Accept payments from agents, scripts, and API clients.

Overview

What AgentPay Does

AgentPay turns your existing API into a paid API without requiring clients to integrate with your backend directly. You configure projects, payment channels, endpoints, and optional backend headers in the dashboard. Clients then call generated AgentPay URLs. If payment is missing or invalid, the client receives a protocol-specific HTTP 402 response. If payment is valid, the request is forwarded to your backend and the backend response is returned to the client.

Start here

Quickstart

# Generated URL shape
https://agent-proxy.alchemy.com/v1/{protocol}/{projectId}/{endpointSlug}/{path}

# Example testnet call without payment; this should return HTTP 402
curl https://agent-proxy.alchemy.com/v1/x402-testnet/{projectId}/chat/messages

Launch checklist

Onboarding Steps

1. Create your account and team.Sign up, confirm you can access the dashboard, and pick the plan that matches your launch stage. Free is intended for testnet validation.
2. Create a project.Give the project a customer-facing name and description. This information appears in generated discovery metadata.
3. Enable one or more payment channels.Start with x402 Testnet or MPP Tempo Testnet. Add mainnet or card-backed channels after your client flow is working end to end.
4. Add endpoints.For each API surface, set a slug, HTTP method, backend URL, request schema, response schema, and any public parameters agents should know about.
5. Add backend headers if needed.Use custom headers for secrets your backend expects, such as internal API keys. These are injected into forwarded requests and are not part of the public URL.
6. Test unpaid and paid requests.First confirm unpaid requests return 402. Then confirm a paid retry reaches your backend, returns the expected payload, and includes a payment response header.
7. Publish your URLs and discovery document.Share protocol-specific URLs with clients and give agents the OpenAPI discovery URL so they can inspect routes and payment metadata.

Model

Core Concepts

Runtime

How Requests Work

Reference

Proxy URL Structure

https://agent-proxy.alchemy.com/v1/{protocol}/{projectId}/{endpointSlug}/{path}

Query parameters are preserved and forwarded. For example, a request to /v1/x402/{projectId}/search/items?q=books forwards q=books to the configured backend endpoint after payment passes.

DNS

Custom Domains

Paid teams can attach one custom domain to each project. After a custom domain is active, clients can use shorter URLs without the project ID segment.

# Standard AgentPay URL
https://agent-proxy.alchemy.com/v1/{protocol}/{projectId}/{endpointSlug}/{path}

# Custom domain URL
https://api.example.com/v1/{protocol}/{endpointSlug}/{path}

# Custom domain discovery
https://api.example.com/openapi.json

Discovery

OpenAPI Discovery

Every project can expose a generated OpenAPI document. It describes the public AgentPay routes, request and response schemas, enabled operations, and the x-payment-info metadata agents use to understand supported payment protocols and prices.

# Project-scoped discovery URL
https://agent-proxy.alchemy.com/v1/{projectId}/openapi.json

# Alternate discovery URL
https://agent-proxy.alchemy.com/openapi.json?projectId={projectId}

Protocols

Protocol Pages

A project can enable more than one channel. Each channel gets its own URL segment, credential format, and 402 response shape. Share the protocol URL that matches the client's payment capability.

https://agent-proxy.alchemy.com/v1/x402/{projectId}/{endpointSlug}/{path}

https://agent-proxy.alchemy.com/v1/x402-testnet/{projectId}/{endpointSlug}/{path}

https://agent-proxy.alchemy.com/v1/mpp-tempo/{projectId}/{endpointSlug}/{path}

https://agent-proxy.alchemy.com/v1/mpp-tempo-testnet/{projectId}/{endpointSlug}/{path}

https://agent-proxy.alchemy.com/v1/mpp-stripe/{projectId}/{endpointSlug}/{path}

Clients

Setting Up Agents

Agents should be given the discovery document, one or more starting URLs, and clear spend limits. For x402 channels, the agent needs access to a funded wallet and signing code. For MPP channels, the agent or client runtime needs to understand the returned MPP challenge and retry with the correct Authorization credential.

Usage

Plans and Limits

Plans control project count, monthly request volume, production channel access, and whether overage or custom volume terms apply. The dashboard shows current usage and highlights when your team is approaching its limit.

Operations

Security Checklist

• Use testnet channels before sharing production URLs.
• Keep backend secrets in custom headers rather than public URL parameters.
• Do not expose payment processor secret keys in client-side code or agent prompts.
• Set strict agent spend limits and alert on unexpected usage.
• Validate that your backend only performs paid actions after AgentPay forwards the request.
• Rotate keys and recipient addresses when ownership or operational access changes.

Help

Troubleshooting