x402 Agent Gateway

Pay-per-call APIs for autonomous agents, settled in USDC over x402. No account, no API key, no subscription. An agent discovers the endpoint, gets a 402 with the exact amount, pays, and gets the result.

Live API: https://api.x-402.online

Start here: the free quote

Nothing below costs anything until you choose to pay. Two endpoints are free and require no wallet at all.

npx x402-agent-gateway capabilities                    # what can be solved
npx x402-agent-gateway preview "summarise ethereum etf news"   # the plan and the price

The quote tells you which capability was chosen, why, what it costs, and when a direct route would be cheaper than the gateway. The gateway has a single price, so it overcharges for cheap capabilities. You should know that before you pay, not after.

The flagship product

POST /v1/us/brief — $0.040004

A decision-grade briefing on a US public company, from SEC EDGAR, in one call:

• a summary where every claim cites its origin: [identity], [financials], [filings]
• key points and the open questions the data does not settle
• the underlying facts alongside: identity, three years of annual figures, recent filings

Buying the three underlying routes separately costs $0.090024. This replaces them with a synthesised answer for 56% less, and you can still verify every claim because the raw facts come back with it.

import { Gateway } from "x402-agent-gateway";

const g = new Gateway({ fetch: myX402Fetch });   // any x402-capable fetch
const r = await g.usBrief("AAPL");

r.brief.summary        // "Apple Inc. (CIK 0000320193) is a Nasdaq-listed … [identity]"
r.brief.key_points     // each one cites its source
r.financials.revenue   // the raw figures, to check the summary against
r.filings              // the recent SEC filings

from x402_gateway import Gateway
g = Gateway()
r = g.us_brief("AAPL")
print(r["brief"]["summary"], r["financials"]["revenue"])

Without a payment-capable fetch, usBrief raises PaymentRequired carrying the x402 challenge — amount, network and address. Pay it with whatever tooling you already use. This SDK does not impose its own.

Capabilities behind one endpoint

POST /v1/solve — $0.012002. Send a task in plain words, or name a capability and its input. The gateway resolves which capability is needed, ranks providers by expected net margin and observed success rate, executes, falls back to the next provider on failure, and returns the result with the routing it used.

GET /v1/capabilities returns the input and output schemas, and lists only what is actually servable right now.

Discovery, for machines

Payment

x402, exact scheme, USDC on Base (eip155:8453) and Solana. Each route has a unique amount, so every settlement is attributable on-chain by the amount alone. /v1/us/brief is 40004 micro-USDC, /v1/solve is 12002.

Install

npm install x402-agent-gateway      # Node 20+
pip install x402-agent-gateway      # Python 3.10+, no dependencies

Both are in this repository under node/ and python/. If the published packages are not up yet, point the client at the API directly — the SDK is a thin, optional convenience:

curl -s -X POST https://api.x-402.online/v1/us/brief \
  -H 'content-type: application/json' -d '{"ticker":"AAPL"}'
# → 402 with the exact amount to pay

What this is not

Not investment advice. /v1/us/brief reports what SEC EDGAR contains and cites it; it never recommends buying or selling anything, and it says in open_questions what the filings do not answer rather than filling the gap with a guess.

MIT licensed.