Rank 9inactivex402

x402-mcp (Vercel)

Charge per MCP tool call with x402 — a thin wrapper over mcp-handler

inactive: Version 0.1.1, last published September 2025.

Rank: 9 of 14
Composite score: 7.8 / 10
Schemes: x402
Role: Pays 402 challenges; Charges with 402
Kind: sdk
Maturity: inactive
Protocol / rail: x402 (USDC on Base) for MCP servers
Assets: USDC
Networks: base
Custody model: Self-custodial (your recipient address; clients sign with their own key)
Node management: Not required
MCP native: Yes
License: MIT
Last verified: 2026-10-15

Overview

x402-mcp, announced by Vercel, is a light wrapper around the mcp-handler package that lets an MCP server charge per tool call over x402. paidTool attaches a price to a tool, createPaidMcpHandler configures the receiving wallet and exports Next.js route handlers, and withPayment wraps an AI SDK MCP client so 402 challenges are paid automatically. It is small and ergonomic, but early and quiet: the package is at 0.1.1, was last published in September 2025, and the documented paidTool signature differs between sources, so check the installed version before copying examples.

Key advantages

paidTool attaches a price to individual MCP tools; free and paid tools coexist
createPaidMcpHandler exports Next.js route handlers
withPayment wraps an AI SDK MCP client to pay 402 challenges automatically

Trade-offs

Version 0.1.1, with no release since September 2025
Documented paidTool signatures differ between sources — check the installed version
The code lives in a personal GitHub account rather than a Vercel organization

Evaluation matrix

Custody & Sovereignty8.0
Self-custodial with exit guarantees vs. centralized/custodial risk. A 10 means the holder keeps their own keys and can unilaterally exit to the base chain; a custodial platform scores around 4.
Operational Friction8.5
Infrastructure burden. Zero nodes, channels or liquidity to manage scores a 10; running and maintaining your own Lightning node scores around 4–5.
Agent Native Support9.0
Out-of-the-box MCP server integration, typed tool calls and LLM-friendly setup. A first-party MCP server scores 9–10; a library or CLI an agent can drive scores 6–8.
Payment Rails & Assets7.0
Breadth of settlement rails and assets: Lightning for true micropayments, stablecoins for a stable unit of account, cards for mainstream reach. A single asset on a single network scores around 7.
Settlement Speed & Fees8.0
Instant sub-second settlement with near-zero overhead scores a 10. Block-bound settlement scores around 8; card-network settlement and fees score lower.
Developer DX6.5
SDK quality, documentation, maintenance and copy-paste integration speed. Alpha-stage API churn, stale releases or inconsistent docs lower the score.

Why these scores. Custody 8: payments go to your own address; clients sign with their own key. Friction 8.5: deploys as a Next.js route, needs a facilitator. Agent 9: MCP-native paid tools and a paying client. Rails 7: USDC on Base. Settlement 8: Base. DX 6.5: early, inactive package with inconsistent docs.

Integration

Install

npm i x402-mcp

Best for

Next.js developers who want to charge per call for individual MCP tools.

Sources

Every claim on this page was checked against these sources on 2026-10-15. Maturity “inactive” means: no published release in the last 12 months.

Machine-readable

fetch this entry as JSON

curl "https://402mcp.org/api/v1/solutions?id=vercel-402-mcp-middleware&view=full"

or as Markdown

curl -H 'Accept: text/markdown' https://402mcp.org/solutions/vercel-402-mcp-middleware