

$0.10

50000

$0.05

10000

$0.01

Prerequisites

• Search/Details: No authentication needed

• Pay: Must be authenticated (npx awal@2.10.0 auth login <email>) with sufficient USDC balance (npx awal@2.10.0 balance)

Error Handling

• "Not authenticated" - Run npx awal@2.10.0 auth login <email> first

• "No X402 payment requirements found" - URL may not be an x402 endpoint

• "CDP API returned 429" - Rate limited; cached data will be used if available

• "Insufficient balance" - Fund wallet with USDC (npx awal@2.10.0 balance to check)