Nexflow Smf

Official

by NexFlow-SMF · TypeScript

Smart Meta-Facilitator for x402 payments on Base: route, verify, and settle payments.

Route, verify, and settle cryptocurrency payments on Base blockchain.

Topics

basel2paymentssdksmart-contractsusdcx402batch-settlement

README.md15 KBView on GitHub

NexFlow Smart Meta-Facilitator (SMF)

The x402-native metered billing and routing brain for AI agents and SaaS APIs on Base.

NexFlow SMF routes, verifies, and settles x402 micropayments on Base. It acts as an intelligent intermediary between payers and facilitators, selecting the optimal route based on cost, latency, and reliability. This repository contains the on-chain settlement contracts, TypeScript SDK, agent manifest specification, and integration examples.

🎴 Browse AgentCard Catalog →

Discover AI agent services with x402 payment routing through NexFlow SMF. Submit your service to the catalog.

📦 What's Included

Component	Description
`contracts/`	Solidity contracts for atomic batch settlement with Merkle proof verification
`sdk/`	Zero-dependency TypeScript SDK (`@nexflow-smf/smf`) for routing, verification, and settlement
`examples/`	Ready-to-run examples demonstrating common integration patterns
`examples/workflows/`	JSON workflow definitions for the NexFlow SMF workflow host
`examples/client/`	Minimal TypeScript clients showing the 402 → pay → retry pattern

🧩 Skills (Cursor & AI agents)

Canonical list of NexFlow SMF skills. Each skill has a SKILL.md (for Cursor/agents) and lives in nexflow-smf-skills/. Machine-readable manifest: skills-manifest.json · API: GET https://api.nexflowapp.app/.well-known/skills (redirects to manifest).

Skill	Description
List Facilitators	Discover active x402 facilitators by network/asset before quoting or paying.
Route Matrix	Compare priced routes (fees, latency) across facilitators for USDC on Base.
Route Quote	Get a single priced quote for a chosen facilitator before committing.
Settlement Receipt	Fetch a settlement receipt for a completed x402 payment for logs or audits.
Healthcheck	Ping NexFlow SMF for status and latency before routing payments.
Simulate Charge	See x402 pricing headers without performing a real payment.
Budget Plan	Turn a USDC budget into an approximate number of SMF API calls.

🎴 Browse AgentCard Catalog

Discover NexFlow services as AgentCards, ready for AI agents and x402-aware clients:

https://nexflow-agentcards.pages.dev/

Choose Your Path

Monetize an existing API at the edge (recommended)

Drop a Lambda@Edge function in front of CloudFront. Every request to a protected path must include a valid x402-payment header — otherwise the client gets a 402 Payment Required with payment instructions. No backend changes needed.

How it works:

viewer-request — Lambda calls /x402/verify with the payment proof (not billed). If valid, attaches a settlementIntentId and forwards to origin. If invalid, returns 402.
origin-response — Lambda reads the settlementIntentId. If origin status < 400, calls /x402/settle to confirm delivery (this is the billable event). Returns the response unchanged.

Get started in 15 minutes:

AWS CloudFront + Lambda@Edge Quickstart →

Use the NexFlow SMF SDK directly

For server-side integrations where you control the request lifecycle — route payments, verify intents, and trigger batch settlement from your own code.

bash

npm install @nexflow-smf/smf

typescript

import { NexFlowSMFClient } from '@nexflow-smf/smf';

const smf = new NexFlowSMFClient({
  baseUrl: 'https://api.nexflowapp.app',
  apiKey: process.env.NEXFLOW_API_KEY!,
});

// Route a payment
const route = await smf.route({
  amount_wei: '1000000',
  token_address: '0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913',
  chain_id: 'eip155:8453',
  payment_id: 'order-123',
});

// Verify a payment intent
const result = await smf.verify({
  payment_intent: 'x402:1:base:0xabc...',
  recipient_address: '0xYourAddress...',
});

Full SDK documentation →

What's in This Repo

Path	Description
`examples/aws-cloudfront-lambdaedge/`	15-minute AWS quickstart — Lambda@Edge x402 pay-per-request gating
`examples/basic-settlement.ts`	End-to-end SDK example: route, verify, settle
`sdk/`	Zero-dependency TypeScript SDK (`@nexflow-smf/smf`)
`contracts/`	Solidity contracts for atomic batch settlement with Merkle proofs
`docs/`	API reference, facilitator contract, production checklist
`AGENT_MANIFEST_V1.md`	Agent Manifest spec for machine-to-machine discovery
`nexflow-smf-skills/`	Cursor-style agent skills (route-matrix, quote, receipt, facilitators, health, simulate, budget)
`PRICING.md`	Pricing model with example scenarios

Services Overview

Service	Description	Status
Smart Meta-Facilitator	Intelligent payment routing, verification, and batch settlement	Live
CloudFront Edge Gating	Lambda@Edge adapter for pay-per-request access via CloudFront	Live
Agent Manifest & Discovery	Machine-readable capability manifest for AI agent integration	Live
Pulse Scheduler	Metered job scheduling with x402 billing (cron, webhooks, tasks)	Live
Action Catalog	Pre-built metered actions (Shopify, Salesforce, data enrichment)	Live

Base Mainnet Contracts

Contract	Address	Explorer
AtomicBatchSettlement	`0x43A04228152115fDd5663B2Aa559Ebd84D17A49D`	BaseScan
USDC	`0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`	BaseScan

🔄 Agent Workflows

NexFlow SMF allows agents to define, publish, and monetize hosted workflows — multi-step compositions of core SMF operations that other agents can invoke via the 402/MPP payment gateway.

