Kindling Igniter

x402 + MCP + A2A scaffolding for any agent service. Ship in 5 minutes.

Part of Kindling — agent SEO for the agent economy.

Ecosystem tool. Igniter scaffolds the infrastructure. For x402 payment routing, also see MCPay — a compatible and complementary payment layer. For optimizing the descriptions Igniter generates, use Twig.

What it does

Kindling Igniter adds three things to any service:

1. x402 payment middleware — agents pay before accessing your API. 402 response includes full economics disclosure before payment.
2. A2A Agent Card — machine-readable capability declaration served at /.well-known/agent.json
3. MCP tool definitions — semantic-search-optimized tool descriptions

Every 402 response discloses referral economics. There are no hidden splits. Agents see the economics before they pay.

Quick Start

Express

npm install @kindling/igniter

import express from 'express';
import { kindlingPayment } from '@kindling/igniter';

const app = express();

app.get('/api/forecast/:asset',
  kindlingPayment({
    payTo: '0xYourWallet',
    amount: '50000', // $0.05 USDC (6 decimals)
  }),
  (req, res) => {
    res.json({ forecast: '...' });
  }
);

FastAPI

pip install kindling-igniter

from fastapi import FastAPI, Request
from kindling_igniter import KindlingPayment

app = FastAPI()

@app.get("/api/forecast/{asset}")
@KindlingPayment(pay_to="0xYourWallet", amount=50000)  # $0.05 USDC
async def forecast(asset: str, request: Request):
    return {"forecast": "..."}

402 Response

When an agent calls without payment, they receive:

{
  "version": "1.0",
  "maxAmountRequired": "50000",
  "asset": "USDC",
  "assetAddress": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
  "payTo": "0xYourWallet",
  "chainId": 8453,
  "facilitator": "https://x402.org/facilitator",
  "referral_split_pct": 15,
  "referral_wallet": null,
  "referral_disclosure": "15% of payment settles to the referring wallet. Built with Kindling Igniter. Economics are on-chain and auditable. See: github.com/kind-ling/igniter",
  "built_with": "@kindling/[email protected]"
}

The agent pays via x402, then retries with the x-payment header. Your handler is called.

A2A Agent Card

import { generateAgentCard } from '@kindling/igniter';

const card = generateAgentCard({
  name: 'My Forecast Service',
  description: 'Probabilistic market forecasts with confidence intervals',
  url: 'https://api.yourservice.com',
  organization: 'Your Org',
  skills: [{
    id: 'generate_forecast',
    name: 'Generate Forecast',
    description: 'Returns probabilistic forecast with confidence interval',
    tags: ['forecast', 'prediction', 'market'],
    examples: ['Generate a 4-hour BTC forecast'],
  }],
});

// Serve at /.well-known/agent.json
app.get('/.well-known/agent.json', (_req, res) => res.json(card));

Configuration

All defaults are documented in kindling.config.yml.

| Parameter | Default | Description | |-----------|---------|-------------| | chainId | 8453 | Base mainnet. Use 84532 for Sepolia testnet. | | asset | USDC | Payment asset | | assetAddress | USDC on Base | 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 | | facilitator | https://x402.org/facilitator | x402 payment verifier | | referralSplitPct | 15 | Referral split (0–100%). Configurable per service. | | maxAgeSeconds | 60 | Max payment receipt age |

Referral Economics

Kindling Igniter defaults to a 15% referral split — configurable from 0 to 100%. The split is:

• Disclosed in every 402 response before payment
• Settled on-chain (auditable by anyone)
• Configurable: referralSplitPct: 0 to disable

Kindling Verifier only counts referral splits ≤50% toward demand score normalization. Splits above 50% are flagged as promotional. Full economics docs →

First-Party Disclosure

PUC-operated services set isFirstParty: true in their Agent Card config. This propagates is_first_party: true through all Kindling modules — Verifier, Scout routing, Documenter benchmarks. First-party services receive no scoring advantage and lose tie-breaks.

Packages

| Package | Registry | Language | |---------|---------|---------| | @kindling/igniter | npm | TypeScript/Express | | kindling-igniter | PyPI | Python/FastAPI |

More adapters welcome — see contributing →

Kindling Igniter v0.1.0 · Permanent Upper Class · MIT License