AgentCash

AgentCash, from Merit Systems, is a CLI and MCP server that gives AI coding and research agents a single USDC wallet to discover and pay for thousands of third-party APIs per call over the x402 and MPP payment standards. It targets developers and platform teams who want agents to use premium data without managing API keys, signups or subscriptions.

AgentCash is a command-line tool, agent skill and Model Context Protocol (MCP) server from Merit Systems that lets an AI agent pay for web APIs out of one prefunded stablecoin balance instead of holding a separate API key and subscription for each vendor. When an agent calls a paid endpoint, the provider answers HTTP 402 Payment Required with a price; AgentCash signs a USDC payment from a local wallet and retries the request with proof of payment, all inside one call. It supports two open payment standards, x402 (developed by Coinbase, now managed by the Linux Foundation) and MPP (created by Stripe and Tempo Labs), and picks whichever the provider accepts. Payments default to USDC on Base, with Solana supported and Tempo listed as testnet; keys are generated into ~/.agentcash/ and, per the documentation, stored in plaintext on disk. Discovery reads providers' OpenAPI files annotated with x-payment-info, and the MCP server exposes tools such as fetch, search, discover_api_endpoints and get_balance, with an optional per-call maxAmount cap. Installation is one command (npx agentcash install), and documented clients include Claude Code, Claude Desktop, Cursor and Codex. Merit Systems showed it on Hacker News in March 2026 with 280+ APIs and published a formal launch post on 7 July 2026; the docs now cite 3,200+ APIs and the homepage 1.3M+ paid tool calls. Integrations include Zerion on-chain data at roughly $0.01 per call and Rye checkout across 15,000+ retailers, and sellers can price their own routes with the MIT-licensed agentcash-router framework. Merit Systems raised a $10M seed co-led by a16z crypto and Blockchain Capital in January 2025, originally to build open-source contributor attribution, before pivoting its product line toward agentic commerce.

Category

Agent Development

Pricing

Usage-based

Target Market

CTOs, Enterprise Developers, Platform Engineering Teams, API Product Managers

Deployment

API-based, Self-hosted

• ✓
  Single USDC wallet

  One local balance (Base by default, Solana supported) pays any x402 or MPP endpoint, removing per-vendor API keys, signups and subscriptions.

• ✓
  Automatic 402 payment handling

  Detects a 402 Payment Required response, signs the payment from the local wallet and retries with proof, so the agent receives a clean response in one call.

• ✓
  Dual protocol support (x402 and MPP)

  Automatically selects Coinbase's x402 or Stripe and Tempo's MPP based on what each provider accepts, with a paymentProtocol parameter to force one.

• ✓
  MCP server and CLI

  npx agentcash install auto-detects clients such as Claude Code and Cursor and exposes fetch, search, discover_api_endpoints and get_balance tools to the agent.

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  Endpoint discovery

  Reads provider OpenAPI files annotated with x-payment-info, falling back to /.well-known/x402, so agents can find and price APIs before paying.

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  Per-call spend cap

  The fetch tool's optional maxAmount parameter sets the maximum USD a single request may pay, limiting the damage from an unexpectedly expensive route.

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  Wallet-authenticated requests (SIWX)

  Sign-In With X lets an agent authenticate to services with its wallet signature rather than a separately provisioned user account or API key.

• ✓
  AgentCash Router for sellers

  An MIT-licensed TypeScript framework, with Hono and Next.js support, for building x402 and MPP-compatible priced APIs that agents can discover and pay.

• •
  Lead enrichment for GTM agents

  A sales-prospecting agent pays per call for people and company enrichment and social-media data routes, avoiding annual data-vendor contracts for a pilot.

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  Research agents buying premium data

  An analyst agent pulls Zerion on-chain portfolio data across 38+ chains at roughly $0.01 per call, without signing up for a Zerion API key.

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  Agent-initiated physical purchases

  Through Rye's x402 integration an agent creates a checkout intent for $0.02 and places an order for the purchase total plus $0.03 across 15,000+ retailers.

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  Monetising an API to agents

  A data provider adds pay-per-call pricing with the open-source router and publishes a discovery spec so agents in Claude, Cursor and Codex can find and pay for it.

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  Travel and email tasks for assistants

  A personal or ops agent uses bundled travel-search and agent-email routes, paying per request from the shared balance instead of provisioning separate accounts.

There is no subscription or seat fee: you prefund a USDC wallet (Base by default, Solana supported) and each call is priced by the provider, typically $0.001 to $0.10 per request per the docs; examples include Zerion at about $0.01 per call and Rye at $0.02 per checkout intent plus $0.03 to place an order, with network fees separate. New users can receive up to $25 in credits. The documentation reviewed does not publish an AgentCash take rate, invoicing option or enterprise plan.

This page was written from 16 sources, 8 on domains other than agentcash.dev.

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3. 3.agentcash.dev — overview.mdvendor
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5. 5.agentcash.dev — funding.mdvendor
6. 6.agentcash.dev — mcp mode.mdvendor
7. 7.agentcash.dev — fetch.mdvendor
8. 8.agentcash.dev — introducing agent cashvendor
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13. 13.api.github.com — issues
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