How to Publish a Paid API for AI Agents Using MCP and AgenticTrade

Most API monetization guides assume your consumers are humans who browse a marketplace, read your docs, and manually configure auth. That assumption is becoming outdated.

AI agents do not browse. They query a service registry at runtime, read machine-structured MCP tool descriptors, execute calls autonomously, and handle payment without a human in the loop. The infrastructure for that workflow is what AgenticTrade is building.

This article walks through the practical steps to register your API on AgenticTrade — an MCP-native marketplace where AI agents can discover, authenticate, and pay for your API per call in USDC.

What MCP Actually Does Here

MCP (Model Context Protocol) is a protocol for exposing tools and data sources to LLM-based agents in a standardized format. An MCP server is essentially a structured interface that declares:

• What functions your API exposes (tool names and descriptions)

• What input parameters each function accepts (typed schemas)

• What agents can expect in return

When an agent connects to an MCP server, it can read all of that without touching your documentation. The MCP tool descriptors load directly into the agent's context. The agent then calls your function as if it were a local tool — the MCP layer handles routing to your actual HTTP endpoint.

AgenticTrade adds a marketplace layer on top: discovery, auth proxy, usage metering, and payment settlement. Your API gets a marketplace listing. Agents query the listing. AgenticTrade brokers the call.

AI Agent (Claude / GPT / local LLM)  |  | MCP protocol  v AgenticTrade MCP Marketplace  | service discovery + auth proxy + metering + settlement  v Your API endpoint (FastAPI / Flask / anything that speaks HTTP)

AI Agent (Claude / GPT / local LLM)  |  | MCP protocol  v AgenticTrade MCP Marketplace  | service discovery + auth proxy + metering + settlement  v Your API endpoint (FastAPI / Flask / anything that speaks HTTP)

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Prerequisites

• A working HTTP API endpoint (we use FastAPI in the examples below)

• Python 3.10+

• An account at agentictrade.io

The platform provides a free FastAPI starter kit with auth middleware, metering hooks, and proxy key validation already wired in. Download it from your dashboard or directly:

curl -O https://agentictrade.io/api/v1/download/starter-kit unzip starter-kit

curl -O https://agentictrade.io/api/v1/download/starter-kit unzip starter-kit

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If you prefer to adapt your existing API, read on.

Step 1: Prepare Your API Endpoint

Your endpoint needs to do two things: validate the proxy token that AgenticTrade passes in the Authorization header, and return a response in a consistent JSON shape.

Here is a minimal FastAPI example — a sentiment analysis endpoint:

from fastapi import FastAPI, HTTPException, Request from pydantic import BaseModel

from fastapi import FastAPI, HTTPException, Request from pydantic import BaseModel

app = FastAPI()

class AnalyzeRequest(BaseModel): text: str

class AnalyzeResponse(BaseModel): text: str sentiment: str # "positive", "negative", "neutral" confidence: float

@app.post("/v1/analyze", response_model=AnalyzeResponse) def analyze(body: AnalyzeRequest, request: Request):

AgenticTrade passes a scoped proxy token — your real key never leaves

the platform. Validate the token is present; the proxy layer has already

verified it against your registered credentials.

token = request.headers.get("Authorization", "") if not token.startswith("Bearer "): raise HTTPException(status_code=401, detail="Missing bearer token")

Your business logic

result = run_sentiment_model(body.text)

return AnalyzeResponse( text=body.text, sentiment=result.label, confidence=result.score, )`

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The proxy key system means you register your actual upstream API key once in the AgenticTrade dashboard. From that point, all consuming agents receive a scoped proxy credential. If you need to revoke access for a specific buyer, you revoke their proxy key — your underlying service is not exposed.

Step 2: Register on AgenticTrade

Sign up at agentictrade.io and complete the 3-step listing wizard. It takes about two minutes.

The wizard collects:

• Service name and description — This becomes part of the MCP Tool Descriptor that agents read. Write it for a machine audience: precise, functional, no marketing language.

• Endpoint URL and auth type — The URL you deploy your API to. Auth type: bearer, api_key, or oauth2.

• Pricing — Price per call in USDC (e.g., 0.002), optional per-MB charge, rate limit per hour.

For the detailed walkthrough of each field, see the onboarding guide.

