Nexflow Smf

What nexflow-smf MCP server does

The nexflow-smf MCP server supports x402 payment flows for AI agents and SaaS APIs on Base. Its core lifecycle covers routing a payment, checking a payment intent, and settling completed charges. Routing can compare facilitator options using pricing, latency, and reliability information, while verification checks payment proof before a request proceeds.

The repository is organized around several integration pieces. The TypeScript package @nexflow-smf/smf provides a zero-dependency SDK for application code. Solidity contracts implement atomic batch settlement with Merkle proof verification. Examples cover direct SDK usage, AWS CloudFront with Lambda@Edge, and hosted workflows. The project also publishes an Agent Manifest and a catalog of agent services.

How it works

For an edge-gated API, a Lambda@Edge viewer-request function sends the client’s x402-payment header to /x402/verify. A valid payment receives a settlement intent and continues to the origin; an invalid payment receives HTTP 402 payment instructions. After a successful origin response, the origin-response function calls /x402/settle, making delivery the billable event.

Server-side applications can use the SDK with the NexFlow API base URL and an API key. A route request includes values such as the amount, token address, chain identifier, and payment ID. Verification accepts a payment intent and recipient address. The repository’s examples show the route, verify, and settle sequence.

Hosted workflows combine operations such as session creation, budget checks, charge processing, payment verification, batch settlement, route quoting, usage reporting, and alert configuration. Workflow creation and inspection are free, while invocation is paid according to step costs and any creator markup.

Setup and configuration

Install the SDK with:

npm install @nexflow-smf/smf

Configure the client with https://api.nexflowapp.app or another supported NexFlow API base URL and provide NEXFLOW_API_KEY. The repository includes a basic settlement example and an AWS CloudFront plus Lambda@Edge quickstart for pay-per-request access.

Base Mainnet deployments use the listed AtomicBatchSettlement contract and USDC contract. Applications should use the addresses and network values from the repository when building Base payment requests.

Tools and capabilities

Agent-facing capabilities documented in the repository include:

• Listing active facilitators by network and asset
• Comparing USDC routes on Base
• Requesting a quote for a selected facilitator
• Checking NexFlow health and latency
• Simulating charge headers without making a payment
• Retrieving settlement receipts for logs or audits
• Estimating API calls from a USDC budget

The workflow examples add session budgets, spend diagnostics, charge processing, settlement, revenue-share accounting, time-series usage, alerts, and session monitoring.

Limitations and notes

The documented payment target is x402 on Base, with USDC identified in the Base Mainnet contract list. Verification is described as a non-billed step in the CloudFront flow, while settlement is the billable event after a successful origin response.