Workflow creation and inspection are free.
Workflow invocation is paid — the price is computed from the sum of step costs plus a creator-defined markup.
Workflow creators earn rev-share on every invocation.

Available Core Operations

Workflows can compose any of these paid SMF operations:

Operation	Description
`create_session`	Create a metered session with a budget
`budget_check`	Check planned charges against budgets
`budget_diagnostics`	Analyze sessions for overrun risk
`process_charges`	Deduct charges from a session or caller
`verify_payment`	Validate a payment descriptor
`settle_batch`	Settle a batch of transactions
`revenue_share`	Record revenue-share accounting for a period
`route_quote`	Get a payment routing quote
`usage_timeseries`	Time-series spend data for a caller/session
`configure_alerts`	Set budget/usage alert thresholds
`monitor_sessions`	List sessions with budget & spend status
`monitor_alerts`	Return triggered budget/usage alerts
`pricing_estimate`	Estimate cost of a set of operations

Example Workflows

Safety-Capped Session Runner

examples/workflows/safety_capped_session_runner.json

A 5-step workflow that:

Creates a session with a requested budget
Checks a planned charge against that budget
Processes the charge
Configures a 90% budget alert
Returns current session status

Usage Health Check

examples/workflows/usage_health_check.json

A 3-step diagnostic workflow that:

Pulls recent spend timeseries (hourly, configurable window)
Checks budget status (zero-cost probe)
Returns active alerts

Batch Settlement Runner

examples/workflows/revenue_share_settlement.json

A 5-step workflow demonstrating the full payment lifecycle:

Creates a settlement session with a budget
Checks that planned charges fit within the budget
Processes a batch of charges
Settles the batch
Returns final session status

The workflow creator earns their standard rev-share (set via creatorShareBps) on every invocation. Rev-share credits accumulate per wallet and are batched for payout when they reach $5+.

Input example:

json

{
  "sessionBudget": { "amount": 2000000, "currency": "USDC" },
  "charges": [
    { "callerId": "agent_a", "amount": 500000, "description": "API usage week 12" },
    { "callerId": "agent_b", "amount": 300000, "description": "Compute usage week 12" }
  ],
  "settlementPeriod": "2026-03-01/2026-03-31"
}

How to Register a Workflow

bash

# Register the Safety-Capped Session Runner
curl -X POST "$NEXFLOW_SMF_BASE_URL/nexflow/workflows" \
  -H "Content-Type: application/json" \
  -H "X-Caller-Id: demo_caller" \
  --data-binary "@examples/workflows/safety_capped_session_runner.json"

Response:

json

{
  "workflowId": "wf_abc123_1",
  "name": "Safety-Capped Session Runner",
  "invokeUrl": "/nexflow/workflows/wf_abc123_1/invoke",
  "status": "active",
  "steps": 5,
  "pricing": { "billingMode": "per_call", "markupBps": 300 }
}

How to Invoke a Workflow

bash

# First call — no payment proof → 402 Payment Required
curl -X POST "$NEXFLOW_SMF_BASE_URL/nexflow/workflows/wf_abc123_1/invoke" \
  -H "Content-Type: application/json" \
  -H "X-Caller-Id: demo_caller" \
  --data '{
    "requestedBudget": { "amount": 500000, "currency": "USDC" },
    "plannedCost": { "amount": 50000, "currency": "USDC" }
  }'

The first call returns HTTP 402 with a payment challenge:

json

{
  "object": "payment_challenge",
  "operation": "workflow_invoke",
  "workflow_id": "wf_abc123_1",
  "required_amount": 17350,
  "currency": "usdc",
  "price_breakdown": {
    "totalPrice": 17350,
    "baseCost": 7000,
    "markup": 210,
    "platformFee": 149
  },
  "instructions": "Pay via MPP using the challenge above, then retry with X-PAYMENT-PROOF header."
}

After the agent pays (via Tempo MPP or x402), it retries with the proof:

bash

# Second call — with valid proof → 200 OK
curl -X POST "$NEXFLOW_SMF_BASE_URL/nexflow/workflows/wf_abc123_1/invoke" \
  -H "Content-Type: application/json" \
  -H "X-Caller-Id: demo_caller" \
  -H "X-PAYMENT-PROOF: <base64-encoded-proof-json>" \
  --data '{
    "requestedBudget": { "amount": 500000, "currency": "USDC" },
    "plannedCost": { "amount": 50000, "currency": "USDC" }
  }'

