HOW IT WORKS

AgentGate is 5 layers,
not just payments

x402 is the payment rail — one layer. AgentGate solves the full loop: how does an agent find, pay for, and use an API — and how does a developer monetize one?

5
Agent Integrations
MCP · LangChain · CrewAI · SDKs
4
Discovery
Marketplace API · Search · Categories
3
Payment
x402 · USDC · Base · Solana
2
Middleware
Express · Hono · Next.js · 3 lines of code
1
Fulfillment
11 live AI endpoints · Your endpoints
1

Fulfillment — The Endpoints

The actual AI services that do real work

At the bottom of the stack are real API endpoints — services that accept input and return results. AgentGate runs 11 live endpoints powered by Whisper, Claude, Gemini, and pure Node.js. But any developer can add their own.

try it — this is a real endpoint
curl -X POST https://fulfill.agentgate.online/v1/email-validate \
  -H "Content-Type: application/json" \
  -d '{"email": "test@gmail.com"}'

# → 402 Payment Required
# This endpoint works. It just needs payment first.
💡These aren't stubs. Every endpoint runs real AI inference or real utility logic. The payment gate is the only thing between you and the result.
2

Middleware — The Payment Gate

Add pay-per-call to any existing API in 3 lines

The middleware sits in front of your endpoint and handles the x402 payment flow. When a request comes in without payment, it returns 402 Payment Required. When payment is attached, it verifies and lets the request through.

your-api.ts — that's it, 3 lines
import { paymentMiddleware } from '@agent-gate/middleware/hono';

app.use('/api/translate', paymentMiddleware({
  price: '$0.02',          // USDC per call
  wallet: process.env.MY_WALLET,
}));

// Your handler runs ONLY after payment is verified
app.post('/api/translate', async (c) => {
  const { text, to } = await c.req.json();
  return c.json({ translated: await translate(text, to) });
});

Works with Express, Hono, and Next.js. Your existing code doesn't change — you just add the middleware.

🔑This is the key insight: sellers don't need to build a billing system, manage API keys, or send invoices. The middleware handles everything. Set a price, set a wallet, deploy.
3

Payment — x402 + Facilitator

USDC payments over HTTP, verified on-chain

x402 is Coinbase's open protocol for native HTTP payments. It adds a payment header to standard HTTP requests — no API keys, no accounts, no invoices. AgentGate uses x402 under the hood, but you don't need to understand it to use AgentGate.

the x402 payment flow
# Step 1: Agent calls endpoint (no payment)
POST /v1/transcribe → 402 Payment Required
← Header: price=$0.015, network=base, payTo=0x4C...

# Step 2: Agent signs USDC payment and retries
POST /v1/transcribe
→ Header: X-PAYMENT: <signed USDC transfer>

# Step 3: Facilitator verifies payment on-chain
✓ Payment valid → settle on Base/Solana

# Step 4: Endpoint returns result
← 200 OK: { "transcript": "Hello world..." }

The Facilitator is the payment verifier. It checks that the USDC payment is real before the endpoint runs. AgentGate runs its own facilitator supporting both Base (EVM) and Solana mainnet — unlike the public x402 facilitator which only supports testnet.

⛓️Payments are real USDC on real chains. Not wrapped tokens, not IOUs, not credits. When an agent calls your endpoint, USDC moves to your wallet.
4

Discovery — The Marketplace

Agents search for endpoints by capability, price, or category

Before an agent can pay for a service, it needs to find one. The Discovery API lets agents search the marketplace by capability, category, or keyword — and get back endpoint URLs, pricing, and descriptions.

discovery — find what you need
# Search for transcription endpoints
curl https://api.agentgate.online/v1/discover?q=transcribe

{
  "endpoints": [{
    "url": "https://fulfill.agentgate.online/v1/transcribe",
    "description": "Audio → transcript with timestamps",
    "category": "audio",
    "price_usdc": "0.015",
    "active": true
  }]
}

# Browse by category
curl https://api.agentgate.online/v1/discover?category=code

# List all categories
curl https://api.agentgate.online/v1/discover/categories
🔍Discovery is what makes AgentGate a marketplace, not just a payment system. Agents don't need hardcoded URLs — they search for capabilities and find the best option.
5

Agent Integrations — The Distribution Layer

Let any AI agent framework discover and call endpoints natively

The top of the stack is what agents actually interact with. AgentGate has native integrations for every major agent framework — so agents can discover, pay, and use endpoints without custom HTTP code.

CLI
Init, configure, and register endpoints
npx @dkerpal/agent-gate init
Discovery API
Browse endpoints via REST
curl api.agentgate.online/v1/discover
MCP ServerSoon
Claude Code, Cursor, any MCP client
Coming Soon
TypeScript SDKSoon
Full client with x402 payment handling
Coming Soon
Python SDKSoon
Client + LangChain + CrewAI tools
Coming Soon
discover and call — it's just HTTP
# 1. Discover endpoints
curl https://api.agentgate.online/v1/discover?category=code

# 2. Call an endpoint (returns 402 — needs x402 payment)
curl -X POST https://fulfill.agentgate.online/v1/email-validate \
  -H "Content-Type: application/json" \
  -d '{"email": "test@gmail.com"}'

# Agent's x402 client handles payment automatically.
# No API keys. No signup. Just HTTP + USDC.
🤖This is the endgame. An agent that can discover capabilities, pay for them, and use the results — all autonomously. No human signing up for APIs, managing keys, or paying invoices.

The Full Loop

Agent (MCP/LangChain/SDK)
↓ "I need transcription"
Discovery API → finds /v1/transcribe at $0.015
↓ POST with audio file
Middleware → returns 402, price=$0.015
↓ signs USDC payment, retries
Facilitator → verifies payment on Base
↓ payment valid
Endpoint (Whisper) → returns transcript
Total time: ~3 seconds · Cost: $0.015 USDC · No signup · No API key
Start Building →Browse Endpoints