Once submitted, AgenticTrade generates the MCP Tool Descriptor automatically from your endpoint spec and makes your service discoverable to agents.

Step 3: Understand What Agents See

After registration, your service appears in the AgenticTrade MCP registry. When an agent queries the registry, it receives something like this:

{  "name": "sentiment-analysis-v1",  "description": "Analyze sentiment in text. Returns positive, negative, or neutral label with confidence score.",  "input_schema": {  "type": "object",  "properties": {  "text": {  "type": "string",  "description": "The text to analyze. Max 10,000 characters."  }  },  "required": ["text"]  },  "price_per_call_usdc": 0.002,  "provider": "your-vendor-name" }

{  "name": "sentiment-analysis-v1",  "description": "Analyze sentiment in text. Returns positive, negative, or neutral label with confidence score.",  "input_schema": {  "type": "object",  "properties": {  "text": {  "type": "string",  "description": "The text to analyze. Max 10,000 characters."  }  },  "required": ["text"]  },  "price_per_call_usdc": 0.002,  "provider": "your-vendor-name" }

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The agent loads this descriptor as a tool. When it invokes sentiment-analysis-v1, AgenticTrade:

• Verifies the calling agent has sufficient balance

• Routes the call to your endpoint with a scoped proxy token

• Records the metered usage

• Deducts USDC from the agent's pre-funded balance

• Credits your vendor account

You receive a settlement to your configured payout address. No invoicing, no chasing, no manual reconciliation.

Step 4: Test with a Real Agent Call

Before going live, test the full call path from your local environment:

import anthropic

client = anthropic.Anthropic()

In production, the agent discovers this via the MCP registry.

For testing, you can hardcode the tool definition.

tools = [ { "name": "sentiment_analysis_v1", "description": "Analyze sentiment in text", "input_schema": { "type": "object", "properties": { "text": {"type": "string"} }, "required": ["text"] } } ]

response = client.messages.create( model="claude-opus-4-6", max_tokens=1024, tools=tools, messages=[ { "role": "user", "content": "What is the sentiment of this headline: 'Markets rally on strong jobs data'?" } ] )

The agent will call the tool; you handle tool_use blocks in your loop.

for block in response.content: if block.type == "tool_use": print(f"Agent called: {block.name} with input: {block.input}")`

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In production, agents connected to the AgenticTrade MCP server discover your tool without any hardcoding on the consumer side.

Commission Structure

AgenticTrade uses a graduated commission schedule that rewards providers for staying on the platform:

Month Commission

Month 1 0% (free trial)

Months 2-3 5%

Month 4+ 10% (standard)

Providers who maintain a health score above 95% (uptime >=99.5%, p99 latency <500ms, sustained over 90 days) qualify for the Premium quality tier at 6% permanently.

For comparison, RapidAPI charges 25% with no pathway to reduce it.

If you were referred by another provider, your free trial extends to two months before the 5% growth rate begins.

Payment Settlement

Buyers pre-fund a balance in USDC. Per-call charges are deducted automatically. As a provider, you receive settlement to:

• A USDC wallet address (Base network, via x402 protocol)

• PayPal

• Any of 300+ supported tokens via NOWPayments

There is no minimum payout threshold beyond what your configured payout method requires.

Who This Is For

This setup makes sense if you have any of the following:

• A specialized model or data pipeline you want to expose as a paid API

• An existing API sitting on RapidAPI where the 25%+ commission is eating into margins

• A service that AI agents would find useful at runtime (data enrichment, inference, on-chain queries, document processing, etc.)

• Any HTTP endpoint you want to monetize without building auth, billing, and payment infrastructure from scratch

The free FastAPI starter kit removes most of the boilerplate. The 3-step wizard handles listing. First month is zero commission while you validate demand.

Open Source

The Agent Commerce Framework powering AgenticTrade is MIT licensed. If you want to audit the metering logic, deploy a private marketplace instance, or contribute to the protocol:

github.com/JudyaiLab/agent-commerce-framework

Getting Started

• Download the starter kit or adapt your existing endpoint

• Register at agentictrade.io — 3-step wizard, ~2 minutes

• Follow the full onboarding walkthrough: judyailab.com/en/posts/agentictrade-api-onboarding/

• First month: zero commission

The full framework is on GitHub. If you hit something that doesn't work as described, open an issue — we want to know what breaks in practice.