TypeScript Client Example

See examples/client/invokeUsageHealthCheck.ts for a runnable demo of the full 402 → proof → retry flow.

bash

export NEXFLOW_SMF_BASE_URL=http://localhost:3001
export WORKFLOW_ID=wf_abc123_1
npx tsx examples/client/invokeUsageHealthCheck.ts

Environment Variables

Variable	Required	Description
`NEXFLOW_API_KEY`	Yes	Your NexFlow API key (`nf_live_xxx` or `nf_test_xxx`)
`NEXFLOW_BASE_URL`	No	Override API URL (default: `https://api.nexflowapp.app`)
`NEXFLOW_SMF_BASE_URL`	No	NexFlow SMF bridge URL for workflow invocations (default: `http://localhost:3001`)
`WORKFLOW_ID`	No	Workflow ID for the client example scripts

Sign up or log in at nexflowapp.app, go to Developers → API Keys, and click Create API key. Use that key with the examples in this repo.

Never commit API keys or secrets. Use environment variables or a secrets manager.

Supported Networks & Tokens

Network	Chain ID	Status
Base mainnet	`eip155:8453`	Primary

Token	Address	Decimals
USDC	`0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`	6

Documentation

Doc	What's inside
Facilitator API	`/verify` and `/settle` contracts, `settlementIntentId` lifecycle, error handling, retry guidance
API Reference	All endpoints (SMF core, x402 routing, agent discovery), SDK reference, contract ABI
Production Checklist	Idempotency, latency, CloudWatch logging, failure modes, key rotation
Pricing	Pulse metering, facilitator settle-only pricing, example scenarios
Agent Manifest	Machine-to-machine capability discovery spec
SDK README	Full SDK docs: installation, methods, error handling, utilities

Development

Building the SDK

bash

cd sdk
npm install
npm run build       # Build for production (CJS + ESM + types)
npm run dev         # Watch mode
npm run typecheck   # Type checking

Running Examples

bash

# SDK example
cd sdk && npm install
npx tsx ../examples/basic-settlement.ts

# Lambda@Edge example
cd examples/aws-cloudfront-lambdaedge
npm install
npm run build   # requires NEXFLOW_FACILITATOR_URL and NEXFLOW_API_KEY

Contributing

We welcome contributions! See CONTRIBUTING.md for guidelines.

Security

For security concerns, see SECURITY.md.

License

MIT License — see LICENSE for details.

Install

Configuration

Environment variables

NEXFLOW_API_KEYrequiredsecret

NexFlow API key (format: nf_live_* or nf_test_*)

NEXFLOW_BASE_URL

API base URL (default: https://api.nexflowapp.app)

Add to VS Code Add to Cursor

claude_desktop_config.json

json

{
  "mcpServers": {
    "nexflow-smf": {
      "command": "npx",
      "args": [
        "-y",
        "@nexflow-smf/smf@1.0.2"
      ],
      "env": {
        "NEXFLOW_API_KEY": "<YOUR_NEXFLOW_API_KEY>",
        "NEXFLOW_BASE_URL": "<YOUR_NEXFLOW_BASE_URL>"
      }
    }
  }
}

GitHub

Stars: 0
Forks: 0
Open issues: 0
Language: TypeScript
License: MIT License
Default branch: main
Latest release: v1.0.0 · 1/21/2026
Created: 1/4/2026
Updated: 3/20/2026

Trust grades

License: A
Maintenance: C
Quality: Not tested yet

Graded A-F from license permissiveness and commit recency; a cross-model quality score is coming soon.

npm

Package: @nexflow-smf/smf
Downloads/mo: 200
Latest version: 1.0.2
Published: 1/22/2026

Details

Name: io.github.moejeaux/nexflow-smf
Version: 1.0.0
Status: active
Published: 1/22/2026
Updated: 1/22/2026
Official: Yes
Homepage: nexflowapp.app
Repository: moejeaux/nexflow-smf-public
Registry record: View server.json

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Topics

NexFlow Smart Meta-Facilitator (SMF)

🎴 Browse AgentCard Catalog →

📦 What's Included

🧩 Skills (Cursor & AI agents)

🎴 Browse AgentCard Catalog

Choose Your Path

Monetize an existing API at the edge (recommended)

Use the NexFlow SMF SDK directly

What's in This Repo

Services Overview

Base Mainnet Contracts

🔄 Agent Workflows

Available Core Operations

Example Workflows

Safety-Capped Session Runner

Usage Health Check

Batch Settlement Runner

How to Register a Workflow

How to Invoke a Workflow

TypeScript Client Example

Environment Variables

Supported Networks & Tokens

Documentation

Development

Building the SDK

Running Examples

Contributing

Security

License

Links

Install

Configuration